Abstract:Eulaliopsis binata, a newly found apomictic species belonging to Poaceae,was proven to have diverse degree of apomixis among populations as well as individual.A microsatellite-enriched library was constructed by capture with streptavidin coated-beads magnetic beads adsorption.Twentyseven pairs of polymorphic SSR primer were developed.Genetic diversities of 11 populations and 71 individuals of E.binata were analyzed by 8 SSR primers producing 123 alleles.Each SSR marker amplified 6-34 polymorphic fragments.The eleven populations of E.binata had a genetic similarity coefficients ranging from 0.70 to 0.97 and could be classified into 4 clusters,indicating the most populations of E.binata had high similarity consistent with its apomictic reproduction mode.By UPGMA analysis,71 E.binata individuals could be classified into 3 groups consistent with results of population classification.However,three individuals from Xingzi population and one individual from Yangxian population were deviated from their own clusters of population respectively and nested in a different location,indicating that the genetic diversity was appeared in different individual of same population and the genetic difference may be reflected the varying degrees of apomixis of plant.

Abstract:Using five cassava cultivars as explants,different colchicine concentrations (0.1,0.3,0.5 g/L) and time duration of treatment (3,6,9 h) were combined to induce autotetraploids of cassava in vitro using axillary buds.Generated shoots were transferred onto the basic MS medium for further development.Ploidy analysis via both flow cytometry and root tip squash technique verified that recovered plantlets from all five cultivars were stable autotetraploids after several subcultures.Autotetraploid plantlets originated from Col22 and SC8 and its corresponding parental plants were transferred into greenhouse.Phenotypes of autotetraploids were comparatively analyzed after five-month growth.Results showed that leaves of autotetraploids became significantly wider and thicker than those of parental plants.The length and width and density of stomas had significant difference between the control and autotetraploids.These novel autotetraploids have great potential for the further genetic improvement of cassava.

Abstract:A putative type Ⅲ polyketide synthase (PKS) gene orf18 found in genome sequence of Streptomyces sahachiroi ATCC 33158 was cloned and analyzed functionally.Bioinformatics and phylogenetic analyses revealed that orf18 was highly homologous to rppA-like type Ⅲ PKS gene.RT-PCR result demonstrated that orf18 can be transcribed into mRNA in wild-type S.sahachiroi.HPLC and LC-MS analyses verified that Orf18 catalyzes the 1,3,6,8-tetrahydroxynaphthalene (THN) biosynthesis by heterologously expressing in S.lividans.Moreover,brownish red pigments could be produced by heterologous expression of orf18 in Gram-negative bacteria Pseudomonas stutzeri.Experimental results demonstrated that Orf18 belongs to the RppA-like type Ⅲ PKS family and catalyzes THN formation,which could be further oxidized and then polymerized to produce red pigments.

Abstract:To study the function of the all3555,an over-expression strain and a deleted mutant strain of all3555 in Anabaena PCC 7120 was constructed.The defected mutant strain was found to grow in usual condition but be more sensitive to NaCl under salt-stress.When all3555 was over-expressed,the resistance of Anabaena PCC 7120 to oxidative stress and NaCl under salt-stress was improved.Results showed that all3555 almost didn’t affect the growth of Anabaena PCC 7120 under the normal condition,but it was important for the resistance of Anabaena PCC 7120 to oxidative stress and NaCl under the salt-stress.

Abstract:Using melon cultivar ‘Elizabeth 239’ as material,effects of root volume [14 L (CK),8 L,5 L] on physiological characteristics,fruit yield and quality of melon were investigated.Results showed that the chlorophyll content,photosynthetic rate,leaf water content,single fruit weight,contents of titratable acidity and sucrose decreased significantly with the decrease of container volume when comparing with control (14 L) but the soluble sugar/acidity ratio and taste value increased significantly.Compared with control,the single fruit weight decreased by 14% and 20% under 8 L and 5 L container treatment,respectively.In addition,the 8 L container treatment significantly increased the contents of vitamin C,fructose and glucose whereas no significant changes of the contents of soluble solids and total soluble sugar were observed.Meanwhile,the 5 L container treatment obviously delayed the fertile flower flowering and fruit development date,and significantly decreased the contents of total soluble solids and soluble sugars.Results indicated that appropriate root volume restriction (8 L) could improve the fruit quality of melon.However,the treatment of 8 L and 5 L root volume container significantly decreased the fruit yield of melon.The most suitable container volume for melon cultivation needs further investigation.

