显示方式：
2023,42(1):1-11
, DOI: 10.13300/j.cnki.hnlkxb.2023.01.001
Abstract:
Ninty-two accessions of ‘Shazikongxinli’ germplasm with elite traits were selected by visiting and surveying to evaluate the genetic diversity of Prunus salicina Lindl. ‘Shazikongxinli’ IRAP primers were developed based on the conserved regions of RT sequences of plum reverse transcription transposons Ty1-copia and Ty3-gypsy. L16（43） orthogonal experiments were designed to optimize the main factors affecting content of IRAP-PCR with 10 μL volume. 18 IRAP primers were used to analyze the genetic diversity and construct the fingerprint of the germplasm tested. The results showed that the optimized 10 μL IRAP-PCR reaction system was 1.3 μL of 5-10 mol/L IRAP primers， 5.0 μL of PCR mixture， 1.0 μL of template DNA（30 ng/μL）， and the number of PCR cycles was 40 times. A total of 189 loci were amplified from 18 IRAP primers with good repeatability and high polymorphism， including 180 polymorphic loci.The average value of observed number of alleles（Na）， effective number of alleles（Ne）， Nei’s gene diversity（He） and Shannon’s information index（I） for all primers was 1.930，1.426，0.261 and 0.405， respectively. The 92 accessions tested were clustered into 4 groups using the neighbor-joining method. The IRAP primers Ty3-2 and Ty3-6 were identified as core primers， which can be used to efficiently construct the fingerprints of 92 accessions tested.
Ninty-two accessions of ‘Shazikongxinli’ germplasm with elite traits were selected by visiting and surveying to evaluate the genetic diversity of Prunus salicina Lindl. ‘Shazikongxinli’ IRAP primers were developed based on the conserved regions of RT sequences of plum reverse transcription transposons Ty1-copia and Ty3-gypsy. L16（43） orthogonal experiments were designed to optimize the main factors affecting content of IRAP-PCR with 10 μL volume. 18 IRAP primers were used to analyze the genetic diversity and construct the fingerprint of the germplasm tested. The results showed that the optimized 10 μL IRAP-PCR reaction system was 1.3 μL of 5-10 mol/L IRAP primers， 5.0 μL of PCR mixture， 1.0 μL of template DNA（30 ng/μL）， and the number of PCR cycles was 40 times. A total of 189 loci were amplified from 18 IRAP primers with good repeatability and high polymorphism， including 180 polymorphic loci.The average value of observed number of alleles（Na）， effective number of alleles（Ne）， Nei’s gene diversity（He） and Shannon’s information index（I） for all primers was 1.930，1.426，0.261 and 0.405， respectively. The 92 accessions tested were clustered into 4 groups using the neighbor-joining method. The IRAP primers Ty3-2 and Ty3-6 were identified as core primers， which can be used to efficiently construct the fingerprints of 92 accessions tested.
2023,42(1):12-18
, DOI: 10.13300/j.cnki.hnlkxb.2023.01.002
Abstract:
The genetic diversity of Hylocereus germplasm resources was analyzed and evaluated to provide a scientific basis for the innovative utilization of Hylocereus germplasm resources.14 qualitative traits and 9 quantitative traits in 58 Hylocereus germplasm were observed and described.The phenotypic traits were evaluated by variation analysis，index of diversity，correlation analysis.The results showed that most of the traits in the 58 tested germplasm had the characteristics of high degree of variation and rich types.The diversity index（H′） of qualitative traits was 0.234-1.809.The variation range of 9 quantitative traits was large，and the coefficient of variation was 11.25%-35.32%，among which the coefficient of variation of Vc content was the largest.The results of correlation analyses showed that most of the quantitative traits had significant or extremely significant correlations.It is indicated that there are real genetic differences among the 58 Hylocereus germplasm resources，and the genetic diversity is rich.
The genetic diversity of Hylocereus germplasm resources was analyzed and evaluated to provide a scientific basis for the innovative utilization of Hylocereus germplasm resources.14 qualitative traits and 9 quantitative traits in 58 Hylocereus germplasm were observed and described.The phenotypic traits were evaluated by variation analysis，index of diversity，correlation analysis.The results showed that most of the traits in the 58 tested germplasm had the characteristics of high degree of variation and rich types.The diversity index（H′） of qualitative traits was 0.234-1.809.The variation range of 9 quantitative traits was large，and the coefficient of variation was 11.25%-35.32%，among which the coefficient of variation of Vc content was the largest.The results of correlation analyses showed that most of the quantitative traits had significant or extremely significant correlations.It is indicated that there are real genetic differences among the 58 Hylocereus germplasm resources，and the genetic diversity is rich.
2023,42(1):19-26
, DOI: 10.13300/j.cnki.hnlkxb.2023.01.003
Abstract:
The six morphological traits including plant height，leaf length and bulb diameter，leaf width，mid-plant width and root beard length of Allium macrostemon from different habitats in Guizhou were compared to comprehensively evaluate the germplasm resources of Allium macrostemon Bunge with elite traits，high content of amino acid and good flavor quality.The content of 17 free amino acids in its bulbs was determined with HPLC.The taste of amino acids and the principal components were analyzed.The results showed that the six traits including plant height，bulb diameter，leaf length，leaf width，mid-plant width and root beard length of A.macrostemon were significantly different among the 9 populations （P<0.05），with coefficients of variation greater than 10%.The 9 populations were clustered into 2 categories with Euclidean distance clustering analysis.The morphological traits of category Ⅱ were more prominent.The results of principal component analysis showed that the cumulative contribution of the first principal component reached 80.967%.The results of comprehensive evaluation showed that the Qiannan population had the highest overall score.The average content of total free amino acid （TFAA） in each population was 6 078.52 mg/kg，with higher TFAA content in the Qiandongnan （10 365.90 mg/kg） and Guiyang （8 174.55 mg/kg） population.Flavor intensity value TAV>1 indicated that the amino acid contributed to the flavor of the samples.The bitter Arginine （TAV=6.81） was the main factor affecting the flavor of A.macrostemon.The results of principal component analysis showed that the cumulative contribution of the first four principal components reached 90.144%，and the highest overall score was obtained by the Qiannan population.It is indicated that there are regional differences in morphological traits and content of flavoring amino acid in A.macrostemon.The Qiannan population has outstanding morphological traits，excellent flavor quality，and high value of development and utilization.
The six morphological traits including plant height，leaf length and bulb diameter，leaf width，mid-plant width and root beard length of Allium macrostemon from different habitats in Guizhou were compared to comprehensively evaluate the germplasm resources of Allium macrostemon Bunge with elite traits，high content of amino acid and good flavor quality.The content of 17 free amino acids in its bulbs was determined with HPLC.The taste of amino acids and the principal components were analyzed.The results showed that the six traits including plant height，bulb diameter，leaf length，leaf width，mid-plant width and root beard length of A.macrostemon were significantly different among the 9 populations （P<0.05），with coefficients of variation greater than 10%.The 9 populations were clustered into 2 categories with Euclidean distance clustering analysis.The morphological traits of category Ⅱ were more prominent.The results of principal component analysis showed that the cumulative contribution of the first principal component reached 80.967%.The results of comprehensive evaluation showed that the Qiannan population had the highest overall score.The average content of total free amino acid （TFAA） in each population was 6 078.52 mg/kg，with higher TFAA content in the Qiandongnan （10 365.90 mg/kg） and Guiyang （8 174.55 mg/kg） population.Flavor intensity value TAV>1 indicated that the amino acid contributed to the flavor of the samples.The bitter Arginine （TAV=6.81） was the main factor affecting the flavor of A.macrostemon.The results of principal component analysis showed that the cumulative contribution of the first four principal components reached 90.144%，and the highest overall score was obtained by the Qiannan population.It is indicated that there are regional differences in morphological traits and content of flavoring amino acid in A.macrostemon.The Qiannan population has outstanding morphological traits，excellent flavor quality，and high value of development and utilization.
2023,42(1):27-33
, DOI: 10.13300/j.cnki.hnlkxb.2023.01.004
Abstract:
Expansin is a kind of protein widely found in plants.It may relax the cell wall and plays an important role in the growth and development，and the stress response of plants.The PavEXPA2 gene was cloned and bioinformatically analyzed to uncover the structure and function of expansingene（EXPA） in sweet cherries.The gene expression in different tissues including stems，flower buds，blooming flowers，young leaves，old leaves，petioles of young leaves，petioles of old leaves，normal fruit stalks at the 2 abscission peaks and about to abscission，the normal fruits at 2 abscission peaks and shedding，and under the abiotic stresses including using 20% PEG6000 and 20 mmol/L NaCl solutions to simulate drought and salt stress for 0，2，4，6，and 8 h was profiled.The results showed that the full length of PavEXPA2 was 1 035 bp with the open reading frame （ORF） of 852 bp，encoding 283 amino acids.The putative protein has an isoelectric point of 8.90 and a molecular mass of 30.81 ku，containing two transmembrane helical structures and a signal peptide.The results of subcellular location showed that the protein of gene was located in the cell wall.The results of tissue expression analysis showed that the expression level of PavEXPA2 was higher in the easily abscised tissues of sweet cherry including flowers，stalks，fruits and petioles，with the highest level in petioles about to abscission.Compared with the samples untreated，the expression of PavEXPA2 in the drought-treated samples increased，and the expression reached the highest at 6 h，and then decreased.Under the salt stress，the expression level of PavEXPA2 decreased first，then increased and then decreased，and the expression level reached the highest at 6 h.Therefore，sweet cherries may resist stress by promoting abscission through the up-regulation of PavEXPA2 gene.It will lay a theoretical foundation for further understanding the role of PavEXPA2 in the growth and development of sweet cherries.
Expansin is a kind of protein widely found in plants.It may relax the cell wall and plays an important role in the growth and development，and the stress response of plants.The PavEXPA2 gene was cloned and bioinformatically analyzed to uncover the structure and function of expansingene（EXPA） in sweet cherries.The gene expression in different tissues including stems，flower buds，blooming flowers，young leaves，old leaves，petioles of young leaves，petioles of old leaves，normal fruit stalks at the 2 abscission peaks and about to abscission，the normal fruits at 2 abscission peaks and shedding，and under the abiotic stresses including using 20% PEG6000 and 20 mmol/L NaCl solutions to simulate drought and salt stress for 0，2，4，6，and 8 h was profiled.The results showed that the full length of PavEXPA2 was 1 035 bp with the open reading frame （ORF） of 852 bp，encoding 283 amino acids.The putative protein has an isoelectric point of 8.90 and a molecular mass of 30.81 ku，containing two transmembrane helical structures and a signal peptide.The results of subcellular location showed that the protein of gene was located in the cell wall.The results of tissue expression analysis showed that the expression level of PavEXPA2 was higher in the easily abscised tissues of sweet cherry including flowers，stalks，fruits and petioles，with the highest level in petioles about to abscission.Compared with the samples untreated，the expression of PavEXPA2 in the drought-treated samples increased，and the expression reached the highest at 6 h，and then decreased.Under the salt stress，the expression level of PavEXPA2 decreased first，then increased and then decreased，and the expression level reached the highest at 6 h.Therefore，sweet cherries may resist stress by promoting abscission through the up-regulation of PavEXPA2 gene.It will lay a theoretical foundation for further understanding the role of PavEXPA2 in the growth and development of sweet cherries.
2023,42(1):34-41
, DOI: 10.13300/j.cnki.hnlkxb.2023.01.005
Abstract:
The cDNA sequence of HpGST gene was cloned，and bioinformatics analysis and expression analysis of it were carried out to study the function of glutathione S-transferase gene （HpGST） in Hylocereus.The results showed that the cDNA sequence of HpGST was 666 bp in length，encoding 221 amino acids.The encoded protein belonged to non-secretory unstable hydrophilic protein，and its subcellular localization predicted its role in the cytoplasm.The phylogenetic tree shows that it is closely related to Chenopodium quinoa，and belongs to the Tau family of glutathione transferases.The results of real-time fluorescent quantitative PCR analysis showed that HpGST was expressed in the flesh of different color types of Hylocereuss.The expression levels of HpGST in purple and pink flesh of Hylocereuss with pigment accumulation were significantly higher than those in white flesh types without pigment accumulation.The expression trend was first increased and then decreased with the development of fruit.Its expression level was positively correlated with content of betaine，and the expression trend in different varieties is highly consistent with the accumulation trend of betaine.It is indicated that HpGST gene plays an important role in the synthesis and distribution of betaine in Hylocereus.
The cDNA sequence of HpGST gene was cloned，and bioinformatics analysis and expression analysis of it were carried out to study the function of glutathione S-transferase gene （HpGST） in Hylocereus.The results showed that the cDNA sequence of HpGST was 666 bp in length，encoding 221 amino acids.The encoded protein belonged to non-secretory unstable hydrophilic protein，and its subcellular localization predicted its role in the cytoplasm.The phylogenetic tree shows that it is closely related to Chenopodium quinoa，and belongs to the Tau family of glutathione transferases.The results of real-time fluorescent quantitative PCR analysis showed that HpGST was expressed in the flesh of different color types of Hylocereuss.The expression levels of HpGST in purple and pink flesh of Hylocereuss with pigment accumulation were significantly higher than those in white flesh types without pigment accumulation.The expression trend was first increased and then decreased with the development of fruit.Its expression level was positively correlated with content of betaine，and the expression trend in different varieties is highly consistent with the accumulation trend of betaine.It is indicated that HpGST gene plays an important role in the synthesis and distribution of betaine in Hylocereus.
2023,42(1):42-50
, DOI: 10.13300/j.cnki.hnlkxb.2023.01.006
Abstract:
The LcC2DP1 gene was cloned from the Lotus corniculatus L.by RACE method to study the function of C2 calcium dependent protein kinase gene LcC2DP1 of Lotus corniculatus L.in the process of adventitious root development.The spatial expression mode of LcC2DP1 gene was detected with qRT-PCR.The overexpression and function of LcC2DP were identified by Agrobacterium mediated transient expression system.The results showed that the full length of LcC2DP1 gene was 705 bp，encoding 235 amino acids.Its molecular weight was 25.95 ku，with the highest homology of Medicago truncatula （82%）.It was continuously expressed during the differentiation of adventitious roots in Lotus corniculatus L..The expression sites were roots，stems and leaves.Compared with wild-type parents （WT），the adventitious root differentiation of the LcC2DP1 transgenic Lotus corniculatus L. plants（TP） was 1-2 days earlier.On the 9th to 15th day of adventitious root differentiation，the total root length was 168% and 155% of WT，the root volume was 249% and 161% of WT，and the number of root tips was 156% and 137% of WT，respectively.The total root length （P<0.01），root volume （P<0.01） and number of root tips （P<0.05） of TP root had certain advantages of development，indicating that LcC2DP1 gene may be related to the regulation of adventitious root development in Lotus corniculatus L..
The LcC2DP1 gene was cloned from the Lotus corniculatus L.by RACE method to study the function of C2 calcium dependent protein kinase gene LcC2DP1 of Lotus corniculatus L.in the process of adventitious root development.The spatial expression mode of LcC2DP1 gene was detected with qRT-PCR.The overexpression and function of LcC2DP were identified by Agrobacterium mediated transient expression system.The results showed that the full length of LcC2DP1 gene was 705 bp，encoding 235 amino acids.Its molecular weight was 25.95 ku，with the highest homology of Medicago truncatula （82%）.It was continuously expressed during the differentiation of adventitious roots in Lotus corniculatus L..The expression sites were roots，stems and leaves.Compared with wild-type parents （WT），the adventitious root differentiation of the LcC2DP1 transgenic Lotus corniculatus L. plants（TP） was 1-2 days earlier.On the 9th to 15th day of adventitious root differentiation，the total root length was 168% and 155% of WT，the root volume was 249% and 161% of WT，and the number of root tips was 156% and 137% of WT，respectively.The total root length （P<0.01），root volume （P<0.01） and number of root tips （P<0.05） of TP root had certain advantages of development，indicating that LcC2DP1 gene may be related to the regulation of adventitious root development in Lotus corniculatus L..
2023,42(1):51-59
, DOI: 10.13300/j.cnki.hnlkxb.2023.01.007
Abstract:
The endangered plant Oreocharis esquirolii and two species of the same genus including O.elegantissima and O. duyunensis were used to compare the photosynthetic physiological characteristics and anatomical structures of leaves in the same cultivation habitat to study the differences in photosynthetic capacity between O. esquirolii and two species of the same genus.The results showed that Chl a and （Chl a+Chl b） of O. esquirolii was significantly lower than that of the other two kinds of Gesneriaceae （P<0.05）.The results of chlorophyll fluorescence characteristics showed that Fo was significantly higher（P<0.05）， Fv/Fm，Fv/Fo，Y（Ⅱ） and ETR were the smallest among the three plants.During the photosynthetic diurnal process， the Pn of the three plants showed a relatively consistent bimodal curve.The intercellular CO2 concentration trend had a “W” shape， and the stomatal conductance had a downward trend with the passage of time.The transpiration rate had a downward trend， then increased and then decreased with the passage of time， and the three plants all had obvious photosynthetic “napping” phenomenon.Each index showed the lowest characteristic of O. esquirolii.In the photo response， the average Pmax value of O. esquirolii was 2.24 μmol/（m2·s）， which was significantly lower.The average value of Rd and LCP was 1.14 μmol/（m2·s） and 51.85 μmol/（m2·s）， significantly higher than that of the other two plants（P<0.05）.The results of CO2 response curve fitting showed that the vcmax and Jmax of O. esquirolii were 7.6 μmol/（m2·s） and 26.04 μmol/（m2·s）， significantly lower than that of the other two plants（P<0.05）.The results of histological section showed that the upper epidermis and the lower epidermis of O. esquirolii were 37.80 μm and 38.09 μm， higher than that of the other two plants.The PT and ST of O. esquirolii were 40.79 μm and 30.07 μm， significantly lower than that of the other two plants（P<0.05）， which may be related to the long-term adaptation of O. esquirolii to shady and barren habitats.It is indicated that the photosynthetic physiological characteristics of O. esquirolii are overall lower than two species of the same genus including O. elegantissima and O. duyunensis， and its ability to adapt to the light environment and the utilization rate of light energy is relatively weak， which may be one of the main internal factors of the endangered species.
The endangered plant Oreocharis esquirolii and two species of the same genus including O.elegantissima and O. duyunensis were used to compare the photosynthetic physiological characteristics and anatomical structures of leaves in the same cultivation habitat to study the differences in photosynthetic capacity between O. esquirolii and two species of the same genus.The results showed that Chl a and （Chl a+Chl b） of O. esquirolii was significantly lower than that of the other two kinds of Gesneriaceae （P<0.05）.The results of chlorophyll fluorescence characteristics showed that Fo was significantly higher（P<0.05）， Fv/Fm，Fv/Fo，Y（Ⅱ） and ETR were the smallest among the three plants.During the photosynthetic diurnal process， the Pn of the three plants showed a relatively consistent bimodal curve.The intercellular CO2 concentration trend had a “W” shape， and the stomatal conductance had a downward trend with the passage of time.The transpiration rate had a downward trend， then increased and then decreased with the passage of time， and the three plants all had obvious photosynthetic “napping” phenomenon.Each index showed the lowest characteristic of O. esquirolii.In the photo response， the average Pmax value of O. esquirolii was 2.24 μmol/（m2·s）， which was significantly lower.The average value of Rd and LCP was 1.14 μmol/（m2·s） and 51.85 μmol/（m2·s）， significantly higher than that of the other two plants（P<0.05）.The results of CO2 response curve fitting showed that the vcmax and Jmax of O. esquirolii were 7.6 μmol/（m2·s） and 26.04 μmol/（m2·s）， significantly lower than that of the other two plants（P<0.05）.The results of histological section showed that the upper epidermis and the lower epidermis of O. esquirolii were 37.80 μm and 38.09 μm， higher than that of the other two plants.The PT and ST of O. esquirolii were 40.79 μm and 30.07 μm， significantly lower than that of the other two plants（P<0.05）， which may be related to the long-term adaptation of O. esquirolii to shady and barren habitats.It is indicated that the photosynthetic physiological characteristics of O. esquirolii are overall lower than two species of the same genus including O. elegantissima and O. duyunensis， and its ability to adapt to the light environment and the utilization rate of light energy is relatively weak， which may be one of the main internal factors of the endangered species.
2023,42(1):60-65
, DOI: 10.13300/j.cnki.hnlkxb.2023.01.008
Abstract:
In the process of transplanting and acclimating tissue culture seedlings of Bletilla striata in summer，they will face fluctuating light and heat stress at the same time.The tissue culture seedlings of Bletilla striata in June 2021 transplanting greenhouse were used to determine the variation trend of the acclimation time on the growth and physiological indexes of Bletilla striata transplanting seedlings to study the effect of light-temperature coupling in summer on the growth and development changes of acclimated seedlings of Bletilla striata and provide a scientific basis for the adaptive exercise of Bletilla striata in summer.At 90 days of acclimation，the temperature （25 ℃，30 ℃，35 ℃ and 38 ℃） and fluctuating light （50 mmol/（m2·s），2 min； 1 000 mmol /（m2·s），2 min） were set to simulate the light and temperature stress of Bletilla striata in summer.The results showed that the root-shoot ratio of Bletilla striata seedlings increased first and then decreased within 90 days.The content of polysaccharide in the tuber increased by 51% in 90 days compared with that in 60 days.Under the combined stress of fluctuating light and high temperature，the amount of carbon assimilated by Bletilla striata was lost 2-3 times.The Fv/Fm，FPSII，qP，Fv'/Fm' and ETR of transplanted Bletilla striata seedlings were reduced，and FNPQ and NPQ were increased with the increase of temperature.It is indicated that the high temperature and fluctuating light in summer cause serious harm to the growth and development of Bletilla striata，which is not conducive to the transplantation and domestication of Bletilla striata.
In the process of transplanting and acclimating tissue culture seedlings of Bletilla striata in summer，they will face fluctuating light and heat stress at the same time.The tissue culture seedlings of Bletilla striata in June 2021 transplanting greenhouse were used to determine the variation trend of the acclimation time on the growth and physiological indexes of Bletilla striata transplanting seedlings to study the effect of light-temperature coupling in summer on the growth and development changes of acclimated seedlings of Bletilla striata and provide a scientific basis for the adaptive exercise of Bletilla striata in summer.At 90 days of acclimation，the temperature （25 ℃，30 ℃，35 ℃ and 38 ℃） and fluctuating light （50 mmol/（m2·s），2 min； 1 000 mmol /（m2·s），2 min） were set to simulate the light and temperature stress of Bletilla striata in summer.The results showed that the root-shoot ratio of Bletilla striata seedlings increased first and then decreased within 90 days.The content of polysaccharide in the tuber increased by 51% in 90 days compared with that in 60 days.Under the combined stress of fluctuating light and high temperature，the amount of carbon assimilated by Bletilla striata was lost 2-3 times.The Fv/Fm，FPSII，qP，Fv'/Fm' and ETR of transplanted Bletilla striata seedlings were reduced，and FNPQ and NPQ were increased with the increase of temperature.It is indicated that the high temperature and fluctuating light in summer cause serious harm to the growth and development of Bletilla striata，which is not conducive to the transplantation and domestication of Bletilla striata.
2023,42(1):66-74
, DOI: 10.13300/j.cnki.hnlkxb.2023.01.009
Abstract:
Three Stachys sieboldii Miq.varieties were used to study the effects of waterlogging stress on the physiological characteristics of S. sieboldii Miq..Correlation analysis and principal component analysis were used to evaluate the waterlogging resistance of S. sieboldii Miq. to provide a reference for the identification of waterlogging resistance of S. sieboldii Miq..The results showed that the content of chlorophyll，soluble sugar，soluble protein，and the activity of POD and CAT of the three S. sieboldii Miq.varieties increased first and then decreased with the prolongation of waterlogging stress.The content of Pro in Luyin No.1 and Ganyin No.1 first increased and then decreased，while the content of Pro in Guizai No.1 kept increasing.The activity of SOD in Guizai NO.1 and Luyin No.1 increased first and then decreased，while the activity of SOD in Ganyin No.1 kept increasing under the waterlogging stress.The accumulation of MDA in the three S. sieboldii Miq. varieties increased all the time with the extension of stress time.The results of correlation analyses showed that the content of chlorophyll，soluble sugar，soluble protein，Pro，and MDA，the activity of SOD，POD，and CAT of S. sieboldii Miq.was closely related，but the degree of correlation was inconsistent.The results of comprehensively evaluating waterlogging resistance based on the principal component analysis showed that the waterlogging resistance of the three S. sieboldii Miq. varieties was in the decreasing order of Ganyin No.1>Luyin No.1> Guizai No.1.
Three Stachys sieboldii Miq.varieties were used to study the effects of waterlogging stress on the physiological characteristics of S. sieboldii Miq..Correlation analysis and principal component analysis were used to evaluate the waterlogging resistance of S. sieboldii Miq. to provide a reference for the identification of waterlogging resistance of S. sieboldii Miq..The results showed that the content of chlorophyll，soluble sugar，soluble protein，and the activity of POD and CAT of the three S. sieboldii Miq.varieties increased first and then decreased with the prolongation of waterlogging stress.The content of Pro in Luyin No.1 and Ganyin No.1 first increased and then decreased，while the content of Pro in Guizai No.1 kept increasing.The activity of SOD in Guizai NO.1 and Luyin No.1 increased first and then decreased，while the activity of SOD in Ganyin No.1 kept increasing under the waterlogging stress.The accumulation of MDA in the three S. sieboldii Miq. varieties increased all the time with the extension of stress time.The results of correlation analyses showed that the content of chlorophyll，soluble sugar，soluble protein，Pro，and MDA，the activity of SOD，POD，and CAT of S. sieboldii Miq.was closely related，but the degree of correlation was inconsistent.The results of comprehensively evaluating waterlogging resistance based on the principal component analysis showed that the waterlogging resistance of the three S. sieboldii Miq. varieties was in the decreasing order of Ganyin No.1>Luyin No.1> Guizai No.1.
2023,42(1):75-81
, DOI: 10.13300/j.cnki.hnlkxb.2023.01.010
Abstract:
There are spatial differences in fish population structure and individual growth， which are affected by hydrology， water environment， and fishing. In order to study the population structure and growth differences of Megalobrama terminalis in the estuary， dam downstream， and dam upstream in the middle and lower reaches of the Pearl River， a total of 228 fish samples were collected in the middle and lower reaches of Pearl River from July to August in 2020. The body length and weight of the samples were measured， and the scales were used to determine the age. The von Bertalanffy growth equation， Beverton-holt model， and Pauly empirical formula were applied to estimate the growth and death parameters of M. terminalis. The results of comparative analysis showed that the dominant body length of M. terminalis was 17.0-27.2 cm in the Pearl River estuary， 18.9-28.7 cm in the dam downstream， and 28.6-40.0 cm in the dam upstream. The dominant body weight was 93.0-447.9 g in the Pearl River estuary， 148.8-480.0 g in the dam downstream， and 39.5-1 420.8 g in the dam upstream. The dominant ages were 3+ （32.14%） and 2+ （24.11%） in the Pearl River estuary， 3+ （32.14%） and 2+ （24.11%） in the dam downstream， and 4+ （31.58%） and 5+ （26.32%） in the dam upstream. The von Bertalanffy equation of M. terminalis was L=47.2 （1-e-0.177（t+0.387）） in the Pearl River estuary， L=42.9 （1-e-0.199（t+0.377）） in the dam downstream， and L=53.7 （1-e-0.155（t+0.401）） in the dam upstream. The exploitation ratio （E） of M. terminalis was 0.410 in the Pearl River estuary， 0.373 in the dam downstream， and 0.248 in the dam upstream. The critical length （Lc） was 25.1 cm in the Pearl River estuary， 23.0 cm in the dam downstream， and 28.4 cm in the dam upstream. The results of comparative analysis showed that the frequency distribution of body length， body weight， age， and the growth equation of M. terminalis had spatial differences.
There are spatial differences in fish population structure and individual growth， which are affected by hydrology， water environment， and fishing. In order to study the population structure and growth differences of Megalobrama terminalis in the estuary， dam downstream， and dam upstream in the middle and lower reaches of the Pearl River， a total of 228 fish samples were collected in the middle and lower reaches of Pearl River from July to August in 2020. The body length and weight of the samples were measured， and the scales were used to determine the age. The von Bertalanffy growth equation， Beverton-holt model， and Pauly empirical formula were applied to estimate the growth and death parameters of M. terminalis. The results of comparative analysis showed that the dominant body length of M. terminalis was 17.0-27.2 cm in the Pearl River estuary， 18.9-28.7 cm in the dam downstream， and 28.6-40.0 cm in the dam upstream. The dominant body weight was 93.0-447.9 g in the Pearl River estuary， 148.8-480.0 g in the dam downstream， and 39.5-1 420.8 g in the dam upstream. The dominant ages were 3+ （32.14%） and 2+ （24.11%） in the Pearl River estuary， 3+ （32.14%） and 2+ （24.11%） in the dam downstream， and 4+ （31.58%） and 5+ （26.32%） in the dam upstream. The von Bertalanffy equation of M. terminalis was L=47.2 （1-e-0.177（t+0.387）） in the Pearl River estuary， L=42.9 （1-e-0.199（t+0.377）） in the dam downstream， and L=53.7 （1-e-0.155（t+0.401）） in the dam upstream. The exploitation ratio （E） of M. terminalis was 0.410 in the Pearl River estuary， 0.373 in the dam downstream， and 0.248 in the dam upstream. The critical length （Lc） was 25.1 cm in the Pearl River estuary， 23.0 cm in the dam downstream， and 28.4 cm in the dam upstream. The results of comparative analysis showed that the frequency distribution of body length， body weight， age， and the growth equation of M. terminalis had spatial differences.
2023,42(1):82-91
, DOI: 10.13300/j.cnki.hnlkxb.2023.01.011
Abstract:
In order to scientifically formulate the technical plan for the proliferation and release of large water surface and promote the sustainable and healthy development of ecological fishery， this study took the Weishui Reservoir as an example. On the basis of studying the ecological capacity of the reservoir by using the EwE software， 4 sets of proliferation and release schemes were constructed using the Ecopath model and the best scheme was selected through a comprehensive comparison of the ecological， social and economic benefits of each plan. The research results could provide new ideas and references for the scientific formulation of large-surface ecological fishery programs. The results showed that： （1） If economic benefits and social and environmental benefits such as nitrogen and phosphorus removal were taken as the preferred factors， scheme 1 was optimal， that was， breeding and releasing of silver carp and bighead carp， with the annual release numbers of 135 000 and 491 000， respectively. The annual maximum sustainable output of silver carp and bighead carp was 486.6 t and 1 766.8 t， the total output value， total profit value and unit output value are 80.402 million yuan， 70.037 million yuan and 3.502 million yuan/km2， respectively， and the annual net removal of total nitrogen and total phosphorus could reach above 130.41 t and 36.98 t， the total primary productive force/total respiration （TPP/TR） value， connectivity index （CI） value， system omnivorous index （SOI） value and Shannon diversity index value of the ecosystem were 4.030， 0.304， 0.114 and 1.557， respectively. （2） If the health of the ecosystem and the economic benefits of fishery were considered comprehensively， scheme 3 was the best， that was， breeding and releasing of mandarin fish， yellow catfish， common carp， crucian carp， silver carp， and bighead carp with annual discharge numbers of 800，19 000， 9 000， 11 000， 41 000 and 148 000， respectively. The annual maximum sustainable output could reach 1.2 t， 3.8 t， 18.8 t， 5.6 t， 162.8 t and 591.2 t， respectively. The total output value， total profit value and unit output value were 30.418 million yuan， 25.622 million yuan， and 1.281 million yuan/km2， respectively， the annual net removal of total nitrogen and total phosphorus could reach above 46.73 t and 13.21 t， and the TPP/TR， CI， SOI and Shannon diversity index were 4.616， 0.302， 0.117 and 1.597， respectively. The above results show that the Ecopath model can be flexibly used to scientifically formulate large-water ecological fishery schemes according to the corresponding fishery management objectives.
