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- Abstract：To explore the path for building up China's strength in agriculture with Chinese characteristics, its basic characteristics, strategies and implementation path were investigated. Based on the analysis of the basic connotation of agricultural strength, this study summarizes three types and six common characteristics of the strong agriculture countries of the world. The results shows that China is a large agricultural country with limited resources. It is necessary to ensure the self-sufficiency of grain and major agricultural products for China. Small-scale farm will still be the basic feature of agricultural management model in China. The realization of green agricultural under the carbon peaking and carbon neutrality goals and under the diversity and difference of regional agriculture are important features for China agriculture. Based on the understandings above, this study proposes the suggestion of the “four beams and eight pillars” strategic path to build up China's strength in agriculture with Chinese characteristics. The study is expected to provide decision-making reference for formulating the construction plan of building up China's strength in agriculture with Chinese characteristics.Keywords：strength in agriculture;strategic objectives;path;common characteristics;unique feature44|50|1<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：Scientific assessment and prediction of the potential impact of diseases and insect pests on food security is of great significance for formulating effective risk control measures and ensuring stable grain yield and increase. Based on China Agricultural Sector Model(CASM), this study simulates and analyzes the potential impact of disease and insect pest risks on Chinese food security under the scenarios of combination different risks and prevention and control intensity measures. The results show that: 1)As the risk of diseases and insect pests intensifies, according to the prevention and control level in 2016-2020, there is a risk of expansion of the loss of the rice, wheat and maize, and the loss rate of grain yield will increase from 2. 13% to 2. 58%. Under the high risk and low prevention and control scenario, the “absolute grain ration security” cannot even be effectively guaranteed. 2)After effective prevention and control, the direct economic loss of grain recovered is greater than the cost of prevention and control. Under the high-risk scenario, the grain economic losses recovered under different prevention and control measures is 451. 2~505. 6 billion yuan, which is greater than the cost of prevention and control(17. 9 billion yuan). 3)Biotechnology(industrialization of genetically modified insect-resistant maize)is one of the important measures for control of diseases and insect pests and save the cost of pesticides. Planting genetically modified maize can reduce the loss rate caused by diseases and insect pests from 2. 2% to 1. 0%, while saving more than 60% in pesticide costs. In order to effectively deal with the adverse impact of high incidence of diseases and insect pests on food security, and minimize the loss of grain diseases and insect pests. It is suggested to carry out the assessment and prediction analysis of the damage to grain caused by diseases and insect pests as soon as possible, improve the monitoring and early warning capacity of major diseases and insect pests, accelerate the promotion of biotechnology innovation and industrial application, strengthen the development and application of intelligent plant protection technology, and actively participate in the global biosafety governance.Keywords：diseases and insect pests;food security;CASM model;Prevention and control measures24|45|3<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：In order to explore the realization path of “win-win” between food security and agricultural income increase, based on the panel data of 13 major grain producing regions in China from 2008 to 2020, the impact of agricultural insurance level on the consistency of grain output and agricultural income and its mechanism were investigated by using the coupling coordination model, panel regression model and two-stage least square method. The results showed that: 1)From 2008 to 2020, the level of coupling coordination between grain output and agricultural income in the main production areas fluctuated and rose, but it still did not break through the moderate coordination level. The level of coupling coordination in the main production areas was significantly different, showing a “three echelon distribution”; 2)The policy based agricultural insurance guarantee level for staple crops significantly improved the consistency between grain output and agricultural income. The consistency level increased by 0. 835 for every 1 percentage point increase in the guarantee level; 3)The level of policy oriented agricultural insurance for major grain crops promoted the development of moderate scale operation of grain crops in major production areas. The moderate scale operation in both the total amount dimension and the efficiency dimension played a significant intermediary effect in the agricultural insurance to improve the consistency between grain output and agricultural income, with the intermediary effect accounting for 50. 19% and 24. 10%, respectively. Therefore, in order to achieve both food security and agricultural income increase, efforts should be made to improve the insurance level of staple food crops, consolidate and improve the income security mechanism for farmers' grain planting; Agricultural insurance will be used to boost the development of grain crops on a moderate scale, providing a new engine for grain production increase and agricultural income increase.Keywords：agricultural insurance;food security;agricultural income increase;coupling coordination level;moderate scale operation191|45|3<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：Based on the statistical data of 20 cities in Guangdong Province from 2001 to 2020, the SFA model was employed to measure the technical efficiency of grain production. The Tobit model was then used to analyze the impact of the non-grain utilization of cultivated land on the technical efficiency of grain production. The results show that: 1)The average technical efficiency of grain production in Guangdong Province showed a steady and slow upward trend, with an average annual growth rate of 0. 