Abstract:Paddy agroprinology is a branch of farming science， which is a comprehensive applied agricultural science that studies the establishment of a reasonable theoretical and technical system of paddy farming system. Paddy agroprinology has theoretical， practical， comprehensive and regional characteristics.The theoretical system of paddy agroprinology includes the theory of ecological adaptability， the theory of light energy utilization， the theory of life factor， the theory of competition and complementarity， and the theory of allelopathy and biodiversity. The establishment of a reasonable paddy farming systems should follow the principle of combination of use and cultivation， the principle of simultaneous development of economic benefits， social benefits and ecological benefits， the principle of coverage in winter， spring， summer and autumn， the principle of equal emphasis on land saving， water saving， fertilizer saving， pesticide saving and energy saving， and the principles of matching good farmland， good farming systems， good varieties， good methods of cultivation， good input of agricultural material and good environment. Since the founding of New China more than 70 years ago， especially since the new century， paddy agroprinology has made positive progress in the composition and distribution of crop， the patterns of paddy farming， the methods of land maintenance， the development of regional paddy farming systems， and the studies on paddy farming system abroad. The content of studies is deepening， the scope of studies is expanding， the achievements of studies are increasing， and the benefits of studies are emerging.At present， the development of paddy agroprinology still has some outstanding problems including insufficient attention， insufficient investment， incomplete theory， lack of new technology， less studies in depth and little impact compared with the general background and requirements of “high-quality developmen”. It is urgent to take the countermeasures and measures including raising awareness， increasing investment， accelerating construction， deepening studies， strengthening exchanges and services.

Abstract:Five treatments including no nitrogen application （CK），conventional nitrogen application （MRN） and reduced nitrogen application by 20%，40% and 60% （MRN1，MRN2 and MRN3） under the condition of mixed sowing of Chinese milk vetch and rapeseed were used to study the effects of mixed sowing of green manure and combined application of nitrogen fertilizer on the rice yield，the carbon and nitrogen and microbial community in soil，and the main environmental factors affecting microbial community structure.The rice yield and its components，the carbon composition，the nitrogen composition and relative abundance of microbial community in soil were measured.The effects of carbon and nitrogen on microbial community were analyzed.Results showed that the yield of early rice and late rice increased by 24.42%-39.23% and 19.34%-31.59% compared with CK treatment.The effect of MRN1 treatment on early rice and late rice was the best.Compared with CK，the content of nitrate nitrogen，ammonium nitrogen and alkali-hydrolyzable nitrogen in MRN1 was significantly（P<0.05） increased by 22.07%，19.05% and 11.20%，respectively.The content of soluble organic carbon and easily oxidized organic carbon in soil increased with the decrease of nitrogen application.The content of nitrate nitrogen and alkali-hydrolyzable nitrogen in soil decreased with the decrease of nitrogen application rate.The dominant bacteria were Chloroflexi，Proteobacteria，Acidobacteriota，Actinobacteriota，Firmicutes.Applying nitrogen fertilizer increased the evenness index of bacterial community.The content of alkali-hydrolyzable nitrogen，nitrate nitrogen and ammonium nitrogen was negatively correlated with dominant flora.The content of microbial nitrogen，easily oxidizable organic carbon and soluble organic carbon was positively correlated with dominant flora.The environmental factors having the greatest influence on the bacterial community structure were alkali-hydrolyzable nitrogen，microbial biomass nitrogen and soluble organic carbon.It is indicated that the mixed sowing of green manure and nitrogen reduction by 20% increase the rice yield and the content of inorganic nitrogen in soil，the community abundance of dominant bacteria，which is conducive to the reduction of emissions and the increase of efficiency in paddy fields，and the maintenance of the stability of ecosystem in paddy field.

Abstract:The changes of the concentration of nitrogen and phosphorus in the multiple cropping system of rapeseed-rice， the cumulative loss of nitrogen and phosphorus in the runoff water and the yield of crops were studied through the positioning monitoring test under three different modes of fertilization including the optimization of principal factor， the integrated optimization and the conventional treatment to investigate the effects of optimized fertilization on the yield of crops and the dynamic changes of the loss of nitrogen and phosphorus in the runoff water of paddy field.The results showed that the content of total nitrogen， nitrate nitrogen， total phosphorus and soluble phosphorus in the runoff water during the whole growth period increased first， then decreased， and then tended to be stable， while the content of ammonium nitrogen in rapeseed was always low.Compared with the conventional treatment， the average content of total nitrogen， ammonium nitrogen and nitrate nitrogen in the runoff water under the principal factor optimization decreased by 31.44%， 45.45% and 28.84%， respectively.The accumulative loss of total nitrogen， ammonium nitrogen and nitrate nitrogen under conventional treatment were 10.92 kg/hm²， 0.37 kg/hm² and 9.16 kg/hm²， respectively.Under the principal factor optimization and the integrated optimization， the cumulative loss of the total nitrogen， ammonium nitrogen and nitrate nitrogen decreased by 31.41% and 22.99%， 2.71% and 43.24%， 31.01% and 29.81%， respectively.The yield of rapeseedseed under the integrated optimization was 1 954.6 kg/hm²， which was 4.60% and 4.79% higher than that under the principal factor optimization and conventional treatment， respectively.The yield of rice under integrated optimization was 6 375.5 kg/hm²， which was 3.76% and 0.81% higher than that under the principal factor optimization and conventional treatment， respectively.It is indicated that the integrated optimization can not only significantly improve the yield of crops， but also effectively reduce the risk of the loss of nitrogen and phosphorus in paddy fields compared with conventional fertilization， which is of great significance for protecting the environment and controlling the pollution of non-point source.

