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    2021(1):1-11                                                                                                                
    Abstract:
    Carotenoids and anthocyanins are antioxidant metabolites,which play an important role in the resistance of plants to photooxidative stress and contribute to the color of leaves,flowers,and fruits at the same time. The rich color metabolites of fruits are beneficial to human health. This article summarizes the effects of light signals on the biosynthetic metabolic pathways of plant carotenoids and anthocyanins,focusing on the regulatory mechanisms of important transcription factors involved in the light signal pathways of genes for synthesizing carotenoid and anthocyanin,and clarifies a significant role for light signals and photoreceptors in mediating the regulation of carotenoids and anthocyanins biosynthesis. Using sweet orange (Citrus sinensis) as an example,the light response elements of carotenoid and anthocyanin biosynthetic genes were analyzed. The major transcription factors including HY5(elongated hypocotyl 5),BBXs(B BOX containing proteins),COP1(constitutively photomorphogenic 1),PIFs(phytochrome interacting factors),and HY5 BBXs complexes,HY5 PIFs complexes,HY5 PIFs BBXs complexes,HY5 COP1 BBXs complexes that participate in these pathways are summarized. It provides an insight into the regulatory mechanism underlying of HY5,BBXs,COP1,PIFs mediated carotenoids and anthocyanins accumulation. Understanding the crucial role of the transcription regulation of carotenoid and anthocyanin mediated by light may help us to explore effective pathways and target genes for improving fruit quality and increasing the accumulation of carotenoid and anthocyanin via genetic engineering and environmental treatments.
    2021(1):12-21                                                                                                                
    Abstract:
    Nitrogen (N),phosphorus (P),potassium (K),calcium (Ca) and magnesium (Mg) are the mineral nutrients that citrus needs in large number. Insufficient fertilization is not conducive to the growth and development of citrus,nor is it conducive to high yield and quality of fruit. However,with the rapid development of the citrus industry,the application of N,P,K fertilizers have gradually changed from insufficient amounts to generally excessive amounts,which has become a key incentive for the low yield and declining quality of citrus in China. In this paper,the relationships between the yield and quality of citrus fruit and usage of fertilizer were analyzed. It was put forward that the quantification and adjustment of N,P,K rations has become the most urgent practical need. The proper usage is both the high yield and the high quality of citrus fruit. The methods of fertilization and usages of fertilizer for citrus recommended at home and abroad are summarized and compared. A method named as the “determining amount of fertilizer by fruit nutrients removal” method for usage of fertilizer based on the amount of nutrients removal per unit fruit yield and target yield of citrus is proposed. It will be of great significance for guiding citrus production in China.
    2021(1):22-31                                                                                                                
    Abstract:
    Granulation is a physiological disorder of citrus fruits,which causes juice sac crystallization,reduction of juice,loss of sugar and organic acid,and seriously affects the edible and commercial value of citrus fruits. In this article,the physiological and molecular mechanism in the granulation of citrus fruit is expounded from aspects of cytology,quality and nutrition of fruit,hormone levels,activities of enzymes and molecular biology. It will lay a foundation for further studying the mechanism and control measures in the granulation of citrus fruit.
    2021(1):32-39                                                                                                                
    Abstract:
    Flavor is an important factor that determines the overall quality of citrus fruit and directly affects consumers’ purchase intentions. Flavoromics is an omics technology to analyze the metabolites basis of flavor quality. The citrus flavor contains many attributes such as sweetness,sourness,aroma,bitterness,texture and off flavor. This article reviews and prospects the origination,strategies,methods and progress of studying citrus flavoromics. It is proposed that the focus of citrus flavoromics should pay more attention to consumer preference and discover the most important metabolites affecting citrus flavor,with a view to targeted cultivation or using cultivation techniques to enhance and improve the quality of citrus fruits in production,and promote the healthy development of the industry.
    2021(1):40-48                                                                                                                
    Abstract:
    Citrus juice is rich in various minerals and vitamins and has high nutritional value. However,the debittering in citrus juice has always been a main problem faced by the industry of processing citrus. A small amount of bitterness can provide a specific flavor for citrus juice,but the strong bitterness will affect the quality and sales of citrus products. We overviews the biochemical properties,structure,enzymes involved in the catabolic pathway of naringin causing the ‘immediate’ bitterness and limonin causing ‘delayed’ bitterness of citrus juice. It discusses the progress of different physical chemistry and biotechnology of debittering in recent years. The mechanism,advantages and disadvantages of corresponding debittering methods are briefly described. The development trend of debittering technology in citrus juice is prospected.
    2021(1):49-57                                                                                                                
    Abstract:
    Huanglongbing (HLB) is one of the most devastating disease of citrus worldwide,which has caused huge economic losses.It is caused by phloem limited bacteria Candidatus liberibacters ,and disseminated in orchards by Diaphorina citri (Kuwayama) .At present,the main prevention methods of HLB disease are as follows:first,the traditional “three axes” prevention and controlling strategy,namely,planting pathogen free citrus,removing the infected plants,and large scale successive killing of psylla; second,drug control,mainly including antibiotic drugs,narrow E44spectrum targeted drugs,immune inducers,nano agents and other antibacterial agents.This review systematically discusses the development on drug control of citrus HLB at home and abroad,hoping to provide theoretical basis and reference for the research and development of new drug for citrus HLB.
    2021(1):58-69                                                                                                                
    Abstract:
    In order to further promote the in depth study on citrus industry economy at the stage of new development in China, this article divides studies on citrus industry economy in China into three stages including initial development (before 1999), steady development (1999-2007) and rapid development (2007 to present). The development process of researching on citrus industry economy in China at each stage is reviewed. The main domestic research achievements are comprehensively summed up from four aspects including production and industrial technology economy, consumption circulation and market, foreign trade and international trade, and industrial macro development and policies. Results showed that the studies on citrus industry economy in China mainly concentrated in aspects including technical and economic analysis, market price analysis, international trade competitiveness analysis and industrial macro development. By combining theory with practice and the continuing in depth study, the team researching on cirtus industry economy in China continues to grow and the achievements are more abundant. The in depth areas to be studied in the future include the transformation and upgrading path of citrus industry to improve quality and efficiency, the adaptability of supply and demand, the environment and policies of international trade, construction of citrus industry economic database and early warning and forecast for production and sales.
    2021(1):70-76                                                                                                                
    Abstract:
    Six treatments including 70% reduction in phosphorus combined without zinc fertilizer,70% reduction in phosphorus combined with zinc fertilizer,35% reduction in phosphorus combined without zinc fertilizer,35% reduction in phosphorus combined with zinc fertilizer,the habitual amount of phosphorus combined without zinc fertilizer,the habitual amount of phosphorus combined with zinc fertilizer were set up in the white flesh Guanxi pomelo in Pinghe area to investigate the effects of phosphorus reduction combined with zinc foliar fertilizer on the yield and quality of Guanxi pomelo fruit in Pinghe County. The nitrogen,phosphorus and potash fertilizers were orderly applied at the period of flowering (mid March),steady fruiting (mid May),filling fruiting (late July or early August) and wintering (late November). Foliar zinc fertilizer sprayed during the period of flowering (mid March) and filling fruiting (late July or early August). Results showed that reducing the amount of phosphate fertilizer increased fruit yield and improved fruit quality. When phosphate fertilizer is reduced by 35%,the fruit yield is increased significantly,and the weight of single fruit and thick skin is significantly reduced. The content of vitamin C,solid acid ratio and other indicators are increased. 35% reduction in phosphorus combined with zinc fertilizer significantly increased fruit yield,comprehensive quality score,fruit juice rate,water content and vitamin C content. Results of field test showed that phosphate fertilizer can be reduced by 35% in Pinghe Guanxi pomelo orchard. Phosphate fertilizer reduction by 35% combined with zinc fertilizer can significantly increase fruit yield and improve fruit quality. The fertilization rate recommended is phosphate fertilizer (P2O5) 0.85 kg/(plant·a),two sprays of 0.2% zinc fertilizer (ZnSO4·7H2O) 40 g/( plant·a).
    2021(1):77-85                                                                                                                
    Abstract:
    Orange slice is product of dried citrus. Because of its medicinal value and convenience,consumers favor orange slice. Orange slices are easy to be brown in the drying process. In order to better maintain the color of orange slices during processing,the effects of five different color fixatives including ascorbic acid,citric acid,L-E50cysteine,sodium sulfite and β cyclodextrin on browning of orange juice and orange pomace were studied. Different ultrasonic power (300 W,400 W,500W) was used to pretreat and then treated with color fixatives. The product was baked at 70 ℃ for 8 h,and its color was determined every 1 h to explore the best treatment conditions for anti browning. The contents of vitamin C and reducing sugar in orange juice and orange pomace were determined by titration. The results showed that the vitamin C in orange juice and pomace was oxidized and degraded with the extension of drying time,and the content of reducing sugar increased slightly. The browning degree was inhibited to some extent after adding color protecting agents. 0.20% sodium sulfite treatment had the best anti browning effect when the color fixatives was treated alone. Combined with ultrasonic pretreatment,the optimal anti browning effect on orange juice and pomace was 400 W ultrasonic power combined with 0.20% sodium sulfite,which was confirmed on orange segments to have the most obvious anti browning under this condition.
    2021(1):86-92                                                                                                                
    Abstract:
    Content of citrus is one of the important factors affecting storage and processing of citrus. Real time detection of water content of citrus can guarantee the quality of citrus. The visible/near infrared spectroscopy technology,as an increasingly mature non destructive testing method,can effectively detect the water content of citrus. The Satsuma mandarin picked from the Institute of Forest and Fruit at Wuhan Academy of Agricultural Sciences were placed naturally at room temperature for reducing the water content of the Satsuma mandarin and increasing the water content gradient of the citrus. A spectrum collection device was built with Maya2000pro as a carrier. The score is obtained by dewatering in a super electric heating constant temperature blast drying oven and calculated according to GB 5009.3-2016. The fitting accuracy of partial least squares regression (PLS) model established was compared through the use of differential processing,multivariate scattering correction,standard normal variate,SG convolution smoothing,standardization and other pretreatment methods. Results showed that SNV was the most effective preprocessing method. At the same time,a competitive adaptive reweighted sampling algorithm is used to extract characteristic wavelengths to establish a partial least square regression model,a BP neural network model and a least square support vector machine model based on water content of citrus. The results showed that the LSSVM model established with 359 wavelengths obtained by CARS screening using the spectrum after SNV preprocessing had the best prediction effect. The correlation coefficient and root mean square error of the calibration set are 0.937 5 and 0.008 6,respectively. The correlation coefficient of the verification set and the root mean square error are 0.831 6 and 0.012 0. The natural placement method at room temperature improves the water content gradient of Satsuma mandarin,thereby ensuring the adaptability of the model. It is indicated that the visible/near infrared spectroscopy technology is feasible for detecting the water content of Satsuma mandarin.
    2021(1):93-98                                                                                                                
    Abstract:
    A pathogenic bacterium was isolated from the diseased Procambarus clarkiin Qianjiang,Hubei Province.The strain was identified by physiological and biochemical assay,16S rRNA sequencing and phylogenetic analysis.Then susceptibility of the strain to antibiotics was performed by the agar diffusion method,and the minimum inhibitory concentrations (MICs) were evaluated by the micro dilution method.The results showed that the physiological and biochemical characteristics of the isolated strain were similar to that of Klebsiella pheumonia.The 16S rRNA sequencing and phylogenetic analysis showed that the 16S rRNA sequence of the strain shared over 99% similarities with that of K. pheumonia.Therefore,the strain was identified as K.pheumonia.According to the susceptibility results,the strain was sensitive to cefotaxime and polymyxin B among all the tested antibiotics.These results above indicated that the strain was a multi resistant K. pheumonia strain.
    2021(1):99-104                                                                                                                
    Abstract:
    A pathogenic bacterium was obtained from the hepatopancreas of diseased Procambarus clarkii.The isolated strain was determined by physiological and biochemical analysis,16S rRNA sequencing and phylogenetic analysis.Then the sensitivity of the strain to 20 kinds of antibiotics and synergistic effects of antibiotics combined with natural compounds were determined by the agar diffusion method and checkerboard assay.The results showed that physiological and biochemical characters of the isolate were similar to that of Morganella morganii,and 16S rRNA sequence determination and phylogenetic analysis showed that the isolate sequence shared over 99% similarity to that of M. morganii.Taken together,the strain was identified as an M. morganii strain.The susceptibility study showed that the strain was sensitive to enrofloxacin,florfenicol,neomycin and other 4 kinds of antibiotics,and moderate sensitive to kanamycin,resistant to doxycycline,streptomycin,tetracycline and other 9 kinds of antibiotics.Moreover,the synergistic susceptibility showed that doxycycline combined with dihydrocapsaicin had synergistic effect.Taken together,the results demonstrated that the strain isolated from the hepatopancreas of diseased P. clarkii is a resistant M. organii.Florfenicol,enrofloxacin,neomycin and doxycycline combined with dihydrocapsaicin can be chosen as candidates for treatment of M. morgani infections.
    2021(1):105-111                                                                                                                
    Abstract:
    In order to evaluate the safety of imidacloprid to Procambarus clarkii,indoor exposure test and field residual elimination test were carried out,at the recommended mass concentration of 0.2 mg/L. Samples of P. clarkii,paddy mud and field water were collected separately to study the enrichment and residue elimination of imidacloprid in integrated rice and P. clarkii breeding model. The results showed that the order of imidacloprid accumulation in P. clarkii indoor exposure was gill>muscle>hemolymph>intestine>hepatopancreas. In the field residual test,the order of imidacloprid accumulation in P. clarkii was muscle>intestine>gill tissue>hemolymph>hepatopancreas. At the same time,it was found that 28 days after field application,the imidacloprid residue in the muscle tissue was 20.44 μg/kg, the degradation rate of imidacloprid in paddy field water was 97.54%,and the residual amount in the sediment was 10.94 μg/kg. Therefore,in order to avoid harm to the non target biological aquatic product-P. clarkii,it is recommended that the application interval of imidacloprid in rice fields should be properly extend,and in rice fields close to the cultured water,especially in the integrated cultivation mode of rice and shrimp,drugs should be applied cautiously or use other alternative.
    2021(1):112-119                                                                                                                
    Abstract:
    In this experiment,at 18℃ and 2 ℃,enrofloxacin was injected at a dose of 20 μg/kg to study the pharmacokinetics characteristics and residues of enrofloxacin and ciprofloxacin in Procambarus clarkii.The results showed that the recovery rates of enrofloxacin and ciprofloxacin in the hemolymph,muscle,hepatopancreas and pancreas were from 80% to 110%.The intra day variation coefficients of the detection values were less than 5%,and the inter day variation coefficients were less than 6%.The detection limits were all below 0.01 μg/mL (μg/g).The Tmax of enrofloxacin in the hemolymph,muscle,hepatopancreas at 18℃ was 0.083 0 h,0.344 7 h,and 1.933 5 h,respectively,and the Tmax of ciprofloxacin was 0.083 0 h,0.263 4 h,and 1.165 8 h,respectively.Increasing the temperature accelerated the absorption of enrofloxacin in P.clacherii.The order of elimination half life T1/2β was hepatopancreas (55.740 3 h)> muscle (52.743 7 h)> plasma (18.608 7 h).With enrofloxacin and ciprofloxacin as residual markers,the elimination period of enrofloxacin in the hepatopancreas and pancreas was 311.47 h at 25℃,and the elimination period of enrofloxacin in hepatopancreas and pancreas was 417.77 h at 18℃.It is recommended that the enrofloxacin withdrawal period is 325 (℃·d).
    2021(1):120-128                                                                                                                
    Abstract:
    In order to explore the function and molecular mechanism of sex-lethal gene in Procambarus clarkii,four Sxl cDNA sequences from P. clarkii were obtained using rapid amplification of cDNA ends,and their expression in different tissues and at early developmental stages were detected by quantitative fluorescence PCR. Bioinformatics analyses revealed that PcSxlβ and PcSxlδ were 77 bp longer than PcSxlγ,and the predicted amino acid sequence of PcSxlβ and PcSxlδ were shorter than that of PcSxlγ. The PcSxl sequences was highly similar to that of Cherax quadricarinatus (75.76%). The analysis of conservative domain showed that all the predicted amino acid sequences of the four transcriptional isomers had two highly conservative RRM domains. The expression analyses showed that PcSxl was highly expressed in the antennal glands and gills of adult males,and in the midgut and foregut of adult females,and was significantly higher in the female ovaries than the male testis. During the early developmental period of the crayfish,the expression of the genes was the highest at the nauplius stage,but decreased at the zoea stage; however,the expression level increased at the first day after hatching,and then showed a gradually decreasing trend. The results of this study suggested that PcSx was involved in sexual differentiation in P. clarki.
    2021(1):129-136                                                                                                                
    Abstract:
    To elucidate the function of the doublesex(PcDsx)gene in Procambarus clarkii ,the PcDsx cDNA sequence was obtained by the rapid amplification of cDNA ends (RACE) and the expression of PcDsx was determined by quantitative real time PCR (qRT-PCR). The results of bioinformatics analysis showed that the full length PcDsx cDNA was 1 584 bp,with a 243 bp 5′ untranslated region,a 765 bp open reading frame (ORF) (coded 254 aa) and a 576 bp 3′ untranslated region. The deduced protein of PcDsx was 254 aa and the predicted PcDsx protein was found to contain a conserved DM domain. Phylogenetic analysis revealed that the PcDsx DM domain share high similarity to the DM domain of Sagmariasus verreauxi doublesex. The gene expression analysis showed that PcDsx was widely expressed in various tissues of the adult crayfish,highest in the antennary glands,followed by the muscle and gonads. The expression of PcDsx in various adult female tissues was significantly different from that in adult male tissues. During the early development of P. clarkii ,the expression level of PcDsx reached a peak at 3 day after hatching,while the highest expression of PcDsx in male and female juveniles appeared at 41 and 115 day after hatching,respectively. Besides,the expression of PcDsx also showed significant differences between male and female juveniles.
    2021(1):137-146                                                                                                                
    Abstract:
    Rapid detection as an efficient and convenient detection method is considered to be an important means to effectively improve food safety detection and clinical diagnosis capabilities. Magnetic relaxation switching (MRS) biosensor has become a new method and new tool for rapid detection due to its excellent analytical performance and simple analysis process. The development of MRS biosensor began with the discovery of magnetic relaxation. When the state (dispersion or aggregation) of superparamagnetic nanoparticles changes in aqueous solution,the uniformity of its local magnetic field can be changed to form a non uniform local magnetic field followed by a transverse relaxation speed acceleration of the surrounding water molecules and shortening of the transverse relaxation time. Based on this principle,different biomolecular recognition elements including antibody,enzyme,nucleic acid can be used to assemble MRS biosensor for rapid detection of targets. MRS biosensors can be mainly classified into four types: (1) Magnetic nanoparticles-mediated MRS biosensors,which contain the MRS biosensors based on the state change of magnetic nanoparticles; (2) MRS biosensors based on the number change of magnetic nanoparticles ; (3) MRS biosensors based on the state and number changes of magnetic nanoparticles; (4) Paramagnetic ion mediated MRS biosensors,a novel MRS biosensors based on the spatial dipole dipole interactions between paramagnetic ions (contain multi unpaired electrons) and hydrogen protons. Combined with portable miniature NMR instrument,MRS biosensors can be realized on site quick testing. In this paper,we reviewed the different sensing principles and the progresses of MRS. In addition,we discussed the development and improvement of MRS in the aspects of signal transformation mechanism,the performance of magnetic probe,signal amplification system and biosensor stability. Finally,we discussed the main problems of MRS biosensors. The future development or breakthrough of MRS biosensors in the field of rapid detection was prospected.
    2021(1):147-153                                                                                                                
    Abstract:
    In order to explore the effects of different plant height,center of gravity height and basal stem traits on lodging resistance of rice,10 traits of 533 rice core germplasm under two cultivation modes including pot culture and field culture were analyzed with correlation and path analysis. The results showed that the first internode wall thickness and basal stem breaking resistant strength of the low plant rice had synergy on the lodging index,indicating that improving lodging resistance of low-plant rice should focus on the first internode stem thickness and wall thickness. The lodging of high-plant rice is more affected by plant height and height of gravity center,indicating that improving lodging resistance of high-plant rice should concentrate in the second internode stem thickness. The improvement of lodging resistance of rice germplasm with different plant height can be achieved by enhancing the bending strength of rice basal stem. It will provide an important reference for improving lodging resistance of rice with different plant height.