15% from 2001 to 2020. There was a significant convergence of temporal changes and differences in spatial distribution among the core PRD region, the coastal economic zone and the northern eco-region. 2)An anti-driving effect between non-grain utilization of cultivated land and technical efficiency of grain production was discovered, which was more pronounced in the core PRD region and the coastal economic zone, but not significantly in the northern eco-region. 3)The impact of different levels of non-grain utilization of cultivated land on the technical efficiency of grain production varied and the anti-driving effect was stronger for high levels of non-grain utilization of cultivated land. In conclusion, it is necessary to focus on the impact of non-grain utilization on grain production. By strengthening the management of non-grain utilization of cultivated land, implementing regional differentiated upgrading strategies, and coordinating with socio-economic instruments, the technical efficiency of grain production in major grain-consuming areas will be stabilized and improved, and the food crop production strategy based on farmland management and technological application will be implemented.Keywords：non-grain utilization of cultivated land;SFA model and Tobit model;technical efficiency;major grain-consuming areas23|46|5<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：In order to explore an effective way to make full use of water resources and increase the output value of maize, maize variety ‘Shaandan 609' was used as the test material in Hetao irrigation area, and the local conventional planting density 6. 0×104 plants/hm2 was used as the control(CK). The effects of increasing planting density to 7. 5×104(D1), 9. 0×104(D2)and 10. 5×104(D3)plants/hm2 on soil moisture, irrigation amount, field water consumption, maize yields and output values were investigated. The results showed that: The soil moisture decreased with the increase of planting density. Compared with conventional planting density, irrigated water increased by 3. 81%(D1), 9. 72%(D2)and 13. 90%(D3), and field water consumption increased by 5. 23%(D1), 10. 71%(D2)and 15. 42%(D3), respectively. The biomass of maize straw increased by 21. 97%(D1), 41. 34%(D2)and 39. 40%(D3), and the grain yields increased by 12. 54%(D1), 18. 47%(D2)and -0. 86%(D3), respectively. The water productivity rate increased by 6. 93%(D1), 7. 01%(D2)and -14. 11%(D3), and water use efficiency increased by 11. 00%(D1), 16. 39%(D2)and 1. 74%(D3), respectively. The production cost increased by 2. 17%(D1), 4. 35%(D2)and 6. 52%(D3), the total output value increased by 13. 27%(D1), 20. 47%(D2)and 2. 67%(D3), and the net output value increased by 21. 46%(D1), 32. 12%(D2)and -0. 12%(D3), respectively. To sum up, when the planting density of ‘Shaandan 609' in Hetao irrigation area increased to 9. 0×104 plants/hm2, water resources could be fully utilized, maize yields could be increased, and greater economic benefits could be obtained.Keywords：maize;planting density;soil moisture;irrigation water;field water consumption;yield and output value20|27|2<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：The aim of this study was to investigate the effects of mulching and nitrogen application on the growth characteristics and nitrogen transport of maize in northern Shaanxi Province. Maize variety ‘Zhengdan 958' was taken as the test material, and a total 11 treatments were set up. Planting patterns were open field(M0)and mulching(M1), and the N application rates were 80(N1), 120(N2), 160(N3), 200(N4)and 240(N5)kg/hm2, respectively. No N application under open field was used as control group, to determine the growth, yield, nitrogen transport and N fertilizer utilization efficiency of maize. The results showed that: Mulching and N application had significant effects on maize height, stalk thickness and leaf area index in the field. The growth indexes of maize showed a trend of rapid growth until leveling off as the fertility period progressed, and the mutual effect of mulching and N application had a highly significant effect on plant height. Mulching and N application had a highly significant effect on maize yield. Mulching significantly increased maize yield, and with the increase of N application, maize yield showed a trend of first increasing and then decreasing. With the increase of N application, maize yield showed a trend of increasing and then decreasing, and M0 and M1 models reached the highest yield of 12 469. 02 and 13 181. 66 kg/hm2 at N3 and N2 levels, respectively. Nitrogen accumulation in all nutrient organs showed a trend of increasing and then decreasing with increasing N application, and nitrogen accumulation in all organs at maturity was seed>leaf>stalk. Nitrogen transport in maize nutrient organs showed a trend of decreasing and then increasing; N application and mulching significantly affected maize nitrogen transport efficiency. Nitrogen uptake efficiency showed a significant decreasing trend. Mulching significantly improved N fertilizer utilization rate, N fertilizer bias productivity and N fertilizer agronomic utilization rate. With the increase of N application, N fertilizer utilization rate, N fertilizer bias productivity and N fertilizer agronomic utilization rate all decreased significantly, while the fertilizer yield contribution increased first and then decreased. In conclusion, through the comprehensive evaluation of principal components, M1N3 had the highest score, so the better model for maize cultivation in northern Shaanxi was to set the N application rate under mulching at 160 kg/km2.Keywords：nitrogen application rate;film mulching;growth index;nitrogen transport;principal component analysis12|30|7<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：The aims of this study were to enrich the genetic diversity information of Indica rice phenotypic traits and excavate excellent genetic materials. The results showed that: A total of 91 421 SNPs were obtained from 198 samples using two simplified genome sequencing techniques. The heterozygous sites accounted for 5. 85%. The genetic distance based on Nei's ranged from 0. 014 to 0. 596, with an average genetic distance of 0. 284. The 198 samples were clustered into three subclasses by Bayes algorithm. Among the total variation of 91 421 SNPs, the first three PC could explain 10. 98%, 10. 47% and 4. 81% of the population variation, respectively. The average coefficient of variation and the average diversity index based on the 15 phenotypic traits were 30. 