Abstract:Four farming patterns including double rice （DR），middle rice （MR），middle rice-rapeseed rotation （MROR）， and middle rice-pakchoi-rapeseed rotation （MRPOR） in a long-term （10 years） practices were selected to analyze the abundance and differences in community structure of fungi under different farming systems in China. The abundance and community composition of fungi in paddy soils were determined by real-time fluorescence quantitative PCR and high-throughput sequencing to analyze the differences in the abundance and community structure of fungi in soil under different farming patterns and their influencing factors. Results showed that MR， MROR and MRPOR had a significant influence on the abundance of fungi. MRPOR increased the abundance of fungi. The result of correlation analyses showed that nitrate nitrogen was significantly and positively correlated with the abundance of fungi. The crop rotation had a significant influence on the gene community structure of fungi in soil. The result of redundancy analyses showed that the content of soil water was the most significant factor affecting the community structure of fungi. In conclusion， the abundance， composition and diversity of communities of fungi in soil were different under different farming patterns of rice. The abundance of fungi was greatly affected by the content of nitrate nitrogen in soil under different farming patterns， and the community structure of fungi was mainly affected by the content of water in soil.

Abstract:The physicochemical properties，denitrification differences and related microbial composition in soil under four rotation and fallow patterns including B （Chinese milk vetch - early rice- maize || batatas） ，C （ rapeseed - sugarcane || spring soybeans），D （Chinese milk vetch - spring soybeans - autumn soybeans ） and E （annual fallow） were compared and analyzed using the traditional cropping pattern A （Chinese milk vetch-early rice-late rice） as the control to study the effects of different rotation and fallow patterns on the nitrogen loss，the denitrification potential and related microbial community structure in soil of paddy fields.The acetylene inhibition method was used to determine the denitrification rate.The high-throughput sequencing was used to analyze the diversity and composition of denitrifying microbial communities.The results showed that the denitrification potential in soil under four rotation and fallow patterns was significantly lower than that under the control，which effectively reduced the gaseous loss of nitrogen in soil.There were significant differences in the community structure of functional genes nirK and nirS under different rotation and fallow patterns，among which the community structure of gene nirK was less affected by the rotation and fallow patterns than that of gene nirS.Compared with the control，the E pattern was more conducive to the accumulation of α-diversity of gene nirS.In terms of the relative species abundance of nirS and nirK gene communities，the abundance of dominant species under four rotation and fallow patterns was higher than that under the control，and the abundance of fungal genera in the pattern B and pattern E was relatively higher.The key genera affecting denitrification potential were Bradythizobium （r² = 0.85，P<0.05） and unclassified_p，Proteobacteria （r² = 0.88，P <0.05）.The results of correlation and redundancy analyses showed that pH，the available phosphorus （AP），available potassium （AK） and nitrate-nitrogen （NO₃^--N） in soil was significantly correlated with the denitrification potential in soil，while the important factor affecting the community structure of gene nirK and nirS was the content of water in soil （SWC）.It is indicated that the rotation and fallow patterns of appropriate water-drought and dry-drought crop in paddy fields can change the flooding environment in soil，affect the community structure of gene with denitrification function，help inhibit the gaseous loss of nitrogen in soil，and promote the improvement of the fertility and structure in soil，among which the pattern B and pattern E is the best.

Abstract:The effects of rotation and fallow patterns on the soil organic carbon and its components in paddy fields were studied through two consecutive years of field experiments to optimize and screen the green and efficient multiple cropping mode of rotation and fallow in the rice fields with double cropping.The results showed that the total biomass of “Rapeseed - sugarcane || spring soybean → Chinese milk vetch-early rice-maize || sweet potato” pattern for two years was 31.68% - 65.91% higher than that of other patterns.In 2018-2019，the “Rapeseed - sugarcane || spring soybean” and the “Chinese milk vetch - spring soybean - autumn soybean” pattern were more conducive to the accumulation of total carbon in soil.The multiple cropping rotation pattern and fallow pattern were more conducive to the accumulation of active organic carbon in soil than the continuous cropping pattern.The “Chinese milk vetch - early rice and maize || sweet potato” and the “Rapeseed - sugarcane || spring soybean” were the best patterns.The “Rapeseed - sugarcane || spring soybean” pattern was more conducive to the accumulation of soluble organic carbon，microbial biomass carbon in soil.In 2019，the A（carbon pool activity），AI（carbon pool activity index）and carbon pool management index（CPMI） of the “Rapeseed - sugarcane || spring soybean” pattern reached the maximum and were 59.46%-84.38%，59.06%-84.47% and 52.81%-71.40% higher than those of other patterns （P<0.05）.The rotation pattern was more conducive to improving A，AI and CPMI，especially the “Chinese milk vetch - early rice and maize || sweet potato” and the“Rapeseed - sugarcane || spring soybean” patterns had good performance.Under the condition of local soil fertility，paddy-upland multiple cropping rotation pattern increased the content of organic carbon and its components in soil，which is conducive to improving the soil quality and the soil fertility.Among the five patterns，the “Rapeseed - sugarcane || spring soybean to Chinese milk vetch - early rice - maize || sweet potato” pattern was the best.

Abstract:The DNDC model is a relatively mature dynamic simulation model that simulates biogeochemical processes with time factors，and can be used to simulate and evaluate the production of crop （such as rice），the dynamic evolution of carbon and nitrogen，and greenhouse gas emissions in paddy ecosystem. In order to understand the DNDC model more fully and make it used more widely，this article analyzed and summarized the progress of DNDC model in paddy soil carbon sequestration potential，greenhouse gas CO₂ and CH₄ emission simulation，paddy management model evaluation and model parameter sensitivity analyses from the perspective of paddy soil carbon dynamics based on the composition and function of the DNDC model，the comparison of the six world-famous biogeochemical models，and the module optimization of the DNDC model in the paddy ecosystem. It also pointed out that the DNDC model affected by factors including large spatial heterogeneity of soil properties and differences in regional field management measures has problems including difficulty in extending point-scale verification to location-scale simulation and difficulty in model correction，which limit the accuracy of the model. In order to enable the DNDC model to carry out simulation under the complex characteristics of the agricultural development in China in the future，we should pay attention to optimize the function of the DNDC model module and improve the accuracy of input parameters to further improve the accuracy of model simulation and the reliability of the prediction and evaluation system，to provide methodological reference for studying the carbon dynamics of paddy ecosystem and making the model play a better role in the carbon sequestration，emission reduction of paddy field and the formulation of management scheme.