    2021(1):154-159                                                                                                                
    Abstract:
    The method of isolating and transiently transforming oil palm leaf protoplasts was established. Protoplasts were isolated from leaves of oil palm with 30 g/L cellulase and 8 g/L macerozyme for 3.5 h,and collected by centrifugating at 2 000 r/min for 5 min at 4℃. The dual plasmid transient co expression system was optimized with green fluorescent protein (GFP) and red fluorescent protein (RFP). The best transformation efficiency was the obtained when the plasmids were mixed with oil palm protoplasts with the mass ratio of 8∶1,heat shocked at 45℃ for 20 min after placed on ice for 30 min,and incubated at room temperature under the dark condition for 30 min with equal amount of PEG/Mg2+ (200 g/L PEG 4000 and 100 g/L MgCl2). It will provide a novel method for further identifying the function of the genes from oil palm.
    2021(1):160-167                                                                                                                
    Abstract:
    The contents of heavy metals Cd,Hg,As,Pb,Cr,Cu,Ni and Zn were monitored in the surface soils at 208 monitoring points in the area studied. The environmental baseline values of heavy metals and the cumulative changes of the baseline value relative to the background value were obtained. Based on this,the degree of disturbance of heavy metals in the regional surface soil by human activities can be judged. Standardized methods and relative cumulative frequency statistics were used to acquire the environmental baseline value and deviation of heavy metals in regional surface soil. The average environmental baseline values obtained by these two methods were used as the environmental baseline values of heavy metals in the surface soil of the area studied. The contents of heavy metals Cd,Hg,As,Pb,Cr,Cu,Ni,Zn exceeded the risk screening values for soil contamination of agricultural land of monitoring points in regional surface soil. The ratio of monitoring points was 17.3%,1.0%,4.3%,0.0%,2.4%,3.8%,1.9%,E95and 0.0%,respectively. Compared to the regional background values,the heavy metals had accumulated to different degrees of monitoring points in regional surface soil,and the ratio of monitoring points was 26.9%,26.0%,29.8%,17.3%,16.8%,20.2%,28.4%,and 21.6%,respectively. The mean environmental baseline value of heavy metals Cd,Hg,As,Pb,Cr,Cu,Ni and Zn obtained by the standardized method and the relative cumulative frequency statistics was 0.22 mg/kg,0.09 mg/kg,13.34 mg/kg,30.7 mg/kg,82.0 mg/kg,29.7 mg/kg,38.0 mg/kg and 89.1 mg/kg,with the relative deviation ranged from 0.5% to 12.0%. According to accumulation index of heavy metal,the environmental baseline values of heavy metals Cd,Hg,As,Pb,Cr,Cu,Ni,Zn increased to different degrees relative to the regional background values of the monitoring points in regional surface soil. The increasing change rate was less than 50%,which was not significant. The cumulative index of environmental baseline value of heavy metals Cd,Hg,As,Pb,Cr,Cu,Ni and Zn was 1.5,1.2,1.0,1.1,1.0,1.0,1.0,and 1.0,respectively. Among them,the environmental baseline value of heavy metal Cd is slightly accumulated compared to the regional background value,indicating that the soil heavy metal Cd has been disturbed by a certain degree of human factors,but the impact is small. The heavy metal Hg had slight risk of accumulation,and the heavy metals As,Pb,Cr,Cu,Ni,Zn had no obvious accumulation.
    2021(1):168-178                                                                                                                
    Abstract:
    A field experiment with two treatments including NK (-P) and NPK (+P) was conducted in 2011 to study the effects of long-term application of phosphorus (P) fertilizer on the phosphorus fractions and microbial diversity of rice-rapeseed rotation. The soil layer was divided into 0-10、10-20、20-3+E1070 and 30-40 cm for sampling and analyzing. Soil available P,total P and organic P were determined with conventional analytical methods. Chemical continuous extraction method was used to determine the inorganic P fractions in the soil samples,and Illumina miseqpe 250 platform was used for high-throughput sequencing of surface soil (0-10 cm) microorganisms. The results showed that long-term application of P fertilizer (+P) significantly increased the content of total P,inorganic P and available P in each soil layer compared with the CK (-P treatment),but the organic P content did not increase significantly. P content in soil layer of 0-10 cm and 10-20 cm significantly increased by application of P fertilizer,but the effect on the bottom layer of 20-30 cm and 30-40 cm was not obvious. Compared with -P treatment,long-term application of P fertilizer reduced the alpha of microbial community diversity and changed the structure of microbial community. At the level of phylum,the dominant bacteria were Chloroflexi,Acidobacteria and Proteobacteria. The relative abundance of Chloroflexi and Acidobacteria was increased,while that of Proteobacteria decreased. Ascomycota and Basidiomycota were the dominant phylum,the relative abundance of Ascomycota decreased and that of Basidiomycota increased. Compared with CK,although the application of P fertilizer significantly decreased the number of bacteria and fungi in the layer soil in each taxa,the relative abundance of the dominant flora decreased from the perspective of the genus level. The results of analyzing redundancy showed that the content of Al-P and Fe-P was closely related to the abundance of various bacteria and fungi. It is indicated that long-term phosphorus deficiency induce an increase in the number of microorganisms to activate soil nutrients,and a sufficient supply of phosphorus fertilizer meet crop nutrient requirements and maintain the dynamic balance of soil microbial communities. Therefore,it is necessary to optimize the application of P fertilizer in the entire crop rotation system to promote the activation and release of soil phosphorus,thereby reducing the amount of P fertilizer and improving its recovery rate.
    2021(1):179-186                                                                                                                
    Abstract:
    The effects of soil acidification on soil nutrient availability and plants nutrient uptake,accumulation and distribution were investigated to provide a basis for soil acidification treatment,especially nutrient efficient utilization. Cherry tomatoes (Lycopersivon esculentum Mill) was used to conduct pot experiment with acidic red soil (pH 5.05). The soil pH was adjusted to 4.0,5.0,6.0 and 7.0 with citric acid sodium hydrogen phosphate buffer and sodium carbonate-sodium bicarbonate buffer. There were 4 treatments with 5 replicates per treatment in the experiment. The results showed that measured soil pH were 4.35,4.92,5.89,6.85,adjusted down by 0.70,0.13 and increased by 0.84 and 1.80 pH unit,respectively. Soil acidification significantly reduced the leaf area and biomass of cherry tomato,especially the root biomass,and root to shoot ratio. Soil acidification severely inhibited the accumulation of N,P,K,Mg and Fe in roots,promoted the accumulation and distribution of Fe and Mn in stem,and Ca and Mg in leaves. Soil acidification significantly decreased accumulation of N,P,K,Ca,Mg and Fe in roots. More N,K,Fe and Mn was accumulated in stems,more P,Ca and Mg was accumulated in leaves. Particularly,Mn concentration in all parts of plants was raised significantly. It is indicated that the root is the most severe and sensitive part of whole tomato plant inhibited by soil acidification and most nutrients are absorbed by the roots. Soil acidification blocked migration and reduced accumulation significantly.
    2021(1):187-194                                                                                                                
    Abstract:
    In order to reveal the importance of leaching on mountainous nutrients cycling,the characteristics of altitude distribution of soil C and N in the coniferous forest at an altitude of 2 600-3 200 m on the eastern slope of the Gongga mountain were studied. The soil C,N content and C/N of the conifers at 4 sampling points at different altitudes were analyzed. Combined with other soil physical,chemical and biological indicators,the effects of the leaching process on the characteristics of altitudinal distribution of soil C and N were explored. The results showed that the spatial distributions of C,N contents and C/N in the humified litter horizon (OH horizon) exhibited a similar decreasing trend with the increase of altitude. Since the content of C in litters (Clit) was positively correlated with soil C and N in the OH horizon(P<0.05),the production of Clit was the main factor affecting the altitudinal distributions of soil C and N in the OH horizon. The obvious altitudinal trend was not observed for soil C,N contents and C/N in the mineral horizons (A,B and C horizon). The contents of soil C and N in the A horizon were lower than those in the 2 781 m site,while the maximums were for the B and C horizon in this site. The contents of soil C and N in the rainfall were significantly lower than those in the interflow,which showed the effects of leaching on the spatial distributions of soil C and N. It is indicated that the effects of leaching process on the spatial distributions of soil C and N in subalpine coniferous forest in Southwest Asia can not be ignored.
    2021(1):195-201                                                                                                                
    Abstract:
    The mineralogy and geochemical composition of the cutan and matrix soil in the S5-1 pedon at the Wugong section on the southern Chinese Loess Plateau (CLP) was investigated to provide more insight in the characteristics and environmental significance of the cutan in the S5. The broad band between 400-800 cm-1 in the Raman spectrum of the dark cutan was attributed to the groups of Fe and Mn hydroxide/oxide. Enrichment of Mn and free iron (Fed) in the cutan confirmed the presence of Fe-Mn cutan in the S5-1 pedon which signified a periodic reduction under waterlogged conditions during the pedogenesis of S5-1 pedon on the southern CLP. The low permeability of S5-1 pedon as a result of lessivage of clay fraction characterized by high bulk density and low total porosity made the development of a seasonal perched water table possible. It provided favorable environmental conditions for the formation of Fe-Mn cutan. However,the low Mn/Fe ratio in the cutan indicated that the separation and accumulation of iron and manganese in the S5-1 pedon was not up to the level of typical Fe-Mn cutan from subtropical regions. Silicate minerals in the Fe-Mn cutan was almost identical to the matrix soil. The difference of chemical weathering between the cutan and the matrix soil reflected by the Fed/Fet ratio was not epitomized by the mineralogical composition. The subtropical climate prevailed on the southern CLP during the pedogenesis of S5-1 pedon was further confirmed by the occurrence of Fe-Mn cutan.
    2021(1):202-209                                                                                                                
    Abstract:
    Rice is one of the staple food crops in China and one of the three staple food crops all over the world. The combine harvester has been widely used due to the improved level of rice harvesting mechanization year by year. The longitudinal axial flow threshing and separating device is of widespread use in combine harvester because of its advantages of long threshing time,soft threshing process and good adaptability. However,the device has the disadvantages of high power consumption,broken stalks and high content of impurity. The power consumption of the device plays an important part in the combine harvester. The researches on energy saving and consumption reduction have great significance for developing combine harvester with large feeding capacity,lightweight and high efficiency. In order to reduce the power consumption and blockage of threshing roller,then improve the harvesting efficiency of rice combine harvesters,a new longitudinal axial flow threshing roller with drum-shaped rod-E130tooth was designed based on the idea that the power consumption of the threshing roller can be reduced by improving the uniformity of the longitudinal axial flow threshing roller power consumption along the axial direction. Its structural parameters and motion parameters were determined by analyzing the working principle of the device. The models of power consumption and threshing roller dynamic were established by observing the process of threshing and separation. Based on the EDEM simulation analysis,the instantaneous total torque of rotating shaft of threshing roller with time was simulated and studied with feeding rate of 1.2 kg/s and rotating speed of 1 100 r/min. Taking the total torque of the rotating shaft of the threshing roller as the test index,the performance of the two kinds of rollers was compared with the feeding rate of 0.8 kg/s,1.2 kg/s and 1.6 kg/s. The results showed that the total torque of the rotating shaft of the threshing roller increased with the increase of the feeding rate for the same roller size and motion parameters. When the feeding rate increases from 0.8 kg/s to 1.6 kg/s,the total torque of the drum shaped threshing roller rotating shaft increases from 38.12 N·m to 118.99 N·m,and the cylinder shaped threshing roller increased from 60.13 N·m to 189.91 N·m. Under the same feeding rate,the total torque of rotating shaft of drum shaped threshing roller is lower than that of cylinder shaped threshing roller. The performance testing platform of a small longitudinal axial flow threshing and separating device was designed and built. The power consumption comparison bench test of two kind structures of threshing roller under conditions consistent with the simulation was carried out. The results showed that the power consumption of drum shaped threshing roller and cylinder shaped threshing roller increased from 4.88 kW to 11.20 kW and from 5.58 kW to 12.20 kW in the feeding rate range of 0.8 1.6 kg/s. Compared with the cylinder shaped threshing roller with the same external size,the power consumption of drum shaped threshing roller is lower than that of cylinder shaped threshing roller. The results of bench test and simulation are basically consistent. It will provide a reference for designing the drum structure of the rice low power threshing roller.
    2021(1):210-217                                                                                                                
    Abstract:
    Parameters of physical and mechanical characteristics are indispensable in designing potato minituber related mechanical equipment planter and classifier.Parameters of the contact mechanics are indispensable in developing simulation technology as well.The virus free potato minitubers (referred as “minituber”) including “Daxiyang”,“Zhongshu No.5” and “Huashu No.1” and the relevant parameters required for discrete element software EDEM in potato minituber were used to measure physical parameters and contact mechanical parameters of three kinds of potato minitubers.Self made equipment was used to measure and calculate the triaxial dimensions,weight,radius of curvature,density,Poisson's ratio and shear modulus.The contact mechanical parameters of three kinds of minitubers and three materials (steel plate,ABS and the same variety potato minitubers) including the collision recovery coefficient were measured by using a self-made collision device.The static friction coefficient was measured by using the method of sliding on an inclined plane.The combination of rolling on an inclined plane and high speed photography was used to record the rolling distance and measure the rolling friction coefficient of potato minituber,steel plates or ABS.The response surface method was used to design the test by using coefficient of static friction and coefficient of rolling friction as test variables,and the stacking angle as test index.The parameters measured in the above experiment were input into the EDEM for simulation to obtain coefficient of the rolling friction in minitubers.Using the stacking angle as the response value,and the credibility of the simulation results was verified by raising a round pipe slowly.Results showed that density,shear modulus and Poisson’s ratio had little correlation with the basic parameters of physical characteristics of minitubers.The triaxial dimensions,weight and radius of curvature were quite different.The varieties were different as well.The contact mechanical parameters of the three types of minitubers and their own same variety were lower than those of the steel plate and ABS.The coefficients of static and dynamic friction of the three types of minitubers and ABS were higher than that of the steel plate.The collision recovery coefficient showed the opposite trend.ABS was lower than the steel plate.The contact mechanical parameters of “Daxiyang” were higher than those of “Zhongshu No.5” and “Huashu No.1”.Among the three materials,the contact mechanical parameters with the steel plate were the largest,indicating that its elastic recovery performance is the best,with relatively large friction and relative difficulty to be damaged.The fluidity and the mechanized seeding performance was poor.The difference of contact mechanical parameters between “Zhongshu No.5” and “Huashu No.1” was small.The measurement results of different varieties of minitubers were quite different.Users can select the required parameters in the text according to their needs.The variety should be fully considered in the design and simulation calculations.Compared with the actual accumulation angle of the experiment,the simulation results of different varieties of potato minituber were less than 3%,indicating that the results are reliable and the actual parameters of the minituber particles measured can be used as simulation parameters in the EDEM software.
    2021(1):218-226                                                                                                                
    Abstract:
    Biomass gasification is a technology that converts biomass into gas fuel. However,complex tar compounds will be formed in the process,resulting in reduced gasification efficiency and blockage of downstream equipment. Catalytic steam reforming has been widely used for tar removal. Nickel based steam reforming catalysts have attracted people’s attention due to its high activity and low cost. Among them,deactivation caused by coke deposition is the biggest challenge of this technology. The nickel-based catalyst came into being. The loading of metal Ni in the modified nickel-based catalyst not only affects the activity of the nickel-based catalyst,but also restricts the preparation cost. At present,there is no report on the steam reforming of biomass tar with a catalyst supporting Ni-Mg active components on the by-E143product RHA (rice husk ash,RHA) of biomass pyrolysis in the treatment of tar with nickel-based catalysts. This article introduces a promoter and RHA as a carrier to improve the catalytic performance of the catalyst. It will be of great significance for improving the economic efficiency and anti-coking performance of the catalyst. Biomass combustion product of rice husk ash was selected as the carrier,and Ni-Mg/RHA catalyst was prepared by co-impregnation method. The catalytic performance of Ni-Mg/RHA for steam reforming of toluene was studied using toluene as a model compound of biomass tar. The effects of Ni and Mg loadings,reaction temperature and S/C ratio on toluene conversion and gas product composition were investigated in a fixed-bed reactor. The catalysts before and after reaction were characterized by XRD,BET and SEM. The results showed that RHA as a support of single metal Ni-based catalyst had a certain catalytic activity. Compared with Ni/RHA and Ni/HZSM-5,RHA is a biomass combustion product with small specific surface area and simple pore size structure. In the Ni/RHA catalyst,the active metal is gathered in the outer layer of the catalyst,and there is no porous structure inside. After catalytic reforming of toluene,carbon deposition is easy form to cover the active site,resulting in the low catalytic activity of Ni/RHA catalyst supported by single metal Ni. After adding MgO modification,the catalyst surface area and pore volume was increased and the surface generated porous structure,indicating that the MgO load improved the specific surface area and pore volume of RHA supported catalyst providing more reaction sites for toluene and water vapor. Results of crystal structure analysis showed that after adding MgO style,Ni characteristic peak did not appear on the Ni-Mg/RHA. NiMgO characteristic peak,peak diffraction angle shifted to the left. Because of the interaction between NiO and MgO style,NiMgO crystal phase structure more easily formed under the low degree of diffraction is detected,indicating that MgO style improves the dispersion of active metal Ni and provides NiMgO solid solution activity sites,which improved the catalytic performance. When Mg load was 6%,the performance was the best,with the toluene conversion rate of 98.6%. The optimal reaction temperature of 3Ni-6Mg/RHA catalyst was 700℃ and S/C was 3,having good catalytic stability. The optimal reaction temperature of 3Ni-6Mg/RHA was 700 ℃ and S/C was 3,having good catalytic stability. The feasibility of using rice husk ash as the support of nickel based catalyst in the presence of MgO is confirmed.
    2021(1):227-235                                                                                                                
    Abstract:
    The yield of rice is closely related to the panicle number and the panicle weight of rice. The accurate prediction of rice yield can accelerate the speed of breeding. In order to study the relationship between rice yield and rice phenotypic characteristics,the visible light images combined with image processing technology was used for extracting feature of potted rice. 51 phenotypic traits of whole rice were obtained. Combined with deep learning technology,the Faster R convolutional neural network training model was used to detect the number of rice spikes. At the same time,the SegNet model was trained using the SegNet network framework to segment the rice spikes to obtain the binary image of the rice spikes. 33 phenotypic feature data of the panicle were extracted with image processing technology. A total of 85 phenotypic parameters of color,shape,and texture were extracted,and all 85 data were normalized. The 85 phenotypic data normalized were gradually linearly regressed with the fresh and dry quality of rice panicle,and the correlation was selected. The artificial measurement data in the experiment included the fresh weight and dry weight of potted rice panicle. The models of predicting fresh and dry panicle weight of potted rice were established separately by using panicle number and characteristic panicles,51 characteristics of whole plants and all 85 characteristics of high correlation characteristic data. The prediction model was optimized according to the determination coefficientR2,mean relative error (MAPE) and standard deviation of absolute relative error (SAPE). The optimal prediction model was selected according to the decision coefficient R2,average relative error (MAPE) and standard deviation of relative absolute value (SAPE) of the model. The results of prediction showed that the effect of predicting panicle characteristics is the best. The decision coefficients R2 of the predicted value and the real value of the model with the best effect are 0.787±0.051 and 0.840±0.054,respectively. Combined with deep learning,the number and characteristics of panicle difficult to obtain automatically by traditional methods are extracted. It will provide a new idea and method for predicting rice panicle weight,and further improving the accuracy of predicting rice panicle weight.
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    Abstract:
    BiOI/BiOBr heterojunction composite catalytic material was synthesized by solvothermal method, its degradation ability of rhodamine B was investigated, the photocatalytic performance of the BiOI/BiOBr heterojunction, BiOBr and BiOI was compared. The structure, morphology and optical properties of the samples were characterized by X- ray diffraction(XRD), field emission scanning electron microscopy (FESEM), UV-vis diffuse reflection spectrum (UV-vis DRS), steady-state and transient-state PL spectra. The degradation rate of rhodamine B was analysised by spectrophotometry, the results show that the BiOI/BiOBr heterojunction photocatalytic materials have good degradation ability to 100 mg/L rhodamine B, it showed that the degradation rate of rhodamine B was 100% in forty minutes, which was also significantly higher than the degradation rate of pure BiOBr (80%) and BiOI (72%). The first order kinetic rate constant is was 0.1028 min-1, which are 2.6 and 3 times of BiOBr(0.0403 min-1) and BiOI(0.0344 min-1) respectively. This heterojunction photocatalyst can not only effectively promote the photogenerated charge separation but also maintain the strong redox ability of the composites, which may be the internal reason for the efficient degradation of Rhodamine B by BiOI/BiOBr heterostructures.
                                                                                                                   