33% and 1. 95, respectively. The correlation coefficients between the 15 phenotypes ranged from -0. 55 to 0. 92. The first three PCs of 15 phenotypic traits could explain 29. 44%, 16. 63% and 10. 59% of the population variation, respectively. The traits that had significant contributions on the first principal component included spike lengths, plant heights, kernel numbers per spike, the period from seeding to heading, grain number, leaf length, chalky rice rate and chalkiness. The contribution values of 8 traits to the first principal component were all above 0. 6, and were the main factor for the variation of Indica phenotypic traits. The first five principal components of the phenotype group reflected 73. 003% of the total information, and the first two principal components divided the 198 resources into two subgroups. The Mantel test showed that the coefficient of correlation between the genetic distance matrix based on SNPs and phenotypic traits was r=0. 041. In summary, the correlation between SNPs and the diversity analysis of 15 phenotypic traits was low, and the SNPs cluster was closer to the genealogical analysis than the phenotypic trait cluster. The genetic structure of the population consisting of the 198 SNPs of Indica rice germplasm resources in the Qinling-Ba region was relatively simple. Eight traits could be used as comprehensive evaluation indexes for the phenotypic traits in Indica rice.14|28|3<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：In order to explore the effect of exogenous jasmonic acid(JA)on the transcriptome of oat under different drought stress, the transcriptome of ‘Mengyan 1' treated with JA after mild(0. 017 mol/L PEG-6000 treatment)and severe drought stress(0. 034 mol/L PEG-6000 treatment)was determined. GO and KEGG functional enrichment analysis were adopted to investigated the significant differentially expressed genes(DEGs). GO function enrichment analysis showed that JA mainly affected membrane, catalytic enzyme, transferase and response to stimulation under different water conditions. The results of KEGG functional enrichment analysis showed that 1 955 up-regulated genes and 4 666 down-regulated genes were induced by JA under CK. DEGs was significantly enriched in metabolic pathway and secondary metabolite synthesis pathway. Gene expression pattern in phenylpropanoid biosynthesis pathway changed significantly. A total of 1 574 genes up-regulated and 933 genes down-regulated were induced by JA under mild drought stress. DEGs was significantly enriched in the biosynthesis of secondary metabolism, plant hormone signal transduction, arginine and proline metabolic pathways. Genes involved in ABA and JA signal transduction and arginine and proline metabolism were up-regulated. About 223 genes up-regulated and 456 down-regulated were induced by JA under severe drought stress. Sphingolipid metabolic pathway was significantly enriched. Compared with the untreated JA, the application of JA under different drought stress induced the up-regulation of CTK N-glycosylation gene(UGT73C5)and the down-regulation of oxidase/dehydrogenase gene(CKX11)in the cytokinin(CTK)metabolic pathway, as well as the significant changes in the expression of abscisic acid(ABA)signal transduction related gene(THI1. 3)and unknown functional gene(AT1G71250). To sum up, under mild and severe drought stress, exogenous JA can induce significant changes in the expression of oat CTK and ABA-related genes responsive to drought stress.17|31|1<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：In order to explore the morphological development and physiological-biochemical change in flower bud differentiation of giant lily, bulbs of Cardiocrinum giganteum were used as experimental material. The process of inflorescence differentiation was observed by scanning electron microscope. The physiological indices at different stages of differentiation were measured by SRM/MRM technique. The results showed that: The inflorescence differentiation process of C. giganteum could be divided into 6 stages, which were undifferentiation period, start of inflorescence primordium differentiation period, bract primordium differentiation period, floret primordium differentiation period, perianth differentiation period, flower bud differentiation completed period, respectively. Both IAA and GAs showed an increasing trend, indicating that high levels of IAA and GAs were beneficial to the differentiation of inflorescence and floral organs. ZR and SA both showed a pattern of increase-decrease, and they played an active regulatory role in the middle stage of differentiation. ACC and JA declined continuously, which may be due to the release of inhibition on the development of inflorescences. High IAA/GA3-o-cZR/GA3 ratio was conducive to the transition from vegetative growth to reproductive growth of C. giganteum. The changes in soluble sugar and soluble protein contents were completely opposite, suggesting that the two components regulated the process of flower formation through equilibrium relationship. In general, ZR plays an important role in the formation of new organs such as bract primordium and floret primordium, and IAA and GAs play more significant roles in flower bud morphogenesis at the late stage of inflorescence differentiation. Higher soluble sugar content can promote the development of inflorescence and bud, and a large amount of protein is needed to supply the flower organ morphogenesis in the early stage of differentiation. During the whole process of inflorescence differentiation of C. giganteum, the development of florets is gradually synchronized. This study provides a theoretical basis for the study of flowering mechanism and flowering regulation of C. giganteum.Keywords：Cardiocrinum giganteum;inflorescence differentiation;endogenous hormones;soluble sugar;soluble protein10|30|2<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：In order to explore the diversity of seed melon germplasm resources and explore the application potential of excellent seed melon germplasm resources, correlation, principal component and cluster analysis were used to identify 21 agronomic traits and analyze the genetic diversity of 100 seed melon germplasm resources. The results showed that the genetic diversity of germplasm resources was rich. The diversity index of 7 quality traits ranged from 0. 53-1. 65, and the coefficient of variation of 14 quantitative traits ranged from 10. 41%-35. 