Abstract:The pollen dispersal and its spatial distribution was studied in Pinus massoniana clonal seed orchard located in Taizishan,Hubei Province.The results showed that the pollen quantity in the air in the clonal seed orchard of Pinus massoniana had a date rhythm of low-high-low.The pollen dispersal peak stage appeared in the mid of the whole pollen dispersal period with a duration of 3-5 days.The pollen quantity in the air had significant differences among dates and had a time regular of low-high-low with the peak time occurring from 10:00 to 14:00.However,the peak time was impacted by climatic factors.The pollen quantity in the atmosphere outside the seed orchard decreased with the distance increase showing an S curve regression.The pollen dispersal and its distribution were affected by a lot of factors,such as wind speed,relative humidity,temperature,terrain and so on.Based on the characteristics of the pollen dispersal and its distribution outside the seed orchard,the minimum isolation distance for a seed orchard was more than 1 000 m in order to prevent pollen pollution by external pollen.

Abstract:Based on plot data of shoot utilizing (Ⅰ),shoot and timber utilizing (Ⅱ) and timber utilizing (Ⅲ) of Phyllostachy edulis forests located at the hilly region in central Hunan,studies were carried out to investigate the vertical distribution,seasonal dynamics of soil hot water-extractable carbon(HWC) concentrations and storages in these three typical managing target patterns and its relationship with soil temperature and moisture.The results showed that the average HWC concentrations of type Ⅰ,Ⅱ and Ⅲ were 21.59-84.54,21.41-58.95 and 24.70-61.58 mg/kg,respectively.The average HWC storages were 0.14-0.53,0.14-0.41 and 0.15-0.37 t/hm2，respectively.HWC concentrations and storages decreased with the increase of soil depth in three forests,moreover,the soil layers of 0-20 cm were the main distribution of HWC.For seasonal dynamics,HWC concentrations and storages were the highest in January and the lowest in October.HWC was negatively correlated with the soil temperature and moisture.The relationship could be described well by cubic polynomial and growth curve.It was obvious to some extent for HWC decomposition and mineralization aggravating with the rise of soil temperature and moisture.

Abstract:A new species of the genus Menglacris (Orthoptera, Catantopidae) from Yunnan Province, was described. The type specimen are deposited in the Institute of Zoology,Shaanxi Normal Univeristy.Menglacris zhengi Li et Xu,sp.nov.(Fig.1)The new species is allied to Menglacris maculata Jiang et Zheng,1994,but differs in: 1)Body small； 2)Frontal ridge with low longitudinal sulcus in whole length； 3)Apex of lower kneelobes of hind femur acute angle； 4)Female,length of median segment of antennae about 3.1 times its width； 5)Ancora located apex of anterior projection and apodemes short. Body length: ♂19.0-20.0 mm, ♀26.5 mm; Pronotum length: ♂5.0-5.2 mm, ♀7.5 mm; Length of tegmen: ♂3.0-3.5 mm, ♀4.5 mm; Length of hind femur: ♂13.0-13.5 mm, ♀17.0 mm;Holotype♂，Paratypes 2♂♂，1♀,Caiyanghe Nature Reserve (101°27′-101°15′E , 22°30′-22°38′ N), Pu′er, Yunnan Province,2007-Ⅶ-28,collected by XU Sheng-quan. Etymology: In honor Prof. ZHENG Zhe-min on ocusts classification work contribution for China,named after the new species with his surname Zheng.

Abstract:The infection cushion of penetration the leaf of oilseed rape was investigated by transmission electron microscopy and scanning electron microscopy. During the initial infection process, the hypha of grey mould fungus （Botrytis cinerea ） which formed infection cushions broken down the cell wall then penetrated into the leaf tissue of oilseed rape. After invading into the leaf epidermis cells, the hypha of infection cushions multiplied between the mesophyll cells or grew in mesophyll cells through breaking the cell wall. These results will illustrate the degradation of plant cell wall plays an important role in the infection and development of grey mould fungus infection cushion and provide clues to explain pathogenicity of grey mould fungus.

Abstract:Maize seeds imported from Thailand were tested for Maize chlorotic mottle virus (MCMV) with DAS-ELISA. Among 6 varieties, Sample 5 was positive and others were negative. The result of RT-PCR also showed that Sample 5 was positive. The sequence of the RT-PCR product was determined. This sequence was aligned with 23 sequences of other MCMV isolates and a phylogenetic analysis was completed. The result illustrated that this isolate had short genetic distance to Chinese or Thai isolates and clustered in the same group. 100 seeds of sample 5 were detected for MCMV with DAS-ELISA method and 2 seeds were positive,so the detection rate of MCMV was 2%.