    Abstract:
    Objective Six root herbs consist of Subprostrate Sophora, ardisia crispa, rhizoma menispermi, philippine flemingia root, Yunnan bean root, and Yunnan cowpea were identified based on near infrared diffuse reflectance (NIR) spectroscopy. Methods NIR spectra was acquired in the range of 900 to 1700 nm and then combined with principal component analysis (PCA), systematic cluster analysis (SCA), k-nearest neighbor (k-NN), and linear discriminant analysis (LDA) to develop qualitative discriminant models. Results Samples can be well clustered based on PCA and SCA, furthermore, the classification accuracy rate for 46 unknown samples up to 93.48% and 95.65% for k-NN and LDA, respectively. Conclusion Results indicate that NIR coupled with pattern recognition techniques, which is rapid, accurate, and low-cost, has potential to discriminate root herbs.
                                                                                                                   
    Abstract:
    碳基量子点主要包括碳量子点及石墨烯量子点两大类,具有优异的发光性质及良好的生物相容性,在生物分析、细胞成像及医学诊断等领域受到研究者的广泛关注。近年来研究发现,碳基量子点不仅可用于建立高灵敏的病毒检测新方法,而且具碳基量子点,包括球形碳点和石墨烯量子点,是一类新兴的具有良好的生物相容性的光致发光材料,在生物分析、细胞成像及医学诊断等领域受到研究者的广泛关注。近年来研究发现,碳基量子点不仅可用于建立高灵敏的病毒检测新方法,而且具有良好的抗病毒活性。基于此,本论文在简要介绍碳基量子点合成方法和光学性质的基础上,系统总结了碳基量子点在病毒检测及抗病毒领域的研究进展,并对该领域目前存在的问题及未来的发展方向进行了展望。
                                                                                                                   