56%. There was genetic correlation among phenotypic traits. Using Euclidean distance as genetic distance, 100 seed melon germplasm resources could be grouped into 5 groups, among which group Ⅴ had high yield and could be used as breeding parent material. The first 7 principal components were extracted by principal component analysis, and their cumulative contribution rate reached 74. 185%, which could be used as the main evaluation index of germplasm resources of seed melon. The comprehensive scores of seed melon germplasm resources ranged from -2. 78-2. 86, and three excellent seed melon germplasm resources were selected according to the comprehensive scores. This study systematically evaluated the genetic diversity of seed melon germplasm resources from multiple perspectives, which could provide a scientific basis for the efficient utilization and genetic breeding of seed melon germplasm resources in the future.Keywords：seed melon;germplasm resources;phenotype identification;genetic diversity;comprehensive assessment20|26|3<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：To identify ginsenosides-tolerant Trichoderma strains with antagonistic and growth promotion activity from the rhizosphere soil of healthy Panax notoginseng, rhizosphere soil of one-year-old healthy P. notoginseng was collected. Ginsenosides-tolerant Trichoderma strains were then screened by measuring the effect of P. notoginseng root exudates and ginsenosides on the spore germination and mycelium growth of Trichoderma. After the taxonomic identification test, the ginsenosides-tolerant Trichoderma strains were further assayed for their antagonistic activity against root rot pathogens as well as their growth promotion effect, rhizosphere colonization capacity and the alleviation effect of continuous cropping obstacles. The results showed that: A total of 6 Trichoderma strains were isolated, among which, two strains showed low sensitivity to the root exudates. Based on the morphological characteristics and ITS sequence comparison, the two strains were identified as T. viride strain T3 and T. viridescens strain T20. Both T3 and T20 strains had strong antagonistic effects against the major root rot pathogens of P. notoginseng, including Phytophthora cactorum, Cylindrocarpon destructans, Fusarium solani, Fusarium oxysporum and Monographella cucumerina, and their inhibition rates against Phytophthora cactorum reached 61. 76% and 70. 59%, respectively. Both T3 and T20 strains promoted the growth of P. notoginseng. And the two strains inoculating in P. notoginseng continuous crop soil had high colonization ability in the rhizosphere after inoculation of 20 days and also increased the survival rate of P. notoginseng plants and reduced the root rot incidence. This study provided important biocontrol resources for alleviating the continuous cropping obstacles of P. notoginseng.Keywords：Panax notoginseng;Trichoderma;root exudates;ginsenosides;root rot;biological control10|29|5<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：To understand the research characteristics, hot issues and development trends in the crop fertigation field, a bibliometric analysis was conducted on relevant literature in the filed of crop water and fertilizer intergration(2003—2022)based on the Web of Science(WOS)database using visualization software such as CiteSpace and VOSviewer. The results showed that: 1)The number of published papers fluctuated and increased, with research involving disciplines such as agronomy, water resources sciences and plant science. The most influential and authoritative journal was Agricultural Water Management. 2)In terms of international cooperation, Chinese scholars have close cooperation with the United States and Canada, among which the scholars from relevant institutions in the United States have the closest cooperation; The research institutions and scholars of crop fertigation field are scattered. Many institutions such as China Agricultural University, University of Florida, Chinese Academy of Sciences, and Northwest A&F University, as well as Zhang Fucang, Kang Yaohu, Lin Shan and Morgan Kelly T. , have carried out a lot of research on water and fertilizer integration. 3)The crop fertigation research mainly adopts field experiments and model simulation methods. The research content ranges from the early research on the yield and fruit quality of cultivated crops such as fruit trees and bell peppers, to crop soil water and nutrient transport and nitrate leaching, and then to the focus on improving crop nutrient uptake and water and fertilizer use efficiency while taking into account environmental benefits. In summary, the research direction of crop fertigation mainly focuses on the simulation of soil water and nutrient transport and nitrate leaching dynamics, the coupling effects of water and fertilizer on crop yield research, the improvement of water and fertilizer use efficiency and the precise regulation of water and fertilizer, and greenhouse gas emissions and agronomy management measures of emission reduction in the crop fertigation process. With the development of emerging technologies such as the Internet of Things and Artificial Intelligence, future research on crop fertigation will move towards the direction of digitalization, intelligence and precision.Keywords：crop fertigation;fertilization management;nitrate leaching;environmental impact;greenhouse gas emissions;bibliometric analysis14|33|2<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：To explore the basis of genetic variation among individuals with extreme differences in adipose phenotype in Nanyang black pig population, in this study, the whole siblings or half siblings of Nanyang black pig population with similar body weight but significant differences in adipose phenotypes at 6 months of age were used as test subjects, and statistical analysis of carcass traits and meat quality traits were performed respectively. High-throughput sequencing technology was used to re-sequence the whole genome of samples from High-fat and Low-fat groups, and the transcriptome data of the previous group were integrated to mine genetic loci and functional genes related to fat deposition of Nanyang black pig. The results showed that: 1)Intramuscular fat content was significantly higher in the High-fat group((4. 96±0. 62)%)than that in the Low-fat group((3. 61±0. 11)%)(P<0. 05), the mean backfat thickness was extremely significantly higher in the High-fat group((43. 74±2. 33)mm)than that in the Low-fat group((28. 36±4. 17)mm)(P<0. 