Abstract:Integrated ricecrayfish farming is an ecological breeding model which can make full use of the light,heat,water and biological resources of the rice field. It has good social,economic and ecological benefits,and a broad application prospect. Based on the characteristics of regional resources,situation and problems of developing integrated ricecrayfish farming in Hubei Province,this paper analyzes the technical characteristics of ricecrayfish cocultivation model and ricecrayfish rotation model. It clarifies the resource utilization,environmental requirements and appropriate types and regions of integrated ricecrayfish farming in Hubei Province. The Shuangshui Shuanglü concept based development ideas and countermeasures of integrated ricecrayfish farming are put forwared.

Abstract:In order to explore characteristics of rice growth and development,photosynthetic change rules and nitrogen nutrient absorption in the ricecrayfish system under different straw returning and feeding treatment,7 200 kg/hm2 straw returning amount and no feeding (NS+NF,CK) and treatments of 12 200 kg/hm 2 straw returning amount (S) and 1 600 kg/hm2 feeding amount (F) was used to study changes of characteristics of rice growth and development,leaf photosynthetic,population canopy structure,nitrogen utilization efficiency and yield at middle and late growth stage of rice. The results showed that S+F significantly increased the yield,and the number of effective panicle,the seedsetting rate and the number of grains per tassel. The nitrogen content in rice mature plants was also significantly increased. The actual yield of NS+F treatment was 9.34 t/hm2,being the highest and 3.43%11.72% higher than that of other treatment. S treatment was mainly effective in the late growth stage of rice,which delayed the senescence of rice leaves and reduced the decrease of the intensity of root wound flow in the mature stage. F treatment increased the tiller number of rice,promoted tiller stability,significantly reduced the transpiration rate of rice,and increased the accumulation of dry matter in the mature stage of rice. NS treatment significantly increased the photosynthetic rate and transpiration rate of rice. Straw returning to the field and feeding treatment has its own advantages. In farming practice,when the amount of straw returned to the field is relatively large,appropriate feeding can supplement nitrogen for microbial decomposition of straw and plant growth.

Abstract:In order to explore the influence of ricecrayfish ecosystems on weed in paddy fields,the characteristics of weed community changes and grass control effect in paddy fields with different years of ricecrayfish ecosystem were studied with ecological approaches to plant communities. This paper studied the differences of weed diversity between rice monoculture and ricecrayfish coculture in 1 year,2 years,4 years and 9 years. Field experiments were conducted to investigate the changes of weed species,weed quantity and weed coverage in fields and ridges after a complete 1year ricecrayfish coculture system. The results showed that the indexes of weed biodiversity in ricecrayfish coculture systems had a trend of decreasing first and then increasing with the increase of years. The Simpson index and Shannon diversity index under CK treatment had the highest weed dominance,which was significantly different from ricecrayfish treatments. The RC4 treatment had the lowest weed dominance. The evenness index of Pielou treated by RC9 has the highest evenness,which is not significantly different from that of CK but significantly different from that of other treatments. The total number of weeds in the sample plots with different years of ricecrayfish coculture system decreased first and then increased with the increase of the number of years,which were significantly lower than those treated with CK. The importance values (I values)of different weeds had different regularities with the increase of ricecrayfish cocultivation years. The I values of Leptochloa chinensis，Echinochhloa crausgalli，Paspalum paspaloides and Fimbristylis dichotoma decreased first and then increased with the increase of years. The I values of Mazus japonicus，Alternanthera philoxeroides，Eclipta prostrata and Monochoriav aginalis in ricecrayfish cocultivation paddy fields were smaller than those in rice monoculture paddy fields and decreased year by year. After 1 year ricecrayfish coculture farming，the number of weed species,weed individuals and weed coverage in the paddy field and the ridge were significantly reduced. The results showed that shortterm ricecrayfish coculture significantly improved the weed control effect. Longterm ricecrayfish coculture gradually formed a new weed community structure,and corresponding weed control measures need to be taken.