    Abstract:
    Abstract: To explore the influence of tea leaves with different tenderness on the quality of Qingzhuan tea. Qingzhuan teas were made from 4 different tender tea leaves of Fudingdabai tea tree cultivar. The sensory quality of Qingzhuan teas was evaluated according to the way of sensory evaluation. The main chemicals and aroma components were analyzed by chemical analysis and GC-MS method. The sensory evaluations showed, as the decrease of tenderness, the sensory score of appearance and liquor color decreased while the score of aroma and taste increased. The main quality components analysis showed that, Qingzhuan teas with 1 bud with 1 leaf and 1 bud with 2 or 3 leaves were richer in content of water extract, tea polyphenols, catechins, amino acids and soluble sugars than that of 1 bud with 4 or 5 leaves or pruned leaves. With the decrease of tea leaves tenderness, theaflavin content decreased while fluorine content increased. The total amount of aroma components increased significantly with the increase of raw material maturity. The aroma amount of Qingzhuan tea from 1 bud with 1 leaf was the lowest (12.88) , with the highest percentage of alcohols, next ketones and heteroxygens, as 47.28%, 14.13%, 13.74% and 6.99% respectively; The total aroma of 1 bud with 2 or 3 leaves was 62.43, with the highest percentage of alcohols, next to aldehydes and hydrocarbons, as 36.14%, 19.09% and 14.50% respectively; The total aroma of 1 bud with 4 or 5 leaves was 72.43, with the highest percentage of ketones, then aldehydes and alcohols, as 25.21%, 20.35% and 19.34% respectively; The total aroma of pruned leaves was 79.61, with the highest percentage of ketones (32.58%), followed by aldehydes (27.71%) and alcohols (16.40%). According to the quality of Qingzhuan tea and the safety requirement of fluorine content, the fresh leaves of 1 bud with 4 leaves can be considered as the main raw materials of Qingzhuan tea.
                                                                                                                   