01). There were significant differences between the two groups in the traits related to intramuscular fat content(shear force, pH45 min, steaming loss and 48 h drip loss). There was no significant difference between the two groups in other traits; 2)A total of 208. 00 Gb of effective sequence data was obtained, and the sequencing coverage reached more than 98. 68%. A total of 25 827 091 single nucleotide polymorphisms(SNPs)were detected in the High-Low fat group, and 5 802 822 small fragment insertions and deletion(InDels)were detected 56 358 chromosome structural variation(SVs)and 1 898 copy number Variation(CNVs)were detected in the High-Low fat group. Through functional annotation of SNP non-synonymous mutations and InDel frameshift mutations, it was found that 209 intergroup differential genes were mainly involved in the mTOR signaling pathway, thyroid signaling pathway, ABC transporter signaling pathway and other pathways related to fat deposition; 3)Two key genes related to adipose differentiation(PLP1 and ITGA6)were screened after joint analysis with the transcriptome data of our research group, and the polymorphisms of these genes may be the key to the difference of intramuscular adipose deposition in Nanyang black pig. In conclusion, the study screened the genes and sites related to fat deposition in Nanyang black pig population from the whole genome level, which laid a foundation for further research on the regulation mechanism of pig fat deposition and breed breeding.Keywords：Nanyang black pig;resequencing;fat deposition;candidate genes6|24|2<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：In order to screen the key target genes of miR-133a-5p affecting chicken muscle development, in this study, the online database was used to predict the target genes of miR-133a-5p, enriched and analyzed the target genes, and constructed the protein-protein interaction(PPI)network to find meaningful modules in the network diagram. The expression of miR-133a-5p in muscle and other tissues was compared and analyzed by one-way ANOVA. Then, according to the mechanism of negative correlation between microRNA and target genes, the intersection of miR-133a-5p target genes and relatively down-regulated genes in muscle was to screen the key target genes. Finally, the screening results were evaluated by RNA22 v2. The results showed that: 1)A total of 157 target genes were obtained; 2)GO enrichment analysis showed that the target genes were involved in the regulation of multiple biosynthetic and metabolic processes; KEGG enrichment results included a variety of signaling pathways such as MAPK signaling pathway, as well as pathways directly related to muscle development such as actin cytoskeleton; 3)A total of 4 meaningful modules were screened by PPI network map, involving 17 genes; 4)miR-133a-5p expression was significantly up-regulated in muscle(relative to lung, liver and kidney), and interlaced with relative down-regulated genes in muscle, SOX5(SRY-box 5), PRTFDC1(Phosphoribosyl transferase domain containing 1)and THRB(Thyroid hormone receptor)were obtained beta), THBS2(Rhrombospondin 2), ARRDC3(Arrestin domain containing 3); 5)In the GSE93855 expression profile, PRTFDC1 and THRB had the lowest expression in muscle, while the evaluation results of RNA22 v2 showed that only SOX5 and THRB had P<0. 05 binding sites. In conclusion, miR-133a-5p may affect muscle development through SOX5, PRTFDC1, THRB, THBS2, and ARRDC3, of which SOX5 and THRB are particularly important. This study provides theoretical basis and data support for further study of chicken miR-133a-5p.Keywords：chicken;muscle;miR-133a-5p;bioinformatics2|23|0<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：To establish a rapid and accurate method for the analysis of T-DNA integration sites in transgenic coccidia, in this study, EtM2e, a transgenic E. tenella strain, was sequenced with whole-genome resequencing. The insertion site of T-DNA was analyzed by chimeric reads and the T-DNA copy number was analyzed by sequencing depth of T-DNA unique sequences and homologous sequences with Eimeria tenella. The insertion site was further validated by PCR amplification. The results showed that 1)7. 2 Gb of clean data were obtained after filtering. Q20 was 96. 1% and Q30 was 89. 2%, with the number of matched reads was 23 992 361×2 and mean coverage depth was 80×. The whole genome coverage of reads showed the chromosomes were covered evenly and the randomness of sequencing was good. 2)The number of matched reads mapped to the T-DNA sequence was 3 106 and 3 036, with the mean coverage depth was 140×. The sequence of chimeric reads indicated that there was only one insertion site, located at HG994969. 1: 2 704 213-2 705 255. 3)The mean coverage depth of T-vector backbone unique sequence Kanamycin and EYFP were 67× and 85×, while the mean coverage depth of homologous sequence of the 5′ regulatory region of E. tenella His 4 and 3′ regulatory region of Actin was 154× and 167×. The average sequencing of the homologous sequence was about twice of the unique sequence, which indicated that the T-DNA was single copy and was consistent with the result of finding one insertion site. 4)The integration site was successfully identified by PCR validation analysis. The success of validation of T-DNA insertion site in transgenic E. tenella EtM2e strain provides a technique for the identification of other transgenic Eimeria parasites, as well as providing a potential genomic safe harbor for the subsequent anticoccidial vaccine vector development.Keywords：T-DNA insertion sites;Eimeria tenella;second-generation sequencing;transgene7|26|3<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：To explore the regulatory effect of membrane permeability enzyme(EII)of Listeria monocytogenes(LM)pathogenicity island 4(LIPI-4)on the expression of LM virulence genes, in the study, the EII deletion mutant(LM928ΔEII), strong promoter complemented strain(CLM928ΔEII-Phelp)and native promoter complemented strain(CLM928ΔEII-Pnative)were constructed, respectively, and the growth curve in vitro and intracellular proliferation in HCMEC/D3 of each strain were measured. The transcription levels of 9 key virulence genes in each strain were detected by RT-qPCR in vitro and HCMEC/D3 cells. The results showed as follows: 1)EII gene deletion mutant LM928ΔEII was successfully constructed. The recombinant complemented plasmid pIMK2-EII and pIMK2-EII-Pnative, complemented strain CLM928ΔEII-Phelp and CLM928ΔEII-Pnative were successfully constructed. 