Abstract:Rice varieties including Xiangyaxiangzhen,Tianliangyou953,Ezhong5,Tianyuanjing036，and Taiyou390 were used to study effects of sowing date on the growth period,lodging index,yield,yield components and quality of rice in the ricecrayfish ecosystem. The results showed that the main factor affecting the shortening of whole growth period was the delay of the period from sowing to jointing and the lodging resistance of most rice varieties gradually increased with the delay of sowing date. Tianyuanjing036,Tianliangyou953 and Taiyou390 had good lodging resistance.The yield of 5 rice varieties increased with the delay of sowing date.The main factors affecting rice yield are the effective panicle and 1000grain weight per unit area. The brown rice rate,white rice rate of 5 rice varieties increased and the chalkiness and chalky rice rate of 5 rice varieties decreased with the delay of sowing time.

Abstract:Genetic analysis of 13 red swamp crayfish (Procambarus clarkii) populations from different regions of the Yangtze River basin in China were performed using 8 simple sequence repeats (SSR) makers. The allele number,herterozygosity,polymorphism information content (PIC),Hardy einberg equilibrium index and genetic distance in the 13 populations were identified,respectively. The results showed that there were 3-5 alleles at each SSR marker locus in the population,the expected heterozygosity were 0.37-0.57,the observed heterozygosity were 0.23-0.48,and the PIC were 0.40-0.56,respectively,suggesting a higher genetic diversity among the investigated populations. In addition,3 groups were classified by a neighborjoining method based on the genetic distance among the populations. Taihu (TH) and Poyanghu (PYH) populations represented the first group,Chongqing (CQ) and Chaohu (CH) populations represented the second group and Honghu (HH),and Dongtinghu (DTH) and Hongzehu (HZH) populations represented the third group. These results indicate that China has a red swamp crayfish resource of high genetic diversity.

Abstract:To reveal the effect of white spot syndrom virus (WSSV) infection on the intestinal flora of crayfish (Procambarus clarkii),16S highthroughput sequencing technology was used to analyze the composition and diversity of the intestinal flora of crayfish in the healthy and artificialinfected group.The results showed that there was no significant difference in intestinal abundance and diversity between the WSSV infected group and the control group,but the composition of their dominant flora was different.The dominant bacteria in the control group were Proteobacteria (75.42%) and Tenericute (19.17%).The dominant intestinal bacteria in the infection group were Proteobacteria (78.14% ) and Bacteroidetes (17.38%).LEfSe analysis showed that compared with the control group,the abundance of Candidatus bacilloplasma was significantly reduced (P ＜0.05) in the infected group,and the abundance of Bacteroidaceae and Flavobacteria was significantly increased (P＜0.05).In addition,the abundance of some potential pathogens such as Flavobacterium and Aeromonas increased significantly after infection (P＜0.05).These results indicated that WSSV infection caused changes in the intestinal flora of crayfish,suggesting that WSSV may cause disease by altered the homeostatic balance of the crayfish intestine.

Abstract:In southeast Yunnan typical karst wetland’s black river basin as the research object,under the precondition of regionalization goal set,based on the regional ecological environment survey combined with geographic information system and remote sensing tools,from the importance of the ecological environment sensitivity and ecological service function and advantage of area development degree of three aspects,the importance of the ecological environment sensitivity and ecological service function,regional differentiation rules,the study area is divided into three district six subregion (specific),and based on this division,the black river basin ecological function areas,clear the area of the main ecological problems,points out its developing direction.(1) agricultural and forestry ecological agriculture construction function zone in western China:low agricultural production structure,regional economic development needs to be based on water protection;(2) the eastern ecotourism functional zone:the livelihood mode is not properly matched,and the region should combine the ecological and environmental protection concept with the economic development structure;(3) ecological protection function area of the southern wetland:water conservation and water and soil conservation are prominent,but industrial pollution is serious,so relevant water and soil conservation measures should be taken to control industrial pollution in the region.