    Abstract:
    [Objective] Combined application of chemical fertilizer and biochar is one of the important procedures to improve the nitrogen fertilizer utilization rate (NUE) of crops, but the nitrogen fertilizer utilization rate of crops is affected by factors such as region, soil properties, biochar properties, and biochar and nitrogen fertilizer application rates. Since most of the current research is only carried out under certain conditions, the impact of biochar on the utilization rate of nitrogen fertilizer is a lack of systematic analysis and comparison. Therefore, this article explores the impact of biochar on nitrogen fertilizer utilization, quantifies the impact of biochar on crop nitrogen fertilizer utilization under different soil and biochar application rates, and guides the use of biochar to provide an important basis for improving nitrogen fertilizer utilization. [Method] In this study, 33 publicly published documents were collected, and 170 sets of nitrogen fertilizer utilization data including biochar combined with chemical fertilizer (NPK+BC) and single chemical fertilizer (NPK) treatment were established, and integrated analysis (Meta- analysis) to study the differences in nitrogen use efficiency in different regions under NPK and NPK+BC treatments. [Result] Generally speaking, the application of biochar can improve the nitrogen fertilizer utilization rate of crops, which is increased by about 4.76%. Among them, the effect of increasing nitrogen fertilizer utilization rate in the southern region is the most obvious. In the southern regions with acid soils and nutrient deficiency, the application of potassium and phosphate fertilizers should be increased in conjunction with biochar to improve the nitrogen fertilizer utilization rate of the crops; in the northeast region of fertile nutrients, the application of nitrogen and organic fertilizers should be controlled to maximize the effect of nitrogen fertilizers. The application rate of biochar should be controlled at about 1~ 3%. When the application amount of nitrogen fertilizer is less than 120kg.hm-2, the synergistic effect of biochar is the most obvious. Secondly, in terms of physicochemical properties of biochar, biochar made from wood materials can increase the nitrogen fertilizer utilization rate by 7.99%; when the nitrogen content of biochar > 2%, the synergistic effect of nitrogen fertilizer utilization rate reaches 19.43%; the biochar pH is From 9 to 10, the increase in nitrogen fertilizer utilization rate is the most obvious, reaching 5.01%. Finally, the synergistic effect of food crop biochar is better than that of economic crops, and the synergistic effect of field trials is better than pot experiments. [Conclusion] The application of organic fertilizers and nitrogen fertilizers should be reduced and the cultivation of nutrients should be controlled in the northeast region where nutrients are distributed; in the southern regions with poor nutrients, attention should be paid to increase the pH of the soil and increase the application of potassium and phosphate fertilizers to more effectively use biochar For the synergistic effect of nitrogen fertilizer utilization rate and the effect of increasing yield and efficiency, the application amount of biochar and nitrogen fertilizer should be formulated according to the local soil properties. Secondly, for the selection of biochar, we should pay attention to comprehensive factors such as raw materials, application amount and nitrogen content, and select the best preparation materials.
                                                                                                                   
    Abstract:
    In order to obtain a new efficient and environment-friendly control method for the main Miridae pests in cotton field, Apolygus lucorum and Adelphocoris suturalis, the ethanol extracts from the seeds of Allium tuberosum and Helianthus annuus were prepared by soaking in room temperature. Three-arm olfactometer was used to compare the olfactory responses of A. lucorum to two extracts and cotton leaves. The results showed that A. lucorum had the highest response rate (56.04%±3.77%) to the extract of A. tuberosum, which was significantly higher than that of H. annuus and cotton leaves. When the A. tuberosum seed extract and H. annuus seed extract were mixed according to the volume ratio of 3:7, they had synergistic effect and showed strong attraction to both A. lucorum and A. suturalis. The selective response rates were above 80%. This study provides some new perspectives for the development of pest control using plant resources.
                                                                                                                   