Abstract:From 2011 to 2012,147 samples of pomegranate (Punica granatum L.) roots and rhizospheres have been collected in Taishan, Tai′an and Yicheng, Zaozhuang in Shandong Province,China.A preliminary survey was conducted about the species and distribution of parasitic nematodes on pomegranates. With comparative morphology, three species of the subfamily Criconematinae Taylor,1936 from the rhizospheres of pomegranates were extracted and identified. They were Criconema aberrans,Criconemella informis and Hemicriconemoides mangiferae. Therein,Punica granatum L. was the new host for C.informis and H.mangiferae.

Abstract:To define the population dynamics of white back planthoppers Sogatella furcifera （Horváth） and the infection rates of southern rice black-streaked dwarf virus (SRBSDV) in the 4 counties in Jiangxi, i.e. Chongyi, Jinggangshan, Lianhua and Wan′an, the population dynamics of white back planthoppers under the insect luring light and in the field were determined through insect luring light observing and field sampling, and the infection rates of white back planthoppers in different periods were determined using RT-PCR method. The results revealed that the regulation of the population dynamics of white back plant hoppers and the infection rates tended to be the same.That is the infection rates were much higher in the high-incidence periods. The peak period of white back planthoppers in Chongyi and Wan′an was earlier, which was around July 28th, followed by Jinggangshan around August 8th. The peak period in Lianhua was the latest in the four counties, which was around August 18th. A conclusion was drawn that white back planthoppers with SRBSDV came into Jiangxi Province from the Southeast and then went to the neighboring provinces.

Abstract:In order to describe the biological characteristics of Catalpa fargesii f.duclonxii leaf spot pathogen (Glomerella cingulate),and to select suitable fungicides against it, the mycelial growth in different conditions were observed,and the fungicides against the pathogen were investigated in this paper. The results indicated that the pathogen mycelia grew well under 21-28 ℃, pH 4-7, and the lethal temperature was 45 ℃.Optimal carbon and nitrogen source were sucrose and NaNO3 respectively. The most effective fungicide was 10% difenoconazole among the 5 tested reagents, and the relative inhibition rate was 93.6% with the recommended concentration.

Abstract:Soil samples on Xiaojiang watershed water-level fluctuation zone in the Three Gorges Reservoir Area were collected for the study.By simulation incubation and chemical analysis,the basic physical-chemical properties of soils and the changing forms of heavy metals (Fe2+,Mn2+,available Cu and Zn) were examined in continuous anoxic conditions.The results showed that flooding increased the contents of the Fe2+,Mn2+,available Cu.The contents increased on average from 58.88,35.26,0.96 mg/kg to 1 383.8,782.7,1.73 mg/kg,respectively.After 15 days’ flooding,the contents of available Zn in both Gaoyang and Yanglu increased at the rates of 12.18% and 10.15%,but the other forms decreased at the rates of 7.12% and 3.69%.After 30 days’ flooding,the contents of available Zn increased with the increment rate ranging from 10.9% to 46.6%.The changing form of heavy metals were influenced by the basic physical and chemical properties of soils.

Abstract:A pot experiment was conducted to determine the effects of application of molybdenum (Mo) and selenium (Se) on the yield,contents of Mo and Se in Chinese cabbage,and contents of soil-available Mo and Se during the two successive planting periods.The results showed that the yield was significantly increased by application of Mo and Se in the first harvest,while yield was not significantly increased by application of Mo and Se in the second harvest.Both application of Mo and Se could prompt the Mo uptaking of Chinese cabbage during the two successive planting periods.Soil-available Mo maintained high level during the two successive planting periods,and application of Mo could meet the needs of producing Mo-rich cabbage during the two successive planting periods.Though both application of Mo and Se could prompt Se uptaking of Chinese cabbage during the two successive planting periods,water-soluble Se and exchangeable Se were decreased after the first harvest and application of Se only could meet the needs of producing Se-rich cabbage in the first harvest.

Abstract:Boron contents of soil samples from navel orange orchards of 18 counties in Gannan were analyzed systematically using skewness coefficient,normal distribution,confidence intervals statistical and ArcGIS mapping methods.The results showed that boron deficiency of navel orange orchard soil was serious on the whole with proportion reaching upto 87.1%.It was found that there were differences among districts.The status of soil available boron in Longnan County is best (boron content of 0.26 mg/kg),while the severe district is Zhanggong (boron content of only 0.09 mg/kg).Distribution map of soil available boron clearly revealed that boron deficiency is the main limited factor for the regional development.The application of modern mathematical methods can quickly and intuitively reflect the situation of agricultural resources.