2)In vitro, EII had no effect on the growth curve of LM. The number of proliferation of LM928ΔEII in HCMEC/D3 cells was significantly higher than that of LM928 at 8 and 12 h(P<0. 05), and the amount of intracellular bacteria was extremely significantly higher than that of LM928 at 2, 4 h(P<0. 01). CLM928ΔEII-Pnative was restored to the level of wild type strain at 2, 4 and 6 h(P>0. 05), while CLM928ΔEII-Phelp was significantly lower than that of wild type strain at 2, 4, 6, 8, 10 and 12 h(P<0. 01). 3)In vitro, compared with the wild type strain, 66. 7%(6/9)of virulence gene transcription levels in LM928ΔEII were extremely significantly up-regulated(P<0. 01), CLM928ΔEII-Phelp increased the gene transcription levels of 66. 7%(6/9)by 1-4 times, while 88. 9%(8/9)gene transcription levels fold change of CLM928ΔEII-Pnative were less than 1 time. In HCMEC/D3 cells, compared with the wild type strain, 66. 7%(6/9)of virulence gene transcription levels in LM928ΔEII were extremely significantly up-regulated(P<0. 01), CLM928ΔEII-Phelp increased the gene transcription levels of 33. 3%(3/9)by 1-3 times while the gene transcription levels of CLM928ΔEII-Pnative were all less than 1 time. In conclusion, LIPI-4EII negatively regulates the transcription of key virulence factors of LM. This study laid the foundation for systematically exploring the mechanism of LIPI-4 involvement in LM pathogenicity.Keywords：Listeria monocytogenes;LIPI-4;membrane permeability enzyme Ⅱ;deletion mutants;virulence gene4|23|0<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：In order to discover how to make efforts in the market-oriented context of comprehensive land remediation and ecological restoration in the whole area, this study takes the market of comprehensive land remediation and ecological restoration in the whole area as the research object, and sorts out the mechanism, model and implementation path of market-oriented remediation and restoration by means of systematic summary and logical thinking. Research results: 1)The key to deepening and promoting social capital participation in comprehensive land consolidation and restoration in the entire region is to realize the value of ecological products. Ecological product supply is handled by public administration and market-based allocation, and the realization process should primarily involve quasi-public and non-public ecological products. 2)Consolidation and restoration activities can obtain two types of benefits: equity and ecological value incremental accounting indicators, and capital operation benefits of resources created through its own capacity and resources, and the implementation process should focus on the development of differentiated investment and financing mechanisms as well as industry-integrated operation mechanisms. 3)In the realization mode can be specifically implemented through a variety of ways such as government assessment performance mode, PPP mode, EPC mode, etc. In the implementation path, it is mainly carried out through the development rights and interests of various elements, indicators, development and utilization of resources, etc. , and matching the demand through different degrees of marketization to promote the participation of social capital in the comprehensive land improvement and ecological restoration work in the whole area. In summary, this study provides a theoretical basis for the marketization of comprehensive land remediation and ecological restoration in the whole region.Keywords：comprehensive land consolidation;national ecological restoration;marketization;mechanism;model;path7|24|11<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：In order to understand the development process and future development trend of ammonia volatilization in composting at home and abroad, by taking“composting or compost”, “ammonia or NH3” and “emission or volatilization” as keywords, the core collection database of Web of Science was searched. Visualization analysis software such as VOSviewer and Citespace were used. Visualization analysis was conducted on the changing trend of the number of publications at home and abroad, major research institutions, highly cited articles, research hotspots and frontiers from 2000 to 2021. The results show that: From 2000 to 2011, the annual publication volume in the field of ammonia volatilization in compost was small and stable. Since 2012, the number of articles published in the field of ammonia volatilization in composting increased rapidly in China, and China occupied first in the world. In the field of ammonia volatilization in composting. China Agricultural University ranked first in the world both the number of articles published and the total citation frequency, while Northwest A & F University and the University of Barcelona had a higher citation frequency. The research hotspots include mainly the raw materials of the rich protein such as livestock manure and sludge. The main influencing factors of ammonia volatilization such as the physical and chemical properties of the heap and external environment, composting additives and composting process regulation and emission reduction measures and mechanism. From 2000 to 2010, the biological filtration technology was used to reduce ammonia emissions in composting, and temperature was considered to be an important factor affecting ammonia volatilization in composting. From 2011 to 2021, ammonia, nitrous oxide and biochar have become hot keywords, and biochar is an important amendment to reduce ammonia volatilization and greenhouse gas emissions, so that has become a hot topic of concern for scholars. The results of keyword outburst analysis show that the biochar has a high outburst intensity and a recent outburst year, which is the hot spot in the recent five years and may be the hot spot in the future. The development and application of new low-cost, recyclable conditioners, the stability of nitrogen fixed by biochar and other conditioners, as well as the collaborative control of nitrogen gases, sulfur-containing odors, greenhouse gases and heavy metals, antibiotics, resistance genes and other pollutants of different nature will be the research frontiers in the future. In conclusion, this study can provide reference for understanding the development trend of ammonia volatilization in composting in the past two decades, and provide inspiration for the future research of ammonia volatilization in composting.Keywords：ammonia volatilization in composting;bibliometrics;Web of Science;keyword co-occurrence