    Abstract:
    The pod-setting characteristics of 59 materials of mustard (Brassica juncea) which included 30 cytoplasmic sterile lines and 29 maintainers were studied using field investigations in this experiment, molecular markers and cytological observation methods. The results from molecular markers methods indicated 23 of the 59 mustard materials are hau cytoplasmic male sterile lines,7 of the 59 mustard materials were ogu cytoplasmic male sterile line. The results from cytological observation methods showed that siliques of the 29 maintainers、7 ogu cytoplasmic male sterile lines and 5 hau cytoplasmic male sterile lines were plump and vertical, while siliques of the 18 hau cytoplasmic male sterile lines were abnormal to different degree. The flower organ development and anther abortion of hau cytoplasmic male sterile line and Ogu cytoplasmic male sterile line in Brassica juncea using cytological observation. The results showed the characteristic of flower abortion of ogu cytoplasmic male sterile line and hau cytoplasmic male sterile line(normal pods) were the tapetum degraded in advance, while that of hau cytoplasmic male sterile line(abnormal pods) was the formation of stamen-pistil chimera. The results of this study revealed the mechanism of the siliques cytological malformation traits of mustard male sterile lines.
                                                                                                                   
    Abstract:
    Navel orange peel residue is the main residue in the navel orange processing industry. It has a wide range of sources and rich nutrients. However, there are still a large amount of navel orange peel slag being thrown away, resulting in waste of resources and environmental pollution. In order to develop and utilize navel orange peel residue resources, single-factor and orthogonal experiments were carried out to study the debittering effect of ultrasonic wave-assisted NaCl-NaHCO3 solution on navel orange peel residue. The D-Optimal Design method was used to optimize the formula of filling of navel orange peel residue. The results showed that the order of influencing the debittering effect of navel orange peel residue were as follows: ultrasonic power>ultrasonic time>NaCl-NaHCO3 solution concentration. The best effect of removing bitterness and astringency was soaking the navel orange peel residue in NaCl-NaHCO3 solution with a concentration of 3% (mass ratio 1:1), ultrasound for 15 minutes under the conditions of ultrasonic temperature 30℃ and ultrasonic power 120W. According for the correlation analysis, the sensory quality of filling was significantly negatively correlated with hardness, gumminess and resilience of TPA parameters (P<0.01). The results of one-way analysis of variance demonstrated that citrus peel pulp had a significant effect on the hardness and gumminess of filling (P<0.05). Sugar had a significant effect on filling hardness (P<0.05) and a very significant impact on the resilience (P<0.01). Peanut oil and corn starch had no significant effects on hardness, gumminess and resilience (P>0.05). Mixture design and verification experiment results illustrated that the optimal formula of navel orange peel filling was: peel pulp 77.0%, sugar 17.0%, peanut oil 4.5%, corn starch 1.5%. The navel orange peel residue filling using this formulation was fragrant and delicious, smooth and non-sticky, with a high sensory quality.
                                                                                                                   
    Abstract:
    Citrus juice is rich in various minerals and vitamins and has high nutritional value. However, the removal of bitterness in citrus juice has always been a major problem faced by the citrus processing industry.A small amount of bitterness can give citrus juice a specific flavor, but too strong bitterness will affect the quality and sales of citrus products. This article outlines the biochemical properties of naringin, which causes the “immediate” bitterness of citrus juice, and the limonin, which causes “delayed” bitterness. In addition, this article also discusses the research progress of different physical chemistry and biotechnology methods for debittering in recent years, briefly describes the corresponding debittering mechanism and existing advantages and disadvantages, and finally makes an outlook on the future development trend of citrus debittering methods.
                                                                                                                   
    Abstract:
    In the surimi production process, in order to obtain white-colored, high-elastic and high-quality surimi products, a large amount of water is usually used for rinsing, resulting in organic wastewater mainly composed of sarcoplasmic protein, which will be discharged into the environment and cause environmental pollution and waste of resources. If the protein in the surimi rinsing wastewater can be recycled, it will produce excellent economic value and environmental benefits. This study explored the effect of acid-chitosan flocculation coupling treatment on the recovery rate of sarcoplasmic protein in surimi rinsing water. The results found that acid treatment (pH 3.0) can significantly increase the recovery rate of sarcoplasmic protein from 35.52% to 81.54% when chitosan is used as a flocculant. Then through single factor experiments and Box-Bechnken central combination design to optimize the flocculation conditions, the optimal flocculation conditions for sarcoplasmic protein is determined as follows: pH 6.5, chitosan additive amount 250 mg·L-1, temperature 30℃, time 90 min, a high recovery rate of protein of 85.23% and the removal rate of COD of 73.32% can be obtained. This research provides not only a theoretical basis for the recovery and utilization of sarcoplasmic protein in surimi rinsing water, but also a technical support and reference for the purification treatment of rinsing wastewater in the processing of surimi.
                                                                                                                   
    Abstract:
    The edible film was prepared from myofibrillar protein and chitosan. Based on temperature, glycerin concentration and film-forming material ratio (myofibrillar protein:chitosan), the effects on the physical properties of edible film were investigated. Moreover, the response surface analysis test was designed according to the central combination design principle to explore the interaction between factors. The optimum technological conditions of myofibrillar protein / chitosan edible film were as follows: temperature 55℃, glycerol 1.6%, and film-forming material 4.3:3.7. The results showed that the myofibrillar protein molecules in the optimized film had good compatibility with chitosan molecules.
                                                                                                                   
    Abstract:
    The walnut kernel was ball milled for different durations (2, 4, 8, 16, and 24 min) to develop walnut butter products, reduce the particle size and improve its rheological properties. The average particle diameter of walnut butter after ball milling for 24 minutes decreased from 79.89 μm to 37.88μm, by 53% overall. It was a typical non-Newtonian pseudoplastic fluid, which had the characteristics of viscoelasticity and positive thixotropy. The results revealed that the hardness and consistency of the walnut butter decreased, and the fluidity gradually increased during the ball milling treatment. The walnut butter ball milled for 8 minutes showed the higher viscosity and smaller in particle size, and was suitable for processing as a spreadable butter. As for ball milling process for 16 and 24 minutes exhibited the best fluidity and was suitable for the processing of salad sauce. Results could be useful in development of the walnut butter making process system design. Therefore, high-energy ball milling technology could be used as a technique for preparing walnut butter, and gradually change the rheological properties of finely divided walnut butter through the process.
                                                                                                                   
    Abstract:
    Based on NDVI, LSWI, land use data and various meteorological and statistical data, with the help of CASA-VPM model and ecological economic coordination coupling degree model, the characteristics of the vegetation NPP temporal and spatial differentiation in the Yellow River Basin from 2001 to 2018 are analyzed; the current ecological and economic development status is discussed , And use it to evaluate the degree of ecological-economic coordination and coupling. The results show that the annual average NPP of vegetation in the Yellow River Basin from 2001 to 2018 was 288.33gC/m2·a-1, and the fluctuations continued to increase. The spatial distribution characteristics of the NPP are high in the south and low in the north, high in the plains and basins, and low in the plateaus and mountains. ; The monthly average NPP changes of different vegetation types show the characteristics of periodic single-peak changes, and the trends and cycles of different vegetation types over time are the same, but the amplitude and rate of change have obvious distinctions; the total annual ecological value of the study area After the economic value is fitted, they show "U"-shaped and linear change characteristics, and the latter has a much higher growth rate than the former. The cold spots are mainly distributed in the transitional area between the northwestern mountain and the plateau edge, and the hot spots are mainly located in the Yellow River The "Golden Triangle" area of the river basin; the ecological and economic coordination coupling degree of the study area presents a strip-like spatial distribution characteristic of "large dispersion, small aggregation" and rising with a "W" curve. The level of economic development is the ecological economic coordination coupling degree of the river basin The dominant factor.
                                                                                                                   
    Abstract:
    In this study, CRISPR/Cas9-mediated homologous recombination technology was used to perform gene editing on the isolated PRV HB2017 strain to construct a pseudorabies virus (PRV) with deletion of TK, gE and gI genes. After techniques such as plaque purification, we have obtained the gene-deleted PRV strain. Subsequently, the characteristics of attenuated PRV were preliminarily studied by PCR, gene sequencing, indirect immunofluorescence assay, growth curve determination and animal experiments. The results showed that the TK, gE and gI genes of the PRV HB2017 strain have been deleted, and the growth curves of the attenuated PRV strain PRV HB2017ΔTKΔgE/gI and the parent strain PRV HB2017 strain in PK-15 cells are not significantly different and have high virus titer. PRV HB2017ΔTKΔgE/gI strain has the advantages of high safety, genetic stability and superior immunogenicity.
                                                                                                                   