Abstract:The subtropical paddy soils have the racteristics of long-term and sustainable carbon sequestration，and the dynamics of soil organic carbon （SOC） storage is of great significance for accurately assessing the “source-sink” function of regional carbon in China.This article discussed the temporal and spatial distribution and evolution of soil carbon storage in subtropical paddy soils，the input of soil organic carbon in paddy fields，the function of microbial carbon sequestration，the characteristics of organic carbon mineralization and its mechanism.The soil carbon sequestration and emission reduction in paddy soils under the background of "carbon neutrality" was prospected.The soil organic carbon storage and carbon sequestration of paddy soils in the subtropical region of China are obviously higher than those in other regions.Its outstanding carbon sequestration ability is mainly due to the input of photosynthetic carbon in rice，soil autotrophic microbial carbon sequestration and flooding，which limits microbial activity，inhibits the microbial decomposition process of plant residues，and promotes the direct accumulation of plant residues.The mineralization rate of soil organic carbon in paddy soils is regulated by factors including the stoichiometetry of carbon，nitrogen and phosphorus，management of water and fertilizer，and temperature，which affect the efficiency and potential of carbon sequestration and emission reduction in paddy soils.Based on the importance of subtropical paddy soils to soil carbon sequestration and carbon reduction of farmland soil in China，a systematic study on the mechanism of soil organic carbon accumulation and transformation in paddy ecosystems was proposed，and a high-precision regional soil organic carbon simulation model and methods for estimating soil organic carbon storage were constructed.It will help improve the soil fertility of farmland，accelerate the double-carbon goal of agriculture and promote the green development of agriculture in China.

Abstract:In order to explore the comprehensive benefits of different planting patterns in paddy fields in the middle reaches of the Yangtze River and screen the efficient planting patterns suitable for the middle reaches of the Yangtze River，five typical planting patterns in the middle reaches of the Yangtze River were selected.The resource utilization and comprehensive benefits of typical planting patterns in the middle reaches of the Yangtze River were compared through two consecutive years of field experiments.The results showed that in two years，the annual total light energy utilization rate of each treatments were higher than that of the control treatment，except the treatment RRR in 2020.The annual total light energy utilization rate of each treatments were significantly higher than that of the control treatment 10.98%-35.37% and 22.22%-50.00%.In two years，the anniversary of light energy and annual total light energy utilization efficiency under the treatment of RRI were higher，the second is treatment of CRI.During two years，the annual accumulated temperature production efficiency of the other three treatments were significantly higher than that of the control 8.28%-25.44% （2019） and 21.09%-26.78% （2020），except for the treatment of CRI.The effective accumulated temperature of utilization rate under the models of winter milk vetch were higher，the treatments of CRI and CRR have good performance，improve the utilization rate of accumulated temperature.For consecutive two years，comprehensive benefit weighted correlation degree under the treatment of CRI was 0.75 and 0.81 respectively，the comprehensive benefit was optimal.To sum up，in consideration of high yield，low greenhouse gas emissions，high soil quality，high resource utilization efficiency and the most optimal comprehensive benefit，the model of Chinese milk vetch-early rice-sweet potato||late soybean had good performance，which played an important role in the optimization of paddy planting pattern in the middle reaches of the Yangtze River.

Abstract:The middle reaches of the Yangtze River is an important rice production base in China，which has made great contributions to the national food security and ecosystem safety and health.Scientific and reasonable evaluation of the service function value of paddy field ecosystem can provide an important basis for the evolution，improvement and promotion of its service function value and the promotion of the green sustainable development model of paddy field.On the basis of sorting out the connotation of paddy field ecosystem service function and the evaluation system and methods of service function value，this paper classified and compared the methods of evaluating the ecosystem service function of different paddy fields in the middle reaches of the Yangtze River，and summarized the research framework and research ideas of the evaluation of paddy field ecosystem service function value in this region.Due to the differences in types，distribution areas and value evaluation index systems of paddy fields，there are some differences in the evaluation methods of ecosystem service function value and the value of service function per unit area. It is suggested that future research should constantly modify the evaluation index system of different paddy ecosystem services value，improve the evaluation method，and raise the evaluation accuracy.At the same time，this paper also analyzed the service function of some paddy fields in the middle reaches of the Yangtze River，and found that the research perspectives mainly focused on the micro experiment of paddy fields and the macro measurement of provinces，cities and counties. The static evaluation of the service function value of a certain part of the paddy ecosystem or the overall service function value of the system was carried out，but the long-term dynamic tracking research on its value evaluation was insufficient. The research on the net value of paddy field ecosystem services also needs to be further studied.

Abstract:Rice production in super large cities is not only significant for food security，but also important for sustainable development of cities as a special type of constructed wetlands.This article summarizes and studies the evolution and status quo of the paddy farming system in Shanghai，and puts forward the development direction of the farming system.Over the past 70 years，the farming system transformed from a triple-cropping system to a double-cropping system in the 1980s，and to a single-cropping system gradually in the 2010s.Recently，the farming systems concerning soil-improving measures were established.Rice production and animal husbandry were combined in some districts of Shanghai based on the application of manure or biogas slurry.Moreover，much more ratio of rice was sold through the branding strategies.Nevertheless，rice production in Shanghai is also facing many challenges including the demand for keeping stable grain yield，the limitations imposed by resource and environment capacity，and inadequate profitability of rice selling which leads to high dependence on financial subsidies.Measures and advices including ensuring that both the area of cultivated land and proportion of paddy land does not decrease，stabilizing the yield potential per unit area，integrating and innovating green farming techniques to improve the ecological function of paddy wetlands，and upgrading the branding strategies for converting the ecological value of green rice planting to the economic benefits are proposed in the view of the challenges mentioned above.