In order to scientifically formulate the technical plan for the proliferation and release of large water surface and promote the sustainable and healthy development of ecological fishery， this study took the Weishui Reservoir as an example. On the basis of studying the ecological capacity of the reservoir by using the EwE software， 4 sets of proliferation and release schemes were constructed using the Ecopath model and the best scheme was selected through a comprehensive comparison of the ecological， social and economic benefits of each plan. The research results could provide new ideas and references for the scientific formulation of large-surface ecological fishery programs. The results showed that： （1） If economic benefits and social and environmental benefits such as nitrogen and phosphorus removal were taken as the preferred factors， scheme 1 was optimal， that was， breeding and releasing of silver carp and bighead carp， with the annual release numbers of 135 000 and 491 000， respectively. The annual maximum sustainable output of silver carp and bighead carp was 486.6 t and 1 766.8 t， the total output value， total profit value and unit output value are 80.402 million yuan， 70.037 million yuan and 3.502 million yuan/km2， respectively， and the annual net removal of total nitrogen and total phosphorus could reach above 130.41 t and 36.98 t， the total primary productive force/total respiration （TPP/TR） value， connectivity index （CI） value， system omnivorous index （SOI） value and Shannon diversity index value of the ecosystem were 4.030， 0.304， 0.114 and 1.557， respectively. （2） If the health of the ecosystem and the economic benefits of fishery were considered comprehensively， scheme 3 was the best， that was， breeding and releasing of mandarin fish， yellow catfish， common carp， crucian carp， silver carp， and bighead carp with annual discharge numbers of 800，19 000， 9 000， 11 000， 41 000 and 148 000， respectively. The annual maximum sustainable output could reach 1.2 t， 3.8 t， 18.8 t， 5.6 t， 162.8 t and 591.2 t， respectively. The total output value， total profit value and unit output value were 30.418 million yuan， 25.622 million yuan， and 1.281 million yuan/km2， respectively， the annual net removal of total nitrogen and total phosphorus could reach above 46.73 t and 13.21 t， and the TPP/TR， CI， SOI and Shannon diversity index were 4.616， 0.302， 0.117 and 1.597， respectively. The above results show that the Ecopath model can be flexibly used to scientifically formulate large-water ecological fishery schemes according to the corresponding fishery management objectives.
2023,42(1):92-99
, DOI: 10.13300/j.cnki.hnlkxb.2023.01.012
Abstract:
To study the utilization and budgets of nitrogen and phosphorus in higher-place aquaculture ponds of gentian grouper （Epinephelus lanceolatus ♂ × Epinephelus luscoguttatus ♀），and to illuminate the dynamics of water quality and the sources and fate of nitrogen and phosphorus，during 55 days of cultivation，fish，pond water，input and output water and feed were regularly sampled and analyzed in three higher-place ponds. The results showed that： （1） the average concentration of dissolved oxygen during culture was between 8.64 and 9.55 mg/L； Ammonia nitrogen，nitrite，nitrate and phosphate showed irregular fluctuation in the three ponds； The contents of total nitrogen and total phosphorus varied from 6.14 to 7.11 mg/L and 0.38 to 1.41 mg/L，indicating serious eutrophication of the aquaculture pond. （2） During the cultivation period，the survival rate of gentian grouper was high. The weight gain rate of fish and feed conversion ranged from 96.0% to 227.0% and 0.55 to 0.90. The utilization rates of feed nitrogen and phosphorus were 47.0%-59.0% and 52.0%-63.0%，respectively. （3） Feed accounted for 61.0%-66.8% of total nitrogen input and 66.9%-71.0% of total phosphorus input. Fish harvest from the ponds accounted for 43.0%-60.9% of nitrogen output and 45.0%-67.7% of phosphorus output. The rest of the nitrogen and phosphorus were exported as drainage，sediment and other ways. The results of the study showed that higher-place aquaculture ponds of gentian grouper had high level nitrogen and phosphorus content， feed is the major way of nitrogen and phosphorus input to the pond and fish harvest is the major way of nitrogen and phosphorus output. The rest output was discharged through aquaculture effluents. Appropriate management of the waste water discharge in aquaculture is needed to decrease negative effect on nearby waterbody.
To study the utilization and budgets of nitrogen and phosphorus in higher-place aquaculture ponds of gentian grouper （Epinephelus lanceolatus ♂ × Epinephelus luscoguttatus ♀），and to illuminate the dynamics of water quality and the sources and fate of nitrogen and phosphorus，during 55 days of cultivation，fish，pond water，input and output water and feed were regularly sampled and analyzed in three higher-place ponds. The results showed that： （1） the average concentration of dissolved oxygen during culture was between 8.64 and 9.55 mg/L； Ammonia nitrogen，nitrite，nitrate and phosphate showed irregular fluctuation in the three ponds； The contents of total nitrogen and total phosphorus varied from 6.14 to 7.11 mg/L and 0.38 to 1.41 mg/L，indicating serious eutrophication of the aquaculture pond. （2） During the cultivation period，the survival rate of gentian grouper was high. The weight gain rate of fish and feed conversion ranged from 96.0% to 227.0% and 0.55 to 0.90. The utilization rates of feed nitrogen and phosphorus were 47.0%-59.0% and 52.0%-63.0%，respectively. （3） Feed accounted for 61.0%-66.8% of total nitrogen input and 66.9%-71.0% of total phosphorus input. Fish harvest from the ponds accounted for 43.0%-60.9% of nitrogen output and 45.0%-67.7% of phosphorus output. The rest of the nitrogen and phosphorus were exported as drainage，sediment and other ways. The results of the study showed that higher-place aquaculture ponds of gentian grouper had high level nitrogen and phosphorus content， feed is the major way of nitrogen and phosphorus input to the pond and fish harvest is the major way of nitrogen and phosphorus output. The rest output was discharged through aquaculture effluents. Appropriate management of the waste water discharge in aquaculture is needed to decrease negative effect on nearby waterbody.
2023,42(1):100-107
, DOI: 10.13300/j.cnki.hnlkxb.2023.01.013
Abstract:
To improve the calculation process of infer consumer trophic position using stable isotope analysis and to reduce the influence of the current methods and sample quality， this paper applied Bayesian mixing model to estimate the trophic position of silver carp （Hypophthalmichthys molitrix） and bighead carp （Hypophthalmichthys nobilis） in Chinese waters from published literature. The results showed that the trophic position of silver carp and bighead carp had no significant correlation with total phosphorus （TP） and total nitrogen （TN） under Bayesian method. Some studies have the limitation of small sample sizes， low sampling frequency， and ignored the seasonal and spatial variations in baseline， thus failing to accurately represent the trophic signatures of target organisms， which may have led to deviation in trophic position estimates. No significant difference between the Bayesian method and the current method indicates that even more accurate models cannot overcomes the limitations of an irrational sampling design. The results of curve fitting show that the Bayesian approach performs more constrained with the sample size ≥6， and the accuracy is improved. Therefore， in the experimental design， we suggest that the sample size should be ≥6， and that seasonal and spatial variations should be considered and avoid single， small collections.
To improve the calculation process of infer consumer trophic position using stable isotope analysis and to reduce the influence of the current methods and sample quality， this paper applied Bayesian mixing model to estimate the trophic position of silver carp （Hypophthalmichthys molitrix） and bighead carp （Hypophthalmichthys nobilis） in Chinese waters from published literature. The results showed that the trophic position of silver carp and bighead carp had no significant correlation with total phosphorus （TP） and total nitrogen （TN） under Bayesian method. Some studies have the limitation of small sample sizes， low sampling frequency， and ignored the seasonal and spatial variations in baseline， thus failing to accurately represent the trophic signatures of target organisms， which may have led to deviation in trophic position estimates. No significant difference between the Bayesian method and the current method indicates that even more accurate models cannot overcomes the limitations of an irrational sampling design. The results of curve fitting show that the Bayesian approach performs more constrained with the sample size ≥6， and the accuracy is improved. Therefore， in the experimental design， we suggest that the sample size should be ≥6， and that seasonal and spatial variations should be considered and avoid single， small collections.
Nitrogen and phosphorus balance and eco-economic benefits under different rice-crab co-culture modes
2023,42(1):108-117
, DOI: 10.13300/j.cnki.hnlkxb.2023.01.014
Abstract:
To formulate safe， high quality and efficient polyculture technical specifications and explore sustainable development of aquaculture technology， a comparative experiment of three co-culture modes， including experimental group （rice-crab， RC； rice-crayfish-crab， RCC） and control group （intensive crab， IC）， was set up in Suzhou， Anhui Province. By comparing and analyzing the N and P balance， N and P utilization， biomass and diversity of plankton and eco-economic benefits of the three modes， the advantages of rice-fish polyculture and the best rice-crab co-culture mode were explored. The results showed that the content of N and P in the substrate increased in all three culture modes， and the most significant increase was in the IC mode （P<0.05）. The N and P balance showed surplus in all patterns， the N surplus in IC， RC and RCC modes were 1 030.92 kg/hm2， 364.37 kg/hm2 and 188.75 kg/hm2， and the P surplus were 171.35 kg/hm2， 81.67 kg/hm2 and 76.96 kg/hm2， respectively. The N utilization rate in IC， RC and RCC modes were 16.47%， 48.98% and 65.71%， and the P utilization rate were 7.61%， 18.22% and 24.29%， respectively. Compared with IC and RC modes， the total amount and increase of phytoplankton species and the Shannon-Wiener diversity index were the highest in the RCC mode. The economic benefit of RC and RCC were 22.78% and 4.48% lower than those of IC， respectively. The economic benefit of RCC was not significant different from that of IC. In conclusion， compared with the intensive cultivation mode， the rice-fish co-culture pattern is more friendly to the ecological environment， while RCC has better economic benefits than RC.
To formulate safe， high quality and efficient polyculture technical specifications and explore sustainable development of aquaculture technology， a comparative experiment of three co-culture modes， including experimental group （rice-crab， RC； rice-crayfish-crab， RCC） and control group （intensive crab， IC）， was set up in Suzhou， Anhui Province. By comparing and analyzing the N and P balance， N and P utilization， biomass and diversity of plankton and eco-economic benefits of the three modes， the advantages of rice-fish polyculture and the best rice-crab co-culture mode were explored. The results showed that the content of N and P in the substrate increased in all three culture modes， and the most significant increase was in the IC mode （P<0.05）. The N and P balance showed surplus in all patterns， the N surplus in IC， RC and RCC modes were 1 030.92 kg/hm2， 364.37 kg/hm2 and 188.75 kg/hm2， and the P surplus were 171.35 kg/hm2， 81.67 kg/hm2 and 76.96 kg/hm2， respectively. The N utilization rate in IC， RC and RCC modes were 16.47%， 48.98% and 65.71%， and the P utilization rate were 7.61%， 18.22% and 24.29%， respectively. Compared with IC and RC modes， the total amount and increase of phytoplankton species and the Shannon-Wiener diversity index were the highest in the RCC mode. The economic benefit of RC and RCC were 22.78% and 4.48% lower than those of IC， respectively. The economic benefit of RCC was not significant different from that of IC. In conclusion， compared with the intensive cultivation mode， the rice-fish co-culture pattern is more friendly to the ecological environment， while RCC has better economic benefits than RC.
BAI Xuelan, FAN Zeyu, XU Juchen, LIN Shen, MA Shuaibing, HUANG Luquan, LI Jinneng, HOU Jie, HE Xugang
2023,42(1):118-127
, DOI: 10.13300/j.cnki.hnlkxb.2023.01.015
Abstract:
In order to clarify the characteristics of plankton community structure and understand the current status of water quality in Weishui Reservoir， in this study， plankton and water quality surveys were carried out in the typical area of Weishui Reservoir in July （summer） and November （autumn） 2021， January （winter） and March （spring） 2022. The results showed that there were 75 genera and 129 species of phytoplankton， mainly Chlorophyta， and 23 genera and 31 species of zooplankton （rotifers and planktonic crustaceans）， mainly rotifers. The dominant plankton species mainly included Cyclotella catenate， Scenedesmus biguga， Pseudoanabaena limnetica， Keratella cochlearis， nauplius， etc. The annual mean density and biomass of phytoplankton were 1.656×107 ind./L and 6.32 mg/L， respectively， and the annual density and biomass of zooplankton were 1.75×102 ind./L and 1.92 mg/L， respectively. In terms of spatial distribution， the abundance and biomass of plankton decreased gradually from the upstream channel-type area to the downstream open-water area. Canonical correspondence analysis showed that PO43--P， WT， pH and DO all had important effects on the ecological distribution of plankton communities in Weishui Reservoir， while NO3--N and Cond only had an effect on phytoplankton. According to the evaluation of species diversity， the plankton community structure of Weishui Reservoir is relatively stable， and the water quality in the reservoir area is in the mesotrophic status.
In order to clarify the characteristics of plankton community structure and understand the current status of water quality in Weishui Reservoir， in this study， plankton and water quality surveys were carried out in the typical area of Weishui Reservoir in July （summer） and November （autumn） 2021， January （winter） and March （spring） 2022. The results showed that there were 75 genera and 129 species of phytoplankton， mainly Chlorophyta， and 23 genera and 31 species of zooplankton （rotifers and planktonic crustaceans）， mainly rotifers. The dominant plankton species mainly included Cyclotella catenate， Scenedesmus biguga， Pseudoanabaena limnetica， Keratella cochlearis， nauplius， etc. The annual mean density and biomass of phytoplankton were 1.656×107 ind./L and 6.32 mg/L， respectively， and the annual density and biomass of zooplankton were 1.75×102 ind./L and 1.92 mg/L， respectively. In terms of spatial distribution， the abundance and biomass of plankton decreased gradually from the upstream channel-type area to the downstream open-water area. Canonical correspondence analysis showed that PO43--P， WT， pH and DO all had important effects on the ecological distribution of plankton communities in Weishui Reservoir， while NO3--N and Cond only had an effect on phytoplankton. According to the evaluation of species diversity， the plankton community structure of Weishui Reservoir is relatively stable， and the water quality in the reservoir area is in the mesotrophic status.
2023,42(1):128-138
, DOI: 10.13300/j.cnki.hnlkxb.2023.01.016
Abstract:
To clarify the characteristics of rotifer community structure and distribution，and environmental affecting factors in the mainstream of Yangtze River，the habitat space of 27 river segments from the source to the lower reaches of the Yangtze River mainstream were divided into four regions based on physical and chemical parameters of water quality.The community structure and distribution of rotifers in the high mountain area，canyon area，plain area and estuary area was investigated，and biological methods were employed to evaluate the water quality status of the mainstream of Yangtze River.The results showed that 85 rotifer species belonging to 37 genera were identified，containing 63 indicator species，mainly oligosmal species.There were 12 dominant species in the four research areas，and Keratella ualega and Keratella cochlearis were dominant in most water areas.The average zooplankton density and biomass were 19.66 ind./L.and 0.11 mg/L，respectively.The distribution patterns of rotifers were as follows： the density and biomass of rotifers were the highest in the canyon area，followed by the plain area，high mountain area and estuary area.The average Shannon-Wiener diversity index and Pielou evenness index were 2.62 and 0.78，respectively.Specifically，Shannon-Wiener index showed significant differences among different regions （P<0.05），and the Pielou index in each region was relatively uniform.The results of NMDs analysis suggested that the similarity of rotifers community structure between crayon and plain areas was higher than that among other areas.The RDA analysis indicated that WT，density of the phytoplankton，DO，and TP were important factors affecting the spatial distribution of rotifers in the mainstream of Yangtze River.In conclusion，the community structure of rotifers in different areas of the Yangtze River mainstream showed high spatial heterogeneity，which was jointly caused by the change of natural environment and the disturbance of human activities.
To clarify the characteristics of rotifer community structure and distribution，and environmental affecting factors in the mainstream of Yangtze River，the habitat space of 27 river segments from the source to the lower reaches of the Yangtze River mainstream were divided into four regions based on physical and chemical parameters of water quality.The community structure and distribution of rotifers in the high mountain area，canyon area，plain area and estuary area was investigated，and biological methods were employed to evaluate the water quality status of the mainstream of Yangtze River.The results showed that 85 rotifer species belonging to 37 genera were identified，containing 63 indicator species，mainly oligosmal species.There were 12 dominant species in the four research areas，and Keratella ualega and Keratella cochlearis were dominant in most water areas.The average zooplankton density and biomass were 19.66 ind./L.and 0.11 mg/L，respectively.The distribution patterns of rotifers were as follows： the density and biomass of rotifers were the highest in the canyon area，followed by the plain area，high mountain area and estuary area.The average Shannon-Wiener diversity index and Pielou evenness index were 2.62 and 0.78，respectively.Specifically，Shannon-Wiener index showed significant differences among different regions （P<0.05），and the Pielou index in each region was relatively uniform.The results of NMDs analysis suggested that the similarity of rotifers community structure between crayon and plain areas was higher than that among other areas.The RDA analysis indicated that WT，density of the phytoplankton，DO，and TP were important factors affecting the spatial distribution of rotifers in the mainstream of Yangtze River.In conclusion，the community structure of rotifers in different areas of the Yangtze River mainstream showed high spatial heterogeneity，which was jointly caused by the change of natural environment and the disturbance of human activities.
2023,42(1):139-145
, DOI: 10.13300/j.cnki.hnlkxb.2023.01.017
Abstract:
In order to obtain the best coverage of Ipomoea aquatica floating-bed in pond culture of Qihe crucian carp， Carassius auratus， a total of 360 individuals of Qihe crucian carp were randomly cultured in four groups with coverage of the I. aquatica floating-bed of 0（C0）， 10%（C1）， 20%（C2） and 30%（C3）， respectively， with 3 replicates per group and 30 fish per replicate. After culture for 90 days， the aquaculture water quality， growth， general nutritional composition and amino acid contents were examined， and the differences were compared. The results showed that only the contents of three amino acids （glycine， valine and arginine） were significantly affected by I. aquatica floating-bed coverage （P<0.05）， with the maximum value mostly in group C1， followed by the control. In addition， the changes of valine and arginine contents were consistent with that of weight gain rate among the four treatments. Moreover， compared with C0， the crude protein and ash contents of the three treatments （C1-C3） were higher， and the crude lipid content was lower， among which 10% treatment （C1） exhibited the highest crude protein content and lowest crude lipid content. Therefore， we suggest that 10% I. aquatica floating-bed coverage is most beneficial to the excellent quality of Qihe crucian carp， but too high coverage would have opposite effect.
In order to obtain the best coverage of Ipomoea aquatica floating-bed in pond culture of Qihe crucian carp， Carassius auratus， a total of 360 individuals of Qihe crucian carp were randomly cultured in four groups with coverage of the I. aquatica floating-bed of 0（C0）， 10%（C1）， 20%（C2） and 30%（C3）， respectively， with 3 replicates per group and 30 fish per replicate. After culture for 90 days， the aquaculture water quality， growth， general nutritional composition and amino acid contents were examined， and the differences were compared. The results showed that only the contents of three amino acids （glycine， valine and arginine） were significantly affected by I. aquatica floating-bed coverage （P<0.05）， with the maximum value mostly in group C1， followed by the control. In addition， the changes of valine and arginine contents were consistent with that of weight gain rate among the four treatments. Moreover， compared with C0， the crude protein and ash contents of the three treatments （C1-C3） were higher， and the crude lipid content was lower， among which 10% treatment （C1） exhibited the highest crude protein content and lowest crude lipid content. Therefore， we suggest that 10% I. aquatica floating-bed coverage is most beneficial to the excellent quality of Qihe crucian carp， but too high coverage would have opposite effect.
2023,42(1):146-153
, DOI: 10.13300/j.cnki.hnlkxb.2023.01.018
Abstract:
Freshwater product logistics plays an important role in connecting fishing， processing， and marketing of freshwater products. It is a major way to ensure the large-scale circulation of freshwater products and solve the problems of consumption imbalance. China is a major producer and consumer of freshwater products. Freshwater products are perishable， seasonal， and regional， which bring some challenges to the circulation of freshwater products. In this paper， the present situation of China’s freshwater products logistics was introduced， including freshwater product production， circulation form， infrastructure， and policy environment. And the present problem was analyzed， such as freshwater product processing capacity， storage and transportation equipment， management system， information construction， logistics standard， cold-chain logistics personnel， and other aspects. Some suggestions were put forward to improve the freshwater product logistics industry in China. It was anticipated to provide references for promoting the development of freshwater product logistics industry.
Freshwater product logistics plays an important role in connecting fishing， processing， and marketing of freshwater products. It is a major way to ensure the large-scale circulation of freshwater products and solve the problems of consumption imbalance. China is a major producer and consumer of freshwater products. Freshwater products are perishable， seasonal， and regional， which bring some challenges to the circulation of freshwater products. In this paper， the present situation of China’s freshwater products logistics was introduced， including freshwater product production， circulation form， infrastructure， and policy environment. And the present problem was analyzed， such as freshwater product processing capacity， storage and transportation equipment， management system， information construction， logistics standard， cold-chain logistics personnel， and other aspects. Some suggestions were put forward to improve the freshwater product logistics industry in China. It was anticipated to provide references for promoting the development of freshwater product logistics industry.
2023,42(1):154-162
, DOI: 10.13300/j.cnki.hnlkxb.2023.01.019
Abstract:
Fresh and frozen surimi were prepared by ozone rinsing， and the effects of ozone rinsing and frozen storage on protein oxidation and flavor of silver carp surimi were investigated.Ozone rinsing decreased water-soluble protein content and increased salt-soluble protein content in fresh surimi.After frozen storage， the contents of water-soluble and salt-soluble protein were significantly decreased （P<0.05）.The content of active sulfhydryl in fresh surimi was significantly decreased by ozone rinsing and frozen storage， but the decrease by frozen storage was smaller than that by ozone rinsing.The results of the electronic nose and electronic tongue showed that there was significant difference in the smell and taste between frozen surimi and fresh surimi.However， the ozone rinsing surimi and water rinsing surimi could not be effectively separated.Ozone rinsing and frozen storage significantly decreased the free amino acid content.A total of 59 volatile flavor compounds were identified by GC-IMS.The unsaturated alcohols in ozone-rinsing surimi were significantly lower than those in water-rinsing surimi.After freezing， alcohols decreased， aldehydes increased significantly.The results can provide a theoretical basis for the application of ozone rinsing in surimi and surimi products.
Fresh and frozen surimi were prepared by ozone rinsing， and the effects of ozone rinsing and frozen storage on protein oxidation and flavor of silver carp surimi were investigated.Ozone rinsing decreased water-soluble protein content and increased salt-soluble protein content in fresh surimi.After frozen storage， the contents of water-soluble and salt-soluble protein were significantly decreased （P<0.05）.The content of active sulfhydryl in fresh surimi was significantly decreased by ozone rinsing and frozen storage， but the decrease by frozen storage was smaller than that by ozone rinsing.The results of the electronic nose and electronic tongue showed that there was significant difference in the smell and taste between frozen surimi and fresh surimi.However， the ozone rinsing surimi and water rinsing surimi could not be effectively separated.Ozone rinsing and frozen storage significantly decreased the free amino acid content.A total of 59 volatile flavor compounds were identified by GC-IMS.The unsaturated alcohols in ozone-rinsing surimi were significantly lower than those in water-rinsing surimi.After freezing， alcohols decreased， aldehydes increased significantly.The results can provide a theoretical basis for the application of ozone rinsing in surimi and surimi products.
2023,42(1):163-169
, DOI: 10.13300/j.cnki.hnlkxb.2023.01.020
Abstract:
The basic nutrient composition， minerals， amino acids and fatty acids of the gill edge meat， fish face meat and fish brain of bighead carp （Aristichthys nobilis） head were determined， and the differences of the nutrients in the three parts of bighead carp head were analyzed to study the edible value of bighead carp head and expand the development of its product.The results of comparing the basic nutrient composition of the edible part of bighead carp head showed that the content of protein was in the decreasing order of gill edge meat>fish face meat>fish brain， and the content of fat was in the increasing order of gill edge meat <fish face meat<fish brain.Compared with the three edible parts of the bighead carp head， the content of potassium， phosphorus， calcium and zinc in the gill meat was higher.The content of various minerals in the fish brain was relatively low.Twenty-six kinds of fatty acids were detected in the meat of fish face and brain of bighead carp， and 25 kinds of fatty acids were detected in gill edge meat.The value of n-6/n-3 in edible parts of bighead carp head was 1.80，1.83 and 1.86， in line with the ideal ratio recommended by the Chinese Nutrition Society. The first limiting amino acid is tryptophan， the second limiting amino acid is methionine + cysteine.The essential amino acid index （EAAI） of bighead carp head is 75.48， which can be used as a source of protein.It is indicated that bighead carp head is a high-quality food source with rich nutrition， reasonable composition of amino acids and fatty acids.
The basic nutrient composition， minerals， amino acids and fatty acids of the gill edge meat， fish face meat and fish brain of bighead carp （Aristichthys nobilis） head were determined， and the differences of the nutrients in the three parts of bighead carp head were analyzed to study the edible value of bighead carp head and expand the development of its product.The results of comparing the basic nutrient composition of the edible part of bighead carp head showed that the content of protein was in the decreasing order of gill edge meat>fish face meat>fish brain， and the content of fat was in the increasing order of gill edge meat <fish face meat<fish brain.Compared with the three edible parts of the bighead carp head， the content of potassium， phosphorus， calcium and zinc in the gill meat was higher.The content of various minerals in the fish brain was relatively low.Twenty-six kinds of fatty acids were detected in the meat of fish face and brain of bighead carp， and 25 kinds of fatty acids were detected in gill edge meat.The value of n-6/n-3 in edible parts of bighead carp head was 1.80，1.83 and 1.86， in line with the ideal ratio recommended by the Chinese Nutrition Society. The first limiting amino acid is tryptophan， the second limiting amino acid is methionine + cysteine.The essential amino acid index （EAAI） of bighead carp head is 75.48， which can be used as a source of protein.It is indicated that bighead carp head is a high-quality food source with rich nutrition， reasonable composition of amino acids and fatty acids.
2023,42(1):170-177
, DOI: 10.13300/j.cnki.hnlkxb.2023.01.021
Abstract:
The collagen extracted from fish scales is processed into fish scale jelly， which is safe and healthy. It contains a large amount of water-soluble collagen， and has the effects of calcium supplementation， beauty， body strengthening and brain strengthening. Fish scale jelly is easier to be digested and absorbed by the human body compared with other collagen proteins. The process of production is simple and can be completed without large equipment. In this article， we optimized the simmering technology of prepared food from the silver carp scale jelly and studied its gelation characteristics. The response surface experiment design was used to study the effects of simmering temperature， simmering time， carrageenan dosage and water to scale ratio on the yield and strength of gel to optimize the simmering process and study the gelation characteristics of fish scale jelly under different conditions. The gelation characteristics of fish scale jelly were analyzed with differential caloric method， nuclear magnetic imaging and dynamic rheological methods. The results showed that the water to scale ratio had the greatest influence on the yield and strength of gel. The yield of gel increased gradually and the strength of gel decreased gradually with the increase of water to scale ratio. According to the comprehensive score of the yield rate and strength of gel， the optimized conditions were as that：the total mass of water and fish scales as 100%,water to scale ratio of 3∶1， simmering temperature of 80 ℃， simmering time of 90 min， carrageenan dosage of 1%. Through the validation test， the yield rate of fish scale jelly was 3.62%， the strength of gel was 206.59 g·mm， and the comprehensive weighted score was 145.699. The proportion of free water in fish scale jelly was over 89%， and the melting temperature was 24-28 ℃.The content of free water gradually increased and the mobility was enhanced with the increase of water to scale ratio. The elastic modulus and enthalpy value gradually decreased. It is indicated that the silver carp scales can be used for processing new type of prepared food with gel.
The collagen extracted from fish scales is processed into fish scale jelly， which is safe and healthy. It contains a large amount of water-soluble collagen， and has the effects of calcium supplementation， beauty， body strengthening and brain strengthening. Fish scale jelly is easier to be digested and absorbed by the human body compared with other collagen proteins. The process of production is simple and can be completed without large equipment. In this article， we optimized the simmering technology of prepared food from the silver carp scale jelly and studied its gelation characteristics. The response surface experiment design was used to study the effects of simmering temperature， simmering time， carrageenan dosage and water to scale ratio on the yield and strength of gel to optimize the simmering process and study the gelation characteristics of fish scale jelly under different conditions. The gelation characteristics of fish scale jelly were analyzed with differential caloric method， nuclear magnetic imaging and dynamic rheological methods. The results showed that the water to scale ratio had the greatest influence on the yield and strength of gel. The yield of gel increased gradually and the strength of gel decreased gradually with the increase of water to scale ratio. According to the comprehensive score of the yield rate and strength of gel， the optimized conditions were as that：the total mass of water and fish scales as 100%,water to scale ratio of 3∶1， simmering temperature of 80 ℃， simmering time of 90 min， carrageenan dosage of 1%. Through the validation test， the yield rate of fish scale jelly was 3.62%， the strength of gel was 206.59 g·mm， and the comprehensive weighted score was 145.699. The proportion of free water in fish scale jelly was over 89%， and the melting temperature was 24-28 ℃.The content of free water gradually increased and the mobility was enhanced with the increase of water to scale ratio. The elastic modulus and enthalpy value gradually decreased. It is indicated that the silver carp scales can be used for processing new type of prepared food with gel.
2023,42(1):178-187
, DOI: 10.13300/j.cnki.hnlkxb.2023.01.022
Abstract:
A silver carp head processing device was designed based on machine vision to solve problems including the lack of domestic freshwater fish head processing equipment and the low degree of mechanization of fish head processing.This device is composed of a fish body conveying device，fish body image acquisition device，fish body turnover part，vertical clamping conveyor belt，fish head cutting part，fish head sectioning part，device control system.The fish body image acquisition device obtains the fish body image on the conveying device and calculates the fish head cutting path.The fish body enters the vertical clamping conveyor belt through the fish body turnover part and moves forward under the action of the vertical clamping conveyor belt.When the fish body reaches the fish head cutting position，the vertical clamping conveyor belt stops after adjusting the fish body position，the fish head cutting part cuts the fish body according to the fish head cutting path and resets，and the vertical clamping conveyor belt drives the fish head forward.The cut fish head is a section in half through the fish head sectioning part.The performance of the prototype was tested with silver carp.The results showed that the determination coefficients of the linear fitting between the actual horizontal distance from the upper cutting point and the lower cutting point and the predicted horizontal distance after the fish head was cut were 0.911 and 0.985，with the root means square errors of 6.31 mm and 2.61 mm.The detection time of fish head cutting path，the processing time of fish head，and the appearance score of the fish head was （0.055±0.009） s，（13.28±0.35） s，and 0.88±0.02，meeting the production requirements of the silver carp head processing.It will provide new methods and equipment for the industry of silver carp head processing and theoretical and methodological references for the automatic processing of silver carp head.
A silver carp head processing device was designed based on machine vision to solve problems including the lack of domestic freshwater fish head processing equipment and the low degree of mechanization of fish head processing.This device is composed of a fish body conveying device，fish body image acquisition device，fish body turnover part，vertical clamping conveyor belt，fish head cutting part，fish head sectioning part，device control system.The fish body image acquisition device obtains the fish body image on the conveying device and calculates the fish head cutting path.The fish body enters the vertical clamping conveyor belt through the fish body turnover part and moves forward under the action of the vertical clamping conveyor belt.When the fish body reaches the fish head cutting position，the vertical clamping conveyor belt stops after adjusting the fish body position，the fish head cutting part cuts the fish body according to the fish head cutting path and resets，and the vertical clamping conveyor belt drives the fish head forward.The cut fish head is a section in half through the fish head sectioning part.The performance of the prototype was tested with silver carp.The results showed that the determination coefficients of the linear fitting between the actual horizontal distance from the upper cutting point and the lower cutting point and the predicted horizontal distance after the fish head was cut were 0.911 and 0.985，with the root means square errors of 6.31 mm and 2.61 mm.The detection time of fish head cutting path，the processing time of fish head，and the appearance score of the fish head was （0.055±0.009） s，（13.28±0.35） s，and 0.88±0.02，meeting the production requirements of the silver carp head processing.It will provide new methods and equipment for the industry of silver carp head processing and theoretical and methodological references for the automatic processing of silver carp head.