    Abstract:
    In order to explore the relationship between the feeding quantity, water quality, and plankton in salt-freshwater intensive grass carp farming ponds,this study regularly sampled and investigated the water qualities, amount of feed, and plankton of three brackish water carp farming ponds in Guangzhou Chengyi Aquaculture Co., Ltd. from September 2017 to September 2018. Spearman and Canoco 5.0 were then used to correlate and rank the data. The results showed that the feeding quantity was significantly positively correlated with the total nitrogen concentration of the water, and its correlation coefficient was 0.614 (P<0.05), which was related to water temperature, pH, transparency, dissolved oxygen, nitrite, ammonia nitrogen, total phosphorus and salinity. There is no significant correlation with other water quality indicators. The feed amount and phytoplankton biomass were significantly positively correlated, the correlation coefficient was 0.354 (P<0.05), and the zooplankton biomass was extremely significantly positively correlated, the correlation coefficient was 0.447 (P<0.01). The RDA ranking analysis was performed on the feed quantity and water quality index and plankton biomass. The sorting results showed that the feed quantity and total phosphorus were the key factors affecting zooplankton and phytoplankton biomass, respectively. The multiple regression data model fitted well. The interpretation rate of the prediction model for phytoplankton and zooplankton biomass were 65.4% and 44.8%, respectively. The models were Y1 = 16.07x4 + 13.60x3 + 11.10x2 + 2.22x6-2.20x5-2.06x1-51.57; Y2 = 2243.92x4 + 5.54x3 + 0.90x2 + 0.006x1-57.48. Conclusion: in brackish water intensive grass carp breeding ponds, the feeding quantity has a significant effect on the total nitrogen concentration and phytoplankton in the pond. At the same time, the purification ability of phytoplankton to the pond nitrogen also limits the amount of pond feed. Therefore, the regulation of the feeding quantity in the pond should take the water quality and plankton into consideration.
                                                                                                                   
    Abstract:
    [Objectives]To avoid the damage of timber caused by the feeding rolls during forest harvesting, a new technique which the Double-V-Wings Honeycomb (DVWH) in the feeding roll was an important object to be studied in the research. The most significant exploration was to deduce the mechanism of undermining in its cell structure parameters to logging woods. [Methods]Primarily, the research method was based on the classical content of theoretical mechanics by constructing a theoretical model of the three parameters of the DVWH structure and the yield strength to conduct experiments. In the experiment, a quasi-static speed compression experiment was performed on the honeycomb structure in the Y direction. The experiment used nylon material as the experimental material. The elastic model quantity of nylon material is 1600MPa and the test data was collected by DIC technology at a compression speed of 1mm/min. Then the next experiment mainly adopted the method of low-speed impact simulation experiment, which was carried out under the condition of 2m/s. Studying the influence of cell structure parameters on the equivalent stress and energy absorption effect of DVWH under this condition.The optimal cell parameters were selected by orthogonal experiment. At this time, the test simulation timber round bar was hit to the feed roller at a speed of V=2m/s through the experiment and the flange of the feeding roll needs to be fixed. After the experiment, according to the pixel-based physical length measurement method for each graphic, the relative increase percentage of the contact area between the simulated log and the feeding roller with different structural parameters was obtained. Furthermore, the purpose of studying the coupling relationship between the cell structure parameters of the feeding roller and the contact area of the log was realized.[Results]In the experiment, the maximum displacement of the DVWH negative Poisson's ratio structure after being compressed by 5 mm in the Y direction was 2.908 mm and the maximum strain was 0.0134. At the same time, the performance under quasi-static compression conditions verified the theoretical formula of yield strength. Under low-speed impact conditions, the equivalent stress in the Y direction of the DVWH structure increased with the increase of the angle θ1 and the thickness t, and increased with the decrease of the angle θ2. The peak value of kinetic energy increases with the increase of the thickness t and the angle θ1, and the change of angle θ2 had no obvious effect on the peak value of kinetic energy. In addition, the total internal energy absorption decreased with the increase of its parameter angle θ2 and increased with the increase of its parameter thickness t. The rule of changes in angle θ1 was less obvious. After selecting polyurethane as the material for roller drive applications, the orthogonal test method was used to select the optimal parameters in the θ1, θ2, t interval to increase the contact area between the feeding roller and the log by 14.5%~26%. In addition, specific cell structure parameters could be selected according to the requirements of specific working conditions, and the log damage area of the honeycomb structure feed roller in forestry production could be predicted.[Conclusions]The structural parameter thickness t was an important index that affects the compaction strain of the DVWH structure with negative Poisson's ratio. By changing the materials selected for the negative Poisson's ratio structure and the size parameters of the DVWH negative Poisson's ratio structure, the contact area between the feeding roller and the wood was improved and the pressure on the log can be reduced. The results of this study are inspiring and helpful to reduce the damage of felled wood.
                                                                                                                   
    Abstract:
    D101 resin was used to obtain polymethoxyflavones extracts from the Chenpi . High-speed countercurrent chromatography was used to obtain nobiletin and tangeretin. The purity was identified by high performance liquid chromatography. The structure was identified by mass spectrometry and 1H NMR. The mice model of acute lung injury was constructed by intranasal instillation of LPS in the exprienment.Continuous gastric gavage with 25, 50, 100mg/kg low , medium,high-nobiletin group and 250mg/kg PMFs group for 7d.The anti-oxidant and anti-inflammation of PMFs and NOB was evaluated by assessing pulmonary histopathological changes,lung injury score,the wet weight to dry weight ratio, MPOactivity, MDA content, GSH-PX activity,the cytokine content of lung tissue.The results showed that the PMFs group and middle-NOB group can significantly relieve lung tissue damage, reduced the wet/dry weight ratio, MPO activity, MDA content and pro-inflammatory cytokine content, increased GSH-PX activity.The anti-oxidation and anti-inflammatory effects of the middle-NOB group and the 10 mg/kg dexamethasone group on acute lung injury mice are similar. The above results indicated that PMFs extracts and NOB have anti-oxidant and anti-inflammatory effects, and have certain protective effects on acute lung injury.
                                                                                                                   
    Abstract:
    Abstract: 【Objective】By comparing and analyzing the 2 varieties winter wheat changes of stem morphological characteristics, basal node coarse cell wall composition and stem mechanical characteristics under different molybdenum-nitrogen ratio treatments, to explore the effect of molybdenum and nitrogen combined application on lodging resistance of winter wheat. 【Method】 By using 97003 and 97014 as materials, four nitrogen application levels (N 0 kg/hm2, N120 kg/hm2, N 210 kg/hm2, N 300 kg/hm2) and three Mo application levels ((NH4)2MoO4 0 kg/hm2, (NH4)2MoO4 0.75 kg/hm2 and (NH4)2MoO4 1.5 kg/hm2 were set up to compare the lodging rate of different, and the reasons of wheat lodging difference were analyzed from physiological, morphological and mechanical indexes. 【Result】 1) The distance from the break to the top and the bending moment of the wheat molybdenum low-efficiency cultivar 97014 at the same nitrogen and molybdenum levels were higher than those of the wheat molybdenum high-efficiency cultivar 97003; compared with no nitrogen application, the three levels of nitrogen application could increase both varieties of wheat the upper fresh weight and bending moment, the difference was more obvious when the nitrogen level was 210 kg N/hm2, nitrogen application had a significant effect on the section coefficient and bending stress. The nitrogen level was 0 kg N/hm2 and 210 kg N/hm2 , the bending moment would increase as the amount of molybdenum applied increases; 2) The basal node length of wheat variety 97003 was higher than that of wheat variety 97014 under all Mo and N fertilization levels, while the upper node length and ear length were lower than that of wheat variety 97014; the outer diameter of long axis and the inner diameter of long axis and ear length of wheat molybdenum efficient variety 97003 increased with the increase of nitrogen application level In addition, the outer diameter and inner diameter of long axis, basal stem length and ear length of wheat variety 97014 increased with the increase of nitrogen application level; 3) With the increase of nitrogen application rate, the non structural carbohydrate of wheat stem decreased significantly, and the application of (NH4)2MoO4 1.5 kg/hm2 efficient wheat variety 97003 was observed Ammonium Molybdate / hm2 can reduce the amount of non structural carbohydrate in wheat stem; 4) The cellulose and lignin content in the base of two wheat varieties were different. The cellulose and lignin contents of 97003 wheat variety with high molybdenum efficiency were basically unchanged under all treatment levels. The cellulose content of wheat variety 97003 with low molybdenum efficiency was increased by applying (NH4)2MoO4 1.5 kg/hm2 under four nitrogen levels. The lignin content of basal internode decreased when 0.75 kg/hm2 (NH4)2MoO4 was applied at 210 kg N/hm2 and 120 kg N/ hm2 . 【Conclusion】 The optimal combination of the main physical properties of the two winter wheat lines under different Mo and N application rates were different. The short and thick basal internode, large stem wall thickness, increased total amount of structural carbohydrates and good stalk plumpness were the direct reasons for the high bending resistance, small lodging index and enhanced lodging resistance of winter wheat.
                                                                                                                   
    Abstract:
    For a long time, whether eating persimmons can lead to gastric bezoars was controversial. The public's concerns about eating persimmons have severely restricted the development of persimmon industry. However, until now, no systematic studies have confirmed that eating persimmons can cause bezoars. Therefore, this study aimed to evaluate whether daily consumption of persimmon fruits could cause gastric bezoars. In stimulated gastric fluid system, we confirmed that the flocculation ability of tannins with food ingredients cannot been considered for its bezoars formation risk. In the animal system, our results showed that no bezoars were found in the stomach, and no intracorporal pathogenic properties were observed according to the hematological and stomach parameters after 30 days’ continuous intake of persimmon. Additionally, both volunteer tests and questionnaires in typical persimmon growing region revealed that consuming two persimmon fruits (400-500 g) daily for healthy person did not lead to gastric bezoars. Altogether, this study preliminarily confirmed that healthy adults eating two persimmons daily did not cause gastric bezoars.
                                                                                                                   