network;hotspots and frontiers13|33|0<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：In order to explore the meteorological and agricultural drought propagation laws of different sub-basins and land use types in the Weihe River Basin, based on the meteorological data of the study area from 1980 to 2014, the standardized precipitation index and standardized soil moisture index were used to characterize meteorological and agricultural drought, respectively. Based on Pearson correlation analysis and de Martonne dryness index, the propagation time and response relationship of meteorological drought to agricultural drought were evaluated. The duration and severity of meteorological and agricultural drought were extracted using run length theory, and the drought propagation threshold and risk characteristics were measured by Copula function. The results show that: 1)The propagation time of meteorological drought to agricultural drought in the main stream of the Weihe River and the Jing River Basin is three months, and the propagation time of drought in the Beiluo River Basin is two months; 2)Changes of hydrothermal conditions have a certain effect on the spread of drought, and this effect varies piecewise linearly along the aridity gradient; 3)The drought resistances among different sub-basins and land use types are different. Among them, the grassland in each sub-basin and the forest land in the Jinghe and Beiluo River basins have a small drought propagation threshold, which is prone to agricultural drought; 4)The meteorological drought in each region lasts longer and its intensity increases after spreading to agricultural drought, and the expansion of farmland in the Jing River and Beiluo River basins is the strongest. The research can provide new insights for evaluating the drought response relationship and building a basin drought early warning system.Keywords：meteorological drought;agricultural drought;drought propagate;dryness index;copula functions8|24|6<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：Aiming at the problem of hill sowing of female parent rice in mechanized seed production, a metering device with leaf-shaped curved model-hole was designed according to the physical characteristic parameters and agronomic requirements of female parent rice seeds. EDEM simulation analysis, bench test of high-speed camera and orthogonal experiment were applied to investigate the force and posture of rice seeds, model-hole structure and model-hole parameters during seeding process. The results showed that: 1)The seeding performance was better for seed-filling probabilities with the sum of longitudinal and lateral position more than 76% in leaf-shaped model-hole. 2)When the length, width and depth of the model-hole were 20. 27 mm, 16. 84 mm and 7. 46 mm, respectively, the seeding qualified rate and missed seeding rate were 92. 63% and 2. 81%, respectively. The field experiment results showed that the sowing qualified rate and missed rate were 82. 69% and 8. 52%, respectively. The hill spacing and diameter were 120. 60 mm and 38. 90 mm, respectively. The variation coefficient of hill spacing and diameter were 15. 07% and 29. 03%, respectively. Therefore, the hill-seeding centralized metering device of hybrid rice sterile line could meet the agronomic requirements of female parent direct seeding for hybrid rice seed breeding.Keywords：hybrid rice breeding;female parent of hybrid rice;hill seeding;centralized seed-metering device;seeding performance9|28|1<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：Aming at the problem of the impact damage during apples pipe transport, the parameter combination of pneumatic conveying device was studied. Taking the inner diameter of the conveying pipe, pipe shape and wind speed of the inlet as the influencing factors, and the wind speed of the windward side of the apple as the response value, the influence rule of each factor on the response value was determined by single factor simulation test. Based on the results of single factor simulation, through multi-factor simulation test the optimal combination of transport parameters was obtained and the reliability of the optimal combination is tested through verification test. The single factor simulation test results showed that: When the inner diameter of pipeline is 88, 96, 104, 112 and 120 mm, the number of the inner diameter of pipeline increased, and the wind speed on the upwind side of apple first increased and then decreased. The order of the influence of pipe type on the windward side of Apple's wind speed was lower arc tube>spiral tube>S-shaped tube>Upper circular arc tube>inverted S-shaped tube. When the inlet wind speed was 14. 07, 15. 83, 17. 59, 19. 35 and 21. 11 m/s, the number of the inlet wind speed increased, the wind speed on the windward side of apple increased first and then decreased. The results of multi-factor simulation test showed that the optimal combination of transport parameters was as follows: pipe inner diameter 112 mm, lower arc tube shape, inlet wind speed 19. 35 m/s, under the circumstances, the wind speed on the upwind side of apple was 18. 46 m/s. The tested experimental results showed that in the case of pipeline pneumatic conveying device with optimal combination of conveying parameters, the damage rate of apples was 14%, the damage area of apples was 0 to 14. 82 mm2 and the damage volume of apples was 0 to 23. 84 mm3. About 86% of apples were first-class and above fruits and 14% were second-class fruits. In conclusion, the pneumatic conveying device of pipeline is able to effectively reduce the damage of apples when they fall into the fruit basket after being picked.Keywords：pipeline transmission;pneumatic conveying;reduction of fruit;apple7|24|2<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：Aiming at the problems of limited natural ventilation capacity in plastic tunnel, too low airflow velocity in crop canopy, uneven temperature distribution, etc. , a pipe air supply system between crops in plastic tunnel was designed. CFD model was built to simulate and analyze the application effect of the system. The theoretical model was verified by the measured data. The maximum relative errors of the simulated and measured values of temperature and wind speed are respectively 4. 7% and 7. 1%, and the average relative errors are respectively 1. 6% and 3. 0%. The simulated and measured values are in good agreement, which indicates that the model has good reliability. The results show that: After the pipe air supply system is turned on, the average wind speed reaches 0. 