2023,42(1):188-196
, DOI: 10.13300/j.cnki.hnlkxb.2023.01.023
Abstract:
The field plot experiments were conducted to apply organic fertilizer to vegetables including cabbage， radish， pepper for three consecutive seasons and citrus （Majia pomelo） for many years to compare the effects of applying organic fertilizer instead of chemical fertilizer on the yield， quality of fruits and vegetables and the content of heavy metals in soil. Using no fertilization （CK） and fertilizer application （CF） as the control， two organic fertilizer treatments with equal nitrogen fertilizer application including OF1， OF2 were set up. The results showed that both OF1 and OF2 treatments ensured that the yield of vegetables in the first two seasons and Majia pomelo do not decrease， and significantly increase the contents of soluble solids in Majia pomelo and the content of organic matter in vegetable soil compared with CF treatment. There was no significant difference in the content of heavy metals between vegetables under different treatments in the first two seasons， but the content of Pb in the edible part of radish treated with OF1 and OF2 was close to the limit standard. In the vegetables of third season， the contents of Cr， As， Cu and Zn in edible parts of pepper treated with OF1 and OF2 were significantly higher than those treated with CF. The content of Pb in the pulp and peel of Majia pomelo fruit treated with OF1 exceeded the limit standard， and that with OF2 treatment was close to the limit standard. The content of various heavy metals in vegetable soil was far lower than the value of risk control， but the content of Pb， Cd， Hg had significantly accumulated compared with CF treatment， among which the content of Hg was the fastest. It is indicated that the application of two organic fertilizer with equal nitrogen fertilizer can increase the yield and quality of fruits and vegetables， improve the physical and chemical properties of soil in a short time， but increase the accumulation of heavy metals in soil as well. Therefore， continuous application of organic fertilizer will lead to the risk that the content of heavy metals in fruits and vegetables exceeds the limit standard.
The field plot experiments were conducted to apply organic fertilizer to vegetables including cabbage， radish， pepper for three consecutive seasons and citrus （Majia pomelo） for many years to compare the effects of applying organic fertilizer instead of chemical fertilizer on the yield， quality of fruits and vegetables and the content of heavy metals in soil. Using no fertilization （CK） and fertilizer application （CF） as the control， two organic fertilizer treatments with equal nitrogen fertilizer application including OF1， OF2 were set up. The results showed that both OF1 and OF2 treatments ensured that the yield of vegetables in the first two seasons and Majia pomelo do not decrease， and significantly increase the contents of soluble solids in Majia pomelo and the content of organic matter in vegetable soil compared with CF treatment. There was no significant difference in the content of heavy metals between vegetables under different treatments in the first two seasons， but the content of Pb in the edible part of radish treated with OF1 and OF2 was close to the limit standard. In the vegetables of third season， the contents of Cr， As， Cu and Zn in edible parts of pepper treated with OF1 and OF2 were significantly higher than those treated with CF. The content of Pb in the pulp and peel of Majia pomelo fruit treated with OF1 exceeded the limit standard， and that with OF2 treatment was close to the limit standard. The content of various heavy metals in vegetable soil was far lower than the value of risk control， but the content of Pb， Cd， Hg had significantly accumulated compared with CF treatment， among which the content of Hg was the fastest. It is indicated that the application of two organic fertilizer with equal nitrogen fertilizer can increase the yield and quality of fruits and vegetables， improve the physical and chemical properties of soil in a short time， but increase the accumulation of heavy metals in soil as well. Therefore， continuous application of organic fertilizer will lead to the risk that the content of heavy metals in fruits and vegetables exceeds the limit standard.
2023,42(1):197-204
, DOI: 10.13300/j.cnki.hnlkxb.2023.01.024
Abstract:
The topsoil （0-20 cm） and subsoil （20-40 cm） under five typical vegetations including Carex cinerascens， Triarrhena lutarioriparia， Phragmites australis， Miscanthus sacchariflorus， and Cynodon dactylon was collected in Sizhoutou wetland of Poyang Lake to study the effect of soil texture on the content of soil organic carbon （SOC）. The distribution of soil particle size was identified with laser particle size analyzer. The parameters of soil grain size were calculated with the Folk-Ward formula. The characteristics of soil grain size distribution were discussed. The relationship between composition of soil grain size and SOC was analyzed with structural equation model （SEM） and Pearson correlation. The results showed that the soil texture of Sizhoutou wetland was mainly silty clay and sandy loam， and the soil sorting was poor. The texture of silty clay was mainly composed of silt （67.76%-79.28%）， with mean value of main grain size of 6.91 Φ. The frequency curves of grain size presented a distribution with bimodal or three peaks. The texture of sandy loam was mainly composed of fine sand （32.90%-56.55%）， with mean value of main grain size of 3.00 Φ. The frequency curves of grain size presented a unimodal distribution. The content of SOC in silty clay （（10.52±3.86） g/kg） was significantly higher than that in sandy loam（ （1.67±1.66） g/kg， P<0.05）. The texture of soil had a direct impact on the content of SOC. Clay， silt and sand were important factors affecting the content of SOC. The retention capacity of clay and silt to soil organic carbon in the area studied was significantly higher than that of sand. It is indicated that the impact of the texture of soil on the sequestration of carbon should be emphasized in protecting the wetland of Poyang Lake.
The topsoil （0-20 cm） and subsoil （20-40 cm） under five typical vegetations including Carex cinerascens， Triarrhena lutarioriparia， Phragmites australis， Miscanthus sacchariflorus， and Cynodon dactylon was collected in Sizhoutou wetland of Poyang Lake to study the effect of soil texture on the content of soil organic carbon （SOC）. The distribution of soil particle size was identified with laser particle size analyzer. The parameters of soil grain size were calculated with the Folk-Ward formula. The characteristics of soil grain size distribution were discussed. The relationship between composition of soil grain size and SOC was analyzed with structural equation model （SEM） and Pearson correlation. The results showed that the soil texture of Sizhoutou wetland was mainly silty clay and sandy loam， and the soil sorting was poor. The texture of silty clay was mainly composed of silt （67.76%-79.28%）， with mean value of main grain size of 6.91 Φ. The frequency curves of grain size presented a distribution with bimodal or three peaks. The texture of sandy loam was mainly composed of fine sand （32.90%-56.55%）， with mean value of main grain size of 3.00 Φ. The frequency curves of grain size presented a unimodal distribution. The content of SOC in silty clay （（10.52±3.86） g/kg） was significantly higher than that in sandy loam（ （1.67±1.66） g/kg， P<0.05）. The texture of soil had a direct impact on the content of SOC. Clay， silt and sand were important factors affecting the content of SOC. The retention capacity of clay and silt to soil organic carbon in the area studied was significantly higher than that of sand. It is indicated that the impact of the texture of soil on the sequestration of carbon should be emphasized in protecting the wetland of Poyang Lake.
LI Fengfeng, ZHANG Yipeng, GONG Dalin, LIU Sanbo, HUANG Qiyuan, MEI Zhinan, WANG Xuekui, SHU Shaohua
2023,42(1):205-211
, DOI: 10.13300/j.cnki.hnlkxb.2023.01.025
Abstract:
QuEChERS pretreatment combined with ultra performance liquid chromatography tandem mass spectrometry （UPLC-MS/MS） method was developed and used to determine pesticide residues including phoxim，cypermethrin and spinetoram in T. wilfordii root and its rhizosphere soil to establish the method for detecting the content of three pesticide residues commonly used in the process of planting Tripterygium wilfordii. The sample was soaked with appropriate amount of water and then extracted by acetonitrile ultrasonic，purified by N-propyl ethylenediamine （PSA） adsorption，detected by optimized UPLC-MS/MS method，and quantified by matrix external standard method. The results showed that the detection limit of pesticides in root like matrix was 0.001-0.714 μg/kg，LOQ was 0.002-2.380 μg/kg。The limit of detection （LOD） of three pesticides in root and soil samples was 0.001-0.714 μg/kg and 0.002-0.810 μg/kg，respectively. The limit of quantitation （LOQ） of three pesticides in root and soil samples was 0.002-2.380 μg/kg and 0.006-2.410 μg/kg，respectively. The linear relationship，recovery rate and relative standard deviation were in line with the relevant provisions of detecting pesticide residue. It is indicated that the method established is simple，rapid，sensitive and accurate，and can meet the requirements of rapidly determining three pesticide residues in Tripterygium wilfordii and rhizosphere related soil.
QuEChERS pretreatment combined with ultra performance liquid chromatography tandem mass spectrometry （UPLC-MS/MS） method was developed and used to determine pesticide residues including phoxim，cypermethrin and spinetoram in T. wilfordii root and its rhizosphere soil to establish the method for detecting the content of three pesticide residues commonly used in the process of planting Tripterygium wilfordii. The sample was soaked with appropriate amount of water and then extracted by acetonitrile ultrasonic，purified by N-propyl ethylenediamine （PSA） adsorption，detected by optimized UPLC-MS/MS method，and quantified by matrix external standard method. The results showed that the detection limit of pesticides in root like matrix was 0.001-0.714 μg/kg，LOQ was 0.002-2.380 μg/kg。The limit of detection （LOD） of three pesticides in root and soil samples was 0.001-0.714 μg/kg and 0.002-0.810 μg/kg，respectively. The limit of quantitation （LOQ） of three pesticides in root and soil samples was 0.002-2.380 μg/kg and 0.006-2.410 μg/kg，respectively. The linear relationship，recovery rate and relative standard deviation were in line with the relevant provisions of detecting pesticide residue. It is indicated that the method established is simple，rapid，sensitive and accurate，and can meet the requirements of rapidly determining three pesticide residues in Tripterygium wilfordii and rhizosphere related soil.
2023,42(1):212-218
, DOI: 10.13300/j.cnki.hnlkxb.2023.01.026
Abstract:
The whole area of soil and typical profiles in Jianshi County were used to analyze the characteristics of the content of selenium in different soil types， the distribution of the content of selenium in vertical soil profiles， and the correlation between the content of in soil and the physical and chemical properties based on the survey results of geochemical evaluation of land quality in Jianshi County， Hubei Province from 2015 to 2020 to study the characteristics and influencing factors of selenium enrichment in the soil in Jianshi County. Results showed that the content of Se in the soil in Jianshi ranged from 0.08 mg/kg to 64.20 mg/kg， with a mean of 0.94 mg/kg. In general， the content of Se in the soil in Jianshi reached the level of seleniferous soils. Among the main types of soil in Jianshi County， the content of selenium in red soil， brown soil and yellow soil was relatively higher than that in other soil types， and the content of selenium in purple soil was the lowest. The depth of soil profile had a significant effect on the content of selenium in soil. The content of selenium in soil was gradually decreased with the increase of the depth of soil profile， consistent with the change trend of organic matter in soil. The content of SiO2， Al2O3， TFe2O3 and CaO in the soil was significantly positively correlated with the content of selenium in the soil. In addition， the content of selenium in the soil was strongly correlated with the content of Cr， Cd， Ni， and Mo in the soil， indicating that the source of Se in the soil is closely related to organic matter in the soil. At the same time， the content of available Se in soil was significantly positively correlated with the pH in soil， indicating that increasing the pH in soil is an effective approach for improving the bioavailability of Se in soil.
The whole area of soil and typical profiles in Jianshi County were used to analyze the characteristics of the content of selenium in different soil types， the distribution of the content of selenium in vertical soil profiles， and the correlation between the content of in soil and the physical and chemical properties based on the survey results of geochemical evaluation of land quality in Jianshi County， Hubei Province from 2015 to 2020 to study the characteristics and influencing factors of selenium enrichment in the soil in Jianshi County. Results showed that the content of Se in the soil in Jianshi ranged from 0.08 mg/kg to 64.20 mg/kg， with a mean of 0.94 mg/kg. In general， the content of Se in the soil in Jianshi reached the level of seleniferous soils. Among the main types of soil in Jianshi County， the content of selenium in red soil， brown soil and yellow soil was relatively higher than that in other soil types， and the content of selenium in purple soil was the lowest. The depth of soil profile had a significant effect on the content of selenium in soil. The content of selenium in soil was gradually decreased with the increase of the depth of soil profile， consistent with the change trend of organic matter in soil. The content of SiO2， Al2O3， TFe2O3 and CaO in the soil was significantly positively correlated with the content of selenium in the soil. In addition， the content of selenium in the soil was strongly correlated with the content of Cr， Cd， Ni， and Mo in the soil， indicating that the source of Se in the soil is closely related to organic matter in the soil. At the same time， the content of available Se in soil was significantly positively correlated with the pH in soil， indicating that increasing the pH in soil is an effective approach for improving the bioavailability of Se in soil.
2023,42(1):219-226
, DOI: 10.13300/j.cnki.hnlkxb.2023.01.027
Abstract:
Combined with the soil conditions of water chestnut planting field and the existing manual harvesting methods， a self-propelled water chestnut harvester for harvesting with water was designed to solve the problem of the high labor intensity of water chestnut harvesting and the lack of harvesting machines that can be used in practical production. The machine is composed of walking system， transmission system， rotating disturbance device， lifting and separation device， collection device， etc. It can conduct the excavation of water chestnuts， separation of fruit and soil， lifting and collection of water chestnut and other work at one time. The transmission system of the whole machine is divided into hydraulic transmission part and mechanical transmission part. The hydraulic transmission part provides power for the walking system of the harvester and the digging and harvesting device， which can realize the walking speed control of machines， the height adjustment of the digging and harvesting device， the speed control of the rotating disturbance device and the speed control of the lifting and separation device. The mechanical transmission part provides a stable speed difference between the rotating disturbance rollers at all levels and the lifting and separation device to ensure the smooth progress of the harvesting process. The three-stage rotating disturbance roller forms a rotating disturbance device to realize the full disturbance and mixing of soil and water. The toothed digging shovel and lifting chain form a lifting and separation device to perform the excavation of water chestnut fruits， the separation of fruit and soil and lifting of water chestnut fruits. The performance of the track chassis of this type of water chestnut harvester was analyzed theoretically. The results showed that the theoretical minimum steering radius of chassis differential steering， the theoretical steering radius of in-situ steering， the theoretical value of the uphill limit overturning angle， and the theoretical value of the downhill limit overturning angle was 1.5 m， 1.0 m， 55.63° and 55.08°， respectively. It is indicated that the machine has small turning radius and large ultimate overturning angle， which is very suitable for the working environment of water chestnut planting field. The results of the field trial showed that the maximum driving speed of this type of water chestnut harvester on the field road， the minimum steering radius of differential steering the in-situ steering radius， the maximum climbing angle， the fruit digging rate， and the damage rate under the experiment conditions is 0.97 m/s， 2.1 m， 1.3 m， 24.2°， 53.19%， and 4.21%， which can meet the performance requirements of water chestnut mechanized harvesting to a certain extent.
Combined with the soil conditions of water chestnut planting field and the existing manual harvesting methods， a self-propelled water chestnut harvester for harvesting with water was designed to solve the problem of the high labor intensity of water chestnut harvesting and the lack of harvesting machines that can be used in practical production. The machine is composed of walking system， transmission system， rotating disturbance device， lifting and separation device， collection device， etc. It can conduct the excavation of water chestnuts， separation of fruit and soil， lifting and collection of water chestnut and other work at one time. The transmission system of the whole machine is divided into hydraulic transmission part and mechanical transmission part. The hydraulic transmission part provides power for the walking system of the harvester and the digging and harvesting device， which can realize the walking speed control of machines， the height adjustment of the digging and harvesting device， the speed control of the rotating disturbance device and the speed control of the lifting and separation device. The mechanical transmission part provides a stable speed difference between the rotating disturbance rollers at all levels and the lifting and separation device to ensure the smooth progress of the harvesting process. The three-stage rotating disturbance roller forms a rotating disturbance device to realize the full disturbance and mixing of soil and water. The toothed digging shovel and lifting chain form a lifting and separation device to perform the excavation of water chestnut fruits， the separation of fruit and soil and lifting of water chestnut fruits. The performance of the track chassis of this type of water chestnut harvester was analyzed theoretically. The results showed that the theoretical minimum steering radius of chassis differential steering， the theoretical steering radius of in-situ steering， the theoretical value of the uphill limit overturning angle， and the theoretical value of the downhill limit overturning angle was 1.5 m， 1.0 m， 55.63° and 55.08°， respectively. It is indicated that the machine has small turning radius and large ultimate overturning angle， which is very suitable for the working environment of water chestnut planting field. The results of the field trial showed that the maximum driving speed of this type of water chestnut harvester on the field road， the minimum steering radius of differential steering the in-situ steering radius， the maximum climbing angle， the fruit digging rate， and the damage rate under the experiment conditions is 0.97 m/s， 2.1 m， 1.3 m， 24.2°， 53.19%， and 4.21%， which can meet the performance requirements of water chestnut mechanized harvesting to a certain extent.
2023,42(1):227-236
, DOI: 10.13300/j.cnki.hnlkxb.2023.01.028
Abstract:
The truss structure of header in the caterpillar type rapeseed windrower is complex and changeable，which leads to the problem of large vibration of the header.Based on the variable density method，the multi-objective topology optimization of frame structure of the header was carried out to reduce the vibration of the header under different working conditions. The topology optimization model of header was established by using Hypermesh software. The virtual prototype model of rapeseed windrower based on RecurDyn was established by using multi-body dynamics method. The dynamic loads of the moving pair of the header under parts debugging conditions，transport conditions and field operation conditions were obtained. The comprehensive objective function of static stiffness and dynamic frequency of the header was constructed with the compromise programming method. The weight of each sub- object was determined according to the analytic hierarchy process （AHP）. Taking the volume fraction and maximum load of moving pair as constraints，the ideal material density distribution of the header spatial structure was obtained. Considering the practical engineering application，the optimized frame of header was normalized. The finite element model of the optimized frame of header was established and the finite element static analysis and modal analysis were carried out. The vibration amplitudes at the measuring points of the header before and after optimization were compared and analyzed. The results showed that the maximum stress value decreased from 107.99 MPa to 65.45 MPa after optimization. The maximum deformation decreased from 0.82 mm to 0.36 mm. The natural frequencies of the first three orders were increased to varying degrees，and the natural frequency of the first order was increased to 24.187 Hz. The results of actual vibration test showed that the vibration amplitude of each measuring point of the header decreases after optimization. The overall vibration of the header decreased，in which the amplitude of the longitudinal cutter support decreased from 4.83 m/s2 to 1.49 m/s2. It will provide reference for the structure improvement and optimization of rapeseed windrower.
The truss structure of header in the caterpillar type rapeseed windrower is complex and changeable，which leads to the problem of large vibration of the header.Based on the variable density method，the multi-objective topology optimization of frame structure of the header was carried out to reduce the vibration of the header under different working conditions. The topology optimization model of header was established by using Hypermesh software. The virtual prototype model of rapeseed windrower based on RecurDyn was established by using multi-body dynamics method. The dynamic loads of the moving pair of the header under parts debugging conditions，transport conditions and field operation conditions were obtained. The comprehensive objective function of static stiffness and dynamic frequency of the header was constructed with the compromise programming method. The weight of each sub- object was determined according to the analytic hierarchy process （AHP）. Taking the volume fraction and maximum load of moving pair as constraints，the ideal material density distribution of the header spatial structure was obtained. Considering the practical engineering application，the optimized frame of header was normalized. The finite element model of the optimized frame of header was established and the finite element static analysis and modal analysis were carried out. The vibration amplitudes at the measuring points of the header before and after optimization were compared and analyzed. The results showed that the maximum stress value decreased from 107.99 MPa to 65.45 MPa after optimization. The maximum deformation decreased from 0.82 mm to 0.36 mm. The natural frequencies of the first three orders were increased to varying degrees，and the natural frequency of the first order was increased to 24.187 Hz. The results of actual vibration test showed that the vibration amplitude of each measuring point of the header decreases after optimization. The overall vibration of the header decreased，in which the amplitude of the longitudinal cutter support decreased from 4.83 m/s2 to 1.49 m/s2. It will provide reference for the structure improvement and optimization of rapeseed windrower.
2023,42(1):237-247
, DOI: 10.13300/j.cnki.hnlkxb.2023.01.029
Abstract:
Aiming at the problem of poor single seed and uniformity of the existing seed metering device under the condition of small plant spacing and dense planting， according to the agronomic requirements of soybean maize strip composite planting mode， a small plant spacing and dense planting air suction precision seed metering device with double seed clearing function is designed.By analyzing the working principle of the seed metering device and determining the structural parameters of key components， taking the qualified rate， over-seeding rate， and missed seeding rate as the evaluation indexes， and taking the number of holes in the seed metering disc， the outer clearing distance， and the inner clearing distance as the experimental factors， the three-factor five-level orthogonal test is carried out to determine the primary and secondary order and the optimal level of the experimental factors.Through the central combination test， the test factors and levels are optimized and verified.The results showed that the number of holes in the seed metering disc and the distance between inner and outer seed eliminating had significant effects on the seed metering performance； The optimal working parameter combination of corn seed metering is 35 holes， the outer seed eliminating distance is 6.2 mm and the inner seed eliminating distance is 1.6 mm； The optimal working parameter combination of soybean seed metering is 62 holes， the outer seed eliminating distance is 4.1 mm and the inner seed eliminating distance is 1.6 mm.The results showed that the qualified rate of maize seed metering was 95.40%， the over-seeding rate was 1.50%， and the missed seeding rate was 3.10%.The qualified rate of soybean seed metering was 97.78%， the over-seeding rate was 0.32%， and the missed seeding rate was 1.90%， which was consistent with the optimization prediction results， and all indexes met the seeding demand.
Aiming at the problem of poor single seed and uniformity of the existing seed metering device under the condition of small plant spacing and dense planting， according to the agronomic requirements of soybean maize strip composite planting mode， a small plant spacing and dense planting air suction precision seed metering device with double seed clearing function is designed.By analyzing the working principle of the seed metering device and determining the structural parameters of key components， taking the qualified rate， over-seeding rate， and missed seeding rate as the evaluation indexes， and taking the number of holes in the seed metering disc， the outer clearing distance， and the inner clearing distance as the experimental factors， the three-factor five-level orthogonal test is carried out to determine the primary and secondary order and the optimal level of the experimental factors.Through the central combination test， the test factors and levels are optimized and verified.The results showed that the number of holes in the seed metering disc and the distance between inner and outer seed eliminating had significant effects on the seed metering performance； The optimal working parameter combination of corn seed metering is 35 holes， the outer seed eliminating distance is 6.2 mm and the inner seed eliminating distance is 1.6 mm； The optimal working parameter combination of soybean seed metering is 62 holes， the outer seed eliminating distance is 4.1 mm and the inner seed eliminating distance is 1.6 mm.The results showed that the qualified rate of maize seed metering was 95.40%， the over-seeding rate was 1.50%， and the missed seeding rate was 3.10%.The qualified rate of soybean seed metering was 97.78%， the over-seeding rate was 0.32%， and the missed seeding rate was 1.90%， which was consistent with the optimization prediction results， and all indexes met the seeding demand.
2023,42(1):248-257
, DOI: 10.13300/j.cnki.hnlkxb.2023.01.030
Abstract:
A double-layer paddle piglet milk mixing tank was designed to study the effects of agitator parameters in piglet milk mixing tank on mixing effect of milk.The method combining CFD numerical simulation and response surface analysis was used. A four factor and three-level orthogonal simulation experiment was designed by taking the rotating speed, layer spacing, paddle angle and distance from the bottom as the design optimization parameters, and the mixing power, mixing time and average temperature rise rate as the response indexes. The regression model of response index was established. The parameters of double-layer paddle agitator were optimized. The results showed that the rotating speed and blade angle significantly affected the mixing power. The rotating speed, layer spacing, blade angle and distance from the bottom had a significant impact on the time of mixing. The rotating speed had an extremely significant impact on the average rise rate of temperature. The layer spacing and blade angle had a significant impact on the average rise rate of temperature. The rotating speed had the greatest impact on the performance of the agitator. The response surface regression model had good fitting. The parameters optimized by the response surface regression model were the speed of 80 r/min, the layer spacing of 170 mm, the blade angle of 30°, and the distance from the bottom of 100 mm. Compared with that before optimization, the stirring power and the time of mixing was reduced by 27.08% and 70.15%, respectively. The average rise rate of temperature was increased by 9.57%. The cloud diagram distribution of turbulent flow energy and temperature were significantly better than those of the primary model. It will provide theoretical basis and reference for the design and application of agitator in piglet milk preparation tank.
A double-layer paddle piglet milk mixing tank was designed to study the effects of agitator parameters in piglet milk mixing tank on mixing effect of milk.The method combining CFD numerical simulation and response surface analysis was used. A four factor and three-level orthogonal simulation experiment was designed by taking the rotating speed, layer spacing, paddle angle and distance from the bottom as the design optimization parameters, and the mixing power, mixing time and average temperature rise rate as the response indexes. The regression model of response index was established. The parameters of double-layer paddle agitator were optimized. The results showed that the rotating speed and blade angle significantly affected the mixing power. The rotating speed, layer spacing, blade angle and distance from the bottom had a significant impact on the time of mixing. The rotating speed had an extremely significant impact on the average rise rate of temperature. The layer spacing and blade angle had a significant impact on the average rise rate of temperature. The rotating speed had the greatest impact on the performance of the agitator. The response surface regression model had good fitting. The parameters optimized by the response surface regression model were the speed of 80 r/min, the layer spacing of 170 mm, the blade angle of 30°, and the distance from the bottom of 100 mm. Compared with that before optimization, the stirring power and the time of mixing was reduced by 27.08% and 70.15%, respectively. The average rise rate of temperature was increased by 9.57%. The cloud diagram distribution of turbulent flow energy and temperature were significantly better than those of the primary model. It will provide theoretical basis and reference for the design and application of agitator in piglet milk preparation tank.
2023,42(1):258-267
, DOI: 10.13300/j.cnki.hnlkxb.2023.01.031
Abstract:
For the application of deep learning in the field of Chinese herbal medicine， especially in the field of southern Chinese medicine， the complex background will reduce the accuracy of recognition.If a complex network structure is used， high computing power is required to support training and detection， but the actual embedded or mobile devices are difficult to meet， which affects the effect of on-site detection.This article proposed to improve the EfficientNetv2 network model to classify and identify 8 kinds of southern Chinese medicine leaves in the complex background collected in the field.The network structure was redesigned.The scope of the Fused-MBConv and MBConv architectures was adjusted.Some 3×3 convolutional kernels were replaced with 5×5 convolutional kernels to increase the perceptual field size， reduce the number of convolutional layers of the network， and to further reduce the network complexity.The transfer learning was introduced to train the model.The adaptive moment estimation optimization algorithm was used to optimize the hyperparameters with multiple tests to determine the learning rate.MultiMarginLoss was selected as the loss function to solve the problem of complex background information affecting the accuracy of recognition.The diversity of the data set was increased and the problem of model over-fitting was avoided by adopting data augmentation methods including affine transformation and Gaussian blur and other methods to the experimental data set to improve the stability of the model training process.The results showed that the model improved achieved 99.12% accuracy in recognizing the image of southern Chinese medicine leaves with complex backgrounds， 1.17% more accurate than the baseline model EfficientNetv2-S.The size of parameters was reduced by 85% approximately.The average training time was reduced by 47.62%.The improved model had significant advantages in model storage space， accuracy， and training time， comparing with lightweight models including DenseNet121， ShuffleNet， and RegNet.It is indicated that the model proposed performs well in classifying leaves of multi-variety southern Chinese medicine.The lightweight degree and performance of the model are further improved.
For the application of deep learning in the field of Chinese herbal medicine， especially in the field of southern Chinese medicine， the complex background will reduce the accuracy of recognition.If a complex network structure is used， high computing power is required to support training and detection， but the actual embedded or mobile devices are difficult to meet， which affects the effect of on-site detection.This article proposed to improve the EfficientNetv2 network model to classify and identify 8 kinds of southern Chinese medicine leaves in the complex background collected in the field.The network structure was redesigned.The scope of the Fused-MBConv and MBConv architectures was adjusted.Some 3×3 convolutional kernels were replaced with 5×5 convolutional kernels to increase the perceptual field size， reduce the number of convolutional layers of the network， and to further reduce the network complexity.The transfer learning was introduced to train the model.The adaptive moment estimation optimization algorithm was used to optimize the hyperparameters with multiple tests to determine the learning rate.MultiMarginLoss was selected as the loss function to solve the problem of complex background information affecting the accuracy of recognition.The diversity of the data set was increased and the problem of model over-fitting was avoided by adopting data augmentation methods including affine transformation and Gaussian blur and other methods to the experimental data set to improve the stability of the model training process.The results showed that the model improved achieved 99.12% accuracy in recognizing the image of southern Chinese medicine leaves with complex backgrounds， 1.17% more accurate than the baseline model EfficientNetv2-S.The size of parameters was reduced by 85% approximately.The average training time was reduced by 47.62%.The improved model had significant advantages in model storage space， accuracy， and training time， comparing with lightweight models including DenseNet121， ShuffleNet， and RegNet.It is indicated that the model proposed performs well in classifying leaves of multi-variety southern Chinese medicine.The lightweight degree and performance of the model are further improved.
2023,42(1):268-276
, DOI: 10.13300/j.cnki.hnlkxb.2023.01.032
Abstract:
As one of the important raw materials for sugar production，sugar cane extracted is not only a necessity but also belongs to national strategic reserve materials. At present，the sugarcane industry as a whole is inefficient，especially in terms of machine seeding，and the efficiency of manual seed cutting is low. The developed methods for sugarcane stem node identification are all based on clean background conditions，but the working environment of agricultural machinery is disgusting. A large amount of debris，miscellaneous leaves and other dirt produced by seed cutting will lead to background pollution in image acquisition area and reduce the recognition ability of algorithm. Therefore，a sugarcane stem node identification method is put forward based on improving YOLOv5 to solve the problems of low recognition accuracy of sugarcane stem node under complex background. To optimize the neck structure and enhance the information fusion capability among different levels by using cross-level connection. At the same time，the model loss function is improved. On the one hand，EIoU loss is introduced to replace original CIoU loss to improve the precision of boundary box regression； on the other hand，Focal loss function is used to replace the cross-entropic loss function to solve the problem of unbalanced proportion of positive and negative samples. Finally，Ghost module is introduced to lightweight network model. The experimental results show that compared with the original model，the average precision value of the model proposed in this study is increased to 97.80%，the single detection time is 16.9 ms and the memory of the model is only 11.4 Mb，which realizes the identification of sugarcane stem joints in different chaotic scenes and reduces the impact of background chaos when cutting injurious buds.
As one of the important raw materials for sugar production，sugar cane extracted is not only a necessity but also belongs to national strategic reserve materials. At present，the sugarcane industry as a whole is inefficient，especially in terms of machine seeding，and the efficiency of manual seed cutting is low. The developed methods for sugarcane stem node identification are all based on clean background conditions，but the working environment of agricultural machinery is disgusting. A large amount of debris，miscellaneous leaves and other dirt produced by seed cutting will lead to background pollution in image acquisition area and reduce the recognition ability of algorithm. Therefore，a sugarcane stem node identification method is put forward based on improving YOLOv5 to solve the problems of low recognition accuracy of sugarcane stem node under complex background. To optimize the neck structure and enhance the information fusion capability among different levels by using cross-level connection. At the same time，the model loss function is improved. On the one hand，EIoU loss is introduced to replace original CIoU loss to improve the precision of boundary box regression； on the other hand，Focal loss function is used to replace the cross-entropic loss function to solve the problem of unbalanced proportion of positive and negative samples. Finally，Ghost module is introduced to lightweight network model. The experimental results show that compared with the original model，the average precision value of the model proposed in this study is increased to 97.80%，the single detection time is 16.9 ms and the memory of the model is only 11.4 Mb，which realizes the identification of sugarcane stem joints in different chaotic scenes and reduces the impact of background chaos when cutting injurious buds.