    Abstract:
    In order to definite the effect of salt pretreatment on barley seed germination and microspore culture, the salt tolerant cultivar ‘H11’ and salt sensitive cultivar ‘H30’ were used as materials and the germination rate, taproot length during the seed germination as well as the callus yield in the microspore culture stage were compared under the different salt pretreatment conditions. Meanwhile, the expression of four key genes to salt stress at the microspore stage were also investigated in the two cultivars. The results showed that the seeds and microspores of ‘H30’ were less tolerant to salt than ‘H11’ under 0 g/L NaCl and low NaCl pretreatment conditions, but under the high concentration of NaCl pretreatment (15 g/L NaCl in germination stage and 300 mg/L in microspore stage), the salt tolerance of ‘H30’ was significantly enhanced, and the germination rate, taproot length as well as callus yield with high concentration of salt stress were significantly superior to that of ‘H11’. Through the correlation analysis of germination rate, taproot length and callus yield between the two cultivars, it was found that the relative values of the differences between the two cultivars at the germination stage and the microspore stage were significantly positively correlated. Moreover, in the microspore culture stage, after 300 mg/L NaCl pretreatment, the genes HvsHSP1 and HveIF1A of ‘H30’ were significantly up-regulated in comparison with ‘H11’ under higher concentration of salt stress. It is concluded that the differences in the response of tested barley cultivars to salt pretreatment during seed germination and microspore stage may be consistent. HvsHSP1and HveIF1A of salt sensitive cultivar may be related with the response of NaCl induction in the microspore stage.
                                                                                                                   
    Abstract:
    Phosphorus (P) and zinc (Zn) are both essential elements for plant growth and development. There are strong relationships between different nutrients that changing one or more nutrients in the growth medium affects the concentrations of many other nutrients in plants. Phosphorus in the form of Pi can influence the mobility and bioavailability of many metal elements such as iron, manganese, copper, and Zn. Early studies performed in various crop species indicate the existence of a negative relationship between Pi and Zn accumulation in plants. In this study, the indica hybrid rice cultivar Guangliangyou 35 and conventional japonica rice cultivar Nipponbare were treated with combined application of three Zn levels and four P levels in field trials to investigate the effects of combinations of P and Zn on rice growth and yield production, as well as the nutrient utilization. We analyzed the shoot dry weight at different growth stages, the yield and its components at mature stage as well as the P, Zn, N and K concentrations, accumulations and distributions in different organs and tissues. Results showed that the combined application of P and Zn fertilizers had synergistic effect or antagonistic effect on the rice biomass, yield production, the nutrient absorption and distribution. Under the middle- and low P levels, the proper application of Zn increased the rice biomass and yield production. However, under the high P level, the application of Zn decreased the biomass. For different rice cultivars, under different P levels, the proper application of Zn increased the yield. The significantly increased 1000-grain weight and fertility determined the increased yield under the combined application of P and Zn fertilizers. The proper combined application of P and Zn fertilizers not only increased the concentrations of P and Zn in rice plant, but also promoted the P and Zn distribution to the productive organ. Additionally, the proper combined application of P and Zn fertilizers also increased the concentrations of nitrogen (N) and potassium (K) in rice plant, as well as the distribution of N to the productive organ, which is one of the main physiological mechanisms of increased yield production under the combined application of P and Zn fertilizers.
                                                                                                                   
    Abstract:
    Water-soluble nanometer fluorescent carbon points were synthesized in one step by "microwave method", then the silicon dioxide was grafted on the surface of carbon points by “sol-gel” method through tetraethyl orthosilicate (TEOS) as the cross-linking agent and phenyl ether methyl cycloazole as the template molecule. The polymer C-dot@MIP with good application prospects in trace detection of pesticide residues was obtained after the template molecules were washed off. Experimental results showed that the minimum detection limit calculated by 3σ/K was 0.93 μg/mL, and the recoveries of blank and standard spiking sample were not exceeding 25 percent.
                                                                                                                   
    Abstract:
    The effects of four Culture medium on the symbiosis of different varieties of soybean and AM fungi (Rhizophagus irregularis) were studied by pot culture. The difference between black ink and trypan blue staining methods and the application of the magnified grid line and the five-class methods in mycorrhizal symbiosis structures detection were also compared in this research.The results show that vermiculite and soil (V: V = 4: 1) are more conducive to the infection of AM fungi with soybean. The arbuscular abundance, hypha density and vesicle abundance in this culture substrate are significant higher than others, so it can be used as the best culture substrates for soybean and AM fungi symbiosis. For large-scale mycorrhizal symbiosis structures detection, ink staining and the magnified grid line method are the best methods in currently.
                                                                                                                   
    Abstract:
    The popular used rice cultivar Guangliangyou 35 and conventional japonica rice cultivar Nipponbare were treated with combined application of three Zn levels and four N levels in field trials. We analyzed the shoot dry weight at different growth stages, the yield and its components at mature stage as well as the N and Zn concentrations, accumulations and distributions in different organs and tissues. Results showed that the combined application of N and Zn fertilizers had synergistic effect on both the rice biomass at the early growth stage and the yield production at the mature stage. The combined application of N and Zn fertilizers had significant synergistic effect on rice panicle numbers. The significantly increased panicle numbers determined the increased yield under the combined application of N and Zn fertilizers. The combined application of N and Zn fertilizers not only increased the concentrations of N and Zn in rice plant, but also promoted the N and Zn distribution to the productive organ (spikelet), which is one of the main physiological mechanisms of increased yield production under the combined application of N and Zn fertilizers.
                                                                                                                   
    Abstract:
    Aiming at the disadvantages of the present traditional silage of green or semi-green corn stalk powder, the compactness of lapping and pressing is small, the degree of anaerobic is not enough, the ammoniation is not good, there are some rotten and deteriorated, and it is inconvenient to seal in the process of opening and using. The key part of the high compression ratio packer, compression devices is designed. The compression molding experiments of four times, five times and six times compression ratio were carried out for the key component compression device in advance. The optimal compression ratio of 1:6 was determined through orthogonal design and multi-level analysis. Based on the quality purpose of improving packaging forming rate, the compression box is used by two hydraulic cylinders to open and close the feeding movable cover plate, two main hydraulic cylinders to compress the pressure, one hydraulic cylinder to push out and the pressure maintaining box to complete the compression and pressure maintaining forming. According to the properties of material expansion and springbackdue to stress relaxation after compression,the design experiment was carried out.the length of the pressure maintaining box is 600mm, the width is 300mm and the height is 365mm. After design and inspection the internal effective working range of the compression device is 1800mm in length, 600mm in width and 365mm in height,and the volume compression reaches a high compression ratio of 1:6, the anaerobic conditions is improved, the degree of ammoniation is improved and the use is more convenient.
    Display Method:
    2015,34(4):108-113, DOI:
    [Abstract] (1594) [HTML] (0) [PDF 1.06 M] (8977)
    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.
    2015,34(4):120-124, DOI:
    [Abstract] (1914) [HTML] (0) [PDF 976.50 K] (7180)
    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.
    2013,32(4):48-54, DOI: 1000-2421(2013)04-0048-07
    [Abstract] (1809) [HTML] (0) [PDF 1.58 M] (5761)
    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.
    2015,34(1):128-135, DOI:
    [Abstract] (2072) [HTML] (0) [PDF 1.21 M] (4505)
    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.
    2012,31(1):16-22, DOI: 1000-2421(2012)01-0016-07
    [Abstract] (2305) [HTML] (0) [PDF 1.07 M] (4400)
    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.
    2013,32(5):124-133, DOI: 1000-2421(2013)05-0124-10
    [Abstract] (1398) [HTML] (0) [PDF 4.01 M] (4284)
    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.
    2015,34(3):8-12, DOI:
    [Abstract] (1127) [HTML] (0) [PDF 3.41 M] (4204)
    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.
    2012,31(1):127-132, DOI: 1000-2421(2012)01-0127-06
    [Abstract] (1530) [HTML] (0) [PDF 930.13 K] (3918)
    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.
    2012,31(5):569-573, DOI: 1000-2421(2012)05-0569-05
    [Abstract] (1198) [HTML] (0) [PDF 912.59 K] (3787)
    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. 
    2016,35(1):81-85, DOI:
    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.
    2014,33(2):139-144, DOI: 1000-2421(2014)02-0139-06
    [Abstract] (1303) [HTML] (0) [PDF 968.56 K] (3580)
    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.
    2015,34(3):134-141, DOI:
    [Abstract] (1195) [HTML] (0) [PDF 1.42 M] (3530)
    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.
    2014,33(06), DOI:
    [Abstract] (762) [HTML] (0) [PDF 8.30 M] (3514)
    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.
    2014,33(2):15-21, DOI: 1000-2421(2014)02-0015-07
    [Abstract] (1728) [HTML] (0) [PDF 980.62 K] (3492)
    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.
    2014,33(01):12-17, DOI: 1000-2421(2014)01-0012-06
    [Abstract] (1513) [HTML] (0) [PDF 944.55 K] (3487)
    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.
    2010,29(3):363-368, DOI: 1000-2421(2010)03-0363-06
    [Abstract] (2516) [HTML] (0) [PDF 11.41 M] (3476)
    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.
    2011,30(5):613-617, DOI: 1000-2421(2011)05-0613-05
    [Abstract] (1170) [HTML] (0) [PDF 914.54 K] (3461)
    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.
    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.
    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.
    2011,30(2):249-259, DOI: 1000-2421(2011)02-0249-11
    [Abstract] (1070) [HTML] (0) [PDF 1.05 M] (3305)
    Abstract:
    Chloroplast transformation in plants has many advantages over nuclear transformation.Proteins in chloroplasts can be expressed at high levels with proper folding and disulfide bonds as the cells of higher plants contain a large number of chloroplast genomes.Multiple genes can be co-expressed in chloroplast genomes.Furthermore,chloroplast genes are inherited in a strictly maternal fashion in most angiosperm plant species,and this minimizes the possibility of out-crossing transgenes to related weeds or species.In addition,gene silencing,position effects and random integration have not been reported in chloroplast transformation.Although chloroplast transformation is very attractive,this technology is not as widely used as nuclear transformation.It has been mostly focused on 16 plants species,especially tobacco in which many proteins has been expressed including vaccines and antibodies.In this review we briefly summarize the rationales,methodologies,applications,bottlenecks and prospects of this promising genetic engineering technology for chloroplasts.

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