2 m/s, the area of suitable area(wind speed range 0. 1-0. 5 m/s)accounts for more than 69%; The pipe air supply system promotes the upward flow of cold air, the temperature at the top of the plastic greenhouse dropped by 1. 0 ℃, and the average temperature difference between 0. 5 m and 2. 0 m height planesdecreased by 0. 4 ℃. In conclusion, that active air supply between crop rows can effectively improve the airflow environment and temperature distribution in plastic tunnel.Keywords：plastic tunnel;pipe air supply system;temperature;flow field;computational fluid dynamics9|27|2<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：In order to explore the impact of rural entrepreneurial leaders' poverty reduction mechanism and individual characteristics, based on participatory poverty alleviation theory and trickle-down theory, the research data of rural entrepreneurial leaders from 20 counties and cities are used. the quantile regression method is adopted to analyze the mechanism of rural entrepreneurial leaders driving farmers to reduce poverty and examine the difference of individual characteristics on the effect of rural entrepreneurial leaders driving farmers to reduce poverty. Theresults show that: Rural entrepreneurial leaders have the dual identity of “farmer” and “entrepreneur” at the same time, with a clear initiative to “bring wealth” characteristics. Their impact on farmer income includes the “egoism” and “altruism” two-way characteristics. The education level and skill level of rural entrepreneurial leaders have a significant impact on driving farmers' income increase and poverty alleviation, but there are certain limitations. The existing skills training and management training need to be further deepened. Therefore, cultivating various forms of rural entrepreneurial leaders, expanding the scope of rural economic elites and social elites, and strengthening the systematic skills and management training of rural entrepreneurial leaders are necessary tostrengthen material support and spiritual motivation, improve identity, stimulate the potential of the rich.Keywords：rural entrepreneurial leaders;mechanisms to help poor households reduce poverty;individual characteristics;poverty reduction effect;quantile regression model5|23|0<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：The aims of this study are to explore the connotation of high-quality development of animal husbandry, the key points of the transformation of animal husbandry and its guarantee policies. Firstly, from the perspective of the development history of animal husbandry and the impact of external emergencies, the connotation of high-quality development of animal husbandry is defined as the dynamic structure, development mode, development environment and development results of animal husbandry development that can better meet people's growing demand for high-quality and safe livestock products. On this basis, it is clarified that the specific content of high-quality development of animal husbandry should contain two aspects of development process and result. Subsequently, combined with the realistic basis of China's animal husbandry development, against the connotation and content of high-quality development, the main points for the high-quality development of China's animal husbandry are proposed, including promoting innovation-driven reform, increasing scientific and technological empowerment, advocating green development, promoting institutional innovation, and improving the supply structure of livestock products. Finally, this study puts forward the guarantee policies to help the high-quality development of animal husbandry, including dealing with the relationship between government and the market, innovating policy tools, applying policies according to the matter, improving the efficiency of financial funds, and establishing the mechanism of correction and fault tolerance of animal husbandry policies.Keywords：animal husbandry;high-quality development;key points;policy design10|23|4<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：In order to promote the transformation of farmers' willingness to replace chemical fertilizer with organic fertilizer into action and promote the implementation of China's chemical fertilizer reduction policy, this study constructs a theoretical analysis framework for the consistency of farmers' willingness and behavior of organic fertilizer to replace chemical fertilizer, and explores the consistency of farmers' willingness and behavior of organic fertilizer to replace chemical fertilizer from the perspective of perceived value and policy regulation based on 404 questionnaires in 16 cities in Shandong Province. Based on the interaction effect of policy regulation and perceived value and the mediating effect of willingness to participate in organic fertilizer substitution pilots, further analysis was conducted. The results show that: The perceived economic value, perceived ecological value and incentive policy regulation can significantly positively affect the willingness and behavior consistency of farmers to replace chemical fertilizer with organic fertilizer. Policy regulation plays a certain role in regulating the influence of perceived value on farmers' willingness and behavior consistency of organic fertilizer to replace chemical fertilizer. The willingness to participate in the organic fertilizer substitution pilot plays a covering role in the influence of perceived economic value on the willingness and behavior consistency of farmers to replace chemical fertilizer with organic fertilizer, and plays a part-mediating role in the influence of perceived ecological value on the willingness and behavior consistency of organic fertilizer to replace chemical fertilizer. Therefore, in the process of promoting the replacement of organic fertilizer with chemical fertilizer, the perceived value level of farmers is improved through incentive policies, which promotes farmers' willingness to replace chemical fertilizer with organic fertilizer. In the process of implementing the punishment policy, attention should be paid to avoid excessive punishment policy that causes farmers to have a rebellious mentality and would cause a repressive effect instead.Keywords：perceived value;policy regulation;moderating effect;organic fertilizer instead of chemical fertilizer;consistency of willingness and behavior5|23|9<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