Abstract:The effects of citrate acid-soluble potassium fertilizer on rapeseed growth and soil potassium were studied with the pots experiment.The results showed that the citrate acid-soluble potassium fertilizer could promote the growth of rapeseed and increased the content of soil potassium.The biomass and potassium accumulation of rapeseed were increased and then decreased with the increase of application rate of potassium-silicon mineral fertilizer when the potassium rates was 0.75-3.00 g K2O/pot (0.075-0.300 g/kg).The biomass and potassium accumulation of rapeseed were the highest with potassium rates of 2.25 g/pot.Compared with treatment of no potassium,rapeseed biomass was 70.6% and the total potassium accumulation increased by 3.08 times.The potassium content of rapeseed was increased with the increase of application rate of potassium fertilizer,nevertheless,the nutrient utilization efficiency was opposite.The content of soil available K and slowly available K was increased with the increase of application rate of potassium fertilizer.Comprehensive results showed that the optimum citrate acid-soluble potassium fertilizer application was 1.50-2.25 g/pot.Under the condition of this experiment and the same potassium nutrient supply,the biomass,potassium nutrient content,potassium accumulation nutrient fertilizer utilization and soil potassium content of citrate acid-soluble potassium fertilizer of rapeseed was higher than water-soluble potassium fertilizer,indicating that citrate acid-soluble potassium fertilizer can replace water-soluble potassium fertilizer from the perspective of potassium nutrient supply.

Abstract:By investigating autumn continuous raining disaster in past years in three provinces of Central China and using newly-revised discrimination standard and degree evaluation criteria in climate disaster monitor and analysis system of Wuhan Regional Climate Center,the paper analyses the temporal and spatial feature of autumn continuous raining.Meantime,in terms of disaster losses of autumn continuous raining in representative region,the high influence years and high risk areas are investigated from the angle of disaster risk and some corresponding measures such as risk avoidance and risk shifting et al are proposed for high risk areas.The results show that:during the recent fifty years,the autumn continuous raining in three provinces of Central China decreases significantly at 0.21 time per decade averagely,and the more decreasing trend is caused with closing to the southern.The autumn continuous raining in every area shows consistent decreasing trend,and it will decrease more quickly in the west than in the east of the area,especially the decreasing trend of the part area in the west of Hubei and Hunan reaches significant level.The decreasing trend of autumn continuous raining in heavier level becomes more obvious.The risk analysis method is better applied to the evaluation of high influence years and high risk areas of autumn continuous raining disaster in three provinces of Central China,and the high influence years matches well with actual disaster.The high risk area of autumn continuous raining includes the southwest part of Henan(such as Luanchuan,Xixia),the west of Hubei(such as Fangxian,the west of Yichang,the Enshi area),and the west most part and southeast part of Hunan(such as Chenzhou).Some corresponding measures such as risk avoidance and risk shifting et al are proposed for high risk areas.

Abstract:Mesenchymal stem cells (MSCs) from chicken fetal liver are multipotent stem cells that can differentiate in vitro into various terminally differentiated cells.The majority of studies of MSCs have been focused on human.In this study,chicken liver-derived MSCs were isolated from 7-day-old embryo of Beijing fatty chickens.Primary liver-derived MSCs were sub-cultured to passage 15.The surface markers,CD29,CD44,CD71 and CD73 of liver-derived MSCs were detected by RT-PCR and the surface markers,CD34 and CK19 of hematopoietic progenitor cells/hepatic oval cells were not detected by immunofluorescence.The best culture conditions were determined by drawing growth curve and the cells cycle were investigated.Liver-derived MSCs were successfully induced and differentiated into adipocytes and myocardial cells.The results suggested that the MSCs isolated from chicken fetal liver possess similar biological characteristics with those derived from human,and their multilineage potential would provide many possible applications.

Abstract:In order to clone the formyltransferase gene (Wbkc) of Brucella abortus,express the gene in E.coli and detect the immunogenicity of the expressed protein,the Wbkc gene was amplified from the genomic DNA of Brucella abortus by PCR.The amplified fragments were digested with BamHⅠ and SalⅠ and then cloned into the pET28a vector.The constructed recombinant plasmid pET28a-Wbkc was transformed to E.coli BL-21 and induced to express the fusion protein.The protein was then purified by histidine-binding resin column chromatography and the immunogenicity was detected by Western blot.The recombinant plasmid was verified by PCR,double-enzyme cleavage and sequencing analysis.A specific protein band of 29 000 (relative molecular mass) was identified by SDS-PAGE and the expressed product showed good immunoreactivity by Western blot.