Display Method:
Abstract:
Mushroom sticks need to replenish water one by one for many times in the process of mushroom production. Aiming at the problems of high labor intensity, low efficiency and inability to accurately control the water injection volume of traditional manual water replenishment, this paper innovatively designs a water injection machine for mushroom sticks on the rack, which is mainly composed of six parts: clamping device, water injection device, lifting device, rotating device, driving device and positioning device. The water injection unit is composed of three groups of clamping devices and water injection devices, which can simultaneously complete the clamping and water injection of 15 mushroom sticks in three layers. Driven by the lifting device, the multi-layer mushroom sticks can be used to replenish water, and then the other side of the tunnel can be used to replenish water on the rack through the rotary device. The prototype test results show that the damage rate of the bacteria rod after water supplement is 0%, the average weight ratio is 84.8%, and the average water supplement efficiency is 270 pieces/h. The water injection machine adopts the method of filling water with mushroom sticks on the rack, which improves the working efficiency, reduces the labor intensity, meets the requirements of filling water with mushroom sticks, and provides a theoretical basis for the research and development of mushroom stick water injection machine.
Mushroom sticks need to replenish water one by one for many times in the process of mushroom production. Aiming at the problems of high labor intensity, low efficiency and inability to accurately control the water injection volume of traditional manual water replenishment, this paper innovatively designs a water injection machine for mushroom sticks on the rack, which is mainly composed of six parts: clamping device, water injection device, lifting device, rotating device, driving device and positioning device. The water injection unit is composed of three groups of clamping devices and water injection devices, which can simultaneously complete the clamping and water injection of 15 mushroom sticks in three layers. Driven by the lifting device, the multi-layer mushroom sticks can be used to replenish water, and then the other side of the tunnel can be used to replenish water on the rack through the rotary device. The prototype test results show that the damage rate of the bacteria rod after water supplement is 0%, the average weight ratio is 84.8%, and the average water supplement efficiency is 270 pieces/h. The water injection machine adopts the method of filling water with mushroom sticks on the rack, which improves the working efficiency, reduces the labor intensity, meets the requirements of filling water with mushroom sticks, and provides a theoretical basis for the research and development of mushroom stick water injection machine.
Abstract:
In order to solve the problem that it is difficult to display the field sowing quality information in real time and intuitively during the unmanned sowing operation of rape direct seeding unit, this study designed a remote monitoring system for unmanned sowing operation of rape direct seeding unit by taking the Reeva 804 tractor and its equipped 2BYQ-8 air-fed rape direct seeding machine as the test platform. The system consists of three parts: unmanned sowing platform, unmanned sowing data collection system and sowing quality monitoring cloud platform, through the electric and hydraulic modification of the gear, clutch, power take off (PTO) and suspension mechanism of the Reeva 804 tractor, and the design of corresponding control strategy to realize the unmanned sowing operation of the direct seeding unit; the use of vehicle The system uses a router to establish a local area network between the seeding monitoring terminal and the on-board computer to realize the fusion and synchronization of seeding data and navigation data, and transmits them to the cloud platform through the network connection for data storage and real-time display; the cloud platform calculates the seeding quality data and its corresponding field location data, and generates the seeding status map of the field operation area based on the high-precision map at the web end. The system can realize the unmanned sowing operation of rape direct seeding unit in the field and the accurate collection and intuitive display of sowing information in the operation area. The test shows that the average deviation of the unmanned sowing operation section of the live seeding unit is 0.037m and the maximum deviation is 0.125m, the operation of the electro-hydraulic modification system is stable and reliable, meeting the unmanned operation requirements of the live seeding unit, the maximum data transmission time delay of the cloud platform communication does not exceed 100ms under 4G network conditions, the cloud storage data is complete without omission, the accuracy of field sowing detection of each sowing channel is not less than 96.16%, meeting the real-time and accuracy requirements of remote monitoring system. The system can provide reference for remote monitoring of rape sowing operation, analysis and visualization of sowing data.
In order to solve the problem that it is difficult to display the field sowing quality information in real time and intuitively during the unmanned sowing operation of rape direct seeding unit, this study designed a remote monitoring system for unmanned sowing operation of rape direct seeding unit by taking the Reeva 804 tractor and its equipped 2BYQ-8 air-fed rape direct seeding machine as the test platform. The system consists of three parts: unmanned sowing platform, unmanned sowing data collection system and sowing quality monitoring cloud platform, through the electric and hydraulic modification of the gear, clutch, power take off (PTO) and suspension mechanism of the Reeva 804 tractor, and the design of corresponding control strategy to realize the unmanned sowing operation of the direct seeding unit; the use of vehicle The system uses a router to establish a local area network between the seeding monitoring terminal and the on-board computer to realize the fusion and synchronization of seeding data and navigation data, and transmits them to the cloud platform through the network connection for data storage and real-time display; the cloud platform calculates the seeding quality data and its corresponding field location data, and generates the seeding status map of the field operation area based on the high-precision map at the web end. The system can realize the unmanned sowing operation of rape direct seeding unit in the field and the accurate collection and intuitive display of sowing information in the operation area. The test shows that the average deviation of the unmanned sowing operation section of the live seeding unit is 0.037m and the maximum deviation is 0.125m, the operation of the electro-hydraulic modification system is stable and reliable, meeting the unmanned operation requirements of the live seeding unit, the maximum data transmission time delay of the cloud platform communication does not exceed 100ms under 4G network conditions, the cloud storage data is complete without omission, the accuracy of field sowing detection of each sowing channel is not less than 96.16%, meeting the real-time and accuracy requirements of remote monitoring system. The system can provide reference for remote monitoring of rape sowing operation, analysis and visualization of sowing data.
Abstract:
In the context of global climate change and China's proposed double carbon target, landscape architecture should give full play to its active role. Through an interview with International Federation of Landscape Architects Asia Pacific Region Climate Change Working Group to learn about the practical actions of landscape architecture in various countries to cope with the double carbon target, and propose goals and prospects for its future development in terms of both resilient design and low carbon design of landscape architecture.
In the context of global climate change and China's proposed double carbon target, landscape architecture should give full play to its active role. Through an interview with International Federation of Landscape Architects Asia Pacific Region Climate Change Working Group to learn about the practical actions of landscape architecture in various countries to cope with the double carbon target, and propose goals and prospects for its future development in terms of both resilient design and low carbon design of landscape architecture.
Abstract:
Aiming at the existing problems of poor stability of furrow width, low flatness of furrow bottom and large soil disturbance in the operation of furrow opener device of rapeseed matrix block seedling transplanting machine, which leads to low seedling rate and difficult soil covering operation, this paper designs a kind of seedbed belt preparation device suitable for the construction of rapeseed matrix block seedling transplanting machine based on the large cavity of ship type furrow opener and the characteristics of wide seedbed and flat furrow bottom constructed by core ploughshare furrow opener operation, combined with the excessive connection of ploughshare surface. The mechanical model of the interaction between the soil and the preparation device was established, and the main structural parameters of the stable seedbed were determined. Taking the working speed, working depth, front-end width and edge angle of the surface as the factors, the soil disturbance area and the coefficient of variation of the ditch width as the evaluation indexes, the four-factor and three-level quadratic orthogonal combination simulation test was carried out by EDEM. The quadratic orthogonal combination test showed that when the working depth was 41 mm, the working speed was 0.52 m / s, the width of the front end of the like-share curved surface was 40 mm, and the blade angle was 61 o, the soil disturbance amount was small and the coefficient of variation of the ditch width was small. The bench test under the optimal parameter combination showed that the soil disturbance amount was 13.01 cm2 and the coefficient of variation of the ditch width was 8.52 %. The results of field comparative test showed that compared with the ship opener, the seedling bed preparation device installed on the transplanting unit increased the seedling rate of the seedling matrix block by 2.09 %, the coefficient of variation of the ditch width decreased by 13.3 %, the soil disturbance decreased by 28.3 %, and the compactness of the bottom surface of the ditch increased by 28.67 %, which met the requirements of the mechanical transplanting of rapeseed matrix seedlings.
Aiming at the existing problems of poor stability of furrow width, low flatness of furrow bottom and large soil disturbance in the operation of furrow opener device of rapeseed matrix block seedling transplanting machine, which leads to low seedling rate and difficult soil covering operation, this paper designs a kind of seedbed belt preparation device suitable for the construction of rapeseed matrix block seedling transplanting machine based on the large cavity of ship type furrow opener and the characteristics of wide seedbed and flat furrow bottom constructed by core ploughshare furrow opener operation, combined with the excessive connection of ploughshare surface. The mechanical model of the interaction between the soil and the preparation device was established, and the main structural parameters of the stable seedbed were determined. Taking the working speed, working depth, front-end width and edge angle of the surface as the factors, the soil disturbance area and the coefficient of variation of the ditch width as the evaluation indexes, the four-factor and three-level quadratic orthogonal combination simulation test was carried out by EDEM. The quadratic orthogonal combination test showed that when the working depth was 41 mm, the working speed was 0.52 m / s, the width of the front end of the like-share curved surface was 40 mm, and the blade angle was 61 o, the soil disturbance amount was small and the coefficient of variation of the ditch width was small. The bench test under the optimal parameter combination showed that the soil disturbance amount was 13.01 cm2 and the coefficient of variation of the ditch width was 8.52 %. The results of field comparative test showed that compared with the ship opener, the seedling bed preparation device installed on the transplanting unit increased the seedling rate of the seedling matrix block by 2.09 %, the coefficient of variation of the ditch width decreased by 13.3 %, the soil disturbance decreased by 28.3 %, and the compactness of the bottom surface of the ditch increased by 28.67 %, which met the requirements of the mechanical transplanting of rapeseed matrix seedlings.
Abstract:
Coping with global climate change and realizing China's " carbon neutrality " goal has become a key issue of domestic and foreign research. Except for related technical research, ways to guide the public to engage in climate change also need to be studied. To enhance the key role of landscape architecture in promoting public participation in climate change response, based on the concept of public participation in "cognitive-emotional-behavioral" three dimensions and the theory of planned behavior. This research explores essential strategies of landscape architecture's intervention for public participation in climate change response from three levels: enhancing awareness - stimulating action - long-term guarantee mechanism, including seven key interventions. 1)In terms of enhancing awareness, integrate climate change information into a multi-sensory public space design and activity system, and use spatial elements to simulate possible local climate change impacts, in order to create climate change cognition and establish emotional links; 2)In terms of stimulating action, create pop-up experiences and participatory low-carbon construction; 3)In terms of long-term guarantee mechanism, through the formation of policies, organizations, financial guarantees, and the improvement of feedback mechanisms, to promote sustainable public participation. Finally, based on China's conditions, this study puts forward three specific work suggestions that China needs to focus on in the future in promoting public participation in the climate response.
Coping with global climate change and realizing China's " carbon neutrality " goal has become a key issue of domestic and foreign research. Except for related technical research, ways to guide the public to engage in climate change also need to be studied. To enhance the key role of landscape architecture in promoting public participation in climate change response, based on the concept of public participation in "cognitive-emotional-behavioral" three dimensions and the theory of planned behavior. This research explores essential strategies of landscape architecture's intervention for public participation in climate change response from three levels: enhancing awareness - stimulating action - long-term guarantee mechanism, including seven key interventions. 1)In terms of enhancing awareness, integrate climate change information into a multi-sensory public space design and activity system, and use spatial elements to simulate possible local climate change impacts, in order to create climate change cognition and establish emotional links; 2)In terms of stimulating action, create pop-up experiences and participatory low-carbon construction; 3)In terms of long-term guarantee mechanism, through the formation of policies, organizations, financial guarantees, and the improvement of feedback mechanisms, to promote sustainable public participation. Finally, based on China's conditions, this study puts forward three specific work suggestions that China needs to focus on in the future in promoting public participation in the climate response.
Abstract:
Abstract: Grapes are perennial herbs, with diverse varieties and large price gaps, and some illegal seedlings merchants for their own interests, resulting in inferior and superior and false real phenomena in the market, so the early identification of grape varieties has become an urgent need for people. Grape leaves contain a large amount of species information, and have the advantages of early ripening time and easy collection, which provides a classification basis for early grape variety identification. Because the similarity of grape leaves with the same species is relatively large, it belongs to the fine-grained image classification problem of finer subcategory division, so this paper constructs a feature enhancement layer for the underlying information on the basis of the fine-grained classification mainstream network to achieve full extraction of the underlying features, and at the same time adds the SE attention mechanism to improve the spatial performance of the network and increase the ability to automatically discover the distinguishing region, so as to form an improved statistical texture residual learning network (Statistical Texture Residual Learning Network, STRLNet). Firstly, the SE attention mechanism is added on the basis of the ResNet50 backbone network, and then the feature enhancement layer of the underlying information is constructed, and finally the enhanced underlying features are fused with the high-level semantic information extracted by the backbone network, and the output is connected to the fully connected layer for storing classification characteristics. Based on the training test of 11 ripe grape leaf datasets collected, the results show that STRLNet can improve the performance of cyberspace while making full use of the underlying feature information, and the classification accuracy of the constructed grape leaf dataset can reach 92.26%, which is about 2.8 percentage points higher than that of ResNet backbone network, and has higher accuracy in fine-grained grape leaf classification than mainstream classification networks such as VGG16, Inception V4 and ResNet ,which can be used for the classification and identification of other similar crops.
Abstract: Grapes are perennial herbs, with diverse varieties and large price gaps, and some illegal seedlings merchants for their own interests, resulting in inferior and superior and false real phenomena in the market, so the early identification of grape varieties has become an urgent need for people. Grape leaves contain a large amount of species information, and have the advantages of early ripening time and easy collection, which provides a classification basis for early grape variety identification. Because the similarity of grape leaves with the same species is relatively large, it belongs to the fine-grained image classification problem of finer subcategory division, so this paper constructs a feature enhancement layer for the underlying information on the basis of the fine-grained classification mainstream network to achieve full extraction of the underlying features, and at the same time adds the SE attention mechanism to improve the spatial performance of the network and increase the ability to automatically discover the distinguishing region, so as to form an improved statistical texture residual learning network (Statistical Texture Residual Learning Network, STRLNet). Firstly, the SE attention mechanism is added on the basis of the ResNet50 backbone network, and then the feature enhancement layer of the underlying information is constructed, and finally the enhanced underlying features are fused with the high-level semantic information extracted by the backbone network, and the output is connected to the fully connected layer for storing classification characteristics. Based on the training test of 11 ripe grape leaf datasets collected, the results show that STRLNet can improve the performance of cyberspace while making full use of the underlying feature information, and the classification accuracy of the constructed grape leaf dataset can reach 92.26%, which is about 2.8 percentage points higher than that of ResNet backbone network, and has higher accuracy in fine-grained grape leaf classification than mainstream classification networks such as VGG16, Inception V4 and ResNet ,which can be used for the classification and identification of other similar crops.
Abstract:
Reasonable distribution of urban green space (UGS) is an important prerequisite to ensure that urban residents enjoy UGS resources equally and improve the health level of a city. In the traditional UGS planning, it is difficult to accurately and quantitatively evaluate the rationality and balance of the layout of urban comprehensive parks by the evaluation of urban comprehensive park services based on indicators such as green space rate or green coverage rate. Taking the central urban area of Hefei as an example, this study proposes a multi-mode two-step floating catchment area method based on improved multi-transport mode. Using the path planning model of Gaode map, bivariate local spatial autocorrelation, Lorentz curve and Gini coefficient, the accessibility and equilibrium of urban park green space comprehensive park under different time thresholds are analyzed on the basis of mobile phone signaling data. Further reveal the rationality and balance of the layout of the comprehensive park green space in the central city. The main conclusions are as follows. ( 1 ) By using mobile phone signaling data and Gaode path planning data as data sources to improve the traditional accessibility calculation method and two-step mobile search model, the accessibility evaluation framework of urban comprehensive park green space at micro scale is established, which can accurately evaluate the accessibility of urban comprehensive park. (2) The spatial difference of accessibility of comprehensive parks in the central urban area of Hefei is significant. The areas with high accessibility are usually distributed in the new urban area and the surrounding areas of comprehensive parks. With the increase of time threshold, the spatial distribution of accessibility tends to be average. (3) Under the 15-minute and 30-minute time thresholds, only nearly 5 % of the residential grids in the central urban area of Hefei are in a state of supply and demand matching; nearly 7 % of the residential grids are in a significant mismatch between supply and demand, mainly concentrated in the western part of the old city and the northern part of the lakeside area. The density of residential areas and the number of comprehensive parks are important reasons for the mismatch between supply and demand. (4) By optimizing the accessibility of urban traffic to improve the threshold of residents ' recreational travel in comprehensive parks, the overall equilibrium of urban comprehensive parks can be significantly promoted. The research results can provide important guidance for the future layout optimization of comprehensive parks in the central urban area of Hefei.
Reasonable distribution of urban green space (UGS) is an important prerequisite to ensure that urban residents enjoy UGS resources equally and improve the health level of a city. In the traditional UGS planning, it is difficult to accurately and quantitatively evaluate the rationality and balance of the layout of urban comprehensive parks by the evaluation of urban comprehensive park services based on indicators such as green space rate or green coverage rate. Taking the central urban area of Hefei as an example, this study proposes a multi-mode two-step floating catchment area method based on improved multi-transport mode. Using the path planning model of Gaode map, bivariate local spatial autocorrelation, Lorentz curve and Gini coefficient, the accessibility and equilibrium of urban park green space comprehensive park under different time thresholds are analyzed on the basis of mobile phone signaling data. Further reveal the rationality and balance of the layout of the comprehensive park green space in the central city. The main conclusions are as follows. ( 1 ) By using mobile phone signaling data and Gaode path planning data as data sources to improve the traditional accessibility calculation method and two-step mobile search model, the accessibility evaluation framework of urban comprehensive park green space at micro scale is established, which can accurately evaluate the accessibility of urban comprehensive park. (2) The spatial difference of accessibility of comprehensive parks in the central urban area of Hefei is significant. The areas with high accessibility are usually distributed in the new urban area and the surrounding areas of comprehensive parks. With the increase of time threshold, the spatial distribution of accessibility tends to be average. (3) Under the 15-minute and 30-minute time thresholds, only nearly 5 % of the residential grids in the central urban area of Hefei are in a state of supply and demand matching; nearly 7 % of the residential grids are in a significant mismatch between supply and demand, mainly concentrated in the western part of the old city and the northern part of the lakeside area. The density of residential areas and the number of comprehensive parks are important reasons for the mismatch between supply and demand. (4) By optimizing the accessibility of urban traffic to improve the threshold of residents ' recreational travel in comprehensive parks, the overall equilibrium of urban comprehensive parks can be significantly promoted. The research results can provide important guidance for the future layout optimization of comprehensive parks in the central urban area of Hefei.
Abstract:
The extraction and proportion calculation of complex Watercore characteristics of Watercore apple cross section is of great significance to the production management, quality division and non-destructive testing of Watercore apple. In this paper, a method of Watercore feature extraction and proportion calculation based on BiSeNet is proposed. This method uses BiSeNet network model to process the cross section of Watercore apple, which can obtain the characteristics of irregularly distributed Watercore area, and obtain the specific proportion value through proportion calculation. Compared with the traditional color separation method, this method can solve the problems of difficult separation of fruit core area, light interference and inaccurate segmentation. In this paper, 380 apple samples were used to compare the theoretical values of BiSeNet, FCN, PPLiteSeg and DeepLabV3, such as training time, training accuracy, training loss value and intersection over union, with the relative error value, average error and variance calculated by the proportion of actual verification samples. The lightweight two-sided structure of BiSeNet composed of spatial path and semantic path makes the indicators of BiSeNet reach 98.36 % accuracy and 85.1 % intersection ratio in 2 min 10 s due to other models. In the actual proportion calculation, the average proportion calculation error is 4.04 %, which is lower than other models, and there is no large deviation value. The results show that the feature extraction and proportion calculation of Watercore apple cross section based on BiSeNet can provide a good reference for the Watercore degree of Watercore apple, and make the nondestructive detection of Watercore apple have a comparison target.
The extraction and proportion calculation of complex Watercore characteristics of Watercore apple cross section is of great significance to the production management, quality division and non-destructive testing of Watercore apple. In this paper, a method of Watercore feature extraction and proportion calculation based on BiSeNet is proposed. This method uses BiSeNet network model to process the cross section of Watercore apple, which can obtain the characteristics of irregularly distributed Watercore area, and obtain the specific proportion value through proportion calculation. Compared with the traditional color separation method, this method can solve the problems of difficult separation of fruit core area, light interference and inaccurate segmentation. In this paper, 380 apple samples were used to compare the theoretical values of BiSeNet, FCN, PPLiteSeg and DeepLabV3, such as training time, training accuracy, training loss value and intersection over union, with the relative error value, average error and variance calculated by the proportion of actual verification samples. The lightweight two-sided structure of BiSeNet composed of spatial path and semantic path makes the indicators of BiSeNet reach 98.36 % accuracy and 85.1 % intersection ratio in 2 min 10 s due to other models. In the actual proportion calculation, the average proportion calculation error is 4.04 %, which is lower than other models, and there is no large deviation value. The results show that the feature extraction and proportion calculation of Watercore apple cross section based on BiSeNet can provide a good reference for the Watercore degree of Watercore apple, and make the nondestructive detection of Watercore apple have a comparison target.
Abstract:
In order to solve the problem of poor model generalization ability and low recognition accuracy in the identification of small sample cucumber leaf diseases in the complex field environment. By introducing self-attention mechanism module for activation reconstruction generation confrontation network AR-GAN (Activation Reconstruction GAN), using Smooth L1 regularization as loss function, an improved activation reconstruction generation confrontation network named IAR-GAN (Improved AR-GAN) is designed for enriching dataset of cucumber disease images. By adding dilated convolution and deformable convolution on the basis of Inception network, the dilated and deformable convolutional neural network DDCNN (Dilated and Deformable Convolutional Neural Network) is proposed for recognizing cucumber leaf disease. Experimental results show that the proposed IAR-GAN effectively alleviates the over-fitting phenomenon and enriches the diversity of generated samples; the proposed DDCNN has an average recognition accuracy of 96% for cucumber anthracnose, spot disease and downy mildew, increasing 5-10% compared withVGG16 etc.The data augmentation method and disease identification model proposed in this paper provide new ideas for the accurate identification of crop leaf diseases under condition of small samples in complex environments.
In order to solve the problem of poor model generalization ability and low recognition accuracy in the identification of small sample cucumber leaf diseases in the complex field environment. By introducing self-attention mechanism module for activation reconstruction generation confrontation network AR-GAN (Activation Reconstruction GAN), using Smooth L1 regularization as loss function, an improved activation reconstruction generation confrontation network named IAR-GAN (Improved AR-GAN) is designed for enriching dataset of cucumber disease images. By adding dilated convolution and deformable convolution on the basis of Inception network, the dilated and deformable convolutional neural network DDCNN (Dilated and Deformable Convolutional Neural Network) is proposed for recognizing cucumber leaf disease. Experimental results show that the proposed IAR-GAN effectively alleviates the over-fitting phenomenon and enriches the diversity of generated samples; the proposed DDCNN has an average recognition accuracy of 96% for cucumber anthracnose, spot disease and downy mildew, increasing 5-10% compared withVGG16 etc.The data augmentation method and disease identification model proposed in this paper provide new ideas for the accurate identification of crop leaf diseases under condition of small samples in complex environments.
Abstract:
In order to effectively control jujube dry rot disease, 47 fungal isolates obtained from the samples of dry rot in jujube tree were identified and characterized by comparison of virulence, sequence analysis of internal transcribed spacer (ITS) and elongation factor 1 α (EF-1α) genes. The distribution characteristics and differences in pathogenicity were also studied. The results showed that Botryosphaeria dothidea, Spencermartinsia viticola, Diplodia mutila, D. seriata, and Phaeobotryon rhois were characterized as the major pathogens causing jujube dry rot. Among them, S. viticola was found with the highest isolation frequency (65.96%) in jujube-growing areas. The dominant pathogens were different in different regions. B. dothidea and D. seriata were the predominant species in Henan and Hebei areas, and S. viticola was the predominant species in Shanxi, Gansu, and Ningxia areas. There are some differences in the pathogenicity of different species of pathogens to jujube trees, the results indicated that B. dothidea had the highest virulence, P. rhois had the weakest. At the same time, there are differences in the pathogenicity of the same pathogen strains in different areas, and some differences in the virulence of different species of pathogen strains in the same area as well. The results of this study showed that there were some differences in the species and pathogenicity of jujube dry rot pathogens in different regions, which provided a reference for the precise prevention and control of jujube dry rot in different regions.
In order to effectively control jujube dry rot disease, 47 fungal isolates obtained from the samples of dry rot in jujube tree were identified and characterized by comparison of virulence, sequence analysis of internal transcribed spacer (ITS) and elongation factor 1 α (EF-1α) genes. The distribution characteristics and differences in pathogenicity were also studied. The results showed that Botryosphaeria dothidea, Spencermartinsia viticola, Diplodia mutila, D. seriata, and Phaeobotryon rhois were characterized as the major pathogens causing jujube dry rot. Among them, S. viticola was found with the highest isolation frequency (65.96%) in jujube-growing areas. The dominant pathogens were different in different regions. B. dothidea and D. seriata were the predominant species in Henan and Hebei areas, and S. viticola was the predominant species in Shanxi, Gansu, and Ningxia areas. There are some differences in the pathogenicity of different species of pathogens to jujube trees, the results indicated that B. dothidea had the highest virulence, P. rhois had the weakest. At the same time, there are differences in the pathogenicity of the same pathogen strains in different areas, and some differences in the virulence of different species of pathogen strains in the same area as well. The results of this study showed that there were some differences in the species and pathogenicity of jujube dry rot pathogens in different regions, which provided a reference for the precise prevention and control of jujube dry rot in different regions.
Abstract:
Low-sugar citrus jam was prepared from fresh navel orange without adding any thickener. The effects of vacuum concentration and atmospheric boiling on physicochemical indicators, color, microorganisms, rheological properties and texture properties of low-sugar citrus jam were explored. The results showed that compared with the untreated group, the concentration treatment significantly increased the contents of total soluble solid, titratable acid, total sugar, total phenolics, total flavonoids and total carotenoids of jam samples (P<0.05). Among them, the contents of total phenolics, total flavonoids, and total carotenoids in vacuum concentrated samples were the highest, which were 42.93 ug/g, 63.32 ug/g and 36.33 ug/g, respectively, and the degree of browning was slight, and the brightness value (L*) was the largest. The rheological and texture test results showed that the low-sugar citrus jam was a yield-pseudoplastic fluid, and exhibited positive thixotropy in the shear range of 0.1~100 s-1. The storage modulus (G") and loss modulus ( ) increased with the increase of oscillation frequency, and G">G which showed the characteristics of an elastic viscoelastic body. In the frequency sweep range of 0.1~100 rad/s, the G" of the atmospheric boiling group was the highest (1435~4005 Pa), followed by the vacuum concentration group (722.6~2082 Pa), and the untreated group was the lowest (59.04~214.1 Pa). In addition, vacuum concentrated samples had less hardness, stickiness and chewability, and better taste.
Low-sugar citrus jam was prepared from fresh navel orange without adding any thickener. The effects of vacuum concentration and atmospheric boiling on physicochemical indicators, color, microorganisms, rheological properties and texture properties of low-sugar citrus jam were explored. The results showed that compared with the untreated group, the concentration treatment significantly increased the contents of total soluble solid, titratable acid, total sugar, total phenolics, total flavonoids and total carotenoids of jam samples (P<0.05). Among them, the contents of total phenolics, total flavonoids, and total carotenoids in vacuum concentrated samples were the highest, which were 42.93 ug/g, 63.32 ug/g and 36.33 ug/g, respectively, and the degree of browning was slight, and the brightness value (L*) was the largest. The rheological and texture test results showed that the low-sugar citrus jam was a yield-pseudoplastic fluid, and exhibited positive thixotropy in the shear range of 0.1~100 s-1. The storage modulus (G") and loss modulus ( ) increased with the increase of oscillation frequency, and G">G which showed the characteristics of an elastic viscoelastic body. In the frequency sweep range of 0.1~100 rad/s, the G" of the atmospheric boiling group was the highest (1435~4005 Pa), followed by the vacuum concentration group (722.6~2082 Pa), and the untreated group was the lowest (59.04~214.1 Pa). In addition, vacuum concentrated samples had less hardness, stickiness and chewability, and better taste.
Abstract:
In order to improve the stability and application potential of corn oil emulsion and explore the influence of insoluble citrus fiber on the properties of corn oil emulsion, the corn oil Pickering emulsion was constructed by using insoluble citrus fiber as the stabilizer, and the properties of rheology, morphological structure and stability of the emulsion were analyzed. The results showed that with the increase of insoluble citrus fiber content, the viscosity, energy storage modulus and loss modulus increased, and the emulsion showed the properties of pseudoplastic non-Newtonian fluid. The network structure formed by insoluble citrus fiber in the system caused the grain size of the system to increase gradually. When the content of insoluble citrus fiber was 0.2wt % and 0.3wt %, the absolute potential of Pickering emulsion was more than 30 mV, and the emulsification effect was better. The centrifugal stability and freeze-thaw stability of the emulsion were enhanced with the increase of insoluble citrus fiber content, and no stratification occurred in the emulsion within 30 days when the insoluble citrus fiber content was greater than 0.1wt %. The comprehensive analysis showed that the insoluble citrus fiber had good emulsification stability, and 0.2wt %- 0.3wt % of insoluble citrus fiber could be mixed with corn oil emulsion to construct stable Pickering emulsion, which provided a new direction for the application of corn oil emulsion.
In order to improve the stability and application potential of corn oil emulsion and explore the influence of insoluble citrus fiber on the properties of corn oil emulsion, the corn oil Pickering emulsion was constructed by using insoluble citrus fiber as the stabilizer, and the properties of rheology, morphological structure and stability of the emulsion were analyzed. The results showed that with the increase of insoluble citrus fiber content, the viscosity, energy storage modulus and loss modulus increased, and the emulsion showed the properties of pseudoplastic non-Newtonian fluid. The network structure formed by insoluble citrus fiber in the system caused the grain size of the system to increase gradually. When the content of insoluble citrus fiber was 0.2wt % and 0.3wt %, the absolute potential of Pickering emulsion was more than 30 mV, and the emulsification effect was better. The centrifugal stability and freeze-thaw stability of the emulsion were enhanced with the increase of insoluble citrus fiber content, and no stratification occurred in the emulsion within 30 days when the insoluble citrus fiber content was greater than 0.1wt %. The comprehensive analysis showed that the insoluble citrus fiber had good emulsification stability, and 0.2wt %- 0.3wt % of insoluble citrus fiber could be mixed with corn oil emulsion to construct stable Pickering emulsion, which provided a new direction for the application of corn oil emulsion.
Abstract:
Root exudates are the main medium of communication between crops and soil, play an important role in soil nutrient activation, crop nutrient uptake and crop growth. Understanding the relationship between root exudates, crops, soil and microorganisms is important for using different root exudates to achieve interspecies promotion and improve natural resource utilization and agricultural productivity. This paper summarized the effects of root exudates on nutrients, summarized the classification and function of root exudates, the activation of soil nutrients (nitrogen, phosphorus, potassium and iron), crop nutrient absorption and crop growth. It is proposed that the identification means of root exudates should be strengthened to realize the in-situ non-destructive identification and analysis of root exudate components, to use interdisciplinary knowledge to further reveal the root soil interface biological interaction process of efficient utilization of crop nutrients mediated by root exudates, strengthen the research on functional localization of target genes and microorganisms that verify that root exudates affect plant response to biotic and abiotic stresses, using genetic engineering to improve plant health, promote the process of transforming research results into scientific and technological applications, and apply beneficial root exudates to practical production using bionics principle.
Root exudates are the main medium of communication between crops and soil, play an important role in soil nutrient activation, crop nutrient uptake and crop growth. Understanding the relationship between root exudates, crops, soil and microorganisms is important for using different root exudates to achieve interspecies promotion and improve natural resource utilization and agricultural productivity. This paper summarized the effects of root exudates on nutrients, summarized the classification and function of root exudates, the activation of soil nutrients (nitrogen, phosphorus, potassium and iron), crop nutrient absorption and crop growth. It is proposed that the identification means of root exudates should be strengthened to realize the in-situ non-destructive identification and analysis of root exudate components, to use interdisciplinary knowledge to further reveal the root soil interface biological interaction process of efficient utilization of crop nutrients mediated by root exudates, strengthen the research on functional localization of target genes and microorganisms that verify that root exudates affect plant response to biotic and abiotic stresses, using genetic engineering to improve plant health, promote the process of transforming research results into scientific and technological applications, and apply beneficial root exudates to practical production using bionics principle.