Abstract:In order to find out the transmission route of red imported fire ants （Solenopsis invicta Buren） in Hubei Province and effectively monitor their occurrence，in this study，ant samples collected from Wuhan，Huanggang，Jingmen and Yichang were identified as red fire ants by morphological and molecular identification techniques，and field investigation and suitability analysis of red fire ants in Hubei Province were carried out. The results showed that the newly occurring areas were moderately heavy or severe，and the nests of red fire ants produced winged reproductive ants，which had the ability of marital flight and dispersal. The main transmission route was to introduce the soil nursery plants carrying red fire ants from the occurrence areas of red fire ants in southern China. AcrGIS system was used to analyze the suitable habitat of red imported fire ants in Hubei Province，and the results showed that the climate conditions in most regions of Hubei Province could satisfy the survival and reproduction of fire ants except for the western region of Hubei Province （mainly Enshi City） and the northern region （mainly Shiyan and Shennongjia Forest Region），where the effective accumulated temperature was low and （or） rainfall was less. Therefore，it is necessary to strengthen plant quarantine，monitoring and control in the suitable areas of red fire ants in Hubei Province.

Abstract:In order to establish a simple and easy method to evaluate pathogenicity of Radopholus similis in laboratory， and to determine the pathogenetic difference of different populations， in this study， different populations of Jinfeng No.1 tomato were inoculated with different inoculation concentration and treatment time at （25±1） ℃ by using quartz sand culture. The nematode reproduction rate， root disease severity and plant growth were detected. Four different populations of female worms （HN6， SZ-FZ， GJ-LY323 and DBSR） were inoculated with 50， 100， 150 and 200 worms per plant to 30-day-old plants. After 9， 16， 23 and 30 days of inoculation， it was found that R. similis developed， propagated， and mainly infected the cortical cells of tomato root system. The pathogenicity on tomato was different with different inoculation dose and inoculation time. The reproduction rate of nematodes and the root disease severity increased with the increase of inoculation amount and time， while plant growth decreased. After inoculation with 150 nematodes per plant for 23 days， the most significant differences were observed in each index， which could distinguish the pathogenicity difference among different populations. Eight populations of R. similis were inoculated to 30-day tomato with 150 nematodes per plant for 23 days， and it was found that the pathogenicity of eight populations was in order of SZ-SWK>HaiN-YJ> HL-XY>SZ-FZ≥GJ-LY323>DBSR>HN6>ML-HG. The results showed that tomato was a good host for R. similis， and pathogenicity of different populations can be evaluated by inoculating 30-day-old tomato with 150 nematode per plant indoors for 23 days and analyzing three indexes of nematode reproduction rate， root disease severity and plant growth.

Abstract:The Chinese milk vetch - maize （CM） was used as the control （CK） and five maize based planting patterns including potato-maize || soybean （PMS），“three flowers（Chinese milk vetch× rapeseed × radish in fertilizer field）”mixed sowing-maize || peanut （TMP），broad bean-maize || sweet potato （BMS），rapeseed-maize || soybean （RMS） were set up in red soil dryland to study the effects of planting patterns on the organic carbon pool components，carbon pool management indices and quality in soil.The changes of the organic carbon and carbon pool management index in soil after harvest in the first and second seasons were analyzed.The results showed that the active organic carbon of PMS，TMP，BMS and RMS increased by 53.67%，67.89%，11.01% and 57.80% compared with the control.The activity and activity index of carbon pool of PMS，TMP and RMS were significantly （P<0.05） increased by 52.63%- 89.47% and 53.49% - 93.80%，respectively.The carbon pool management index in soil of PMS，TMP and RMS was significantly （P<0.05） higher than that of the control by 59.24%，60.71% and 80.91%.There was a significant positive correlation between the carbon pool management index and the content of active organic carbon in soil （P<0.01）.The yield of maize intercropping was higher than that of monoculture.The economic yield under different planting patterns was higher than that of the control.The result of comprehensive analyses showed that the different planting patterns with maize as the main body in red soil dryland are conducive to improve the content of active organic carbon，the efficiency of carbon，the carbon pool management index in soil and the yield of maize.The economic yield under the PMS pattern was the highest.TMP pattern was most favorable to improve the carbon pool management index in soil，followed by the RMS pattern.

Abstract:Four fertilization treatments including no fertilization （CK），nitrogen，phosphorus and potassium fertilization （NPK），organic fertilization （OM），and nitrogen，phosphorus and potassium organic fertilization （NPKOM） were applied to the long-term positioning test sites.The denitrification potential of soil under the four fertilization treatments was determined by a combination of field sampling and laboratory analyses.The differences of soil denitrification potential under different fertilization treatments and its intrinsic relationship with environmental factors were compared and analyzed based on the basic physical and chemical properties of soil to study the relationship between the denitrification potential of soil and fertilization treatments.The results showed that the denitrification potential of soil with organic fertilizer was the highest，and that of soil with NPK fertilizer was the lowest.The main factors affecting soil denitrification potential were pH，organic matter，total phosphorus and fast available phosphorus.The application of organic fertilizer increased soil denitrification potential and N₂O emission while increasing soil pH.Nitrogen，phosphorus and potassium fertilizer reduced the soil pH，leading to the reduction of soil denitrification potential.The mixed application of NPK and organic fertilizer can increase soil pH，reduce soil denitrification potential of single application of organic fertilizer，and reduce soil N₂O emissions.

Abstract:Transcriptome sequencing technology （RNA-seq） has been widely used in the field of basic scientific studies， but the bioinformatics analysis of RNA-seq data places high requirements on the programming ability of researchers.In order to enable researchers to analyze RNA-seq data simply and efficiently， this article constructed an automated and modular workflow-RNApipe （On Github：https：//github.com/ywu019/RNApipe.git） based on the Snakemake workflow management system and Conda environment manager.RNApipe can automatically conduct quality control， alignment， quantification， identification of differential genes， and functional annotation analyses including GO， KEGG， and GSEA with RNA-seq data from any species with a reference genome.The results of analysis in each step are presented in high-quality visualizations or reports， and important output files are preserved.RNApipe has been tested and evaluated in multiple model species.The results showed that RNApipe can run smoothly and the results of annotation are accurate.Compared with the existing pipelines of automated analysis， the main features of RNApipe include （i） the workflow is relatively complete， （ii） the default tools consume less time and resources， （iii） applicable to any parametric species， （iv） comprehensive visualization， and （v） user-friendliness （easy to install， use， and expand）.The features of RNApipe mentioned above allow researchers to quickly obtain essential information from large-scale RNA-seq sequencing data.