Abstract:To explore the effects of nutritional conditions on bacterial motility and surface attachment,Pseudomonas aeruginosa WT PAO1 and PAO1 ΔfliC (nonmotile mutant) as a model bacterium was used to study cell motility and attachment under various nutrient conditions in drinking water distribution system. To interpret the experimental results,a model was proposed by linking initial surface attachment with cell motility and growth at small scales via individualbased modeling via MATLAB platform. Results showed that nutritional conditions shaped significantly bacterial motility and surface attachment. Nutritional limitation stimulated bacterial motility and thus favored surface attachment for motile cells. In contrast,reducing nutrient concentrations yielded a decline of surface attachment for nonmotile cells. Under various nutritional conditions,attached cells and ratios of WT PAO1 cells were significantly higher than those of PAO1 ΔfliC,validating the crucial role of cell motility on surface attachment. The quantitative analysis of bacterial growth,motility and interactions with nutritional conditions would be beneficial for predicting nutritional conditionsmediated cellcell and cell surface collisions. It will provide mechanistic understanding of bacterial aggregation and attachment process.

Abstract:A strain of yeast ZJH1 capable of reducing Cr(Ⅵ) was isolated and screened from the intestinal juice of Plodia interpunctella (Hübener) larvae polyethylene plastic. The results of morphological characteristics and molecular biological identification indicated that the strain is Pichia guilliermondii. The minimum inhibitory concentration (MIC) of Cr（Ⅵ） was 17 mmol/L. Under the condition of 50 mg/L Cr（Ⅵ）, the MIC of other heavy metals was Cu（Ⅱ）13 mmol/L,Pb（Ⅱ）6 mmol/L,Ag（Ⅰ）4 mmol/L,Mn（Ⅱ）16 mmol/L,Ni（Ⅱ） 3 mmol/L,Co（Ⅱ） 3 mmol/L,Cd（Ⅱ） 0.9 mmol/L and Hg（Ⅱ） 0.2 mmol/L. The effects of temperature,pH,inoculum size,electron donor and different heavy metal ions on Cr（Ⅵ） reduction rate was investigated by Cr(Ⅵ) reduction rate. The results showed that the optimal pH and temperature of strain ZJH1 for reducing Cr(Ⅵ) were 9.0 and 40 °C in yeast leachate glucose liquid medium (YPD). Under optimal conditions,the inoculum was 8%. When Cr(Ⅵ) is the best,the reduction rate of Cr（Ⅵ） is 100% within 48 h when glucose is used as the electron donor. The strain contains Cu(Ⅱ) in the culture solution containing different heavy metal ions. Except for Pb(Ⅱ) and Co(Ⅱ),both the growth ability and ability of strain ZJH1 to reduce Cr（Ⅵ）were inhibited. The order of inhibition was Mn(Ⅱ)＞Hg(Ⅱ)＞Ag(Ⅰ)＞Ni(Ⅱ) )＞Cd(Ⅱ). The result of a preliminary study on the ability of strain ZJH1 to reduce Cr（Ⅵ） showed that strain ZJH1 has good application potential in the remediation of Cr(Ⅵ) pollution.

Abstract:To investigate roles of the longchain fatty acid elongase 2 and 5 (elovl2,elovl5) genes played in biosynthesis of longchain polyunsaturated fatty acids (LC-PUFA) in loach (Misgurnus anguaudatus),fulllength cDNA sequences of the loach elovl2 andelovl5 were cloned and their expression patterns in different tissues were analyzed in this study. Functional characterizations of the loach elovl2 and elovl5 in synthesis of fatty acids were studied by heterologous expression in Saccharomyces cerevisiae in vitro. Loach were fed with three experimental diets containing fish oil (FO),camelina oil (CO) and soybean oil (SO),respectively,for 8 weeks to evaluate the effects of different dietary lipid sources on expressions of the loach elovl2 and elovl5. The results showed that the open reading frame (ORF) of the loach elovl2 and elovl5 was 888 bp and 876 bp,encoding 295 and 291 amino acids,respectively. Phylogenetic analysis showed that they clustered closely with the zebrafish elovl2 and elovl5 and sequence comparison showed that they were highly conserved in vertebrates,containing the special structure of longchain fatty acid elongases. The expression levels ofelovl2 and elovl5 were highest in the liver. ELOVL2 elongated C20-22 PUFA,while ELOVL5 was able to elongate C18:20 PUFA,having no effect on C22 PUFA. The content of n-3 PUFA in the liver and muscle and 20∶5n-3 in the muscle increased significantly,while 22∶6n-3 in the liver and muscle did not increase significantly in the CO group. In addition,expressions of the loachelovl2,elovl5,scd and srebp1c in the liver were significantly increased. In conclusion,elovl2 and elovl5 played an important role in regulating the synthesis of LC-PUFA and CO used in diet could promote the accumulation of n-3 PUFA in loach.

Abstract:The histology of early gonad differentiation was observed,and expression of the genes related to gonadal development (hormad1,dmrt1a) at different early development stages (4，14，21，23，50，60 and 65 dph (days posthatch)) and in different tissues (gonad,liver,muscle,intestine,gill,fin,skin and brain) of the hybrid triploid loach (4 n ♀×2 n ♂) was quantitatively detected by fluorescence quantitative PCR (qRTPCR). The results showed that at different early developmental stages,thehormad1 and dmrt1a genes were expressed the highest on 4 dph,followed by 14 dph and the lowest on 50 dph. In different tissue,the hormad1 gene was expressed highest in the female fins and lowest in the liver,highest in the male gonads and lowest in the liver. The expression of the dmrt1a gene was highest in the gonads of both male and female loaches and lowest in the brain. The differentiation and occurrence of gonads at early stage of the hybrid triploid loach was not different from that of the diploid loach. The primitive germ cells and its migration,formation of the primitive gonads and differentiation of the gonads were observed. In summary,thehormad1 and dmrt1a genes play a certain role during early gonadal development.

Abstract:To solve the problem of complex redundancy of water quality early warning indexes,an attribute reduction algorithm based on correlation attribute importance was proposed. On the basis of attribute dependence and attribute importance,the concept of attribute relevance importance was introduced to reduce the decision attribute according to the influence of each conditional attribute on the decision attribute. By calculating the attribute importance and mining the interaction degree among water quality indicators,classification of decision attribute of condition attribute intensity was further distinguished,then the water quality of bass culture was taken as an example to analyze the algorithm,and the UCI data set was used for experimental verification. The results indicate that the algorithm is effective and feasible on redundancy attribute reduction.

Abstract:In order to establish an avian original cells infection model of the avian adenovirus type 4,and investigate the pathogenicity of the cell culture viruses to chicken,five serotype 4 avian adenovirus isolated in our laboratory from 2014 to 2017 were inoculated into the LMH cells and transmitted blindly,and supernatants of the LMH cell cultures of each virus were selected and injected into the 4weekold SPF chickens through the leg muscle at a certain dose. The incidence of experimental animals was recorded,the organs of the diseased or dead chickens were collected and pathological sections were made. The histopathological changes of SPF chickens infected by virus were observed and analyzed. The results showed that specific cytopathic effect caused by the group I avian adenovirus began to appear when 5 strains of serotype 4 avian adenovirus were blindly transmitted into the LMH cells. The viral nucleic acid was extracted from the culture and identified by PCR,and a specific amplification fragment of about 564 bp was amplified,indicating that the virus can proliferate stably in the LMH cells. Supernatants of the 10th generation cell culture of each virus were selected for SPF chicken regression test. The results showed that from the 3rd day after the 4weekold SPF chickens were infected,some chickens began to depressed,lost their appetite,became paralyzed and died quickly. Observations of the pathological examination and pathological sections showed that the LMH passaged viruses of HB1,HB2,HB3 and SD1 maintained the pathogenicity to the 4weekold SPF chickens. Typical histopathological changes were observed in the sick and dead chickens,while there were no clinical symptoms and pathological changes in the control group. These results suggest that the LMH cells can be used for the proliferation and passage of avian adenovirus,and it is an ideal cell model for study of the molecular pathogenesis of avian adenovirus. 

Abstract:The protective effect of methylnaphthoquinone MK-4 on the oxidation of carotenoids (β-carotene and lycopene) was studied. By simulating the ferricinduced oxidation of carotenoids at low pH in gastric juice,the effect of MK-4 on the retention rate of dietary carotenoids was evaluated.Taking β-carotene as an example,the type and quantity of reaction products of β-carotene in two different systems (without MK-4,adding MK-4) were identified by liquid chromatographymass spectrometry (LC-MS). The results showed that:MK4 had the best protection effect and the retention rate could be increased by 2 times when the oxidation of carotenoids was induced by Fe（Ⅱ）. For the gastric juice without MK-4 in the presence of Fe（Ⅱ）,there were the most types and quantities of reaction products of β-carotene,including cis isomers,epoxy compounds,aldehydes and degradation products,a total of 10 compounds. After the addition of MK-4,the reaction products of β-carotene were reduced to 7 compounds without aldehydes and degradation products. By comparing the HPLC of MK-4 in the micelles before and after the reaction,it was found that the protective effect of MK-4 on β-carotene did not cosume itself.

Abstract:The compound juice of grapefruit and Passiflora edulisSims was prepared by grapefruit and Passiflora edulis Sims in Yulin of Guangxi.The compound juice was treated by pasteurization and ultrahigh pressure (UHP) sterilization,respectively.The effects of sterilization methods on volatile components and physicochemical index of compound juice were compared by flavor profile analysis,electronic nose technology,HPLC and HS-SPME-GC-MS method.The results showed that:the cooking flavor and bitterness of pasteurized juice changed obviously,and the flavor was quite different from that of unsterilized juice；the flavor of UHP juice had no significant changes,which was similar to that of unsterilized juice.Fortythree,twentyfour and thirtyone volatile components were found in the compound juice by nonsterilization,pasteurization and UHP sterilization,respectively; the total contents of volatile components were 18.67,7.73 and 14.33 μg/mL,respectively;the contents of ferulic acid,eriodictyol and naringin in pasteurized juice were decreased by 31.58%,24.15% and 67.40%,respectively;the contents of naringin of bitter compounds increased,while the content of VC and total phenol decreased significantly; by UHP sterilization,the contents of phenolic substances had no significant change,the retention rate of VC,total phenol,citric acid and etc were all above 90%.Thus pasteurization had worse effect on the volatile components in compound juice of grapefruit and Passiflora edulis Sims,while the original quality could be well preserved by UHP sterilization.

Abstract:In this paper,the single factor test was used to optimize the second derivatization conditions of isobutyl chloroformate,and a gas chromatography quantitative detection method for 18 free amino acids in citrus pulp was established. The results showed that the analysis conditions were the best when pyridine,2methyl1propanol,first isobutyl chloroformate and second isobutyl chloroformate were added in the amount of 20 μL,120 μL,50 μL and 50 μL,respectively,and the extraction solvent was dichloromethane. The 18 amino acids showed good linearities in their respective linear ranges,and the correlation coefficient R2 were greater than 0.99. The detection limits were in the range of 0.02-0.35 μg/mL,and the relative standard deviations of 5 repeated tests were no more than 10.57%. The recoveries in five kinds of citrus extracts were between 72.82% and 132.97%. The method is simple,accurate,reproducible,low in cost,stable in derivatives,which can be used for the detection of 18 free amino acids in citrus pulp.

Abstract:In order to improve the utilization value of bound phenolics from ‘dekopon’ citrus pulp residue, the ‘dekopon’ citrus pulp residue without free phenolics was used as raw materials. The effects of different solvent extractions on the content of bound phenolics were compared. Subsequently, the singlefactor test and response surface analysis method were used to optimize the alkaline extraction process.And the type and content of monomeric phenol in bound phenolics and free phenolics were detected by HPLC method. The results showed that NaOH solution was the best extraction solvent for the extraction of bound phenolics. At a liquidtomaterial ratio of 22 mL/g, NaOH concentration of 4.1 mol/L,and alkaline hydrolysis time of 3.2 h, the content of bound phenol reached 356.51 mg/100 g. Ten monomeric phenols were detected in the free phenolics extract, among which hesperidin was the highest (284.44 μg/g), and ferulic acid was undetectable. Eight monomeric phenols were detected in the combined phenol extract. The content of naringin dihydrochalcone was the highest (297.29 μg/g) and the content of ferulic acid reached as high as 128.07 μg/g. Chlorogenic acid, protocatechuic acid were undetectable. In summary, the phenolic acid composition of bound phenolics is rich, and the content of phenolic acid is significantly higher than that of free phenolics, especially the ferulic acid content.

Abstract:A high throughput crawler car image acquisition suitable for dry field crops is designed to realize the growth image of crops automatically and efficiently. The system uses magnetic guidance sensor and magnetic stripe to realize the automatic walking of the car in the field according to the path,adopts crawler car chassis structure to ensure the stable operation of the system in the complex environment of the field. The overlooking and sideview cameras on both sides of the trolley bracket are installed to improve the work efficiency. The system uses wireless communication technology to monitor the operation of small cars remotely and the solar panel is installed at the top of the system to supply electric energy for small cars at run time. The images of maize plants from seedling period to tasseling stage were collected by this system. The results showed that the system was stable and reliable with the absolute error less than 2 cm in approximate straight line at 0.1 m/s speed and the minimum turning radius of 0.5 m. Single camera acquisition efficiency is 30 sheets per minute in continuous acquisition mode which can meet the actual needs. The system will provide a novel method for crop breeders to screen crop traits in the field.

Abstract:The finite element modal analysis of the frame was performed in designing the frame of doublesided orchard ditching machine. Its first 6order frequency and mode shape was obtained and structural performance was analyzed to deal with strength and stiffness issues of frames after importing into ANSYS Workbench whose parametric solid modeling of fixed and folded frames established by Creo. Results showed that the vibration of the fixed section frame was large. It was easy to cause stress concentration and fatigue cracking or even fracture. An improved solution for the frame structure for the fixed section frame was proposed to increase the reliability by adding trusses and eliminating welding residual stress while using structural strength and stiffness as the optimization target with loworder modal frequencies and vibration amplitude as reference standards. The results showed that the first 6order natural frequency of the improved fixed section ranged from 52.884 to 135.77 Hz. The maximum deformation was 0.055 724 mm. The loworder modal frequency and vibration amplitude were effectively improved. The rigidity has been greatly improved to meet requirements of design. The result of modal test showed that the maximum error percentage of the natural frequency of the finite element modal analysis and the modal test results was 0.857%. The vibration mode was basically same. Field validation indicated that the application of the improved frame proved that work quality was in full compliance with the NY/T 740―2003 operation quality standards. The performance was stable,meeting the horticultural requirements of the orchard ditching machine. The combination of finite element modal analysis and structural performance analysis can reduce the customization steps of the initial design,shortening the cycle of mechanical design. It will provide a reference for its practical applications.

Abstract:A threshing drum feeding measuring system is designed based on the film sensor to realize the realtime feeding volume monitoring of the threshing drum of rice combine harvester. The system can monitor the working state of threshing drum and assist in determining the current realtime feeding quantity by using the thin film sensors to measure the force on the top cover. The bench test was carried out under conditions of 1 100 r/min and a feed rate of 0.2 to 0.8 kg/s,using a small horizontal axial flow threshing drum with a rated feed rate of 0.8 kg/s as test object,the mature Late indica rice 98 and Chuanqi Fengliangyou 1 rice as test materials with the rotational speeds of 650 r/min,800 r/min,950 r/min,respectively. The rated feeding capacity of the platform detachment device was 0.8 kg/s. The results showed that the film sensor was collected. Realtime signal was significantly correlated with realtime feeding. The linear relationship between feeding amount and sensor signal was fitted with good fitting effect. It is indicated that the measuring system designed can measure feeding amount through sensor signal.

Abstract:Shelling is the only important processing step from production to utilization of peanuts. The shelling machine is the most important core equipment of peanut shelling processing operation,which both mainly determines the peanut shelling efficiency and the processing quality such as the degree of loss and damage of peanut kernels. Even though the peanut production ranks first in the world and shelling technology is widely used,China’s peanut shelling technology is far poorer than the United States,which has been seriously restricting the development of peanut food processing industry and the export of peanuts as well as their products in China. In order to explore,analyze and use the experience of the American peanut shelling technology and development for reference,based on onsite observation,public survey of documents and the systematical analysis,the classification and review of the peanut shelling technology of the USA significantly different from China in aspects including the industrialization,and the characteristics of the large scale were conducted. The advanced equipment and wellequipped assembling were summarized. The development history and research status of American peanut shellers were analyzed deeply. The scraping shelling principle and relevant sheller structural type and development of shelling parts were dissected. The technical characteristics of lowspeed,multiroller independent driving and double cleaning device of the latest peanut shelling machine in the United States were pointed out. The studies on shelling factors and the experience in promoting the development of peanut shelling technology of the USA were summed up. It will provide important reference for studying and developing peanut shelling technology in China.