Abstract:
In order to solve the problems of high labor intensity, low efficiency and difficult separation of fruit and soil during dry harvesting of water chestnut, a vibration extrusion type water chestnut harvester was designed to improve the degree of separation of fruit and soil by enhancing the effect of soil fragmentation. The separated water chestnut was scattered on the surface for easy manual picking up. Through the stress analysis of water chestnut soil block in the process of operation, the key parameters affecting the separation performance are determined as vibration plate amplitude, vibration frequency of vibration plate and rotation speed of nail roller, and the value range of key parameters is preliminarily determined according to the existing experience. Taking the vibration amplitude of the vibration plate, the vibration frequency of the vibration plate and the rotation speed of the nail roller as the influencing factors, taking the soil layer breaking rate as the evaluation index, using Design-Expert 10.0 to design the CCD center combination test, and through the simulation of the RecurDyn-EDM coupling, it is determined that when the vibration frequency of the vibration extrusion plate is 33.045mm, the vibration frequency of the vibration plate is 6.631Hz, and the rotation speed of the nail roller is 336.721r/min Hz, there is a better breaking effect, and the soil layer breaking rate is 93.581%. The field verification test was carried out with the actual amplitude of vibration plate 32.41 mm, vibration frequency 6.5 Hz, and nail tooth rolling speed 330 r/min, and the results showed that the actual soil layer breaking rate was 93.546%, the Mingfa rate was 80.334%, and the damage rate was 28.088%. The soil breaking effect was good, and the fitting degree with the simulation results was high.
In order to solve the problems of high labor intensity, low efficiency and difficult separation of fruit and soil during dry harvesting of water chestnut, a vibration extrusion type water chestnut harvester was designed to improve the degree of separation of fruit and soil by enhancing the effect of soil fragmentation. The separated water chestnut was scattered on the surface for easy manual picking up. Through the stress analysis of water chestnut soil block in the process of operation, the key parameters affecting the separation performance are determined as vibration plate amplitude, vibration frequency of vibration plate and rotation speed of nail roller, and the value range of key parameters is preliminarily determined according to the existing experience. Taking the vibration amplitude of the vibration plate, the vibration frequency of the vibration plate and the rotation speed of the nail roller as the influencing factors, taking the soil layer breaking rate as the evaluation index, using Design-Expert 10.0 to design the CCD center combination test, and through the simulation of the RecurDyn-EDM coupling, it is determined that when the vibration frequency of the vibration extrusion plate is 33.045mm, the vibration frequency of the vibration plate is 6.631Hz, and the rotation speed of the nail roller is 336.721r/min Hz, there is a better breaking effect, and the soil layer breaking rate is 93.581%. The field verification test was carried out with the actual amplitude of vibration plate 32.41 mm, vibration frequency 6.5 Hz, and nail tooth rolling speed 330 r/min, and the results showed that the actual soil layer breaking rate was 93.546%, the Mingfa rate was 80.334%, and the damage rate was 28.088%. The soil breaking effect was good, and the fitting degree with the simulation results was high.
Abstract:
At the macro scale, NDVI and EVI are commonly used as representative indices for vegetation studies. It has been shown that there are differences in the representation of vegetation characteristics between the two vegetation indices in the southern subtropical and tropical regions. In order to investigate whether such differences would affect the vegetation-related studies under different index representations, this study is based on the use of two different remote sensing vegetation indices of MODIS-NDVI and MODIS-EVI from 2005 to 2020 to represent the spatial characteristics of vegetation in the Guangdong-Hong Kong-Macao Greater Bay Area. Using 17 natural and anthropogenic factors in the same period as driving factors, the influence of 17 driving factors on the spatial characteristics of vegetation based on different indices of NDVI and EVI was separately calculated by the Geodetector. This study is expected to provide a scientific basis for further research on the characteristics of the ecosystems in the Guangdong-Hong Kong-Macao Greater Bay Area based on different vegetation indices. The results show that although the NDVI and EVI values were different in the Guangdong-Hong Kong-Macao Bay Area, the quantitative and ranking results of the influence of driving factors under different indices calculated by the factor detection module are basically consistent, and are not affected by the differences in index representation. Among the 17 driving factors, land use type and elevation are the dominant driving factors. Their influence on the spatial distribution of vegetation is more than 50% under different indices. Through the factor interaction detection module, the interaction analysis between the driving factors shows that most of the factors have double-factor enhancement effect on the spatial characteristics of vegetation under different representation indices, but there are differences in individual factors. Among them, the synergy of annual population distribution and land use type has the strongest influence on the NDVI-based vegetation cover; while the synergistic effects of average annual population distribution and elevation has the strongest influence on the vegetation cover based on EVI index. This study concludes that although there are differences between NDVI and EVI indices in representing vegetation cover characteristics, the results of the quantitative analysis of the driving factors are still consistent.
At the macro scale, NDVI and EVI are commonly used as representative indices for vegetation studies. It has been shown that there are differences in the representation of vegetation characteristics between the two vegetation indices in the southern subtropical and tropical regions. In order to investigate whether such differences would affect the vegetation-related studies under different index representations, this study is based on the use of two different remote sensing vegetation indices of MODIS-NDVI and MODIS-EVI from 2005 to 2020 to represent the spatial characteristics of vegetation in the Guangdong-Hong Kong-Macao Greater Bay Area. Using 17 natural and anthropogenic factors in the same period as driving factors, the influence of 17 driving factors on the spatial characteristics of vegetation based on different indices of NDVI and EVI was separately calculated by the Geodetector. This study is expected to provide a scientific basis for further research on the characteristics of the ecosystems in the Guangdong-Hong Kong-Macao Greater Bay Area based on different vegetation indices. The results show that although the NDVI and EVI values were different in the Guangdong-Hong Kong-Macao Bay Area, the quantitative and ranking results of the influence of driving factors under different indices calculated by the factor detection module are basically consistent, and are not affected by the differences in index representation. Among the 17 driving factors, land use type and elevation are the dominant driving factors. Their influence on the spatial distribution of vegetation is more than 50% under different indices. Through the factor interaction detection module, the interaction analysis between the driving factors shows that most of the factors have double-factor enhancement effect on the spatial characteristics of vegetation under different representation indices, but there are differences in individual factors. Among them, the synergy of annual population distribution and land use type has the strongest influence on the NDVI-based vegetation cover; while the synergistic effects of average annual population distribution and elevation has the strongest influence on the vegetation cover based on EVI index. This study concludes that although there are differences between NDVI and EVI indices in representing vegetation cover characteristics, the results of the quantitative analysis of the driving factors are still consistent.
Abstract:
Bovine respiratory disease complex (BRDC) is one of the most important infectious diseases that endangers domestic and international cattle industry. The etiological factors include multiple pathogens such as several viruses, bacteria, mycoplasmas, as well as various stressors. Clinical diagnosis is preliminarily drawn by observing the abnormal signs such as dyspnea which has low accuracy for the pathogen determination. Laboratorial diagnosis often lacks targets because of the complicate co-infection. Therefore, the treatment and prognosis for the sick animals is hard to get accurate prediction. In order to provide reference for early and accurate diagnosis, timely treatment and effective prevention and control of BRDC by taking comprehensive measures, this paper outlined the diagnostic methods of BRDC, including both conventional clinical diagnosis and molecular biological diagnosis and new methods based on host biomarkers like acute phase proteins, stress-related hormones, and transcriptomic diagnosis. Further, the application, advantages and disadvantages of these methods were described. The systemic summary of this knowledge would be of significance in guiding clinical practice.
Bovine respiratory disease complex (BRDC) is one of the most important infectious diseases that endangers domestic and international cattle industry. The etiological factors include multiple pathogens such as several viruses, bacteria, mycoplasmas, as well as various stressors. Clinical diagnosis is preliminarily drawn by observing the abnormal signs such as dyspnea which has low accuracy for the pathogen determination. Laboratorial diagnosis often lacks targets because of the complicate co-infection. Therefore, the treatment and prognosis for the sick animals is hard to get accurate prediction. In order to provide reference for early and accurate diagnosis, timely treatment and effective prevention and control of BRDC by taking comprehensive measures, this paper outlined the diagnostic methods of BRDC, including both conventional clinical diagnosis and molecular biological diagnosis and new methods based on host biomarkers like acute phase proteins, stress-related hormones, and transcriptomic diagnosis. Further, the application, advantages and disadvantages of these methods were described. The systemic summary of this knowledge would be of significance in guiding clinical practice.
Abstract:
In order to establish a quick and efficiently visual LAMP molecular detection method for Mannheimia haemolytica (M.haemolytica) in cattle, LAMP primers including inner primers, external primers and loop primers were designed targeting M.haemolytica conservative gene lktC using specific software tool. The reaction temperature, Mg2+ concentration, dNTPs concentration and other conditions were optimized. The sensitivity was evaluated using both bacteria and recombinant plasmids, fifteen related pathogens were used for the specificity evaluation. The applicability was evaluated using mice lung tissue samples with clear background. Results showed that the developed LAMP assay works at 68.2 ℃ for 40 min with 6 mmol/L Mg2+, 1.6 mmol/L dNTPs and judged by naked eyes. The minimum detection limit was 6.7×10-1 CFU/μL for bacteria and 7.9×102 copies/μL for lktC recombinant plasmid; there was no cross reaction with fifteen other pathogens, which showed a high sensitivity and specificity. Applicability test showed that the method had good applicability and was better than ordinary PCR. Getting together, this method could be used for rapid and efficient detection of M.haemolytica in cattle.
In order to establish a quick and efficiently visual LAMP molecular detection method for Mannheimia haemolytica (M.haemolytica) in cattle, LAMP primers including inner primers, external primers and loop primers were designed targeting M.haemolytica conservative gene lktC using specific software tool. The reaction temperature, Mg2+ concentration, dNTPs concentration and other conditions were optimized. The sensitivity was evaluated using both bacteria and recombinant plasmids, fifteen related pathogens were used for the specificity evaluation. The applicability was evaluated using mice lung tissue samples with clear background. Results showed that the developed LAMP assay works at 68.2 ℃ for 40 min with 6 mmol/L Mg2+, 1.6 mmol/L dNTPs and judged by naked eyes. The minimum detection limit was 6.7×10-1 CFU/μL for bacteria and 7.9×102 copies/μL for lktC recombinant plasmid; there was no cross reaction with fifteen other pathogens, which showed a high sensitivity and specificity. Applicability test showed that the method had good applicability and was better than ordinary PCR. Getting together, this method could be used for rapid and efficient detection of M.haemolytica in cattle.
Abstract:
It is an important study direction in the area of smart farming to explore the combination of new progress in the field of pig farming with artificial intelligence. Among them，how to automatically identify the individual identity and behavior of pigs is a key and hot issue to be solved in the current pig breeding industry. This article summarizes the existed methods of using deep neural networks to identify the individual identity and behavior of pigs based on the progress of computer vision and deep learning models in human recognition. The problems in the existed methods are analyzed，and the key study directions in the future are proposed. Five aspects urgently needed to be developed are as follows： 1）the methods of accurately extracting the features of pig’s identity and behavior under the conditions that pig’s behavior cannot be controlled and the key parts of pig’s body are often contaminated；2）the deep learning models based on computer vision that dedicate for pigs to recognize the identity and behavior based on the specific features of pigs；3）the studies on multi-task deep learning models that can recognize pig’s identity and behavior simultaneously；4）the studies on general-purpose pig behavior recognition methods based on basic postures and movements that are applicable to multiple scenarios；5）the studies on the deployment methods of pig identification and behavior recognition based on edge computing.
It is an important study direction in the area of smart farming to explore the combination of new progress in the field of pig farming with artificial intelligence. Among them，how to automatically identify the individual identity and behavior of pigs is a key and hot issue to be solved in the current pig breeding industry. This article summarizes the existed methods of using deep neural networks to identify the individual identity and behavior of pigs based on the progress of computer vision and deep learning models in human recognition. The problems in the existed methods are analyzed，and the key study directions in the future are proposed. Five aspects urgently needed to be developed are as follows： 1）the methods of accurately extracting the features of pig’s identity and behavior under the conditions that pig’s behavior cannot be controlled and the key parts of pig’s body are often contaminated；2）the deep learning models based on computer vision that dedicate for pigs to recognize the identity and behavior based on the specific features of pigs；3）the studies on multi-task deep learning models that can recognize pig’s identity and behavior simultaneously；4）the studies on general-purpose pig behavior recognition methods based on basic postures and movements that are applicable to multiple scenarios；5）the studies on the deployment methods of pig identification and behavior recognition based on edge computing.
Abstract:
In order to improve the clinical diagnosis efficiency of bovine respiratory disease complex (BRD) based on coinfection of multiple pathogens, this study established a real-time quantitative PCR (qPCR) to multiple and rapid detection for common seven pathogens of BRD including Mycoplasma bovis (M.b), Pasteurellae multocida (P.m), Mannheimia haemolytica (M.h), Bovine infectious rhinotracheitis virus (IBRV), Bovine syncytial virus (BRSV), Bovine parainfluenza virus type 3 genotype a (BPIV-3a) and c (BPIV-3c), the specific primers and TaqMan probes were designed for the oppD/F gene of M.b, gcp gene of M.h, ompH gene of P.m, gB gene of IBRV, N genes of BRSV, BPIV-3a and BPIV-3c and synthesized. After optimization of reaction conditions, a multiple qPCR was established for simultaneous detection of the above 7 pathogens in three tubes. This method specifically amplified these 7 pathogens, rather than other main pathogens common in cattle, indicating a high specificity. For M.b, P.m, M.h, IBRV, BRSV, BPIV-3a and BPIV-3c, the analytical sensitivity as limit of detection (LOD) was 102 copies /μL, 102 copies /μL, 101 copies /μL, 102 copies /μL, 102 copies /μL, 102 copies /μL, 102 copies /μL and 101 copies /μL, respectively, suggesting a high sensitivity. In addition, the coefficient of variation of the method within the group and between the groups were less than 2.5% and 5.5%, respectively, indicating a good repeatability. Furthermore, 115 clinical nasal swabs were parallelly detected by this method and conventional PCR, and the positivity was 27.83% for M.b, 36.65% for P.m, 25.22% for M.h, 11.30% for IBRV, 0.95% for BRSV, 8.57% for BPIV-3C. In addition, the proportion of co-infection was 26.1% with 11 patterns of pathogen combinations. Among them, coinfection of M.b with other pathogens ranked the top 1 with the proportion of 72.7% (8/11). Within the 30 coinfection cases, M.b/P.m combination mostly occurred with 60% (18/30); the top three pathogens present in the coinfection was M.b, P.m, and M.h with frequency of 73.3% (22/30), 73.3% (22/30) and 43.3% (13/30); followed by IBRV (26.7%, 8/30) and BPIV-3c (13.3%, 4/30). Overall, this method has a high sensitivity and specificity, and a potential application in clinical detection of single pathogen and multi-pathogen infection causing BRD.
In order to improve the clinical diagnosis efficiency of bovine respiratory disease complex (BRD) based on coinfection of multiple pathogens, this study established a real-time quantitative PCR (qPCR) to multiple and rapid detection for common seven pathogens of BRD including Mycoplasma bovis (M.b), Pasteurellae multocida (P.m), Mannheimia haemolytica (M.h), Bovine infectious rhinotracheitis virus (IBRV), Bovine syncytial virus (BRSV), Bovine parainfluenza virus type 3 genotype a (BPIV-3a) and c (BPIV-3c), the specific primers and TaqMan probes were designed for the oppD/F gene of M.b, gcp gene of M.h, ompH gene of P.m, gB gene of IBRV, N genes of BRSV, BPIV-3a and BPIV-3c and synthesized. After optimization of reaction conditions, a multiple qPCR was established for simultaneous detection of the above 7 pathogens in three tubes. This method specifically amplified these 7 pathogens, rather than other main pathogens common in cattle, indicating a high specificity. For M.b, P.m, M.h, IBRV, BRSV, BPIV-3a and BPIV-3c, the analytical sensitivity as limit of detection (LOD) was 102 copies /μL, 102 copies /μL, 101 copies /μL, 102 copies /μL, 102 copies /μL, 102 copies /μL, 102 copies /μL and 101 copies /μL, respectively, suggesting a high sensitivity. In addition, the coefficient of variation of the method within the group and between the groups were less than 2.5% and 5.5%, respectively, indicating a good repeatability. Furthermore, 115 clinical nasal swabs were parallelly detected by this method and conventional PCR, and the positivity was 27.83% for M.b, 36.65% for P.m, 25.22% for M.h, 11.30% for IBRV, 0.95% for BRSV, 8.57% for BPIV-3C. In addition, the proportion of co-infection was 26.1% with 11 patterns of pathogen combinations. Among them, coinfection of M.b with other pathogens ranked the top 1 with the proportion of 72.7% (8/11). Within the 30 coinfection cases, M.b/P.m combination mostly occurred with 60% (18/30); the top three pathogens present in the coinfection was M.b, P.m, and M.h with frequency of 73.3% (22/30), 73.3% (22/30) and 43.3% (13/30); followed by IBRV (26.7%, 8/30) and BPIV-3c (13.3%, 4/30). Overall, this method has a high sensitivity and specificity, and a potential application in clinical detection of single pathogen and multi-pathogen infection causing BRD.
Abstract:
Near-infrared spectroscopy was applied to qualitatively discriminate whole egg powder adulteration and to quantitatively analyze the adulteration concentration. Six different pre-processing methods were used to pre-process the raw spectral data, and the competitive Adaptive Reweighted Sampling (CARS), Successive Projections Algorithm (SPA) and combined CARS-SPA algorithms were used to filter the spectral data for characteristic wavelengths. Ensemble Learning (EL) model was established to qualitatively discriminate the adulterated egg powder, and Partial Least Squares Regression (PLSR) model was established to quantitatively analyze the adulterated concentration. The results showed that in qualitative discrimination, First order derivative was the best pre-processing method and the CARS algorithm had the best feature filtering effect, and the EL model had an overall discrimination accuracy of 98.18% for adulterated samples, and the discrimination accuracy of different adulterated samples was over 97.78%. For quantitative analysis, MSC was the best pretreatment method and CARS algorithm had the best feature screening effect. The prediction set correlation coefficients of PLSR adulteration concentration prediction models for one-component adulteration, two-component adulteration, three-component adulteration, and all adulterated samples adulteration were 0.9585, 0.9312, 0.9456, and 0.9558, respectively, and the root mean square error RMSEP were 4.6891, 5.8134, 4.6041, and 3.8029, respectively. The study shows that near-infrared spectroscopy can be used for egg powder adulteration detection, and provides a reference for regulatory agencies to detect egg powder adulteration.
Near-infrared spectroscopy was applied to qualitatively discriminate whole egg powder adulteration and to quantitatively analyze the adulteration concentration. Six different pre-processing methods were used to pre-process the raw spectral data, and the competitive Adaptive Reweighted Sampling (CARS), Successive Projections Algorithm (SPA) and combined CARS-SPA algorithms were used to filter the spectral data for characteristic wavelengths. Ensemble Learning (EL) model was established to qualitatively discriminate the adulterated egg powder, and Partial Least Squares Regression (PLSR) model was established to quantitatively analyze the adulterated concentration. The results showed that in qualitative discrimination, First order derivative was the best pre-processing method and the CARS algorithm had the best feature filtering effect, and the EL model had an overall discrimination accuracy of 98.18% for adulterated samples, and the discrimination accuracy of different adulterated samples was over 97.78%. For quantitative analysis, MSC was the best pretreatment method and CARS algorithm had the best feature screening effect. The prediction set correlation coefficients of PLSR adulteration concentration prediction models for one-component adulteration, two-component adulteration, three-component adulteration, and all adulterated samples adulteration were 0.9585, 0.9312, 0.9456, and 0.9558, respectively, and the root mean square error RMSEP were 4.6891, 5.8134, 4.6041, and 3.8029, respectively. The study shows that near-infrared spectroscopy can be used for egg powder adulteration detection, and provides a reference for regulatory agencies to detect egg powder adulteration.
Abstract:
The inhibitory effect and mechanism of Terminalia chebula on Escherichia coli, Klebsiella pneumoniae and Enterobacter cloacae were investigated in vitro . The diameter of the inhibition circle and minimum inhibitory concentration (MIC) were determined respectively by the drug sensitive disc diffusion method and the double dilution method. The total leakage rate and conductivity in the supernatant were measured by optical density method and protein concentration was determined by Bradford method. The effects of Terminalia chebula on bacterial DNA and protein content were analyzed by agarose gel electrophoresis and SDS-PAGE. Gel block method was used to analyze the effect of Terminalia chebula on bacterial DNA. The results showed that Terminalia chebula had stronger inhibitory effect than other Chinese herbs, with larger circle diameter and lower concentration of bacteriostatic. The conductivity and leakage rate of the supernatant increased. The protein concentration of the supernatant of Escherichia coli and Klebsiella pneumoniae increased significantly (P<0.05)after 2 fold MIC Terminalia chebula treatment for 8 h. Terminalia chebula inhibits Escherichia coli protein synthesis and results in the deletion of a protein with a molecular weight of about 80 ku. However, Terminalia chebula had no obvious effect on protein synthesis of Klebsiella pneumoniae and Enterobacter cloacae. Terminalia chebula had no significant gel-blocking effect on bacterial DNA, but could degrade DNA. The above results indicate that Terminalia chebula has exerts its inhibitory effect by disrupting bacterial cell membrane permeability and inhibiting bacterial nucleic acid and protein synthsis.
The inhibitory effect and mechanism of Terminalia chebula on Escherichia coli, Klebsiella pneumoniae and Enterobacter cloacae were investigated in vitro . The diameter of the inhibition circle and minimum inhibitory concentration (MIC) were determined respectively by the drug sensitive disc diffusion method and the double dilution method. The total leakage rate and conductivity in the supernatant were measured by optical density method and protein concentration was determined by Bradford method. The effects of Terminalia chebula on bacterial DNA and protein content were analyzed by agarose gel electrophoresis and SDS-PAGE. Gel block method was used to analyze the effect of Terminalia chebula on bacterial DNA. The results showed that Terminalia chebula had stronger inhibitory effect than other Chinese herbs, with larger circle diameter and lower concentration of bacteriostatic. The conductivity and leakage rate of the supernatant increased. The protein concentration of the supernatant of Escherichia coli and Klebsiella pneumoniae increased significantly (P<0.05)after 2 fold MIC Terminalia chebula treatment for 8 h. Terminalia chebula inhibits Escherichia coli protein synthesis and results in the deletion of a protein with a molecular weight of about 80 ku. However, Terminalia chebula had no obvious effect on protein synthesis of Klebsiella pneumoniae and Enterobacter cloacae. Terminalia chebula had no significant gel-blocking effect on bacterial DNA, but could degrade DNA. The above results indicate that Terminalia chebula has exerts its inhibitory effect by disrupting bacterial cell membrane permeability and inhibiting bacterial nucleic acid and protein synthsis.
Abstract:
To study effects of one-time side deep application of controlled-release fertilizer on rice growth, nitrogen utilization and yield, exploring the simple and efficient cultivation technology of machine-transplanted rice with one-time deep foundation application. Field experiments were conducted using rice cultivar Quanliangyou Efengsimiao as test materials, Set up without fertilization (N0), the one-time side deep basal application of controlled-release fertilizer (N1), the one-time side deep basal application of controlled-release fertilizer by 10% nitrogen reduction (N2), the one-time side deep basal application of controlled-release fertilizer by 20% nitrogen reduction (N3), and the traditional and fertilization (CK).The tillering dynamics, leaf area index and dry matter accumulation at main growth stages, root index at heading stage, various nitrogen use efficiencies and yield were measured. Compared with the treatment of CK, the treatment of N1 and N2 significantly increased the yield by 12.99%~14.85% and 5.47%~6.09%, and the yield of the treatment of N3 was not significantly different from that of CK. After fitting analysis of fertilization amount and yield, the yield was the same as that of CK when the nitrogen was reduced by 18.72%. Compared with CK, the one-time and side deep application of controlled-release fertilizer significantly increased the earbearing tiller percentage, the leaf area index and dry matter accumulation in the middle and late growth stages of rice, promoted root growth and expanded the distribution range of roots. Compared with CK, treatments N1, N2 and N3 increased the apparent nitrogen use efficiency by 1.21%~46.57%, agronomic nitrogen use efficiency by 18.85%~61.73%, physiological nitrogen use efficiency by 8.90%~17.71% and partial factor productivity nitrogen by 12.99%~23.61%. The one-time and side deep application of fertilizer release promotes root growth, increases panicle number, improves the efficiency of various nitrogen use, and greatly reduces the number of fertilizations. Within the scope of reducing nitrogen by 18.72%, high and stable rice yield can be achieved.
To study effects of one-time side deep application of controlled-release fertilizer on rice growth, nitrogen utilization and yield, exploring the simple and efficient cultivation technology of machine-transplanted rice with one-time deep foundation application. Field experiments were conducted using rice cultivar Quanliangyou Efengsimiao as test materials, Set up without fertilization (N0), the one-time side deep basal application of controlled-release fertilizer (N1), the one-time side deep basal application of controlled-release fertilizer by 10% nitrogen reduction (N2), the one-time side deep basal application of controlled-release fertilizer by 20% nitrogen reduction (N3), and the traditional and fertilization (CK).The tillering dynamics, leaf area index and dry matter accumulation at main growth stages, root index at heading stage, various nitrogen use efficiencies and yield were measured. Compared with the treatment of CK, the treatment of N1 and N2 significantly increased the yield by 12.99%~14.85% and 5.47%~6.09%, and the yield of the treatment of N3 was not significantly different from that of CK. After fitting analysis of fertilization amount and yield, the yield was the same as that of CK when the nitrogen was reduced by 18.72%. Compared with CK, the one-time and side deep application of controlled-release fertilizer significantly increased the earbearing tiller percentage, the leaf area index and dry matter accumulation in the middle and late growth stages of rice, promoted root growth and expanded the distribution range of roots. Compared with CK, treatments N1, N2 and N3 increased the apparent nitrogen use efficiency by 1.21%~46.57%, agronomic nitrogen use efficiency by 18.85%~61.73%, physiological nitrogen use efficiency by 8.90%~17.71% and partial factor productivity nitrogen by 12.99%~23.61%. The one-time and side deep application of fertilizer release promotes root growth, increases panicle number, improves the efficiency of various nitrogen use, and greatly reduces the number of fertilizations. Within the scope of reducing nitrogen by 18.72%, high and stable rice yield can be achieved.
Abstract:
Abstract: In order to grasp the status quo of the culture and management technologies in the Chinese citrus industry, the questionnaire is used to investigate 306 farmers in the main citrus planting regions about the winter sanitatoin, grass control, fertilizer and water management. The results showed that 96.7% of the planting subjects conducted the orchard sanitation in winter. The average annual rate of grass control was 3.2 times, fertilization was 4.9 times, irrigation was 6.7 times and spraying pecticide was 11.5 times. 57.5%, 56.2% and 47.4% of the planters used herbicide, knapsack mower and manual grass control methods, respectively; 65.5% and 63.9% of the planters used broadcasting and foliar spraying methods, respectively; 53.1% and 39.3% of the planters used pipe irrigation and drip irrigation methods, respectively; 71.2% of the planting subjects used pipeline injection, and the proportion of air-sent mechanical injection was relatively low (14.7%). Only 34.5% of the planters had regular pruning during the growing season, and the pruning was mainly done by manual methods (86.6%). In addition, the application of citrus cultivation and management technologies is dependant on the orchard area, type and distribution. The annual number of grass control and fertilization, and the proportion of drip irrigation fertilization in large area or gentle slope flat orchard tended to increase compared with small area or mountain orchard, but the annual number of spraying showed the opposite trend. The ratio of irrigation, fertilization and the proportion of fruit holding operation at maturity in central China were the least among different planting regions. Combined with these results, three suggestions were raised for the development of citrus cultivation technology. These includes increasing the fund investment to steadily strength the research and application of suitable cultivation technology, promoting the development of cultivation technology and equipment according to the principle of agriculture and machinery combination, and considering the systematicness for developing cultivation technology and equipment.
Abstract: In order to grasp the status quo of the culture and management technologies in the Chinese citrus industry, the questionnaire is used to investigate 306 farmers in the main citrus planting regions about the winter sanitatoin, grass control, fertilizer and water management. The results showed that 96.7% of the planting subjects conducted the orchard sanitation in winter. The average annual rate of grass control was 3.2 times, fertilization was 4.9 times, irrigation was 6.7 times and spraying pecticide was 11.5 times. 57.5%, 56.2% and 47.4% of the planters used herbicide, knapsack mower and manual grass control methods, respectively; 65.5% and 63.9% of the planters used broadcasting and foliar spraying methods, respectively; 53.1% and 39.3% of the planters used pipe irrigation and drip irrigation methods, respectively; 71.2% of the planting subjects used pipeline injection, and the proportion of air-sent mechanical injection was relatively low (14.7%). Only 34.5% of the planters had regular pruning during the growing season, and the pruning was mainly done by manual methods (86.6%). In addition, the application of citrus cultivation and management technologies is dependant on the orchard area, type and distribution. The annual number of grass control and fertilization, and the proportion of drip irrigation fertilization in large area or gentle slope flat orchard tended to increase compared with small area or mountain orchard, but the annual number of spraying showed the opposite trend. The ratio of irrigation, fertilization and the proportion of fruit holding operation at maturity in central China were the least among different planting regions. Combined with these results, three suggestions were raised for the development of citrus cultivation technology. These includes increasing the fund investment to steadily strength the research and application of suitable cultivation technology, promoting the development of cultivation technology and equipment according to the principle of agriculture and machinery combination, and considering the systematicness for developing cultivation technology and equipment.
The effects of straw returning and feeding on rice quality in the rice-crayfish co-culture ecosystem
Abstract:
In order to improve the quality and economic benefit of rice under rice-crayfish co-culture model, this paper set up 6 test treatments: (1) straw returning with feeding (SF), (2) straw returning without feeding (SNF), (3) straw removal with feeding (NSF), (4) straw removal without feeding (NSNF), (5) rice monoculture with straw returning (CK-S), (6) rice monoculture with straw removal (CK-NS) to explore the changes of rice quality under the effects of feeding and straw returning. The results showed that feeding (F) could significantly increase the yields of rice and crayfish, and the nutritional quality of rice. In the case of straw returning (S) and straw removal (NS), the protein content of the F treatment was increased by 27.41% and 36.16%, respectively, which significantly improved the nutritional quality of rice. The interaction between S treatment and F treatment significantly affected the processing quality of rice. The whole milled rice rate and milled rice rate were the highest under NSNF treatment, which were significantly higher than SF, SNF and NSF. Straw returning, feeding and their interaction had no significant effect on cooking and eating quality, and there was no significant difference in RVA viscosity spectrum of rice. Rice-crayfish co-culture model could improve the appearance quality. Compared with CK-S, the chalky grain rate and chalkiness degree of SF decreased by 15.09%, 15.65% respectively. In general, straw returning and feeding can improve rice quality to a great extent under rice-crayfish co-culture ecosystem.
In order to improve the quality and economic benefit of rice under rice-crayfish co-culture model, this paper set up 6 test treatments: (1) straw returning with feeding (SF), (2) straw returning without feeding (SNF), (3) straw removal with feeding (NSF), (4) straw removal without feeding (NSNF), (5) rice monoculture with straw returning (CK-S), (6) rice monoculture with straw removal (CK-NS) to explore the changes of rice quality under the effects of feeding and straw returning. The results showed that feeding (F) could significantly increase the yields of rice and crayfish, and the nutritional quality of rice. In the case of straw returning (S) and straw removal (NS), the protein content of the F treatment was increased by 27.41% and 36.16%, respectively, which significantly improved the nutritional quality of rice. The interaction between S treatment and F treatment significantly affected the processing quality of rice. The whole milled rice rate and milled rice rate were the highest under NSNF treatment, which were significantly higher than SF, SNF and NSF. Straw returning, feeding and their interaction had no significant effect on cooking and eating quality, and there was no significant difference in RVA viscosity spectrum of rice. Rice-crayfish co-culture model could improve the appearance quality. Compared with CK-S, the chalky grain rate and chalkiness degree of SF decreased by 15.09%, 15.65% respectively. In general, straw returning and feeding can improve rice quality to a great extent under rice-crayfish co-culture ecosystem.