Abstract:The Dmrt4 gene was cloned from the ovary of Megalobrama amblycephala via using rapid amplification of cDNA ends (RACE) PCR.The relative expression of Dmrt4 gene at different stages of embryonic and post-embryonic development,in different adult tissues,and at different stages of gonad in M.amblycephala were analyzed by quantitative real-time PCR.The results showed that the Dmrt4 gene in M.amblycephala contains at least two isoforms named Dmrt4a and Dmrt4b,respectively.The cDNA of Dmrt4a was 1 265 bp encoding 352 amino acids containing DM and DMA domains,and the cDNA of Dmrt4b was 1 081 bp encoding 281 amino acids containing DMA domain.The amino acids sequences of Dmrt4 genes in M.amblycephala had high identities with that of Paralichthys olivaceus and Oreochromis aureus.The Dmrt4 gene was expressed from embryo to 30 dph (day post hatching) continuously and reached the peak at 32 hpf (hour post fertilization),the gene expression in ovary was significantly （P＜0.01） higher than in other adult tissues,and the gene expression at Stage Ⅱ of the ovary was significantly (P＜0.01） higher than that of other ovary stages and the testis stages,suggesting that the Dmrt4 gene may play a vital role in primary oocytes and female gonad development in M.amblycephala.

Abstract:Forty-seven Misgurnus anguillicaudatus microsatellite markers were randomly selected from DDBJ database and used for cross-species amplification in a population of Paramisgurnus dabryanus from Hubei Province.Forty-four pairs of primers amplified P.dabryanus DNA,while 3 primers including Mac31,Mac63 and Mac541 failed.Using genomic DNA of selfing offsprings juveniles of M.anguillicaudatus and P.dabryanus as templates,PCR amplifications were performed using three primers of Mac31,Mac63 and Mac541.The results showed that target bands were detected only in selfing offsprings of M.anguillicaudatus,suggesting that markers of Mac31,Mac63 and Mac541 are useful for identifying M.anguillicaudatus and P.dabryanus at the juvenile stage.

Abstract:The effects of sample pretreatment on the detection of Mei-ting in the muscle of grass carp was explored by high performance liquid chromatography.The results showed that the pretreatment methods of extraction by methanol,purification by methylene chloride,vibratory centrifugation,defatting by n-hexane,concentration at 30℃ by rotary evaporator,is rapid,sensitive,economical,safe and practical.The detection limit of Mei-ting was 1.0 μg/kg.The recovery rate ranged from 67.72％ to 95.52％ at the spiking level of 1.0-100 μg/kg and the relative standard deviation was 7.76％-37.81％.The method described here is suitable to measure the residue of Mei-ting in fish.

Abstract:This study was conducted to estimate essential amino acids (EAA) requirements of juvenile Barbus capito.Feeding experiments of B.capito ((11.29±0.07)g) were conducted with the protein diets (PD) and protein-free diets (FPD) and each diet was randomly assigned in triplicate.The EAA requirements of B.capito were determined based on the daily increment and daily maintenance requirement of each EAA in fish body.Compared with the PD group,the final weight and specific growth rate decreased significantly (P＜0.05) and the whole body moisture content increased significantly (P＜0.05) in the FPD group.When dietary protein level was 43%,feed utilization rate was 90% and feeding rate was 3%,the daily EAA requirements of juvenile B.capito (mg/100 g body weight) were as follows:phenylalanine 25.54,methionine 15.80,arginine 36.08,lysine 53.76,leucine 49.95,threonine 25.05,valine 25.99,isoleuline 25.33 and histidine 19.94.The requirements of EAA for B.capito feed (g/100) were as follows:phenylalanine 0.85,methionine 0.53,arginine 1.20,lysine 1.79,leucine 1.67,threonine 0.84,valine 0.87,isoleuline 0.84 and histidine 0.66.