Abstract:As a major inorganic nitrogen source，ammonium can not only be absorbed by plant roots from the soil，but also generated during a number of biochemical processes inside plants. However，high concentrations of ammonium are toxic to plants resulting in growth inhibition and yield loss， therefore ammonium homeostasis needs to be under fine-tuned modulation in plants. Since currently nitrogen fertilizers are widely and largely used in the agricultural production， plants are facing the challenge of high ammonium presence. It is very important to understand the mechanisms of plant tolerance to ammonium toxicity for improving the use efficiency of nitrogen and the yield of crops. In order to explore the mechanisms of plant tolerance to ammonium toxicity， we reviewed the progress in mechanisms of plant tolerance to ammonium toxicity from three aspects including the source of ammonium nitrogen in plants，the causes of ammonium toxicity，and the physiological and molecular mechanisms of plant tolerance to ammonium. It was pointed out that the acidification of rhizosphere and apoplast caused by the absorption and assimilation of ammonium was a major cause of ammonium toxicity. Plants can alleviate the ammonium toxicity through their own mechanisms and the addition of other nutrients. At the same time， the research on mechanisms of plant tolerance to ammonium toxicity in the future was prospected. It will provide the theoretical reference for the molecular breeding of crops to tolerate ammonium toxicity and utilize nitrogen efficiently.

Abstract:Silicon is one of the most abundant elements in the earth’s crust， and also a beneficial element for plants. It has the effect of promoting plant growth and improving crop yield. Numerous studies have shown that silicon plays an important role in enhancing plant stress resistance as well. This article systematically reviewed the research progress of silicon enhancing plant resistance to biotic stress （including pathogens， pests， etc.） and abiotic stress （drought， salt damage， heavy metals， etc.） to further study the relevant mechanisms of silicon enhancing plant stress resistance. Studies existed have comprehensively shown that silicon can stabilize cell structure and improve plant morphology to enhance plant physical defense， and strengthen chemical defense by balancing nutrient absorption and regulating hormone metabolism. At the same time， it participates in gene expression regulation and improves plant molecular defense. And the future direction of studying silicon was prospected，such as the coupling mechanism of silicon resistance to various stresses， the in-depth study on the biochemical and molecular mechanisms of silicon improving plant stress resistance， and the development of new silicon fertilizers and supporting fertilizationtechnology.

Abstract:With the rapid development of intensive breeding industry，about 3.8 billion tons of livestock and poultry manure will be produced in China every year，causing the accumulation of livestock and poultry manure and environmental pollution.It is one of the main sources of non-point pollution in China.At the same time，there is a serious shortage of feed protein raw materials in China，and more than 80% of them depend on imports.The annual import value exceeds more than 200 billion yuan，making China the largest importer of protein raw materials in the world.Insects can efficiently transform livestock and poultry manure，reduce greenhouse gas emissions，and produce excellent insect protein，fat and insect sand，so as to realize nutrient circulation and resource utilization of livestock and poultry manure.The biotransformation of livestock and poultry manure insect，represented by black soldier fly，has low energy consumption，low emission and good social，ecological and economic benefits.It will be one of the most potential strategies to solve the dilemma of livestock and poultry manure pollution.In recent years，the transformation industry of livestock and poultry manure by black soldier fly has developed rapidly.In this paper，the environmental and resource problems brought about by livestock and poultry breeding and the beneficial resource utilization generated by black soldier fly biotransformation are analyzed and elaborated，and the future development direction is prospected，in order to provide reference for the development of low-carbon livestock industry of black soldier fly transforming livestock and poultry manure.

Abstract:In order to investigate the more complex regulatory network of fat deposition under the influence of alternative splicing，and to clarify the effect of the occurrence of alternative splicing events on the regulatory mechanism of fat deposition，in this study，full-length transcriptome sequencing was performed on abdominal fat，subcutaneous fat and intermuscular fat of Yiling yellow cattle based on the third-generation sequencing technology of PacBio sequencing platform.A total of 50 520 alternative splicing were detected in 15 445 genes，accounting for 33.4% of all bovine genes.Enrichment analysis of these genes revealed that 83 GO items were significantly enriched，among which 16 were associated with lipid synthesis and metabolism，and 27 KEGG pathways were significantly enriched，among which 15 were associated with lipid synthesis and metabolism.The sequenced sequences were annotated using KOG，KEGG，NR，Swiss Prot，and GO databases，and a total of 80 756 sequences were annotated to 69 259 genes，94 458 CDS sequences and corresponding pep sequences.In GO analysis，15 039 sequences were enriched to 507 biological process items，7 907 sequences were enriched to 214 cellular component items，and 30 672 sequences were enriched to 559 molecular function items.A total of 49 710 sequences were enriched in 34 pathways by KEGG data analysis，of which 7 002 sequences were involved in signal transduction pathways.The above results indicate that there are a lot of alternative splicing events in bovine adipose tissue，and these genes with alternative splicing events play an important role in the regulation of fat deposition，which may provide necessary resources and theoretical basis for analyzing the regulatory network of fat deposition from the perspective of gene alternative splicing.

Abstract:To investigate the effects of methionine and lysine supplementation on growth performance，transaminase，body composition and antioxidant performance of juvenile Micropterus Salmoides，three dietary protein gradients （46% （control），41% （LP1） and 36% （LP2）） were set.On the basis of 41% and 36% protein diets，crystal lysine and methionine were supplemented to keep the contents of lysine and methionine consistent with the control group，which were recorded as LP1+AA group and LP2+AA group，respectively.Each experimental group contained 3 biological replicates and the feeding period was 8 weeks.The results showed as follows：compared with the control group，there were no significant differences in weight gain rate （WGR），specific growth rate （SGR），feed conversion ratio （FCR） and protein retention （PR） in LP1+AA group，but significant changes were observed in other groups.With the decrease of protein level，crude protein content in muscle and whole body was significantly decreased，but not in LP1+AA group compared with the control group.There was no significant change in crude fat and ash content.The hepatosomatic ratio （HSI） in low protein diet group was significantly decreased，but there was no significant decrease in LP1+AA group compared with the control group.Compared with the control group，the levels of liver reactive oxygen species （ROS） and total antioxidant capacity （T-AOC） of fish in LP2 and LP2+AA groups were significantly changed.The T-AOC of liver in LP1 group was significantly decreased，but it was significantly increased in lysine and methionine supplementation groups.Reducing dietary protein level （5% or 10%） had no significant effect on liver transaminase activity.Although serum glutamic-pyruvic transaminase （GPT） activity changed significantly in LP2 group，there was no significant difference when lysine and methionine were added compared with the control group.The results showed that when dietary protein content was reduced from 46% to 41% and supplemented with essential amino acids，the growth performance was not significantly affected，but when the dietary protein content was reduced to 36%，lysine and methionine supplementation could not effectively alleviate the negative effects of low dietary protein on growth performance.

Abstract:In order to clarify the molecular mechanism of fish pharyngeal tooth development，taking Megalobrama amblycephala，a unique economic fish in China，as the research object，the cDNA sequence of secretory calciumbinding phosphoprotein （SCPP） family genes was obtained through whole genome sequence Blast. The expression of SCPP family genes in the fourth and fifth branchial arches during the critical stages of pharyngeal tooth development and in different tissues of one-year-old M. amblycephala was analyzed by qRT-PCR method to screen the key genes regulating the development of pharyngeal teeth. Multiple sequence alignment of amino acids showed that enam，scpp1，ambn，scpp9，odam，and spp1 of M. amblycephala and zebrafish share high identity，which were close to each other in the phylogenetic tree. By comparing the amino acid sequences encoded by enam and odam in different vertebrates，it was found that there were two amino acid sequence deletions in fish. The expression levels of enam，scpp1，ambn，scpp9 and spp1 in the fifth branchial arch （with pharyngeal teeth） and ribs were significantly higher than those in other tissues （P<0.05），and the expression levels of them were lowest in the fourth branchial arch （without pharyngeal teeth）. The expression levels of enam，ambn，scpp9，odam，and spp1 in the fifth branchial arch were significantly higher than those in the fourth branchial arch，and the expression level of scpp9 in the fifth branchial arch was extremely high. The results above showed that enam，scpp1，ambn，scpp9，odam，and spp1 were all involved in the regulation of pharyngeal tooth development，among which，scpp9 played a more important role in the regulation of pharyngeal tooth development，suggesting that it was more closely related to the development of pharyngeal teeth.

Abstract:The aim of this study was to investigate the regulatory effect of ddx27 gene on tp53 gene expression in zebrafish （Danio rerio） .The zebrafish ddx27 eukaryotic expression vector pCMV-3×Flag-ddx27 was constructed using homologous recombination technology based on the coding sequence （CDS） of ddx27 gene from NCBI online database.Sub-cellular localization and Western blotting were used to confirm the expression of ddx27 gene，the effect of ddx27 gene overexpression on tp53 gene expression was tested using dual-luciferase reporter gene assay.The results showed that the electrophoretic fragment size and sequencing alignment of ddx27 CDS region and positive clones were consistent with expectations.Western blotting showed that Ddx27 recombinant plasmid could be expressed normally，and the protein size was consistent with the predicted results.Sub-cellular localization showed that Ddx27 protein was expressed in the nucleus of HEK293T cells.Furthermore，the pCMV-3×Flag-ddx27 vector could significantly enhance the activity of tp53 promoter reporter gene pGL3-tp53-Luc，which was 1.8 times than that of the control group （P<0.05）.The above results showed that the zebrafish pCMV-3×Flag-ddx27 eukaryotic expression vector was successfully constructed and could be expressed in the mammalian nucleus，and ddx27 gene could promote the expression of tp53 gene.

Abstract:To understand the molecular mechanism of interleukin in Monopterus albus against Aeromonas veronii infection，the sequence characteristics of six interleukin genes including il-6，il-12p35，il-12p40，il-15，ebi3 and il-34 and their coded proteins in M. albus were analyzed by bioinformatics method，and the expression patterns of these genes in healthy and A. veronii infected M. albus were analyzed by real-time quantitative PCR （qRT-PCR）. The results showed that the amino acids sequences of six interleukin proteins had the highest similarity and the closest evolutionary relationship with those of tilapia. The gene structure of six interleukin genes was basically the same as that of other fish. Synteny analysis showed that il-15 was relatively conserved in evolution. Interleukin genes were expressed in different tissues of healthy M. albus. Compared with the control group，the expression of interleukin genes changed significantly after A. veronii infection. Among them，il-6，il-12p35 and ebi3 were involved in the early stage of antibacterial immune response of M. albus. The results showed that il-6，il-12p35，il-12p40，il-15，ebi3 and il-34 genes all played a regulatory role in the immune defense of M. albus against pathogen invasion.

Abstract:To screen out natural compounds against Aeromonas hydrophila （A. hydrophila） infection， minimal inhibitory concentration determination， growth curves， hemolysis， Western blot， qRT-PCR and cytotoxicity assay were performed to assess the inhibitory effect of diosmetin on the expression of aerolysin secreted by A. hydrophila. The results showed that diosmetin without anti- A. hydrophila activity could inhibit the hemolytic activity of bacterial supernatants by decreasing the transcription of aerolysin gene. Moreover， live/dead staining assay showed that diosmetin could attenuate cell injury mediated by aerolysin in A549 cells. These findings demonstrated that diosmetin could reduce the pathogenicity of A. hydrophila by inhibiting the expression of aerolysin and diosmetin could be chosen as a promising candidate drug against A. hydrophila infection.

Abstract:Suppressor of cytokine signaling （SOCS） plays an important role in inhibiting cytokine receptors in the signaling pathway of JAK/STAT. The cDNA sequences of 10 socs genes including socs1，socs2，socs3a，socs3b，socs4，socs5a，socs5b，socs6，socs7 and socs9 were obtained from the transcriptome of Megalobrama amblycephala to study the sequence characteristics and function of SOCS family genes in M. amblycephala. The theoretical molecular weight， theoretical isoelectric point and functional domain of 10 SOCS in M. amblycephala were predicted with bioinformatics using online websites including ExPASY and SMART. Phylogenetic analysis showed that 10 SOCS were divided into type I subfamily including SOCS4，SOCS5a，SOCS5b，SOCS6，SOCS7 and SOCS9， and type Ⅱ subfamily including SOCS1，SOCS2，SOCS3a and SOCS3b. The results of semi-quantitative RT-PCR showed that the 10 socs genes in healthy M. amblycephala had obvious tissue specificity in the tissues tested. The expression levels of socs1， socs2 and socs3 were high in most tissues tested， followed by socs9， while the expression of other genes was low in all tissues tested. The relative expressions of 10 socs genes in spleen， trunk kidney and head kidney of M. amblycephala were detected after infected with Aeromonas hydrophila. Results showed that the relative expressions of socs1， socs2， socs3a and socs3b were up-regulated significantly at certain time point. It is indicated that the expression patterns of the 10 socs genes in M. amblycephala are different， the functions of the 10 socs genes in M. amblycephala are diverse， and some genes including socs1， socs2， socs3 play an important role genes in immune response. It will lay a foundation for further studying their function.

Abstract:In order to find out the cause of the massive death of largemouth bass （Micropterus salmoides） juveniles in a breeding farm in Shaoguan City， Guangdong Province， clinical observation， and bacteriological， parasitological and virological detection of the affected fish were carried out. And after excluding the possibility of bacterial and parasitic infections， RT-PCR detection， cell isolation and culture， artificial infection， hematoxylin-eosin （H&E） staining of histopathological sections， transmission electron microscope observation of ultrathin sections and phylogenetic tree analysis were performed and a Micropterus salmoides rhabdovirus （MSRV） was isolated and named as the Micropterus salmoides rhabdovirus Shaoguan strain （MSRV-SG01）. The results of the artificial infection test showed that the experimental fish died within 2 days， accompanied by clinical symptoms such as hemorrhage， rotten tail， and dragging stools， and the mortality rate reached 100% within 7 days. Histopathological sections showed that the liver and spleen of the diseased fish showed extensive necrosis， which was consistent with the symptoms of naturally diseased fish. According to the amino acid sequence of protein G， the MSRV-SG01 strain isolated in this study was compared with other rhabdoviruses reported in GenBank by phylogenetic tree analysis and the result showed that FJ985， MSRV-YH01， SCRV， and SCRV are grouped together， and the similarity with the reported MSRV-FJ985 and MSRV-YH01 strains were higher than 97%. Through the above experimental analysis， it was determined that the cause of mass death of largemouth bass juveniles was MSRV infection.

Abstract:The morphology，cooking characteristics，textural properties，sensory attributes，and microstructure of fish vermicelli （FV） and dynamic rheological properties of fish paste processed from frozen surimi under the setting time at 4 ℃，15 ℃，and 25 ℃ were determined to study the effects of setting time before molding on the quality and microstructure of FV.The results showed that the setting treatment significantly improved the cooking characteristics，textural properties，and sensory scores of FV at lower material temperatures （P<0.05）.The water-holding capacity of FV increased 20.18% and 9.94%，and the tensile strength of FV increased 28.97% and 24.11% when the material temperature was 4 ℃ and 15 ℃ and the setting time was 8 h and 4 h，respectively.There was no significant difference in the quality of FV within 0.5 h at 25 ℃ （P>0.05）.The results of analyzing the microstructure of FV and the rheological properties of fish paste showed that the appropriate setting time significantly promoted the dissolution of protein in fish paste and formed a uniform and dense gel network，with more starch encapsulated in the gel network.But the fish paste formed a weak gel after setting for a long time，and the subsequent process of squeezing destroyed the existing structure and reduced the continuity of the gel network，and eventually led to the decline of the quality of FV.It is indicated that the maximum setting time of fish paste at material temperatures of 4 ℃，15 ℃，and 25 ℃ is 8 h，4 h，and 0.5 h，respectively.The excessive setting can lead to the deterioration of the quality and microstructure of FV.

Abstract:In order to optimized the air frying condition of fried flavored fish cake， the samples were prepared by air frying， and the quality changes of fried flavored fish cakes were investigated under different frying temperature（160 ℃， 180 ℃ and 200 ℃） and time（4 min， 6 min， 8 min and 10 min）.With the increase of frying temperature and the extension of frying time， the L^* value significantly decreased， the a^* and b^* values significantly increased and the surface of fish cakes obtain gold color.In the range of 160 ℃ to 180 ℃， the sensory quality of fish cakes gradually increased with the extension of frying time， while the sensory quality of fish cakes increased and then decreased at 200 ℃.Under frying temperature at 200 ℃ and fried for 8 min， the appearance of fish cake fried by air frying was similar to fried fish cake by deep-frying， which endowed fish cakes with flavor and texture of fried food.In addition， the moisture content of fish cake significantly decreased， the hardness and chewiness of fish cakes increased and the degree of lipid oxidation deepened with the extension of frying time at 200 ℃， which led to the decrease of product quality.Compared with the traditional fried fish cakes， the fish cakes fried by air frying at 200 ℃ for 8 min had unique fried flavor and color， and the fat content and malondialdehyde content were lower than traditional fried food.

Abstract:The fish cakes pre-made from silver carp were prepared by second-step heating methods to obtain surimi products with low content of fat and malondialdehyde and good sensory properties.The effects of the second-step heating methods including deep-frying，air-frying，pre-frying+air-frying，frying and roasting on the sensory quality and other physical and chemical indicators of fish cakes were studied.Meanwhile，the effects of second-step heating on the content of fat and malondialdehyde in fish cakes were investigated.The results showed that the surface of the fish cake was golden yellow after being heated in the second step.The content of moisture was significantly reduced.The content of fat and malondialdehyde were significantly increased.Among them，the deep-frying fish cakes were better in color and had the highest overall sensory score.Air-frying fish cakes were lower in fat and malondialdehyde and had a sensory score second only to deep-frying fish cakes.The texture properties and flavors of air-frying fish cakes were close to those of deep-frying fish cakes.The air-frying cakes and deep-frying fish cakes were found to be the closest in flavor via electronic nose and volatile component analysis.It is indicated that air frying reduces the content of fat and malondialdehyde in fish cakes，and imparts fried flavor and texture to fish cakes.It is a better alternative to replace the traditional deep-frying method.

Abstract:A target detection algorithm based EfficientDet-D1 model was proposed to meet the requirements of speed and accuracy in the rapid detection and classification of strawberries using the fast normalized feature weighted fusion feature in EfficientNet network to quickly identify the ripe and unripe strawberries in natural environments.The YOLOv3,YOLOv4,Faster-RCNN and EfficientDet-D0 models were used for comparative experiments.The results showed that mean average precision (mAP) of the five algorithms including YOLOv3,YOLOv4,Faster-RCNN,EfficientDet-D0 and EfficientDet-D1 was 89.51%,69.02%,96.54%,96.71%,and 97.50%,respectively.The detection performance of EfficientDet-D1 in the ripe and unripe strawberries is better than that of the other four target detection algorithms，which has better generalization and robustness,By using the EfficientNet network with a small number of model parameters.It is more suitable for mobile identification,and can provide a new solution for the automatic picking technology of the ripe strawberries.

Abstract:Fertilizer application is an important part of rice production， which affects rice yield and may cause environmental pollution， therefore， it is important to study the technology of precision variable fertilizer application.The monitoring system for the discharge of a hinged lever type fertilizer box， which can actively monitor the remaining fertilizer quantity of fertilizer box in real time， was designed on the self-designed rice direct seeding synchronous side depth fertilizer application machine to realize the real-time monitoring of the accuracy of fertilizer application.The monitoring system consists of a weighing device and a multiplexed fertilizer discharge monitoring device.The weighing device consists of hinged lever frame， balance beam load cell， etc.The parallel beam load cell is used as the working element to carry the fertilizer box installed above the hinged lever mechanism and the real-time fertilizer gravity inside the fertilizer box.The multi-circuit fertilizer discharge monitoring part consists of the controller， fertilizer discharge monitoring， data communication， monitor， etc.It collects the fertilizer discharge signals obtained from each load cell and transmits them to the monitor interactive interface after processing， so that the operator can easily view and configure the operational parameters of the fertilizer application system in real time.The results of the field trial showed that the maximum relative error of monitoring was 4.79% and the minimum was 3.55%.The monitoring system is combined with the fertilizer discharge volume monitoring system based on the rotation of the fertilizer discharge shaft， which can realize the real-time self-adjustment of the fertilizer discharge volume of the fertilizer applicator.It will provide reference for the research of intelligent fertilization technology and equipment.

Abstract:There are problems including intense vibration and unclear vibration transmission characteristics during manipulating the steering wheel by the tractor operators.The ISO 5349 evaluation method was used to evaluate the hand-transmitted vibration of the steering wheel system under two different conditions and analyze the characteristics of vibration transmission of operators’ arm systems at different percentages.The results showed that the daily vibration exposure of the tractor was 4.257 m/s²，which exceeded the limit of daily vibration exposure of 3.5 m/s² specified in the national standard，and had a high risk of causing hand-arm vibration disease.The steering wheel vibration in the axial direction was greatly higher than that in the tangential and radial directions，which was the main factor causing hand-transmitted vibration.The radial vibration was largely absorbed during the transmission from the hand back to the forearm，while the tangential vibration was greatly absorbed in the transmission from the forearm to the upper arm.Moreover，the smaller the operator’s physical size，the greater the vibration transmission rate at the hand back.The significant increase in vibration from the hand back to forearm was found under the frequency of 20 Hz.Therefore，smaller operators in engineering practice should pay attention to the vibration protection at the palms，while larger ones are suggested to focus on the vibration protection at the wrists.In addition，the radial protection should be mainly strengthened for the driver’s wrist，and the tangential protection should be mainly strengthened for the elbow joint.

Abstract:The fishery hard pellet 3.0 medium feed was used to conduct the density measurement test and the uniaxial plate compression test to comprehensively study the physical parameters of fish feed discrete element simulation. The measured values of density， elastic modulus， shear modulus and Poisson's ratio of hard pellet feed were 1 096 kg/m³， 336.32 MPa， 126.65 MPa and 0.33， respectively. At the same time， the discrete element model of hard pellet feed was established with EDEM software. Combined with bench test and simulation test， the restitution coefficient， static friction coefficient and rolling friction coefficient between hard pellet feed-steel and hard pellet feed-nylon were calibrated. The values of them were 0.38， 0.538， 0.028， 0.405， 0.356， 0.033， respectively. The restitution coefficient， static friction coefficient and rolling friction coefficient between hard pellet feeds were calibrated through stacking angle test， the steepest climbing test and Box-Behnken response surface optimization test. The values of them were 0.364， 0.236， and 0.13， respectively. The self-developed baiting machine was used for the verification test of parameters. Taking the distribution variation coefficient of hard pellet feed as the evaluation index， the relative error of distribution variation coefficient between actual hard pellet feed and simulated hard pellet feed was 1.709%. It is indicated that the established discrete element model and the calibrated physical parameters of fishery hard pellet feed can be used for EDEM discrete element simulation test.