Abstract:
Under the condition of mechanical direct seeding, ' Nanjing 9108 ' and ' Huanghuazhan ' were used as materials. Under the condition of total nitrogen 210 kg N / hm2 in the field, three different nitrogen fertilizer treatments were set up. The basal fertilizer, tillering fertilizer and panicle fertilizer were N1 ( 5 : 2 : 3 ), N2 ( 3 : 4 : 3 ), N3 ( 0 : 6 : 4 ), and no nitrogen fertilizer ( N0 ) was used as the control. The results showed that the yield of the two rice varieties was the highest when the fertilization ratio was 3 : 4 : 3. The average yield of Nanjing 9108 was as high as 9691.2 kg / hm2, and the average yield of Huanghuazhan was as high as 1 1596.1 kg / hm2, which was significantly different from other treatments. The brown rice rate, milled rice rate and head rice rate of rice were not significantly different among treatments, but the amylose and protein content increased with the increase of panicle fertilizer ratio, showing N3 > N2 > N1. The chalkiness rate and chalkiness decreased with the increase of panicle fertilizer ratio, showing N1 > N2 > N3. The rice quality of N3 ( 0 : 6 : 4 ) was significantly higher than other treatments. Under the treatment of 3 : 4 : 3 at each growth stage of rice, the nitrogen absorption was significantly higher than other treatments, and the nitrogen agronomic efficiency and nitrogen use efficiency were N2 > N3 > N1, reaching a significant level. In general, under the same nitrogen application rate, N2 ( 3 : 4 : 3 ) had a significant effect on rice yield and nitrogen use efficiency, and N3 ( 0 : 6 : 4 ) had a significant effect on rice quality.
Under the condition of mechanical direct seeding, ' Nanjing 9108 ' and ' Huanghuazhan ' were used as materials. Under the condition of total nitrogen 210 kg N / hm2 in the field, three different nitrogen fertilizer treatments were set up. The basal fertilizer, tillering fertilizer and panicle fertilizer were N1 ( 5 : 2 : 3 ), N2 ( 3 : 4 : 3 ), N3 ( 0 : 6 : 4 ), and no nitrogen fertilizer ( N0 ) was used as the control. The results showed that the yield of the two rice varieties was the highest when the fertilization ratio was 3 : 4 : 3. The average yield of Nanjing 9108 was as high as 9691.2 kg / hm2, and the average yield of Huanghuazhan was as high as 1 1596.1 kg / hm2, which was significantly different from other treatments. The brown rice rate, milled rice rate and head rice rate of rice were not significantly different among treatments, but the amylose and protein content increased with the increase of panicle fertilizer ratio, showing N3 > N2 > N1. The chalkiness rate and chalkiness decreased with the increase of panicle fertilizer ratio, showing N1 > N2 > N3. The rice quality of N3 ( 0 : 6 : 4 ) was significantly higher than other treatments. Under the treatment of 3 : 4 : 3 at each growth stage of rice, the nitrogen absorption was significantly higher than other treatments, and the nitrogen agronomic efficiency and nitrogen use efficiency were N2 > N3 > N1, reaching a significant level. In general, under the same nitrogen application rate, N2 ( 3 : 4 : 3 ) had a significant effect on rice yield and nitrogen use efficiency, and N3 ( 0 : 6 : 4 ) had a significant effect on rice quality.
Abstract:
A three-viability gradient classification model for corn seeds was created using machine learning and deep learning algorithms along with hyperspectral imaging technology to achieve quick, non-destructive detection of corn seed vigor. This method addresses the issues of time-consuming and damaged seeds in traditional seed vigor detection methods.. Firstly, 1012 corn seeds were divided into three vigor gradient samples by artificial aging, and after collecting their hyperspectral data, the hyperspectral noise was removed by convolution smoothing (SG) and multivariate scattering correction (MSC). Then, to synthesize false color images, the three bands of 1156, 1191, and 1463nm were extracted from the reduced dimensionality bands, which were produced by using the principal component analysis (PCA) and continuous projection algorithms (SPA), respectively. Additionally, the texture features of region of interest (ROI) were extracted using local binary mode (LBP) and fused with pure spectral features. The machine learning models were built based on pure spectral features and fused features, respectively. Specifically, decision tree (DT) and SVM models were built using pure spectral features, and random forest (RF), SVM, and extreme gradient boosting tree (XGBoost) models are built using fused features. The false color images were fed into five deep learning models of ResNet18, MobileNetV2, DenseNet121, Efficientb0, and Efficientb2 for viability prediction. According to the results, the PCA-SVM model performed best for pure spectral features, with a test set classification accuracy rate of 92.5%; the SVM model performed best for fusion features, with a test set classification accuracy rate of 93.1%; As far as the deep learning method was concerned, the lightweight MobileNet achieved the greatest test set classification accuracy of 99.5%. Furthermore, a class activation mapping method based on interpretable gradients also revealed that the classification network will concentrate on the bottom or basal region of maize seeds. The above findings offer some references for nondestructive testing of maize seed viability in terms of data sources, deep neural network visual interpretation and machine learning, and deep learning performance analysis.
A three-viability gradient classification model for corn seeds was created using machine learning and deep learning algorithms along with hyperspectral imaging technology to achieve quick, non-destructive detection of corn seed vigor. This method addresses the issues of time-consuming and damaged seeds in traditional seed vigor detection methods.. Firstly, 1012 corn seeds were divided into three vigor gradient samples by artificial aging, and after collecting their hyperspectral data, the hyperspectral noise was removed by convolution smoothing (SG) and multivariate scattering correction (MSC). Then, to synthesize false color images, the three bands of 1156, 1191, and 1463nm were extracted from the reduced dimensionality bands, which were produced by using the principal component analysis (PCA) and continuous projection algorithms (SPA), respectively. Additionally, the texture features of region of interest (ROI) were extracted using local binary mode (LBP) and fused with pure spectral features. The machine learning models were built based on pure spectral features and fused features, respectively. Specifically, decision tree (DT) and SVM models were built using pure spectral features, and random forest (RF), SVM, and extreme gradient boosting tree (XGBoost) models are built using fused features. The false color images were fed into five deep learning models of ResNet18, MobileNetV2, DenseNet121, Efficientb0, and Efficientb2 for viability prediction. According to the results, the PCA-SVM model performed best for pure spectral features, with a test set classification accuracy rate of 92.5%; the SVM model performed best for fusion features, with a test set classification accuracy rate of 93.1%; As far as the deep learning method was concerned, the lightweight MobileNet achieved the greatest test set classification accuracy of 99.5%. Furthermore, a class activation mapping method based on interpretable gradients also revealed that the classification network will concentrate on the bottom or basal region of maize seeds. The above findings offer some references for nondestructive testing of maize seed viability in terms of data sources, deep neural network visual interpretation and machine learning, and deep learning performance analysis.
Abstract:
The urban heat island effect (UHI) directly affects plant phenology through temperature changes and is one of the most important factors affecting plant phenology changes in cities.By analyzing the temporal and spatial response of flowering period of cherry blossoms in Wuhan to urban heat island effect, the accuracy of the cherry blossom period prediction model can be improved, and the cherry blossom period prediction can be better done.Based on the observation data of the first-flowering period of Cherry Blossoms in Wuhan University and the meteorological data of the same period, the results show that, the urban heat island effect in Wuhan has been obviously enhanced since the late 1980s.Compared with the previous 30 years, the heating rate and contribution rate of urban heat island in winter have increased significantly since 1988, which indicates that the increase of winter temperature in recent years is largely caused by the enhancement of urban heat island effect.Urban heat island is the highest in the central city of Wuhan, showing radiation spreading from the urban core to the suburban areas. Huangpi and Xinzhou in the north are hardly affected by the heat island.The flowering period of cherry blossoms in Wuhan has obvious response to the urban heat island effect in winter in time and space. For every 1℃ increase in the average temperature of five years in winter, the initial flowering period of cherry blossoms will advance by about 2.8d days.The flower viewing spots such as Yangtze riverside park and Holiday Inn Riverside, which are located in the center of the city, are the earliest areas where cherry blossoms bloom, 1-2 days earlier than the flowering period of Wuhan University; Cherry Blossom garden in East lake and Dijiao Park are 1-2 days later than the flowering period of Wuhan University.
The urban heat island effect (UHI) directly affects plant phenology through temperature changes and is one of the most important factors affecting plant phenology changes in cities.By analyzing the temporal and spatial response of flowering period of cherry blossoms in Wuhan to urban heat island effect, the accuracy of the cherry blossom period prediction model can be improved, and the cherry blossom period prediction can be better done.Based on the observation data of the first-flowering period of Cherry Blossoms in Wuhan University and the meteorological data of the same period, the results show that, the urban heat island effect in Wuhan has been obviously enhanced since the late 1980s.Compared with the previous 30 years, the heating rate and contribution rate of urban heat island in winter have increased significantly since 1988, which indicates that the increase of winter temperature in recent years is largely caused by the enhancement of urban heat island effect.Urban heat island is the highest in the central city of Wuhan, showing radiation spreading from the urban core to the suburban areas. Huangpi and Xinzhou in the north are hardly affected by the heat island.The flowering period of cherry blossoms in Wuhan has obvious response to the urban heat island effect in winter in time and space. For every 1℃ increase in the average temperature of five years in winter, the initial flowering period of cherry blossoms will advance by about 2.8d days.The flower viewing spots such as Yangtze riverside park and Holiday Inn Riverside, which are located in the center of the city, are the earliest areas where cherry blossoms bloom, 1-2 days earlier than the flowering period of Wuhan University; Cherry Blossom garden in East lake and Dijiao Park are 1-2 days later than the flowering period of Wuhan University.
Abstract:
To identify the dominant strains in the intestinal tract of the worldwide quarantine fruit fly pest, Zeugodacus tau (Walker), and their effects on feeding ability, nutritional status and fecundity of the female adults, here we isolated and identified the culturable bacteria based on traditional microorganism isolation and molecular identification, and then determined the food intake, hemolymph amino acid content and egg production after treating the female adults with antibiotics and subsequently predominant intestinal bacteria. The results indicated that: the elimination of intestinal bacteria significantly reduced the oviposition, food intake and hemolymph amino acid content of female adult fruit flies to 34.9%, 43.2% and 60.8% of the control (without antibiotic treatment) levels. Subsequently, 9 cultivable strains were isolated and identified as Proteobacteria and Firmicutes, and are mainly distributed in Enterococcus, Enterobacter and Bacillus. The dominant strains were Enterococcus sp. ZYY 2-97 (57.41%) and Bacillus sp. ZYY 1-83 (17.59%). In addition, after the "antibiotic treatment - strain replenishment" treatment, the total ovipositions of Z. tau after the addition of ZYY 2-97 and ZYY 1-83 strains were significantly recovered to 75.00% and 86.98% of the control level, and the food intake were significantly recovered to 117.53% and 117.85% of the control level. Meanwhile, the amino acid content in hemolymph was recovered to 94.80% and 87.81% of the control level. Our findings demonstrated that intestinal bacteria regulate the fecundity of Z. tau by regulating their feeding capacity and nutritional status, and the dominant culturable strains play a key role in this process.
To identify the dominant strains in the intestinal tract of the worldwide quarantine fruit fly pest, Zeugodacus tau (Walker), and their effects on feeding ability, nutritional status and fecundity of the female adults, here we isolated and identified the culturable bacteria based on traditional microorganism isolation and molecular identification, and then determined the food intake, hemolymph amino acid content and egg production after treating the female adults with antibiotics and subsequently predominant intestinal bacteria. The results indicated that: the elimination of intestinal bacteria significantly reduced the oviposition, food intake and hemolymph amino acid content of female adult fruit flies to 34.9%, 43.2% and 60.8% of the control (without antibiotic treatment) levels. Subsequently, 9 cultivable strains were isolated and identified as Proteobacteria and Firmicutes, and are mainly distributed in Enterococcus, Enterobacter and Bacillus. The dominant strains were Enterococcus sp. ZYY 2-97 (57.41%) and Bacillus sp. ZYY 1-83 (17.59%). In addition, after the "antibiotic treatment - strain replenishment" treatment, the total ovipositions of Z. tau after the addition of ZYY 2-97 and ZYY 1-83 strains were significantly recovered to 75.00% and 86.98% of the control level, and the food intake were significantly recovered to 117.53% and 117.85% of the control level. Meanwhile, the amino acid content in hemolymph was recovered to 94.80% and 87.81% of the control level. Our findings demonstrated that intestinal bacteria regulate the fecundity of Z. tau by regulating their feeding capacity and nutritional status, and the dominant culturable strains play a key role in this process.
Abstract:
In the context of global climate change and sea level rise, coastal disasters will pose a great impact on coastal urban landscape and social economy. Taking Guangzhou, a coastal city in the Pearl River Delta, as the study area, based on the land use and socio-economic data, this study proposed the "sensitivities-adaptability" vulnerability assessment framework to assess the vulnerability characteristics of Guangzhou urban landscape systems under three different sea-level rise combined with storm surge risk scenarios: the short-term (2030), the medium-term (2050) and the long-term (2100). The results show that: 1) From the perspective of inundation range and economic loss, the agricultural landscape, park green space and wetland landscape will be the most inundated under different risk scenarios in the future, while the industrial landscape and commercial and public service landscape will suffer the most serious economic losses.2) From the perspective of the overall spatial distribution of vulnerability, the areas with high landscape vulnerability in the short-term were mainly concentrated in Liwan District, Baiyun District and Huangpu District in the central part of Guangzhou. In the medium-term and long-term, the landscape vulnerability risk in Haizhu District in the central part of Guangzhou gradually increased. 3) From the spatial distribution of various landscape vulnerability, compared to the transportation landscape, residential landscape, and other types of landscape, the areas with relatively high vulnerability of agricultural landscapes are the most in the short-term, mainly concentrated in Panyu District and Nansha District in southern Guangzhou. In the medium-term and the long-term, the vulnerability risks of various landscapes have increased to varying degrees, and the changes in the vulnerability of park green and wetland landscapes are more significant. This study systematically assessed the impact of sea level rise combined with storm surge on different types of urban landscape in Guangzhou, which can provide decision-making reference for the risk management and prevention of coastal disasters in the future and the construction of urban resilience in Guangzhou.
In the context of global climate change and sea level rise, coastal disasters will pose a great impact on coastal urban landscape and social economy. Taking Guangzhou, a coastal city in the Pearl River Delta, as the study area, based on the land use and socio-economic data, this study proposed the "sensitivities-adaptability" vulnerability assessment framework to assess the vulnerability characteristics of Guangzhou urban landscape systems under three different sea-level rise combined with storm surge risk scenarios: the short-term (2030), the medium-term (2050) and the long-term (2100). The results show that: 1) From the perspective of inundation range and economic loss, the agricultural landscape, park green space and wetland landscape will be the most inundated under different risk scenarios in the future, while the industrial landscape and commercial and public service landscape will suffer the most serious economic losses.2) From the perspective of the overall spatial distribution of vulnerability, the areas with high landscape vulnerability in the short-term were mainly concentrated in Liwan District, Baiyun District and Huangpu District in the central part of Guangzhou. In the medium-term and long-term, the landscape vulnerability risk in Haizhu District in the central part of Guangzhou gradually increased. 3) From the spatial distribution of various landscape vulnerability, compared to the transportation landscape, residential landscape, and other types of landscape, the areas with relatively high vulnerability of agricultural landscapes are the most in the short-term, mainly concentrated in Panyu District and Nansha District in southern Guangzhou. In the medium-term and the long-term, the vulnerability risks of various landscapes have increased to varying degrees, and the changes in the vulnerability of park green and wetland landscapes are more significant. This study systematically assessed the impact of sea level rise combined with storm surge on different types of urban landscape in Guangzhou, which can provide decision-making reference for the risk management and prevention of coastal disasters in the future and the construction of urban resilience in Guangzhou.
Abstract:
The accelerated integration of the agricultural service platform and plant protection drone technology is of great significance for the rapid and accurate solution of farmers' decentralized plant protection needs. Firstly, this paper addresses the task allocation and scheduling of the "single base station-multi-UAV" model of plant protection UAVs under the social agricultural service platform, and establishes a mixed integer planning model with the objective of cost minimization, taking into account factors such as the optimal variable time window of efficacy and the variable power consumption rate of the total load of plant protection UAVs. Secondly, numerical experiments were conducted to verify the validity of the model by considering the optimal variable time window of efficacy and demand size corresponding to the rated battery life, flight mode in farmland and temperature. Finally, the experimental results show that the strategies of choosing long-sided turning grid flight, selecting pesticide types with a large temperature range for optimal efficacy and increasing the upper limit of platform service per unit time period for plant protection UAVs in farmland are important for improving service quality and the cost of agricultural service platform was reduced by 40.02%, 12.45% and 21.17%, respectively.
The accelerated integration of the agricultural service platform and plant protection drone technology is of great significance for the rapid and accurate solution of farmers' decentralized plant protection needs. Firstly, this paper addresses the task allocation and scheduling of the "single base station-multi-UAV" model of plant protection UAVs under the social agricultural service platform, and establishes a mixed integer planning model with the objective of cost minimization, taking into account factors such as the optimal variable time window of efficacy and the variable power consumption rate of the total load of plant protection UAVs. Secondly, numerical experiments were conducted to verify the validity of the model by considering the optimal variable time window of efficacy and demand size corresponding to the rated battery life, flight mode in farmland and temperature. Finally, the experimental results show that the strategies of choosing long-sided turning grid flight, selecting pesticide types with a large temperature range for optimal efficacy and increasing the upper limit of platform service per unit time period for plant protection UAVs in farmland are important for improving service quality and the cost of agricultural service platform was reduced by 40.02%, 12.45% and 21.17%, respectively.
Abstract:
Wind tunnel devices play an important role in the study of oilseed rape's ability to resist overturning under high wind conditions. In this study, the wind tunnel model of oilseed rape was established by the computational fluid dynamics software Fluent, and parametric design and simulation tests were carried out on key parts of the wind tunnel, such as diffusion section, stabilization section and contraction section, to analyse their effects on the quality of the wind tunnel flow field. The results show that, in the single-factor test, the variation coefficient of wind velocity at the outlet of the wind tunnel increases when the length of the shrinkage section increases, and the quality of airflow decreases. Among the nine orthogonal test solutions, the average coefficient of variation of wind speed in the corresponding wind tunnel test area is 0.139 when the shrinkage section length is 600mm, the stabilization section is 800mm and the damping net is 0.65 from the wind tunnel exit, which is more stable than other solutions and has the best airflow quality. The test and simulation results show that there is no significant difference between the measured wind speed and the simulation value in Scheme 2 wind tunnel, which provides data support and proof for the wind tunnel design.
Wind tunnel devices play an important role in the study of oilseed rape's ability to resist overturning under high wind conditions. In this study, the wind tunnel model of oilseed rape was established by the computational fluid dynamics software Fluent, and parametric design and simulation tests were carried out on key parts of the wind tunnel, such as diffusion section, stabilization section and contraction section, to analyse their effects on the quality of the wind tunnel flow field. The results show that, in the single-factor test, the variation coefficient of wind velocity at the outlet of the wind tunnel increases when the length of the shrinkage section increases, and the quality of airflow decreases. Among the nine orthogonal test solutions, the average coefficient of variation of wind speed in the corresponding wind tunnel test area is 0.139 when the shrinkage section length is 600mm, the stabilization section is 800mm and the damping net is 0.65 from the wind tunnel exit, which is more stable than other solutions and has the best airflow quality. The test and simulation results show that there is no significant difference between the measured wind speed and the simulation value in Scheme 2 wind tunnel, which provides data support and proof for the wind tunnel design.
WANG Yu, XIONG Bo, PENG Qingjie, XIANG Zhijie, YUAN Xinwei, WANG Yan, ZOU Liangxun, CHEN Yingyu, GUO Aizhen
Abstract:
Objectives: The lumpy skin disease (LSD) is an emerging bovine disease in China since 2019. Currently, the attenuated Goat Pox Vaccine (AV41 Strain) is used to prevent LSD by intradermal inoculation of 5 times of the goat dose. However intradermal inoculation in cattle is difficult to perform in the field. This study aimed to explore the changing dynamics of neutralising antibodies and ELISA antibodies after subcutaneous and intradermal inoculation of different doses of AV41 strain in cattle. Methods: Twenty-five healthy beef cattle were randomly assigned into five groups for subcutaneous and intradermal inoculation with 5 and 10 times of the goat dose. At days 0, 15, 30, 45, and 60 post-vaccination, the serum antibody response was detected by both virus neutralisation test (VNT) and a commercial ELISA kit. Results: The VNT results were similar to those of ELISA, 60% of the cattle in the subcutaneous inoculation with 5-times dose group seroconverted from the 30th day post-vaccination with the maximum neuralising antibody titer of 1:640, followed by the intradermal inoculation with the 10-times dose group and subcutaneous inoculation with 10-times dose group (40%), while only 20% in the intradermal inoculation with the 5-times dose group seroconverted; the neutralisation index of VNT showed a significant positive correlation with the S/P value of the ELISA. The above results, combined with the inoculation route of internationally similar vaccines, suggest that subcutaneous inoculation of AV41 at a 5-times the goat dose can be used as a clinical vaccination protocol. In conclusion, this study demonstrates that subcutaneous inoculation of 5-times the goat dose can be used as vaccination protocol and produces a better antibody response.
Objectives: The lumpy skin disease (LSD) is an emerging bovine disease in China since 2019. Currently, the attenuated Goat Pox Vaccine (AV41 Strain) is used to prevent LSD by intradermal inoculation of 5 times of the goat dose. However intradermal inoculation in cattle is difficult to perform in the field. This study aimed to explore the changing dynamics of neutralising antibodies and ELISA antibodies after subcutaneous and intradermal inoculation of different doses of AV41 strain in cattle. Methods: Twenty-five healthy beef cattle were randomly assigned into five groups for subcutaneous and intradermal inoculation with 5 and 10 times of the goat dose. At days 0, 15, 30, 45, and 60 post-vaccination, the serum antibody response was detected by both virus neutralisation test (VNT) and a commercial ELISA kit. Results: The VNT results were similar to those of ELISA, 60% of the cattle in the subcutaneous inoculation with 5-times dose group seroconverted from the 30th day post-vaccination with the maximum neuralising antibody titer of 1:640, followed by the intradermal inoculation with the 10-times dose group and subcutaneous inoculation with 10-times dose group (40%), while only 20% in the intradermal inoculation with the 5-times dose group seroconverted; the neutralisation index of VNT showed a significant positive correlation with the S/P value of the ELISA. The above results, combined with the inoculation route of internationally similar vaccines, suggest that subcutaneous inoculation of AV41 at a 5-times the goat dose can be used as a clinical vaccination protocol. In conclusion, this study demonstrates that subcutaneous inoculation of 5-times the goat dose can be used as vaccination protocol and produces a better antibody response.
Abstract:
To explore the effects of rice-crayfish co-culture system on the contents of heavy metals in paddy soil and rice, field experiments were carried out under different soil backgrounds in Jingmen city and Xishui county of Hubei province, with Xiangwanxian 12, Huanghuazhan and Yuzhenxiang as experimental materials under rice monoculture as control. The results showed that under the background of weak alkaline soil, the contents of Cr, As, Cd, Pb, and Hg in paddy soil decreased, and the contents of Cd and Pb in roots, stems, spikes, and brown rice decreased. Under the background of weak acid soil, the contents of Cr, As, Cd, Pb and Hg in paddy soil increased, the contents of Cd and Pb in rice roots increased, the contents of Cd in stems, leaves and spikes of rice increased, while the contents of Pb in stems, leaves, and spikes of rice decreased, and the contents of Cd, Pb in brown rice decreased. The results showed that the effects of rice-crayfish co-culture system on the contents of heavy metals in paddy soil and rice under different pH soil backgrounds are inconsistent, but rice-crayfish co-culture system can significantly reduce the contents of Cd and Pb in brown rice.
To explore the effects of rice-crayfish co-culture system on the contents of heavy metals in paddy soil and rice, field experiments were carried out under different soil backgrounds in Jingmen city and Xishui county of Hubei province, with Xiangwanxian 12, Huanghuazhan and Yuzhenxiang as experimental materials under rice monoculture as control. The results showed that under the background of weak alkaline soil, the contents of Cr, As, Cd, Pb, and Hg in paddy soil decreased, and the contents of Cd and Pb in roots, stems, spikes, and brown rice decreased. Under the background of weak acid soil, the contents of Cr, As, Cd, Pb and Hg in paddy soil increased, the contents of Cd and Pb in rice roots increased, the contents of Cd in stems, leaves and spikes of rice increased, while the contents of Pb in stems, leaves, and spikes of rice decreased, and the contents of Cd, Pb in brown rice decreased. The results showed that the effects of rice-crayfish co-culture system on the contents of heavy metals in paddy soil and rice under different pH soil backgrounds are inconsistent, but rice-crayfish co-culture system can significantly reduce the contents of Cd and Pb in brown rice.
Abstract:
Oil palm (Elaeis guineensis) is an important woody oil crop in tropical area. It is very hard to identification of functional genes in oil palm since very long growth cycle and difficult genetic transformation. In this study, the EgPDS gene was used as a reporter gene to explore the possibility of applying virus-induced gene silencing (VIGS) on oil palm embryoid using the TRV as a vector, and to optimize the relevant parameters. The best gene silencing effect can be obtained by the following parameters: with EHA105 as the strain, the concentration of the infected bacterial solution was OD600 = 0.5, the infection time was 5 min, the AS concentration was 20 mg/L, the co-cultivation time was 48 h, and the incubation time after infection was 12 d. Based on this system, the optimized VIGS system was used to silence the oil palm DGAT gene, and the gene silencing effect was the same as expected. The establishment of this system will provide an efficient technical platform for the study of oil palm functional genes.
Oil palm (Elaeis guineensis) is an important woody oil crop in tropical area. It is very hard to identification of functional genes in oil palm since very long growth cycle and difficult genetic transformation. In this study, the EgPDS gene was used as a reporter gene to explore the possibility of applying virus-induced gene silencing (VIGS) on oil palm embryoid using the TRV as a vector, and to optimize the relevant parameters. The best gene silencing effect can be obtained by the following parameters: with EHA105 as the strain, the concentration of the infected bacterial solution was OD600 = 0.5, the infection time was 5 min, the AS concentration was 20 mg/L, the co-cultivation time was 48 h, and the incubation time after infection was 12 d. Based on this system, the optimized VIGS system was used to silence the oil palm DGAT gene, and the gene silencing effect was the same as expected. The establishment of this system will provide an efficient technical platform for the study of oil palm functional genes.
Abstract:
As a rice cultivation mode with low cost and high benefits, ratooning rice has been advocated in China, but the effects of the mode on carbon footprint of rationing rice production remained unclear. A field experiment was conducted to study the effects of different cultivation modes of ratooning rice (conventional cultivation mode (CK), and two optimized cultivation modes (OM1 and OM2)) on methane (CH4) and nitrous oxide (N2O) emissions, grain yields, carbon footprint and economic benefits in central China. In this study, compared with CK, the OM1 and OM2 modes were optimized from the perspectives of water and fertilizer managements, stubble height, straw treatment in the first season and winter management. The results showed that cultivation modes significantly affected CH4 emissions but had no effect on N2O emissions. OM2 significantly reduced the annual cumulative CH4 emissions by 43.5% and 26.3% relative to CK and OM1, respectively. Cultivation modes also significantly impacted grain yields and carbon footprint. Compared with CK and OM1, OM2 significantly enhanced the yields of first rice season by 15.2% and 5.8, and the yield of ratooning rice season by 44.2% and 34.7%, respectively. OM2 remarkably decreased the carbon footprint by 40.0% and 24.0% relative to CK and OM1, respectively. The highest net ecosystem economic benefit of OM2 was 20768 CNY hm-2, which was 1.28 and 1.38 times of those of OM1 and CK, respectively. Our results indicate that OM2 mitigates CH4 emissions, reduces carbon footprint, increases rice yields and improves NEEB compared with other modes, suggesting that OM2 is a sustainable ratooning rice cultivation mode with low-carbon emission, high yield and high economic benefit. Therefore, the mode is worth promoting in ratooning rice planting area of Hubei province.
As a rice cultivation mode with low cost and high benefits, ratooning rice has been advocated in China, but the effects of the mode on carbon footprint of rationing rice production remained unclear. A field experiment was conducted to study the effects of different cultivation modes of ratooning rice (conventional cultivation mode (CK), and two optimized cultivation modes (OM1 and OM2)) on methane (CH4) and nitrous oxide (N2O) emissions, grain yields, carbon footprint and economic benefits in central China. In this study, compared with CK, the OM1 and OM2 modes were optimized from the perspectives of water and fertilizer managements, stubble height, straw treatment in the first season and winter management. The results showed that cultivation modes significantly affected CH4 emissions but had no effect on N2O emissions. OM2 significantly reduced the annual cumulative CH4 emissions by 43.5% and 26.3% relative to CK and OM1, respectively. Cultivation modes also significantly impacted grain yields and carbon footprint. Compared with CK and OM1, OM2 significantly enhanced the yields of first rice season by 15.2% and 5.8, and the yield of ratooning rice season by 44.2% and 34.7%, respectively. OM2 remarkably decreased the carbon footprint by 40.0% and 24.0% relative to CK and OM1, respectively. The highest net ecosystem economic benefit of OM2 was 20768 CNY hm-2, which was 1.28 and 1.38 times of those of OM1 and CK, respectively. Our results indicate that OM2 mitigates CH4 emissions, reduces carbon footprint, increases rice yields and improves NEEB compared with other modes, suggesting that OM2 is a sustainable ratooning rice cultivation mode with low-carbon emission, high yield and high economic benefit. Therefore, the mode is worth promoting in ratooning rice planting area of Hubei province.
Abstract:
In order to explore the root characteristics of transgenic Cry2A* gene rice lines, the pot experiment was conducted. Using conventional japonica rice and its transgenic Cry2A* rice lines, and conventional indica rice and its transgenic Cry2A* rice lines as experimental materials, the root characteristics of transgenic Cry2A* rice lines under nitrogen application and no nitrogen application were investigated. The results showed that the root length, root surface area and root volume of the transgenic Cry2A* rice lines were significantly lower than those of the parental control under the treatment without nitrogen application at the mature stage, and there was no significant difference under the nitrogen application treatment. The grain yield of KY(Cry2A*) was not significantly different from the parental control, and the grain yield of MH86(Cry2A*) was significantly lower than that of the parental control without nitrogen application. Grain yield was positively correlated with root morphological. Compared with no nitrogen application, nitrogen application could significantly increase the root diameter of KY(Cry2A*), but had no significant effect on the root diameter of MH86(Cry2A*). This study showed that there was a certain difference between the root characteristics of transgenic Cry2A* gene rice and its parents, and this difference was more obvious under the condition of no nitrogen treatment.
In order to explore the root characteristics of transgenic Cry2A* gene rice lines, the pot experiment was conducted. Using conventional japonica rice and its transgenic Cry2A* rice lines, and conventional indica rice and its transgenic Cry2A* rice lines as experimental materials, the root characteristics of transgenic Cry2A* rice lines under nitrogen application and no nitrogen application were investigated. The results showed that the root length, root surface area and root volume of the transgenic Cry2A* rice lines were significantly lower than those of the parental control under the treatment without nitrogen application at the mature stage, and there was no significant difference under the nitrogen application treatment. The grain yield of KY(Cry2A*) was not significantly different from the parental control, and the grain yield of MH86(Cry2A*) was significantly lower than that of the parental control without nitrogen application. Grain yield was positively correlated with root morphological. Compared with no nitrogen application, nitrogen application could significantly increase the root diameter of KY(Cry2A*), but had no significant effect on the root diameter of MH86(Cry2A*). This study showed that there was a certain difference between the root characteristics of transgenic Cry2A* gene rice and its parents, and this difference was more obvious under the condition of no nitrogen treatment.