Abstract:The protein composition and distribution of cadmium in different protein composition were investigated in Pteria penguin.The contents of cadmium in different protein compositions which were separated from Pteria penguin were determined by atomic absorption spectrometry (AAS).Molecular weight distribution of different protein were determined by sodium dodecyl sulfonate-polyacrylamide gel electrophoresis (SDS-PAGE) and high performance size exclusion chromatography (HPSEC) chromatogram.In the present study,three protein compositions were separated from whole viscera of Pteria penguin,and content of each protein component in total protein were 27.3% sarcoplasmic protein,23.1% myofibrillar protein,50.0% total matrix protein (there were 10.3% of acid soluble matrix protein,39.7% of acid insoluble matrix protein,22.1% of alkali soluble matrix protein and 27.9% of alkali insoluble matrix protein in total matrix protein).There were a large respective divergence in the molecular weight distribution of sarcoplasmic protein,myofibrillar protein and acid/alkali soluble matrix protein,with sarcoplasmic proteins and myofibrillar protein exhibiting wide molecular weight distribution range of 20-200 ku and complex compositions,and acid/alkali soluble matrix protein having simple composition,while there were complex compositions of sarcoplasmic proteins and alkali soluble matrix protein and simple compositions of myofibrillar protein and acid soluble matrix protein in the low molecular weight range of 2-20 ku.The distribution of cadmium in three major protein compositions including total matrix protein,sarcoplasmic protein and sarcoplasmic protein exihibted a significantly positive correlation with contents of proteins (r=0.998 5),while the distributions of cadmium in different matrix protein had a significantly negative correlation with contents of proteins(r=0.996 4).The results suggested that cadmium did not evenly distribute in protein of Pteria penguin,but selectively combined with different protein components,and cadmium can not be dissociated from protein under mild extraction conditions,but it was dissociated from protein under extreme pH conditions.

Abstract:The organoleptic quality,main chemical compositions and nutrient elements of Longfeng green teas coming from 11 areas were analyzed.The results showed that the shape,liquor color and refused leaves of all Longfeng teas had no difference,but the flavor and taste were different.The contents of biochemical composition and nutrient elements also had marked difference.The contents of tea biochemical composition:tea polyphenols 28.43%-34.23%,amino acids 2.58%-3.75%,caffeine 1.87%-2.52%,soluble sugar 2.32%-3.07%,chlorophyll 0.084%-0.129%,water extract 21.93%-44.78%,catechins 150.00-171.88 mg/g.The contents of elements:total N 5.47%-6.65%,total P 0.410%-0.502%,K 0.966%-1.129%,Ca 0.097%-0.135%,Mg 603.13-855.39 mg/kg,Fe 50.55-71.25 mg/kg,Cu 8.46-10.86 mg/kg,Zn 22.91-36.51 mg/kg.The Longfeng green teas could be divided into four types according to the systematic cluster analysis:the first type(Qianjin,Longwangya,Qichang,Shuangzhuyuan,Daping) with high contents of N,P,K,amino acids and water extract; the second type(Luohe,Qingcaoping,Jiuligang) with the low contents of nutrient element and biochemical compositions; the third type(Wangjiashan) with high contents of tea polyphenols and soluble sugar; the fourth type(Qinglongzhai,Meiziya) with high contents of Ca,Mg,caffeine and catechins.

Abstract:In order to classify tomatoes nondestructively,this paper put forward method，an image technology to predict tomato weight automatically. The algorithm was based on Matlab platform,using mathematical morphological operation and image local property operation to establish identification algorithm for the tomato. Linear model,second order polynomial model,power model were established through analyzing the relations between tomato external parameters and weight. Weight prediction model was established through regression analysis of the external characteristics. The experiment results showed that the weight was highly related to its area,perimeter,maximum inscribed circle diameter and minimum circumscribed circle diameter. Test results showed that the multivariate linear prediction model was the best. Its determination coefficient (R2) was 0.926 7,the standard deviation (SE) was 4.32. Its mean relative error was 1.535%,and the mean absolute error was 3.260 g. The experiment results show that the program can quickly predict tomato weight through tomato external features.

Abstract:A freshwater fish body mass online grading system based on virtual instrument was designed since the present freshwater fish body mass classification is slow and has low accuracy and poor reliability. The key parameters of the motion control module, information collection module and classification execution module were determined, and a method synchronously tracking freshwater fish body mass information and hierarchical pipeline was researched. The speed of the grading line was 150 mm/s, the correlation coefficient of the measurement results and the real body mass was equal to 0.999 8, the maximum relative error of freshwater fish body mass was 1.04%, the grading accuracy rate of the freshwater fish body mass grading system was 100%, and it handled 3 600 freshwater fish per hour. The test results show that the system can achieve fast, accurate detection of freshwater fish weight, and provide technical support for body mass online grading of the freshwater fish and other agricultural products with irregular shapes.