Effects of associated cultivation on soil fertility and microbial diversity in rhizospheres tomatoes
Abstract:
To investigate the mechanisms of associated cultivations on soil fertility and health, soil biological properties and microbial diversity in rhizospheres of tomatoes under associated systems were analyzed. The results showed that soil enzyme activities, such as Aminopeptidases and Phosphatase, and the soil microbial biomass carbon, nitrogen and phosphorus in rhizospheres of tomatoes were all significantly improved by associated cultivation with four associated crops except of flowering cabbages. In addition, although soil microbial diversities were not significantly improved by associated cultivations, but the proportions of microbial abundance at phylum or genus levels were altered. For example, the dominant bacteria at phylum level the abundances of Proteobacteria, Patescibacteria, and Firmicutes could be promoted by associated cultivations; Meanwhile, norank_f__Microscillaceae, norank_f__norank_o__ Vicinamibacterales, Bacillus, norank_f__Gemmatimonadaceae, and Altererythrobacter were the top ten dominant bacterial genera in rhizospheres of tomatoes under associated systems. Furthermore, compared with monoculture of tomato, soil fungal diversity and richness in rhizospheres of tomatoes under associated systems were also altered. Such as Phaeophyta, Streptomyces and Oleaginous at phylum level and unclassified_o__Sordariales, Olpidium,Conocybe, Phialemonium, unclassified_o__Pleosporales, unclassified_o__Boletales and Sodiomyces at genus levels not only enriched, but also the abundance of Chaetomium increases under associated systems. In conclusions, except of flowering cabbage, soil fertility and health in rhizospheres of tomatoes were all improved or maintained by associated cultivating with lettuce, amaranth, mint and green onion. In comparison to flowering cabbage, amaranth and green onion, lettuce and mint were the suitable associated crops for tomato.
To investigate the mechanisms of associated cultivations on soil fertility and health, soil biological properties and microbial diversity in rhizospheres of tomatoes under associated systems were analyzed. The results showed that soil enzyme activities, such as Aminopeptidases and Phosphatase, and the soil microbial biomass carbon, nitrogen and phosphorus in rhizospheres of tomatoes were all significantly improved by associated cultivation with four associated crops except of flowering cabbages. In addition, although soil microbial diversities were not significantly improved by associated cultivations, but the proportions of microbial abundance at phylum or genus levels were altered. For example, the dominant bacteria at phylum level the abundances of Proteobacteria, Patescibacteria, and Firmicutes could be promoted by associated cultivations; Meanwhile, norank_f__Microscillaceae, norank_f__norank_o__ Vicinamibacterales, Bacillus, norank_f__Gemmatimonadaceae, and Altererythrobacter were the top ten dominant bacterial genera in rhizospheres of tomatoes under associated systems. Furthermore, compared with monoculture of tomato, soil fungal diversity and richness in rhizospheres of tomatoes under associated systems were also altered. Such as Phaeophyta, Streptomyces and Oleaginous at phylum level and unclassified_o__Sordariales, Olpidium,Conocybe, Phialemonium, unclassified_o__Pleosporales, unclassified_o__Boletales and Sodiomyces at genus levels not only enriched, but also the abundance of Chaetomium increases under associated systems. In conclusions, except of flowering cabbage, soil fertility and health in rhizospheres of tomatoes were all improved or maintained by associated cultivating with lettuce, amaranth, mint and green onion. In comparison to flowering cabbage, amaranth and green onion, lettuce and mint were the suitable associated crops for tomato.
Abstract:
In order to classify and identify the aroma type of cigarette formulation modules by using near-infrared spectroscopy, a method of cigarette recipe module aroma type prediction based on near-infrared spectral feature dimensionality reduction was proposed. The near-infrared spectral data of 238 cigarette formula module samples from 2017 to 2019 were selected, combined with the recursive feature elimination method in feature engineering and three machine learning techniques of BP neural network, random forest and XGBoost, to construct a feature variable-based aroma type prediction. Compared with the classification effect of full spectrum data training, the spectral feature variable after dimensionality reduction by recursive feature elimination method can effectively improve the recognition accuracy. Among them, the algorithm of XGBoost had the best classification performance on the test set and the model recognition accuracy rate reached 90.41%. The prediction method of aroma type based on dimensionality reduction of near-infrared spectral features has a certain role in assisting decision-making in the rapid positioning, scientific evaluation and cigarette formulation design of cigarette formulation modules.
In order to classify and identify the aroma type of cigarette formulation modules by using near-infrared spectroscopy, a method of cigarette recipe module aroma type prediction based on near-infrared spectral feature dimensionality reduction was proposed. The near-infrared spectral data of 238 cigarette formula module samples from 2017 to 2019 were selected, combined with the recursive feature elimination method in feature engineering and three machine learning techniques of BP neural network, random forest and XGBoost, to construct a feature variable-based aroma type prediction. Compared with the classification effect of full spectrum data training, the spectral feature variable after dimensionality reduction by recursive feature elimination method can effectively improve the recognition accuracy. Among them, the algorithm of XGBoost had the best classification performance on the test set and the model recognition accuracy rate reached 90.41%. The prediction method of aroma type based on dimensionality reduction of near-infrared spectral features has a certain role in assisting decision-making in the rapid positioning, scientific evaluation and cigarette formulation design of cigarette formulation modules.
Abstract:
The fall armyworm, Spodoptera frugiperda, was a new migratory pest that invaded into China with a great hazard to some kinds of crops. The migrations toward north in spring and summer and toward south in autumn were related to background of atmospheric circulation and the favorable weather process. In this study, a meteorological forecasting model for migration of Spodoptera frugiperda was preliminarily build based on medium-term numerical forecast of ECMWF. This model can forecast the migration routes, immigration time including the first day of emergence and the day with a peak number and falling area very well. This study reviewed two typical forecasting cases of Spodoptera frugiperda’s migration in 2021 in detail. The typical weather processed and meteorological factor field about first migrating to Hubei province from north in spring and migrating back to Hubei province in autumn in 2021 were analyzed. These meteorological forecasting results have been verified by using HYSPLIT model to simulate the backward migration routes, monitoring data in field and from monitoring lamp and migration routes. The results showed that there is a good coincidence between the forecasting results and monitoring data in field, that from monitoring lamp and routes simulation of Spodoptera frugiperda. In this study the numerical forecast model of meteorological forecast is used to forecast the migration route of migratory pest in the first time. The conclusions drawn from this study can provide applied values for forecasting migration route, immigrating time, falling area and taking some prevention measures in advance.
The fall armyworm, Spodoptera frugiperda, was a new migratory pest that invaded into China with a great hazard to some kinds of crops. The migrations toward north in spring and summer and toward south in autumn were related to background of atmospheric circulation and the favorable weather process. In this study, a meteorological forecasting model for migration of Spodoptera frugiperda was preliminarily build based on medium-term numerical forecast of ECMWF. This model can forecast the migration routes, immigration time including the first day of emergence and the day with a peak number and falling area very well. This study reviewed two typical forecasting cases of Spodoptera frugiperda’s migration in 2021 in detail. The typical weather processed and meteorological factor field about first migrating to Hubei province from north in spring and migrating back to Hubei province in autumn in 2021 were analyzed. These meteorological forecasting results have been verified by using HYSPLIT model to simulate the backward migration routes, monitoring data in field and from monitoring lamp and migration routes. The results showed that there is a good coincidence between the forecasting results and monitoring data in field, that from monitoring lamp and routes simulation of Spodoptera frugiperda. In this study the numerical forecast model of meteorological forecast is used to forecast the migration route of migratory pest in the first time. The conclusions drawn from this study can provide applied values for forecasting migration route, immigrating time, falling area and taking some prevention measures in advance.
Abstract:
The effect of mowing on the mechanical properties of Hippophae rhamnoides root soil fixation was analyzed and compared with that of no mowing. It was verified that the measures of mowing could promote the growth of Hippophae rhamnoides. Hippophae rhamnoides is the pioneer of soil and water conservation in arid and semi-arid regions of Inner Mongolia. This paper takes the root system of Hippophae rhamnoides as the research object. The ultimate tensile test of single root and the pull-out friction test of root soil interface were carried out by using TY-8000 tensile machine, which provided a theoretical basis for analyzing the growth and development of Hippophae rhamnoides after mowing. The test root diameter is between 0 ~ 5mm. Under the condition of mowing and not mowing, the ultimate root anti-tension is positively related to the power function of diameter, and the resistance tension is also suitable; the ultimate tensile strength of a single root is positively related to the negative function of diameter, and the pull-out shear strength also suitable. In the range of 0.5 ~ 1.5mm of representative root diameter, the average ultimate root anti-tension of a single root of mowing is 0.46 times higher than that of non mowing; the average ultimate tensile strength of a single root is increased by 0.37 times; the average drawing shear strength is increased by 0.3 times. Therefore, the diameter has an effect on the tensile strength and shear strength of Hippophae rhamnoides root system, and the tensile and shear properties of Hippophae rhamnoides root system are improved after the stubble treatment. This study explored the effect of mowing on the growth of Hippophae rhamnoides in terms of mechanics, and then provide theoretical support for the sustainable management and management of Hippophae rhamnoides artificial shrub forest in terms of biomechanics.
The effect of mowing on the mechanical properties of Hippophae rhamnoides root soil fixation was analyzed and compared with that of no mowing. It was verified that the measures of mowing could promote the growth of Hippophae rhamnoides. Hippophae rhamnoides is the pioneer of soil and water conservation in arid and semi-arid regions of Inner Mongolia. This paper takes the root system of Hippophae rhamnoides as the research object. The ultimate tensile test of single root and the pull-out friction test of root soil interface were carried out by using TY-8000 tensile machine, which provided a theoretical basis for analyzing the growth and development of Hippophae rhamnoides after mowing. The test root diameter is between 0 ~ 5mm. Under the condition of mowing and not mowing, the ultimate root anti-tension is positively related to the power function of diameter, and the resistance tension is also suitable; the ultimate tensile strength of a single root is positively related to the negative function of diameter, and the pull-out shear strength also suitable. In the range of 0.5 ~ 1.5mm of representative root diameter, the average ultimate root anti-tension of a single root of mowing is 0.46 times higher than that of non mowing; the average ultimate tensile strength of a single root is increased by 0.37 times; the average drawing shear strength is increased by 0.3 times. Therefore, the diameter has an effect on the tensile strength and shear strength of Hippophae rhamnoides root system, and the tensile and shear properties of Hippophae rhamnoides root system are improved after the stubble treatment. This study explored the effect of mowing on the growth of Hippophae rhamnoides in terms of mechanics, and then provide theoretical support for the sustainable management and management of Hippophae rhamnoides artificial shrub forest in terms of biomechanics.
Abstract:
With development of our country economics and improvement of the people’s life, cattle industry is stepping into its fast traffic lane. Meanwhile, the important infectious diseases of bovines have become the most restrictive factors for development of cattle industry. The epidemic of bovine infectious diseases is affected by various natural and social factors such as rise in scale and intensification of cattle farming and trade nationally and internationally, and veterinary administration and technical service. To understand the current status on epidemiology, challenge and trend of important infectious diseases of bovines is necessary to effectively prevent and control bovine diseases. Therefore, this review focused on important bovine diseases including emerging and re-emerging diseases to analyze their epidemic characterization, control status and pressure. Further the trend was predicted and some suggestion was proposed. It was expected to provide some help to bovine disease control and eradication.
With development of our country economics and improvement of the people’s life, cattle industry is stepping into its fast traffic lane. Meanwhile, the important infectious diseases of bovines have become the most restrictive factors for development of cattle industry. The epidemic of bovine infectious diseases is affected by various natural and social factors such as rise in scale and intensification of cattle farming and trade nationally and internationally, and veterinary administration and technical service. To understand the current status on epidemiology, challenge and trend of important infectious diseases of bovines is necessary to effectively prevent and control bovine diseases. Therefore, this review focused on important bovine diseases including emerging and re-emerging diseases to analyze their epidemic characterization, control status and pressure. Further the trend was predicted and some suggestion was proposed. It was expected to provide some help to bovine disease control and eradication.
CHEN Huan, FAN Tianning, BAI Yudong, LIANG Gengyuan, LI Shoukun, GUO Qianqian, WANG Haoan, CHEN Gang, GAO Yingxu, LIN JIngwei
Abstract:
FIP-fve is a low molecular-mass protein identified from Flammulina velutipes, which has many biological activities including immunomodulation. Our previous studies found that FIP-fve had certain growth-promoting effect towards F. velutipes mycelia. In order to explore the native biological function of FIP-fve to F. velutipes, we constructed an over-expression vector pCAMBIA1301-pGPD-FIP-fve, and transformed it into Agrobacterium tumefaciens LBA4404 strain. Finally, FIP-fve gene overexpressed F. velutipe was obtained via Agrobacterium transformation. By comparing the biological characteristics of FIP-fve gene-silenced F. velutipe (RNAi:FIP-fve), FIP-fve gene-overexpressed F. velutipe (pGPD:FIP-fve) and wild F. velutipe (CK) in mycelium and fruiting body stages, we found that the growth speed of pGPD:FIP-fve was faster than that of CK, whereas the growth speed of RNAi:FIP-fve was the lowest. After fruiting body cultivation, related yield traits of pGPD:FIP-fve were significantly better than CK in terms of fruiting body numbers, stalk height, fruiting body yield and biological efficiency, and those traits of RNAi: FIP fve were the worst. In conclusion, these results exhibited that FIP-fve could significantly promote the growth of F. velutipe mycelia and might affect the final yields of F. velutipes. Current paper is the first one to illuminate the native bio-functiont of FIP-fve gene towards F. velutipes, which provides some valuable proofs and references e for comprehensive study and further application of FIPs..
FIP-fve is a low molecular-mass protein identified from Flammulina velutipes, which has many biological activities including immunomodulation. Our previous studies found that FIP-fve had certain growth-promoting effect towards F. velutipes mycelia. In order to explore the native biological function of FIP-fve to F. velutipes, we constructed an over-expression vector pCAMBIA1301-pGPD-FIP-fve, and transformed it into Agrobacterium tumefaciens LBA4404 strain. Finally, FIP-fve gene overexpressed F. velutipe was obtained via Agrobacterium transformation. By comparing the biological characteristics of FIP-fve gene-silenced F. velutipe (RNAi:FIP-fve), FIP-fve gene-overexpressed F. velutipe (pGPD:FIP-fve) and wild F. velutipe (CK) in mycelium and fruiting body stages, we found that the growth speed of pGPD:FIP-fve was faster than that of CK, whereas the growth speed of RNAi:FIP-fve was the lowest. After fruiting body cultivation, related yield traits of pGPD:FIP-fve were significantly better than CK in terms of fruiting body numbers, stalk height, fruiting body yield and biological efficiency, and those traits of RNAi: FIP fve were the worst. In conclusion, these results exhibited that FIP-fve could significantly promote the growth of F. velutipe mycelia and might affect the final yields of F. velutipes. Current paper is the first one to illuminate the native bio-functiont of FIP-fve gene towards F. velutipes, which provides some valuable proofs and references e for comprehensive study and further application of FIPs..
Abstract:
In previous work, the global transcriptome databases of Mesorhizobium huakuii 7653R in free living and in symbiotic condition were constructed respectively. Some differential expression genes in free living and symbiotic condition were identified by RNA-Seq and Microarray. Among these genes, MCHK_7135 belongs to the Peroxiredoxin (Prxs) family. Its expression was significantly up-regulated during the stage of symbiotic nitrogen fixation. In this study, MCHK_7135 replacement mutant strain and complement strain was constructed at first. A series phenotype of mutant strain and complement strain were test under free living and symbiotic condition with Astragalus sinicus. Result shown that: compare with wild-type rhizobium strain, MCHK_7135 mutant strain shown much more sensitive to H2O2 stress. The growth of A. sinicus plant inoculated with mutant strain was inhibited, the number of infect thread, primordium and mature nodule formed by mutant strain were significantly reduced. The nitrogen fixation activity also reduced. However, when mutant strain was complemented by complete MCHK_7135 gene, some symbiotic phenotype were recovered in different degree. Above results indicate that the peroxiredoxin gene MCHK_7135 of M. huakuii plays an important role in the symbiotic interaction between rhizobia and host plants.
In previous work, the global transcriptome databases of Mesorhizobium huakuii 7653R in free living and in symbiotic condition were constructed respectively. Some differential expression genes in free living and symbiotic condition were identified by RNA-Seq and Microarray. Among these genes, MCHK_7135 belongs to the Peroxiredoxin (Prxs) family. Its expression was significantly up-regulated during the stage of symbiotic nitrogen fixation. In this study, MCHK_7135 replacement mutant strain and complement strain was constructed at first. A series phenotype of mutant strain and complement strain were test under free living and symbiotic condition with Astragalus sinicus. Result shown that: compare with wild-type rhizobium strain, MCHK_7135 mutant strain shown much more sensitive to H2O2 stress. The growth of A. sinicus plant inoculated with mutant strain was inhibited, the number of infect thread, primordium and mature nodule formed by mutant strain were significantly reduced. The nitrogen fixation activity also reduced. However, when mutant strain was complemented by complete MCHK_7135 gene, some symbiotic phenotype were recovered in different degree. Above results indicate that the peroxiredoxin gene MCHK_7135 of M. huakuii plays an important role in the symbiotic interaction between rhizobia and host plants.
Yuan Xinwei, Yang Caijun, Wang Yu, Adili Abulaiti, Chen Yingyu, Li Jiakui, Cao Yongqiang, Li Hang, Guo Aizhen
Abstract:
In August 2019, the outbreak of Lumpy Skin Disease (LSD) was firstly confirmed in Yili, Xinjiang of China, and then spread countrywide. Due to lack of the full knowledge about LSD and control experience, the farms usually don’t know how to deal with it or the measures taken are non-specific to LSD, resulting in the transmission of this disease and substantial economic losses to the cattle industry. Therefore this paper comprehensively reviewed LSD from the aspects of etiological characteristics, pathogenesis, clinical characteristics, transmission routes, diagnosis, prevention and control measures, focusing on the latest research progress. It was aimed to clarify the critical determinants of LSD occurrence and its control. Further, a suggestion about how to effectively prevent, control and eliminate LSD in China was proposed.
In August 2019, the outbreak of Lumpy Skin Disease (LSD) was firstly confirmed in Yili, Xinjiang of China, and then spread countrywide. Due to lack of the full knowledge about LSD and control experience, the farms usually don’t know how to deal with it or the measures taken are non-specific to LSD, resulting in the transmission of this disease and substantial economic losses to the cattle industry. Therefore this paper comprehensively reviewed LSD from the aspects of etiological characteristics, pathogenesis, clinical characteristics, transmission routes, diagnosis, prevention and control measures, focusing on the latest research progress. It was aimed to clarify the critical determinants of LSD occurrence and its control. Further, a suggestion about how to effectively prevent, control and eliminate LSD in China was proposed.
Zhu Jie, Yang Caijun, Qi Mingpu, Yang Kaihui, Wang Yu, Yang Jianjun, Li Fuqiang, Chen yingyu, Chen Xi, Hu Changmin, Guo Aizhen
Abstract:
Bovine viral diarrhea virus (BVDV) is one of the most important pathogens in cattle diseases, causing serious economic losses to the cattle industry worldwide. The prevalence of BVDV in cattle herds in China is of great significance to the prevention and control of this virus infection. We conducted a systematic review and meta-analysis of BVDV detection rate in cattle in China from studies by searching China National Knowledge Infrastructure (CNKI), Wan Fang Database, VIP Chinese Journals Database, PubMed and ScienceDirect for publication from 1981 to September 1, 2021. A total of 93 studies on BVDV pathogenic detection were selected and included in this Meta-analysis. We estimated the pooled pathogen detection rate of BVDV in China cattle herds was 10.8% (95%CI：8.5-13.3）, among which the detection rate of BVDV antigen was 4.8%（95%CI：3.0-7.0）), and the detection rate of BVDV nucleic acid is 18.6%（95%CI：7.5-23.3）. In the sampling province subgroup, the pooled detection rate was the highest in Jilin province(26.3%, 95%CI：24.3-28.4), followed by Hubei province (24.6%) and Inner Mongolia Autonomous Region (21.9%). Subgroup analysis and Meta regression analysis show that breed (yak vs dairy cattle; OR=1.37,95%CI：1.05-1.79), breeding mode (free-ranging vs large-scale;OR=1.41, 95%CI: 1.08-1.85), diagnosis method (RT-PCR vs ELISA; OR=1.64, 95%CI: 1.38-1.94), and animal health (clinical symptoms vs asymptomatic; OR=1.42, 95%CI: 1.20-1.68) are the factors that significantly increase the prevalence rate of BVDV. In addition, plateau alpine (OR=1.54, 95%CI: 1.20-1.97) and high altitude (>3000m; OR=1.64, 95%CI: 1.21-2.21) geographic climate factors may have promoted the prevalence of BVDV. In summary, this study provides an important basis for the prevention and control of BVDV in cattle herds in China.
Bovine viral diarrhea virus (BVDV) is one of the most important pathogens in cattle diseases, causing serious economic losses to the cattle industry worldwide. The prevalence of BVDV in cattle herds in China is of great significance to the prevention and control of this virus infection. We conducted a systematic review and meta-analysis of BVDV detection rate in cattle in China from studies by searching China National Knowledge Infrastructure (CNKI), Wan Fang Database, VIP Chinese Journals Database, PubMed and ScienceDirect for publication from 1981 to September 1, 2021. A total of 93 studies on BVDV pathogenic detection were selected and included in this Meta-analysis. We estimated the pooled pathogen detection rate of BVDV in China cattle herds was 10.8% (95%CI：8.5-13.3）, among which the detection rate of BVDV antigen was 4.8%（95%CI：3.0-7.0）), and the detection rate of BVDV nucleic acid is 18.6%（95%CI：7.5-23.3）. In the sampling province subgroup, the pooled detection rate was the highest in Jilin province(26.3%, 95%CI：24.3-28.4), followed by Hubei province (24.6%) and Inner Mongolia Autonomous Region (21.9%). Subgroup analysis and Meta regression analysis show that breed (yak vs dairy cattle; OR=1.37,95%CI：1.05-1.79), breeding mode (free-ranging vs large-scale;OR=1.41, 95%CI: 1.08-1.85), diagnosis method (RT-PCR vs ELISA; OR=1.64, 95%CI: 1.38-1.94), and animal health (clinical symptoms vs asymptomatic; OR=1.42, 95%CI: 1.20-1.68) are the factors that significantly increase the prevalence rate of BVDV. In addition, plateau alpine (OR=1.54, 95%CI: 1.20-1.97) and high altitude (>3000m; OR=1.64, 95%CI: 1.21-2.21) geographic climate factors may have promoted the prevalence of BVDV. In summary, this study provides an important basis for the prevention and control of BVDV in cattle herds in China.
Abstract:
Abstract: Using the CLDAS data set of land data assimilation system of China Meteorological Administration from 2008 to 2020 and other environmental factors, the potential suitable distribution of tobacco area in Hubei province and dominant environmental factors affecting tobacco were simulated by using the actual planting sites basing on the maximum entropy model (MaxEnt) and Geographic Information System(ArcGIS 10.2). The results showed that: (1) MaxEnt model had a high accuracy in predicting the suitable distribution of tobacco area (AUC=0.854). (2) Altitude (650-1750 m), soil type (yellow soil), minimum temperature at the rosette stage (8.9-15.0℃), temperature at the prosperously growing stage (16-22.9℃), and temperature at the maturing stage (18.8-25.6℃) are the dominant environmental factors affecting the distribution of tobacco area in Hubei. (3) The highly suitable areas of tobacco are mainly distributed in Enshi, Shiyan, the southern of Xiangyang and the southeastern of Yichang, accounting for 18.2% of the total area of Hubei Province, with the mainly climate characteristics of altitude(700-1350m), the average minimum temperature(11.2-14.5℃), the average temperature (19.2-22.8℃), and the average temperature in the mature period (22.0-25.4℃). (4) Altitude plays a decisive role among all environmental factors, and temperature is an important meteorological factor affecting the growth and development of tobacco. The results are basically consistent with the actual spatial distribution of tobacco growing areas in Hubei Province, which can provide a theoretical reference for the scientific planting and distribution of tobacco.
Abstract: Using the CLDAS data set of land data assimilation system of China Meteorological Administration from 2008 to 2020 and other environmental factors, the potential suitable distribution of tobacco area in Hubei province and dominant environmental factors affecting tobacco were simulated by using the actual planting sites basing on the maximum entropy model (MaxEnt) and Geographic Information System(ArcGIS 10.2). The results showed that: (1) MaxEnt model had a high accuracy in predicting the suitable distribution of tobacco area (AUC=0.854). (2) Altitude (650-1750 m), soil type (yellow soil), minimum temperature at the rosette stage (8.9-15.0℃), temperature at the prosperously growing stage (16-22.9℃), and temperature at the maturing stage (18.8-25.6℃) are the dominant environmental factors affecting the distribution of tobacco area in Hubei. (3) The highly suitable areas of tobacco are mainly distributed in Enshi, Shiyan, the southern of Xiangyang and the southeastern of Yichang, accounting for 18.2% of the total area of Hubei Province, with the mainly climate characteristics of altitude(700-1350m), the average minimum temperature(11.2-14.5℃), the average temperature (19.2-22.8℃), and the average temperature in the mature period (22.0-25.4℃). (4) Altitude plays a decisive role among all environmental factors, and temperature is an important meteorological factor affecting the growth and development of tobacco. The results are basically consistent with the actual spatial distribution of tobacco growing areas in Hubei Province, which can provide a theoretical reference for the scientific planting and distribution of tobacco.
lifutong, yanchaochao, limaosen, pengzhiliang, jiangliya, huangjinhui, rentianbao, zhangyongfeng, liuguoshun
Abstract:
In order to explore the changes of soil microbial community structure under different continuous cropping years of tobacco, the changes of soil nutrients, microbial diversity, community structure and driving factors of four different types of tobacco planting soils in Shangluo area, the hinterland of Qinling Mountains were analyzed. The results showed that the contents of soil organic matter, total nitrogen, available phosphorus, available potassium and pH decreased with the increase of continuous cropping years; The richness and diversity of bacteria decreased significantly. The dominant bacteria were Actinobacteriota, Proteobacteria, Chloroflexi, Acidobacteriota and Firmicutes. The richness of fungi increased significantly. The dominant bacteria were Ascomycota, Basidiomycota and Mucoromycota. Under the condition of Y4 continuous cropping, the relative abundance of beneficial microorganisms in soil decreased, such as Firmicutes and desulfurization bacteria, and the relative abundance of pathogenic microorganisms increased, such as Trichoderma and Trichoderma. Long term continuous cropping will lead to the gradual reduction of soil nutrient content and pH value, and then affect the structure of soil microbial community, reduce the relative abundance of beneficial microorganisms and increase the relative abundance of pathogenic microorganisms, and then increase the risk of tobacco disease. Therefore, establishing a good farming system or constructing microbial community is the key technical way to alleviate or solve the imbalance of microbial community structure in continuous cropping tobacco field.
In order to explore the changes of soil microbial community structure under different continuous cropping years of tobacco, the changes of soil nutrients, microbial diversity, community structure and driving factors of four different types of tobacco planting soils in Shangluo area, the hinterland of Qinling Mountains were analyzed. The results showed that the contents of soil organic matter, total nitrogen, available phosphorus, available potassium and pH decreased with the increase of continuous cropping years; The richness and diversity of bacteria decreased significantly. The dominant bacteria were Actinobacteriota, Proteobacteria, Chloroflexi, Acidobacteriota and Firmicutes. The richness of fungi increased significantly. The dominant bacteria were Ascomycota, Basidiomycota and Mucoromycota. Under the condition of Y4 continuous cropping, the relative abundance of beneficial microorganisms in soil decreased, such as Firmicutes and desulfurization bacteria, and the relative abundance of pathogenic microorganisms increased, such as Trichoderma and Trichoderma. Long term continuous cropping will lead to the gradual reduction of soil nutrient content and pH value, and then affect the structure of soil microbial community, reduce the relative abundance of beneficial microorganisms and increase the relative abundance of pathogenic microorganisms, and then increase the risk of tobacco disease. Therefore, establishing a good farming system or constructing microbial community is the key technical way to alleviate or solve the imbalance of microbial community structure in continuous cropping tobacco field.
Display Method:
Abstract:
In this study,we investigated the effect of bio-floating bed on growth and muscle quality of grass carp (Ctenopharyngodon idellus) and blunt snout bream(Megalobrama amblycephala) in ponds.Two modes of culture ponds were chosen:one equipped with bio-floating bed was the experimental pond,and the other without beds was the control pond.At the end of the experiment,we measured the growth parameters,the muscle conventional nutrients,water holding capacity (WHC),and texture characteristics using biochemical and physical methods.The results showed that the final weight of fish cultured in the experimental pond was higher than that in the control pond.The hepatic somatic index of grass carp (1.77%) in the experimental pond was significantly lower than that of the control (2.47%).The condition factors of grass carp and blunt snout bream (1.73 and 2.56,respectively) were significantly higher than those of the control (1.64 and 2.40,respectively).There was no significant difference in the eviscerated weight of both carp and bream between the experimental (91.06 and 88.28,respectively) and the control (89.22 and 88.49,respectively) ponds.The drop loss (14.49% and 10.69,respectively) and water loss rate (17.52% and 10.34%,respectively) of the experimental grass carp and blunt snout bream were significantly lower than those of the control.The cooked rate of the experimental fish was significantly higher than the control.The muscle crude fat content (1.89%) and crude protein content (14.60%) of grass carp in the experimental ponds were significantly higher than those of the control (1.54% and 13.46%),whereas muscle water content (81.68%) of the experimental fish was significantly lower than that (82.65%) of the control.There is no significant difference in muscle ash content between the two groups.Unlike grass carp,only muscle crude protein content (17.23%) of the experimental bream was significantly higher than that (15.90%) of the control.The muscular hardness,gumminess,and chewiness of the experimental carp (5 298.10 g,2 450.78 g and 770.78 g,respectively) were significantly higher than those of the control (3 226.79 g,1 881.43 g and 602.80 g,respectively).The resilience (0.31) and cohesion (0.48) of experimental carp were significantly lower than those (0.43 and 0.58,respectively) of the control.However,only the muscular springiness of the blunt snout bream in the experimental pond was significantly higher than that in the control pond.
In this study,we investigated the effect of bio-floating bed on growth and muscle quality of grass carp (Ctenopharyngodon idellus) and blunt snout bream(Megalobrama amblycephala) in ponds.Two modes of culture ponds were chosen:one equipped with bio-floating bed was the experimental pond,and the other without beds was the control pond.At the end of the experiment,we measured the growth parameters,the muscle conventional nutrients,water holding capacity (WHC),and texture characteristics using biochemical and physical methods.The results showed that the final weight of fish cultured in the experimental pond was higher than that in the control pond.The hepatic somatic index of grass carp (1.77%) in the experimental pond was significantly lower than that of the control (2.47%).The condition factors of grass carp and blunt snout bream (1.73 and 2.56,respectively) were significantly higher than those of the control (1.64 and 2.40,respectively).There was no significant difference in the eviscerated weight of both carp and bream between the experimental (91.06 and 88.28,respectively) and the control (89.22 and 88.49,respectively) ponds.The drop loss (14.49% and 10.69,respectively) and water loss rate (17.52% and 10.34%,respectively) of the experimental grass carp and blunt snout bream were significantly lower than those of the control.The cooked rate of the experimental fish was significantly higher than the control.The muscle crude fat content (1.89%) and crude protein content (14.60%) of grass carp in the experimental ponds were significantly higher than those of the control (1.54% and 13.46%),whereas muscle water content (81.68%) of the experimental fish was significantly lower than that (82.65%) of the control.There is no significant difference in muscle ash content between the two groups.Unlike grass carp,only muscle crude protein content (17.23%) of the experimental bream was significantly higher than that (15.90%) of the control.The muscular hardness,gumminess,and chewiness of the experimental carp (5 298.10 g,2 450.78 g and 770.78 g,respectively) were significantly higher than those of the control (3 226.79 g,1 881.43 g and 602.80 g,respectively).The resilience (0.31) and cohesion (0.48) of experimental carp were significantly lower than those (0.43 and 0.58,respectively) of the control.However,only the muscular springiness of the blunt snout bream in the experimental pond was significantly higher than that in the control pond.
Abstract:
Effects of soaking temperature,cultivation temperature and watering frequency on the growth characteristics and nutrition of mung bean sprout were investigated. Growth characteristics and nutrition of mung bean sprout were significantly affected by soaking temperature,cultivation temperature and watering frequency (P<0.05). When the bean was soaked at higher temperature (40℃),body weight of the cultivated mung bean sprout was heavier,hypocotyl was longer,contents of free amino acid (FAA),water soluble sugar (WSS) and γ-aminobutyric acid (GABA) were higher. The hypocotyl was longer while the diameter was smaller when the bean was cultivated in the relatively higher temperature (30-35℃). When the watering frequency decreased,weight,hypocotyl length and diameter decreased,WSS content decreased first and then increased,FAA content increased first and then decreased,GABA content was fluctuated. The optimal germination conditions of mung bean sprout were soaking bean at 40℃ for 5 h,with cultivation temperature of 25-30℃ and watering once per hour.
Effects of soaking temperature,cultivation temperature and watering frequency on the growth characteristics and nutrition of mung bean sprout were investigated. Growth characteristics and nutrition of mung bean sprout were significantly affected by soaking temperature,cultivation temperature and watering frequency (P<0.05). When the bean was soaked at higher temperature (40℃),body weight of the cultivated mung bean sprout was heavier,hypocotyl was longer,contents of free amino acid (FAA),water soluble sugar (WSS) and γ-aminobutyric acid (GABA) were higher. The hypocotyl was longer while the diameter was smaller when the bean was cultivated in the relatively higher temperature (30-35℃). When the watering frequency decreased,weight,hypocotyl length and diameter decreased,WSS content decreased first and then increased,FAA content increased first and then decreased,GABA content was fluctuated. The optimal germination conditions of mung bean sprout were soaking bean at 40℃ for 5 h,with cultivation temperature of 25-30℃ and watering once per hour.
2013,32(4):48-54, DOI: 1000-2421（2013）04-0048-07
Abstract:
The spatial distribution of Valley County land use degree in 2009 was studied and the spatial autocorrelation of land use degree and its driving factors in different scales were analyzed.A spatial autoregressive model and geographically weighted regression model was established from the perspective of global local.The results showed that there was a certain spatial autocorrelation in land use degree and its driving factors with scale effect.Spatial regression model could estimate the overall parameter of various factors while geographically weighted regression model could give the local parameter of various factors.Scales of geographical weighted regression model could reflect the detailed geographical information to some extent.
The spatial distribution of Valley County land use degree in 2009 was studied and the spatial autocorrelation of land use degree and its driving factors in different scales were analyzed.A spatial autoregressive model and geographically weighted regression model was established from the perspective of global local.The results showed that there was a certain spatial autocorrelation in land use degree and its driving factors with scale effect.Spatial regression model could estimate the overall parameter of various factors while geographically weighted regression model could give the local parameter of various factors.Scales of geographical weighted regression model could reflect the detailed geographical information to some extent.
Abstract:
pCB302-3 is a plant mini-binary stable transformation vector.To investigate the transient expression of pCB302-3 vector in plant,GFP was inserted into pCB302-3 vector as a reporter gene,and various factors including density of Agrobacterium cell,supplementation of gene silencing suppression p19 and days post infiltration were optimized based on agroinfiltration method in Nicotiana benthamiana leaves.Results showed that high levels of GFP expression were observed in N.benthamiana leaves 3-5 d after infiltration by Agrobacterium cell suspension contained pCB302-3-GFP with an optical density （D600） of 0.8-1.0 co-infiltrated with p19 gene.
pCB302-3 is a plant mini-binary stable transformation vector.To investigate the transient expression of pCB302-3 vector in plant,GFP was inserted into pCB302-3 vector as a reporter gene,and various factors including density of Agrobacterium cell,supplementation of gene silencing suppression p19 and days post infiltration were optimized based on agroinfiltration method in Nicotiana benthamiana leaves.Results showed that high levels of GFP expression were observed in N.benthamiana leaves 3-5 d after infiltration by Agrobacterium cell suspension contained pCB302-3-GFP with an optical density （D600） of 0.8-1.0 co-infiltrated with p19 gene.
2012,31(1):16-22, DOI: 1000-2421（2012）01-0016-07
Abstract:
Nitrogen is one of essential nutrients for plant growth.Under the N deficiency at different time points，the dynamic changes of the expression of genes and activity of enzymes related to nitrogen assimilation in rice were investigated.The results showed that the concentrations of ammonium and nitrate significantly reduced under the N deficiency.Under the N deficiency for a short time，the expression level of genes including NR1, NR2, NiR2,GS2,Fd-GOGAT,GDH2,GDH3 in the shoots as well as NR1,NR2,GDH4 in the roots were up-regulated,and then their expression level decreased after a long time under the N deficiency.Along with the extension of time under the N deficiency,the GS,Fd-GOGAT activities in whole plants,NR activity in shoots and NADH-GOGAT activity in roots decreased while the NADPH-GDH activity in shoots increased.In roots the activities of NR,GDH increased at first and then decreased，while in shoots the NiR activity was just the opposite.Re-supplied N after 7 days of N deficiency,the transcriptional expression level and enzyme activities of NR,NiR,GS,GOGAT,GDH restored,and expression level of some genes increased as well.
Nitrogen is one of essential nutrients for plant growth.Under the N deficiency at different time points，the dynamic changes of the expression of genes and activity of enzymes related to nitrogen assimilation in rice were investigated.The results showed that the concentrations of ammonium and nitrate significantly reduced under the N deficiency.Under the N deficiency for a short time，the expression level of genes including NR1, NR2, NiR2,GS2,Fd-GOGAT,GDH2,GDH3 in the shoots as well as NR1,NR2,GDH4 in the roots were up-regulated,and then their expression level decreased after a long time under the N deficiency.Along with the extension of time under the N deficiency,the GS,Fd-GOGAT activities in whole plants,NR activity in shoots and NADH-GOGAT activity in roots decreased while the NADPH-GDH activity in shoots increased.In roots the activities of NR,GDH increased at first and then decreased，while in shoots the NiR activity was just the opposite.Re-supplied N after 7 days of N deficiency,the transcriptional expression level and enzyme activities of NR,NiR,GS,GOGAT,GDH restored,and expression level of some genes increased as well.
Abstract:
In order to overcome the transition，field operation, and standardized batch production difficulties of the existing track cargo vehicle in mountainous orchard, as well as to raise the utilization rate, the mountain orchard detachable unidirectional traction double track cargo vehicle was developed. This paper introduced the whole machine structure, the wire rope diameter selection，the minimum track inclination，the maximum track distance，the minimum track turning radius and the working principle of the rope brake device. Load experiments were carried out to test the cargo′s synthetic track function. It is indicated by calculation that the wire rope diameter should be 7.7 mm，the minimum track inclination was 5.7°, the maximum track distance was 170 m, the minimum track horizontal turning radius was 7 m, and the minimum track vertical turning radius was 2 m. Load experiment results indicated that the cargo vehicle′s uplink average speed was 0.51 m/s, the downlink average speed was 0.54 m/s, the average energy consumption was 1.235 kW·h and the effective use degree was 100%. This cargo vehicle was suitable for fruit, pesticide, chemical fertilizer and other cargo transportation in the mountain orchard. Meanwhile, it can be applied to carry the spraying machine, the shave machine and other agricultural machines.
In order to overcome the transition，field operation, and standardized batch production difficulties of the existing track cargo vehicle in mountainous orchard, as well as to raise the utilization rate, the mountain orchard detachable unidirectional traction double track cargo vehicle was developed. This paper introduced the whole machine structure, the wire rope diameter selection，the minimum track inclination，the maximum track distance，the minimum track turning radius and the working principle of the rope brake device. Load experiments were carried out to test the cargo′s synthetic track function. It is indicated by calculation that the wire rope diameter should be 7.7 mm，the minimum track inclination was 5.7°, the maximum track distance was 170 m, the minimum track horizontal turning radius was 7 m, and the minimum track vertical turning radius was 2 m. Load experiment results indicated that the cargo vehicle′s uplink average speed was 0.51 m/s, the downlink average speed was 0.54 m/s, the average energy consumption was 1.235 kW·h and the effective use degree was 100%. This cargo vehicle was suitable for fruit, pesticide, chemical fertilizer and other cargo transportation in the mountain orchard. Meanwhile, it can be applied to carry the spraying machine, the shave machine and other agricultural machines.
2013,32(5):124-133, DOI: 1000-2421（2013）05-0124-10
Abstract:
Bacterial canker is a devastating disease of kiwifruit. In recent years,the disease is showing a tendency to outbreak in such countries as Italy and New Zealand,where kiwifruit is a major crop,and has the trends to further spread worldwide,which will be a serious threat to the development of the kiwifruit industry. Based on the latest research reports, this paper summarized the symptoms,pathogen identification,rapid detection methods,virulence differences,infected mechanism,epidemiology and control technology of the disease. Meanwhile,the future research prospect of kiwifruit bacterial canker was also discussed in order to reduce the loss and risk of the kiwifruit industry.
Bacterial canker is a devastating disease of kiwifruit. In recent years,the disease is showing a tendency to outbreak in such countries as Italy and New Zealand,where kiwifruit is a major crop,and has the trends to further spread worldwide,which will be a serious threat to the development of the kiwifruit industry. Based on the latest research reports, this paper summarized the symptoms,pathogen identification,rapid detection methods,virulence differences,infected mechanism,epidemiology and control technology of the disease. Meanwhile,the future research prospect of kiwifruit bacterial canker was also discussed in order to reduce the loss and risk of the kiwifruit industry.
2014,33(2):139-144, DOI: 1000-2421（2014）02-0139-06
Abstract:
Algae are lower photosynthetic autotrophs which have close relationship with agricultural activities.With the deep understanding of physiological and ecological characteristics,algae have used more and more widelyin the practice of agricultural activities.This paper reviews the application of algaeas a resourcein agricultural activities including improvement of agricultural environment,utilized as food or food additives and health care products,as well as feed or bait.
Algae are lower photosynthetic autotrophs which have close relationship with agricultural activities.With the deep understanding of physiological and ecological characteristics,algae have used more and more widelyin the practice of agricultural activities.This paper reviews the application of algaeas a resourcein agricultural activities including improvement of agricultural environment,utilized as food or food additives and health care products,as well as feed or bait.
2012,31(5):569-573, DOI: 1000-2421（2012）05-0569-05
Abstract:
Hydroponic experiments of strawberry were conducted with three formulations of nutrient solution to select the best formulations for soilless cultivation of strawberry.Several main characteristics of growth including the fresh weight and dry weight of overground plant and root，the growth of crown，the photosynthetic and quality of strawberry，the diameter of staminate flower，the growth amass were investigated．The results showed that the effect of nutrient solution with the content of calcium nitrate tetrahydrate,potassium nitrate,ammonium dihydrogen phosphate,magnesium sulfate and ammonium nitrate at 295,303,62,246,0 mg/L on the growing status and fruit quality of strawberry are better than that of the other 2 treatments.This nutrient solution formula was the most propitious for the growth of ‘Jingyao’ strawberry and the enhancement of the fruit quality among the three different treatnments.That is,it facilitated the growth of strawberry in alimentation growth periods,and the leaves of ‘Jingyao’ strawberry was larger and thicker with a dark-green color,and the diameter of the pedicel was also larger. In addition,the nutrient solution formula was also conducive to the flowering promotion and the reproductive growth of strawberry,and resultes showed that the single fruit weight,yield and fruit quality is the best comparing to the other treatments.The results of this study provided academic and technological basis for establishing high yield and quality of strawberry in greenhouse substrate culture of irrigation and nitrogen application system.
Hydroponic experiments of strawberry were conducted with three formulations of nutrient solution to select the best formulations for soilless cultivation of strawberry.Several main characteristics of growth including the fresh weight and dry weight of overground plant and root，the growth of crown，the photosynthetic and quality of strawberry，the diameter of staminate flower，the growth amass were investigated．The results showed that the effect of nutrient solution with the content of calcium nitrate tetrahydrate,potassium nitrate,ammonium dihydrogen phosphate,magnesium sulfate and ammonium nitrate at 295,303,62,246,0 mg/L on the growing status and fruit quality of strawberry are better than that of the other 2 treatments.This nutrient solution formula was the most propitious for the growth of ‘Jingyao’ strawberry and the enhancement of the fruit quality among the three different treatnments.That is,it facilitated the growth of strawberry in alimentation growth periods,and the leaves of ‘Jingyao’ strawberry was larger and thicker with a dark-green color,and the diameter of the pedicel was also larger. In addition,the nutrient solution formula was also conducive to the flowering promotion and the reproductive growth of strawberry,and resultes showed that the single fruit weight,yield and fruit quality is the best comparing to the other treatments.The results of this study provided academic and technological basis for establishing high yield and quality of strawberry in greenhouse substrate culture of irrigation and nitrogen application system.
2012,31(1):127-132, DOI: 1000-2421（2012）01-0127-06
Abstract:
Post-harvest strawberries are susceptible to the decay of fruit and deterioration of quality due to pathogenic fungi infections,a main factor leading to economic losses for both growers and retailers.With the increase of strawberries planting in China,it is urgent to effectively reduce post-harvest rots of strawberry fruits.In this review,new management developments for controlling fungal diseases in post-harvest strawberry were summarized in terms of physical,chemical and biological approaches,which can help to extend the on-shelf time of strawberry fruits.
Post-harvest strawberries are susceptible to the decay of fruit and deterioration of quality due to pathogenic fungi infections,a main factor leading to economic losses for both growers and retailers.With the increase of strawberries planting in China,it is urgent to effectively reduce post-harvest rots of strawberry fruits.In this review,new management developments for controlling fungal diseases in post-harvest strawberry were summarized in terms of physical,chemical and biological approaches,which can help to extend the on-shelf time of strawberry fruits.
Abstract:
Using Mesorhizobium sp.S-15 and Paenibacillus sp.S-17 as experimental strains.After cell disruption,NH4OAc extraction,H2O2 solution digestion or without any pre-treatment,K+ content in the fermentation broth of potassium solubilizing bacteria was determined with flame photometer.The efficiency of K solubilizing by potassium solubilizing bacteria in the culture medium was calculated.The results showed that the standard curves of the three kinds of K series of standard solutions were similar with the R2 values of 0.994 4,0.999 7 and 0.999 8,respectively.After digested by H2O2 solution,concentration of K+ was detected.The efficiency of two strains was 101.1% and 125.1%,significantly higher than that of other groups.The efficiency of potassium solubilizing detected after H2O2 digestion well reflected potassium solubilization of bacteria.
Using Mesorhizobium sp.S-15 and Paenibacillus sp.S-17 as experimental strains.After cell disruption,NH4OAc extraction,H2O2 solution digestion or without any pre-treatment,K+ content in the fermentation broth of potassium solubilizing bacteria was determined with flame photometer.The efficiency of K solubilizing by potassium solubilizing bacteria in the culture medium was calculated.The results showed that the standard curves of the three kinds of K series of standard solutions were similar with the R2 values of 0.994 4,0.999 7 and 0.999 8,respectively.After digested by H2O2 solution,concentration of K+ was detected.The efficiency of two strains was 101.1% and 125.1%,significantly higher than that of other groups.The efficiency of potassium solubilizing detected after H2O2 digestion well reflected potassium solubilization of bacteria.
2014,33(2):15-21, DOI: 1000-2421（2014）02-0015-07
Abstract:
Teosinte is the ancestor of maize,and plays an important role in maize domestication process and gene cloning.Solexa RNA-Seq was used to de novo assembly and analyze the transcriptome of teosintes.40.6 GB raw data were produced,including 175 101 250 reads of 76 bp length.After quality control and de novo assembly,58 147 teosinte transcripts with an average length of 1 335 bp were obtained.After bioinformatically comparing,it was found that 94.3% of teosinte transcripts had good matching with B73 cDNAs,and that 84.1% of the transcript had good matching with rice,84.6% with sorghum and 83.9% with brachypodium at protein level.This research will provide a reference for subsequent studies on maize evolution and gene discovery.
Teosinte is the ancestor of maize,and plays an important role in maize domestication process and gene cloning.Solexa RNA-Seq was used to de novo assembly and analyze the transcriptome of teosintes.40.6 GB raw data were produced,including 175 101 250 reads of 76 bp length.After quality control and de novo assembly,58 147 teosinte transcripts with an average length of 1 335 bp were obtained.After bioinformatically comparing,it was found that 94.3% of teosinte transcripts had good matching with B73 cDNAs,and that 84.1% of the transcript had good matching with rice,84.6% with sorghum and 83.9% with brachypodium at protein level.This research will provide a reference for subsequent studies on maize evolution and gene discovery.
Abstract:
The development of Golden Rice to date has taken longer than anticipated.It has been proven to have the potential to assist in the alleviation of an important public health problem,vitamin A deficiency,affecting millions.Complying with the highly precautionary,and now proven unnecessary,UN Cartagena Protocol for Biosafety has impeded scientific progress and scientific collaboration,particularly by delaying the selection of phenotypes grown in the open field.So far therefore,Golden Rice has not been able to assist in combatting vitamin A deficiency,identified by the UN as an important public health target for 25 years,and which continues to cause preventable deaths and blindness.However,the inventor’s original vision of the donation of the technology to assist the resource poor who want to benefit from it remains firm and achievable,subject to continuing philanthropic and public sector funding.
The development of Golden Rice to date has taken longer than anticipated.It has been proven to have the potential to assist in the alleviation of an important public health problem,vitamin A deficiency,affecting millions.Complying with the highly precautionary,and now proven unnecessary,UN Cartagena Protocol for Biosafety has impeded scientific progress and scientific collaboration,particularly by delaying the selection of phenotypes grown in the open field.So far therefore,Golden Rice has not been able to assist in combatting vitamin A deficiency,identified by the UN as an important public health target for 25 years,and which continues to cause preventable deaths and blindness.However,the inventor’s original vision of the donation of the technology to assist the resource poor who want to benefit from it remains firm and achievable,subject to continuing philanthropic and public sector funding.
2014,33(01):12-17, DOI: 1000-2421（2014）01-0012-06
Abstract:
Seventeen pairs of SSR primers with clear polymorphic bands were screened from 60 pairs of SSR locus covering 17 linkage groups of pear genetic map and amplified with 20 pear cultivars.136 polymorphic bands in total were obtained with 5~11 bands per primer locus (8.0 bands on average).The polymorphism information content (PIC) of the 17 SSR loci ranged from 0.614 to 0.848 with an average of 0.733.All pear cultivars studied could be identified with 38 different combinations of 2 markers each.Bands amplified by each marker were coded based on size of fragment and used as a molecular ID.
Seventeen pairs of SSR primers with clear polymorphic bands were screened from 60 pairs of SSR locus covering 17 linkage groups of pear genetic map and amplified with 20 pear cultivars.136 polymorphic bands in total were obtained with 5~11 bands per primer locus (8.0 bands on average).The polymorphism information content (PIC) of the 17 SSR loci ranged from 0.614 to 0.848 with an average of 0.733.All pear cultivars studied could be identified with 38 different combinations of 2 markers each.Bands amplified by each marker were coded based on size of fragment and used as a molecular ID.
Abstract:
Soil salinity is a major environmental constraint to agricultural productivity.It is a complex network for plant adaptation to salt stress,and it is still a great challenge to improve crop salt tolerance.Mechanisms of SOS signal transduction pathway on Na+ exclusion and compartmentation,the regulation of microRNA and transcription factors involved in salt stress were reviewed.It will provide a fundamental understanding and knowledge for studying salt resistance and breeding salt tolerance in plants.
Soil salinity is a major environmental constraint to agricultural productivity.It is a complex network for plant adaptation to salt stress,and it is still a great challenge to improve crop salt tolerance.Mechanisms of SOS signal transduction pathway on Na+ exclusion and compartmentation,the regulation of microRNA and transcription factors involved in salt stress were reviewed.It will provide a fundamental understanding and knowledge for studying salt resistance and breeding salt tolerance in plants.
2011,30(4):488-493, DOI: 1000-2421（2011）04-0488-06
Abstract:
The morphological variations and discriminant methods of Channa argus (♂)，C.maculata (♀) and their hybrid were studied using traditional morphometrics and the truss network analysis.Body color of C.argus,C.maculata and their hybrid were observed.The results showed significant differences between C.argus and C.maculata from stripe at top of head,side and base of caudal fin,and the hybrid resembled C.maculata from body color.Among eleven meristic characters,the numbers of soft ray of pelvic fin were consistent in these three species,and the numbers of soft ray of pectoral fin deviated from its male parent’s species.The other meristic characters were within the range of its parent’s,the average hybrid index was calculated to be 53.45.The chi-square analysis of meristic characters showed that:there were significant differences(P<0.05) or greater significant differences(P<0.01) between C.argus and C.maculata except the number of pectoral fin rays; greater significant differences(P<0.01) between C.argus and the hybrid except the number of tail fin rays,gill rakers,lateral line scales and scales below lateral line; and significant differences(P<0.05) or greater significant differences(P<0.01) between C.maculata and the hybrid except the number of tail fin rays and gill rakers.Among meristic characters,the number of dorsal fin rays,lateral line scales and scales above lateral line can be used as preliminary indicators to determine the three species.Among ten measurable characters,the average hybrid index was calculated to be 73.90,indicating the measurable character inclined to its male parent’s species (C.argus).Cluster analysis,discriminant analysis and principal component analysis were applied to the measurable character data and the truss network data.The results indicated that the hybrid resembled C.argus from body shape,and there were greater morphological differences among C.argus,C.maculata and their hybrid.Differences between them involved the entire body.Three species could be distinguished by using the 3 formulae established with discriminant analysis which the discrimination accuracy was 100.0%.
The morphological variations and discriminant methods of Channa argus (♂)，C.maculata (♀) and their hybrid were studied using traditional morphometrics and the truss network analysis.Body color of C.argus,C.maculata and their hybrid were observed.The results showed significant differences between C.argus and C.maculata from stripe at top of head,side and base of caudal fin,and the hybrid resembled C.maculata from body color.Among eleven meristic characters,the numbers of soft ray of pelvic fin were consistent in these three species,and the numbers of soft ray of pectoral fin deviated from its male parent’s species.The other meristic characters were within the range of its parent’s,the average hybrid index was calculated to be 53.45.The chi-square analysis of meristic characters showed that:there were significant differences(P<0.05) or greater significant differences(P<0.01) between C.argus and C.maculata except the number of pectoral fin rays; greater significant differences(P<0.01) between C.argus and the hybrid except the number of tail fin rays,gill rakers,lateral line scales and scales below lateral line; and significant differences(P<0.05) or greater significant differences(P<0.01) between C.maculata and the hybrid except the number of tail fin rays and gill rakers.Among meristic characters,the number of dorsal fin rays,lateral line scales and scales above lateral line can be used as preliminary indicators to determine the three species.Among ten measurable characters,the average hybrid index was calculated to be 73.90,indicating the measurable character inclined to its male parent’s species (C.argus).Cluster analysis,discriminant analysis and principal component analysis were applied to the measurable character data and the truss network data.The results indicated that the hybrid resembled C.argus from body shape,and there were greater morphological differences among C.argus,C.maculata and their hybrid.Differences between them involved the entire body.Three species could be distinguished by using the 3 formulae established with discriminant analysis which the discrimination accuracy was 100.0%.
2011,30(5):613-617, DOI: 1000-2421（2011）05-0613-05
Abstract:
Pot experiment was conducted to study the effects of spraying different micronutrients and amino acids into the surface of leaves on yield and quality of Chinese cabbage (Brassica rapa L.).The results showed that methionine,zinc,molybdenum,boron and glycine could increase yield of Chinese cabbage.The treatments of spraying methionine,zinc and molybdenum increased yield of Chinese cabbage significantly.All treatments could reduce the nitrate content of Chinese cabbage with the highest decrease of 35.0% compared with the control.Molybdenum,boron,zinc and methionine might reduce nitrate content of Chinese cabbage significantly.Experiment also indicated that glycine,proline and selenium could both increase the contents of vitamin C,soluble sugar and soluble protein of Chinese cabbage.Therefore,spraying micronutrient or amino acids into the surface of leaves is a good application for increasing yield,reducing nitrate content and improving quality of Chinese cabbage.
Pot experiment was conducted to study the effects of spraying different micronutrients and amino acids into the surface of leaves on yield and quality of Chinese cabbage (Brassica rapa L.).The results showed that methionine,zinc,molybdenum,boron and glycine could increase yield of Chinese cabbage.The treatments of spraying methionine,zinc and molybdenum increased yield of Chinese cabbage significantly.All treatments could reduce the nitrate content of Chinese cabbage with the highest decrease of 35.0% compared with the control.Molybdenum,boron,zinc and methionine might reduce nitrate content of Chinese cabbage significantly.Experiment also indicated that glycine,proline and selenium could both increase the contents of vitamin C,soluble sugar and soluble protein of Chinese cabbage.Therefore,spraying micronutrient or amino acids into the surface of leaves is a good application for increasing yield,reducing nitrate content and improving quality of Chinese cabbage.
2014,33(2):96-102, DOI: 1000-2421（2014）02-0096-07
Abstract:
A 90-day study was conducted to investigate effects of dietary lipid levels on performance,fat deposition,activity and expression of lipoprotein lipase (LPL) in GIFT tilapia (Oreochromis niloticus) juvenile,and to explore the correlation between LPL gene expression and fat deposition.315 GIFT tilapia juveniles(average weight 2.63±0.16 g) were randomly divided into three groups with three replications,and fed with isonitrogenous diets with different lipid levels of 3.7% (low-lipid group),7.7%(middle-lipid group)and 16.6% (high-lipid group) by supplementing with 2%,6% and 15% fish oil as lipid source,respectively.The results showed:(1) the hepatosomatic index (HSI),viscerosomatic index (VSI) and lipid contents in liver and muscle increased with increasing dietary lipid level(P＜0.05),but there was a trends for condition factor (CF) with first increased then decreased (P＞0.05); (2)with increasing dietary lipid levels, the weight gain (WG) first increased, then decreased, and feed conversion ratio (FCR) decreased(P＜0.05); (3)LPL gene was expressed in liver and muscle of GIFT tilapia,while the expression level in liver was significantly higher than that in muscle (P＜0.05); (4) during the 48 h post-refeeding period,liver LPL activity in high-lipid group was significantly higher than that in low-lipid and middle-lipid group at 6 h,but significantly lower than that in low-lipid group at the 12 h,24 h and 48 h.There was a trend in low-lipid and middle-lipid group that liver LPL activity increased first and then decreased; (5) the expression of LPL was significantly higher in high-lipid group than that in low-lipid group (P＜0.05); (6) there were a significant linear positive correlation between HSI,lipid contents in liver and muscle,and liver LPL expression in GIFT tilapia juvenile.The results indicated that LPL expression in GIFT tilapia was in a tissue specific pattern and liver was the main organ for secretion and expression of LPL; high dietary lipid level could inhibit growth of GIFT tilapia juvenile,decrease feed conversion ratio,induce the expression of LPL in liver,and promote fat deposition in liver and muscle; liver LPL expression was involved in fat deposition of GIFT tilapia juvenile.
A 90-day study was conducted to investigate effects of dietary lipid levels on performance,fat deposition,activity and expression of lipoprotein lipase (LPL) in GIFT tilapia (Oreochromis niloticus) juvenile,and to explore the correlation between LPL gene expression and fat deposition.315 GIFT tilapia juveniles(average weight 2.63±0.16 g) were randomly divided into three groups with three replications,and fed with isonitrogenous diets with different lipid levels of 3.7% (low-lipid group),7.7%(middle-lipid group)and 16.6% (high-lipid group) by supplementing with 2%,6% and 15% fish oil as lipid source,respectively.The results showed:(1) the hepatosomatic index (HSI),viscerosomatic index (VSI) and lipid contents in liver and muscle increased with increasing dietary lipid level(P＜0.05),but there was a trends for condition factor (CF) with first increased then decreased (P＞0.05); (2)with increasing dietary lipid levels, the weight gain (WG) first increased, then decreased, and feed conversion ratio (FCR) decreased(P＜0.05); (3)LPL gene was expressed in liver and muscle of GIFT tilapia,while the expression level in liver was significantly higher than that in muscle (P＜0.05); (4) during the 48 h post-refeeding period,liver LPL activity in high-lipid group was significantly higher than that in low-lipid and middle-lipid group at 6 h,but significantly lower than that in low-lipid group at the 12 h,24 h and 48 h.There was a trend in low-lipid and middle-lipid group that liver LPL activity increased first and then decreased; (5) the expression of LPL was significantly higher in high-lipid group than that in low-lipid group (P＜0.05); (6) there were a significant linear positive correlation between HSI,lipid contents in liver and muscle,and liver LPL expression in GIFT tilapia juvenile.The results indicated that LPL expression in GIFT tilapia was in a tissue specific pattern and liver was the main organ for secretion and expression of LPL; high dietary lipid level could inhibit growth of GIFT tilapia juvenile,decrease feed conversion ratio,induce the expression of LPL in liver,and promote fat deposition in liver and muscle; liver LPL expression was involved in fat deposition of GIFT tilapia juvenile.
2010,29(3):363-368, DOI: 1000-2421(2010)03-0363-06
Abstract:
The index of heat injury and leaf anatomical structure under the scanning electron microscope of six Primula species were measured to study the responsive mechanism of Primula to the high temperature and to select the heat resistant Primula species.The results showed that Primula forrestii and P.malacoides franch had higher heat-resistance than that of P.obconica,P.veris,P.saxatilis,P.denticulatess.,P.sinodenticulata with lowest heat-resistance.Leaf anatomical structures of Primula associated with heat-resistance included leaf thickness,tightness of mesophyll cell arrangement,the number of open stomata,the number of epidermal hair and powders of leaves.
The index of heat injury and leaf anatomical structure under the scanning electron microscope of six Primula species were measured to study the responsive mechanism of Primula to the high temperature and to select the heat resistant Primula species.The results showed that Primula forrestii and P.malacoides franch had higher heat-resistance than that of P.obconica,P.veris,P.saxatilis,P.denticulatess.,P.sinodenticulata with lowest heat-resistance.Leaf anatomical structures of Primula associated with heat-resistance included leaf thickness,tightness of mesophyll cell arrangement,the number of open stomata,the number of epidermal hair and powders of leaves.
2010,29(6):798-804, DOI: 1000-2421（2010）06-0798-07
Abstract:
The cracking of fruit skin and the splitting of underlying flesh is a kind of fruit physiological disorder,which downgrades the fruit appearance quality and causes the infection of disease,thereby reducing the commercial value and resulting in serious economic loss.Herein recent studies on fruit cracking were reviewed,mainly focusing on the influence of phenotypic characteristics,genetic factor,physiological characters,mineral nutrients,environmental conditions,plant growth regulators and cultivation practices.The prospect of research was discussed.
The cracking of fruit skin and the splitting of underlying flesh is a kind of fruit physiological disorder,which downgrades the fruit appearance quality and causes the infection of disease,thereby reducing the commercial value and resulting in serious economic loss.Herein recent studies on fruit cracking were reviewed,mainly focusing on the influence of phenotypic characteristics,genetic factor,physiological characters,mineral nutrients,environmental conditions,plant growth regulators and cultivation practices.The prospect of research was discussed.
More+
News & AnnouncementMore+
About UsMore+
- ·Aim and Scope07-23
- ·About the Editors07-23
- ·Editorials Board07-23
Introduction of
the journal
More+
Periodical information
- Supervisor:
Huazhong A gricultural University
- Unit:
Huazhong A gricultural University
- Chief Editor：
ZHANG Xianlong
- Edited and:
Editorial Department of Journal of Huazhong
- Address:
No.1 Shizishan Street,Hongshan District,Wuhan, Hubei,China
- Tel：
027-87287364
- E-mail:
hnlkxb@mail.hzau.edu.cn
- Domestic distribution:
Wuhan post office
- Domestic order:
Post offices all over the country
- Overseas Distributort:
China International Book Trading Corporation(P.O.Box 399,Beijing 100044,China)
- ISSN:
1000-2421
- CN:
42-1181/S
- Postal code:
38-120
- Unit Price:
20.00
- Frequency ：
Bimonthly
WeChat
Access statistics
- Today's visits:
- Total visits: