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- Abstract：In order to elucidate the molecular mechanism and regulatory network of plant wax synthesis and transport, 125 articles published from 1974 to 2022 were retrieved based on PubMed, Web of Science and China National Knowledge Infrastructure by using both Chinese and English keywords “epidermal wax” and “plant”. The metabolisms of the synthesis, transport and regulation networks of wax in maize were summarized. The results show that: Plant wax is composed of long chain fatty acids, alkanes, aldehydes, alcohols, ketones, terpenes and some small molecular secondary metabolites. The content and composition of wax are different in different plants and in different organs even in same plant. The synthesis, transport and regulation mechanism of epidermal waxy acids in model plant Arabidopsis thaliana are relatively clear. The very long chain fatty acids(VLCFAs)were synthesized by fatty acyl-CoA elongase multienzyme system. The synthesized VLCFAs were composed of β-ketoacyl-CoA synthase, β-ketoacyl-CoA reductase, β-hydroxyl-CoA dehydrase and trans-oleyl-CoA reductase. The synthesized VLCFAs participate the corneous wax synthesis pathway through decarbonylation and acyl reduction, and formed various waxy components. The wax synthesis and arrangement in monocotyledon plants are similar to dicotyledon plants and different in some aspect. For example, the lipid transporter ABCG32 in A. thaliana involves in the rosette leaf cuticle wax loading, while its homolog GLOSSY13 plays a role in the wax transport in young leaf epidermis in maize. HvABCG31 and OsABCG31 are the two homologos of GLOSSY13 and AtABCG32 in barley and rice, respectively and mainly function in young leaves. More than 30 waxy mutants were found in maize, and the related genes are still to be discovered.Keywords：plant epidermal wax;VLCFAs;biosynthesis and transport;transcriptional regulation12|26|7<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：In order to clarify the characteristics of soil bacterial communities in tobacco field and their correlations with other soil environmental factors under different long-term planting systems, soil samples from wasteland(AL), flue-cured tobacco continuous cropping(CC)and flue-cured tobacco-maize rotation(CR)were collected. The characteristics and relationships of soil bacterial communities and other soil environmental factors under different planting systems were analyzed by 16S rRNA high-throughput sequencing technology. The results showed that: CC significantly increased the content of available phosphorus, available potassium and catalase activities in soil(P<0. 05), and increased by 55. 21 mg/kg, 108. 06 mg/kg and 4. 36 μmol/g respectively compared with AL. The composition of soil bacterial communities in different planting systems was similar at the phylum level, but there were significant differences at the genus level. Among which, Pseudarthrobacter, which had the highest relative abundance in CC soil, and Haliangium which had the highest relative abundance in CR soil, displayed the largest differences. Their abundances were 3. 99% and 0. 90% higher than AL, respectively. CC and CR increased the abundance and diversity of bacterial biota and the number of OTUs in tobacco soil, with CR being the most significant(P<0. 05). LEfSe difference analysis showed that there were significant differences in the composition of dominant flora in soils with different planting systems(P<0. 05), among which the main dominant bacteria in CC and CR soils were Pseudarthrobacter and Haliangium. RDA analysis and Pearson correlation analysis showed that there was a strong correlation between dominant microbiota and different microenvironmental factors, and soil catalase activity and available potassium content had the greatest impact on the distribution of bacterial communities, which were significantly positively correlated with the relative abundance of Pseudarthrobacter and the relative abundance of Haliangium (P<0. 05). In conclusion, different planting systems lead to significant changes in soil microecological environment, and long-term continuous cropping lead to significant enrichment of soil available potassium content, which significantly increase soil catalase activity, inhibit the growth of beneficial bacteria, reduce the stability of soil bacterial community structure, and then affect the balance of soil microecological environment.Keywords：cropping system;continuous cropping;crop rotation;environmental factors;bacterial community;correlation7|22|8<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：In order to investigate the variation of transposable elements(TEs)in the domestication process of rice and foxtail millet, transposon annotation was carried out on the genome of foxtail millet(Setaria italica), green foxtail(Setaria viridis), cultivated rice(Oryza sativa japonica, Oryza sativa indica)and wild rice(Oryza rufipogon, Oryza nivara), the insertion numbers and positions of various transposons in the genome of these species were statistically analyzed. Genes related to regulation of seed setting, tillering, heading and plant higher acclimation were selected in rice, and similarity comparison was conducted on the genomes of foxtail millet, green foxtail, cultivated rice species and wild rice species. The results showed that the number of transposons inserted in the genome of ‘Jingu 21' was 4 865 more than that in green foxtail, and the number of transposons inserted in the genome of ‘Yugu 1' was 6 286 less than that in green foxtail, while the number and proportion of transposons inserted in the genome of rice cultivated species was only half of that of wild species. There were differences in the number and location of transposon insertion in genes related to domestication, such as shattering and millet color. Transposon insertion was found in foxtail millet genes, but not in green foxtail genes, while in foxtail millet color genes, transposon insertion was found in foxtail millet genes, but not in foxtail millet genes. Transposons mediate functional variation of domestication-related genes, and then stabilize agronomic traits suitable for cultivation through generations of agricultural production.Keywords：transposable elements;foxtail millet;rice;cultivate;domesticate4|22|0<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：In order to explore a method for rapid identification of the browning resistance of sweetpotato germplasm based on image recognition technology, 98 varieties(lines)were selected as study materials. Based on MATLAB R2018b, using binarization to segment the image background and then pixel values of sweetpotato slice images were detected. The pictures were categorized by RGB color and cluster analysis. For different groups, Euclidean distance was adopted to calculate the browning area of different types of sweetpotatoes and the specific weight ratio of the browning area in the whole image was calculated. The results showed that: After segmenting the background, the 98 materials was divided into three groups by color through cluster analysis. There were 40 varieties of white tone flesh, 35 varieties of yellow tone flesh and 23 varieties of orange tone flesh. The highly anti-browning material identified included white tone flesh variety ‘Ziyunshu', ‘Chuanshu 231', ‘Chuanshu 218', yellow tone flesh varieties ‘Longshu 21', ‘Qining 31', and ‘Jicaishu 7', and orange tone fleshvariety ‘Jinshu 69'. Therefore, image segmentation means based on color space and Euclidean distance are suitable for rapid and accurate identification of sweetpotato germplasm for browning resistance.Keywords：sweetpotato;browning resistant;image segmentation;MATLAB4|23|1<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：In order to effectively regulate the flowering of Orchidaceae, one of the largest families of flowering plants, the molecular genetic basis of floral organ regulation and flowering process of orchids with unique floral structures such as stamens and labellum were elaborated. On this basis, the regulation of orchid development was prospected. The results showed that: 1)In the ABCDE model of orchid flower organs, type A and E determine sepals, type A, B and E determine petals, type B, C and E determine stamens, and type D and E determine carpels; 2)Temperature, photoperiod and hormones are the key factors to determine the initiation and development of orchids; 3)Great breakthroughs are made in the research of transcriptome, genome and functional verified genes during flowering. In conclusion, this review can open up new ideas for research on the molecular genetic basis of flower development in orchids.Keywords：Orchidaceae;floral organ;flower formation;gene regulation4|23|1<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：The use of biogas slurry concentrates with active substances to enhance product functionality is a major way to increase value to biogas concentrate products and reduce the cost of membrane concentration treatment. In this study, biogas slurry containing Bacillus spp. was prepared by combining concentrated biogas slurry with Bacillus spp. , and the effect of biogas slurry containing Bacillus spp. on the growth promotion and bacterial inhibition was investigated by seed germination and in-dish inhibition tests. The results showed that: The biogas slurry containing Bacillus spp. significantly promoted crop germination and displayed inhibitory effects on soil-borne pathogenic fungi. Among them, the 1 000-fold dilution of biogas slurry containing Bacillus spp. significantly promoted seed germination and growth, and had the strongest effect on seed root growth. Stored at room temperature of 25 ℃ for one month, compared to CK, the root lengths of cucumber, wheat and cabbage seeds treated with 1 000-fold dilution of biogas slurry containing Bacillus spp. increased by 73. 3%, 45. 2% and 51. 7%, respectively. The inhibitory effect of biogas slurry containing Bacillus spp. on the growth of pathogenic bacteria gradually decreased with the increase of dilution ratio, but the inhibition rate was higher than 60. 0% in the concentration range of this experiment. Besides, the suppressive rates of biogas slurry containing Bacillus spp. with 10 000 dilution and stored for one month on F. oxysporum f. sp. Cucumerinum, F. oxysporum f. sp. lycopersici and Fusarium solani reached 65. 3%, 72. 6% and 79. 5%, respectively. In conclusion, the biogas slurry containing Bacillus spp. displays significant effect on growth promotion and bacterial inhibition.8|26|5<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：To clarify the degradation characteristics of different materials of biodegradable film and its effect on pepper growth and development in humid climate. Through field trial was conducted to investigate the effects of polyethylene film(PE), degradation film based on starch(BM1), polymeric degradation film(butyleneadipate-co-terephthalate(PBAT), polyhydroxyalkanoates(PHA)(BM2, BM3 and BM4))on the soil temperature, degradation properties of field cover, and agronomic traits of pepper, effected by). The degradation process of mulch film at different depth was evaluated by soil burial test. The results show that: 1)The early period of pepper(0-58 d after film mulching)was the main period of heat preservation by film, and film mulching planting mainly improved the soil temperature at 0-5 and 5-10 cm soil depths at 14: 00 and 17: 00 o'clock during this period. Among them, the warming effect of BM3 and BM4 was similar to that of PE, and the average temperature of 0-5 and 5-10 cm soil depths was increased by about 4 ℃ compared with CK. The degradation process of film was affected by the degradation materials. The degradation film based on starch reached the membrane-free stage at 79 d, and was completely degraded within 60 d under buried conditions. The induction period of polymeric degradation film was 51 to 93 d after covering the film, that reached fragmentation stage or membrane-free stage after pepper harvest. According to the fitting equation, the buried soil depth affected the degradation of BM4, and the degradation rate of BM4 buried at 20 cm was 77 days less than that at 10 cm when the degradation rate reached 95%. BM4 mainly improved the stem thick, stem height and dry mass in the mature period, and its promotion effect on pepper growth was close to or better than that of PE. The pepper productionsIn conclusion, or pepper film mulching cultivation, the induction period of degradation film should be 51-93 d to reach the fragmentation stage or membrane-free stage after harvesting of all the pepper. The buried soil depth of 10-20 cm can meet the degradation requirements of degradable film.Keywords：biodegradable film;degradation characteristics;degradation material;pepper yield5|23|4<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：The ornamental value of bearded iris is high, but the frequent occurrence of bacterial soft rot in bearded iris limits the application of bearded iris due to the concentration of rain and heat in summer in China. In order to improve the survival rate of bearded iris under high temperature and high humidity conditions, it is possible to introduce the soft rot resistance characteristics of Iris tectorum and I. sibirica into bearded iris by the distant hybridization between different series within the genus Iris. The artificial pollination of bearded iris with I. tectorum and I. sibirica was carried out. The pollen germination on the stigma and pollen tube behavior were observed to determine the prezygotic barrier. The dynamics of ovary development after hybridization were monitored to determine the embryo rescue period. The results showed that: 1)There were certain prezygotic barriers in interseries crosses in bearded iris, including less pollen eruption, abnormal pollen tube growth and arrested pollen tube growth. Except the bearded iris×I. sibirica showed prezygote obstacles seriously, the rest of the combination of pollen tubes could reach ovary complete fertilization and prezygotic barrier is not the main barrier to interseries crosses in bearded iris; 2)The rate of abortion after crossing bearded iris with I. sibirica was faster than that with I. tectorum, and interseries crosses in bearded iris was positively correlated with the genetic relationship. 3)The best embryo rescue period for bearded iris×I. tectorum was 21 d after pollination, for I. tectorum×bearded iris was 24 d after pollination, and for I. sibirica×bearded iris was 12 d after pollination. In conclusion, postzygotic barrier is the main obstacle to interseries crosses in bearded iris. Embryo rescue can obtain distant hybridization progeny. This study lays the foundation for the cultivation of bearded iris with higher adaptability.Keywords：bearded iris;interseries crosses;prezygotic barrier;embryo rescue1|22|1<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：The novel avian influenza viruses(AIVs)can cause serious economic losses to the poultry industry. Systematic surveillance of novel AIVs in poultry is essential for control of avian influenza. In the present research, we isolated H3N3 subtypes AIVs from chicken farms reporting illness in China during 2022-2023. All of these chickens showed respiratory disease signs and a 10%-40% reduction in egg production. Epidemiological surveys, virus isolation and identification, sequence analysis, pathogenicity and airborne transmissibility in chickens of representative viruses isolated were conducted. The results showed that: 1)In December 2022, H3N3 AIVs was first found in a layer chicken flock in Eastern China, and the virus was transmitted to multiple provinces with high density chicken populations in a short time. The disease group was mainly in laying hens, with high morbidity, and low mortality(1%-5%), which mainly caused an acute decline in the egg production rate(10%-40%). 2)Sequence analysis showed that the novel H3N3 AIVs were evolving as a triple reassortment event, which bearing H3N8-derived HA gene, H10N3-derived NA gene and H9N2-derived internal genes. 3)Similar to the H3N8 virus, the novel H3N3 AIVs were highly susceptible to SPF chickens. The virus replicated efficiently in the turbinate, trachea and lung and infected chickens showed pathological damage. 4)H3N3 viruses were airborne transmission among chickens, whereas H3N8 viruses were not. In conclusion, the novel reassortant H3N3 viruses show serious pathogenicity and airborne transmissibility in chickens. Therefore, comprehensive surveillance of H3N3 AIVs in domestic poultry is imperative and control of the virus endemic is needed.Keywords：H3N3;avian influenza virus;chicken;pathogenicity;airborne transmissibility15|22|1<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：To explore the biological functions of bta-miR-2285f and TBK1 (TANK binding kinase 1), and the potential mechanism of bta-miR-2285f interacting with its target gene in regulating milk fat metabolism in dairy cows, here, the conservation of bta-miR-2285f among different species was analyzed by bioinformatics methods, and the upstream sequence CPG island analysis, promoter prediction, and further tissue expression profiling were performed to predict the target gene, and GO function and KEGG pathway enrichment analysis were performed. The downstream target gene CAB39(calcium binding protein 39) regulated by bta-miR-2285f was verified by dual luciferase reporter assay, and the functional role of bta-miR-2285f was explored at the level of breast epithelial cells. The results showed that: 1)bta-miR-2285f was a bovine specific intronic miRNA; 2)bta-miR-2285f and host gene TBK1 did not contain CPG islands at the 2 kb upstream sequence. Bta-miR-2285f was the transcription start site at 586 bp upstream. The host gene TBK1 is the transcriptional initiation site at 105 bp upstream; 3)TargetScan and miRWalk predicted that miR-2285f had 172 intersection target genes, which were mainly involved in metabolism, genetic information transmission, signal analysis and cell interaction. The mTOR signaling pathway, PI3K-AKT signaling pathway, ErbB signaling pathway, Hippo signaling pathway and triglyceride metabolism were significantly enriched, and the interaction network between bta-miR-2285f target genes was constructed in STRING database; 4)The expression of bta-miR-2285f was the highest in mammary gland tissues, which was significantly different from other tissues(P<0. 05); 5)Dual luciferase reporter assay confirmed the direct targeting relationship between bta-miR-2285f and CAB39 3'UTR seed sequence and bta-miR-2285f mimic significantly up-regulated the expression of milk fat marker genes ELOVL6, SLC27A6, PPARG and FASN, while bta-miR-2285f inhibitor had the opposite effect. In conclusion, Bta-Mir-2285f-1 may participate in milk fat metabolism by feedback regulating host gene TBK1, and bta-miR-2285f participates in milk fat metabolism by targeting gene CAB39. This study provides a basis for further exploring the potential mechanism of bta-miR-2285f in milk fat metabolism in Chinese Holstein dairy cows.Keywords：Chinese Holstein dairy;miR-2285f;bioinformatics;miRNA-mRNA interaction;milk fat5|21|0<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：The study was to construct MARC-145 polyclonal cell line with eIF5A(Eukaryotic translation initiation factor 5A)knockout using CRISPR/Cas9 system and to verify the effect of this cell line on PRRSV infection. In this study, for eIF5A gene, the recombinant lentivirus was successfully constructed and screened. MARC-145 cells were infected with the lentivirus and screened using puromycin though limited dilution method. Viability assays were performed on the transformed cells, T7E1 nucleic acid endonuclease, real-time PCR and western blot to verify the efficiency of eIF5A knockdown in vitro, and viral proliferation assays to verify the effect of this cell line on PRRSV replication. The results showed that: 1)eIF5A knockout had no effect on cell activity. 2)The expression of eIF5A was significantly decreased by T7E1 endonuclease, Real-time PCR and Western blot, and the cell line was named MARC-145-△eIF5A cell line. 3)In vitro assays demonstrated that knockout of eIF5A had an inhibitory effect on PRRSV proliferation. In conclusion, this study successfully constructed MARC-145 polyclonal cell lines with eIF5A gene knockout, and eIF5A knockout can significantly inhibit PRRSV proliferation in vitro, which lay a foundation for further exploration of the molecular mechanism of eIF5A regulation of PRRSV replication.Keywords：eIF5A;PRRSV;CRISPR/Cas9;MARC-145 cell3|21|1<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：To analyze the genotypes and genetic diversity of Tams1 of Theileria annulata in some areas of Xinjiang, in this paper, blood DNA of dairy cows in Toksun, Aiding Lake, Qinghe and Yiwu regions of Xinjiang was detected, cloning and sequencing of the Tams1 gene by PCR and sequences alignment were carried out. The Tams1 gene and its protein sequences were analyzed by MEGA, DNAsp, NetNGlyc and other online software. The results showed that: 1)All of the 23 sequences of T. annulata in Xinjiang were of genotypes 1 except for the sequence of sample 2 in the Yiwu region, which was classified as genotypes 3; In addition, Tams1 gene sequences in Xinjiang showed 90. 1%-100% and 83. 9%-100% similarity at the nucleotide and amino acid levels, respectively. 2)Extensive sequences variation was detected in the Tams1 sequences between nucleotide positions 168-217 and 479-528. The high genetic diversity of Tams1 sequence was shown by Hd=0. 994±0. 006, π=0. 071±0. 002, S=178, h=38 and k=52. 32; The neutrality index results showed that the number of haplotypes in the local T. annulata Tams1 gene was greater than the number of polymorphic sites, genetic diversity showed balanced selection. 3)The N-terminus of the Tams1 protein showed large sequences variability, with extensive variation exists in 3 regions(amino acid positions 27-52, 138-175, and 180-196). Through B cell antigen epitopes prediction and the 3D structural homology modeling, it was found that the Tams1 protein antigenic sites were mostly located on the surface, and its antigenicity was better. In conclusion, the study found that T. annulata at this alternative sampling sites has high genetic diversity, and this data can provide a reference for the follow-up studies on the genotype and population structure changes, different pathogenic characteristics and evasion mechanisms of host immunity.Keywords：Theileria annulata;Tams;1;genotype;genetic diversity5|23|0<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：In order to understand the prevalence, antimicrobial resistance and carriage of resistance genes of Salmonella from human, animal and environment-origin in a large-scale pig farm in Xinjiang, in this study, a total of 855 samples, including fecal and sole swabs of farm workers, pig anal swabs and environmental swabs, were collected and subjected to isolation and identification of Salmonella. The minimum inhibitory concentrations(MICs)were determined by the agar dilution method recommended by CLSI for the isolated Salmonella, and related drug resistance genes were detected by PCR. The results showed that: 1)A total of 288 stains of Salmonella were isolated, and the isolation rate of Salmonella in the three source samples was from the highest to the lowest as follows: farm worker samples(47. 2%), pig anal swabs(33. 9%)and environmental swabs(32. 3%). 2)MIC test showed that the drug resistance rates of the Salmonella from three sources to tetracycline, florfenicol, doxycycline and ampicillin were all above 75. 0%; The drug resistance of environmental Salmonella was the most serious and the drug resistance situation of human and porcine Salmonella was similar. The Salmonella isolates in this farm was highly sensitive to cefotiofur and imipenem, no strains resistant to levofloxacin and amikacin were detected. There were 30 drug resistance patterns in total, of which 81. 3% were resistant to 3 or more antimicrobials, 7 resistant strains are the main ones. The detection rate of 7 resistant strains of environmental Salmonella (65. 4%)was higher than that of porcine and human Salmonella. 3)11 related drug resistance genes could be detected in the isolates, the detection rate of blaTEM gene was 100. 0%, the carrying rates of ant(3″)-Ia, aac(6′)-Ib and floR genes were all higher than 50. 0%. The detection rate of tetracycline-resistant genes tetA and tetM in Salmonella from swine was about 50. 0%, which was higher than that of environmental and human Salmonella. In addition, two Salmonella strains carrying carbapenem multidrug resistance gene blaNDM were detected. To sum up, Salmonella has the highest detection rate in the human samples of the pig farm, and the drug resistance of environmental Salmonella was the most serious, the highest multidrug resistance rate, the widest drug resistance spectrum and the highest drug resistance gene carrier rate. There are differences in the prevalence, drug resistance and drug resistance gene carrying rate for Salmonella from three sources. We should standardize the disinfection and sterilization process and reasonably use antibiotics based on the overall perspective of human-animal-environmental health and the isolation rate and drug resistance status of Salmonella.Keywords：Salmonella;drug resistance;drug resistance gene;human-animal-environment2|21|3<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：In order to improve rice yield and irrigation water productivity(IWP)in Zhanghe Irrigation Area of Hubei Province, based on the soil data, meteorological data and field test data, a ORYZA v3 rice model verified by parameter adjustment was used to simulate the rice yield and irrigation water productivity under different scenarios. ArcGIS 10. 2 was used to expand the point scale simulation results to the regional scale. Combined with soil types in Zhanghe Irrigation Area, the appropriate combination of rice management measures was obtained through comprehensive analysis. The results showed that: 1)The evaluation indicators of the model rate period and the validation period all showed good correlation, indicating that the model had high accuracy and good adaptability for rice growth simulation in Zhanghe Irrigation Area. 2)A localized ORYZA v3 model was used for simulation analysis. Scenario 10(The lower limit of irrigation is 60% of soil saturated water content, the amount of nitrogen application is 198 kg/hm2, and the planting density is 4 plants/hole)was selected as the recommended combination of management measures in wet years, which increased yield and IWP by 5. 28% and 104. 38%, respectively; Scenario 7(The lower limit of irrigation is 70% of the soil saturated water content, the amount of nitrogen application is 198 kg/hm2, and the planting density is 5 plants/hole)was a combination of recommended management measures in normal year, which increased yield and IWP by 4. 23% and 74. 34%, respectively; Scenario 9(The lower limit of irrigation is 60% of soil saturated water content, the amount of nitrogen application is 162 kg N/hm2, and the planting density is 4 plants/hole)was a combination of recommended management measures in dry years, which increased yield and IWP by 1. 60% and 146. 79%, respectively. 3)The influence of different soil textures was considered in the model running process. The 60% to 70% of soil saturated water content as the lower limit of irrigation was recommended for farm fields with clay soil texture. In conclusion, a reasonable multi-factor synergistic configuration scheme was built in this study, which provided a corresponding scientific basis for water efficiency improvement in modern irrigation areas and the realization of local high-efficiency planting.Keywords：Zhanghe Irrigation Area;ORYZA v3 rice model;yield;irrigation water productivity2|23|2<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：To evaluate the change of the effective irrigated area in different parts of China accurately, effective irrigated area and related agricultural statistics of 31 provincial administrative regions(Data did not include those of HongKong, Macao and Taiwan regions. The same below)were used to explore the characteristics of effective irrigated area in China by using the trend analysis and conventional mathematical statistics method from 1978 to 2020. The results are as follows: 1)Overall, the effective irrigated area was constantly increasing. The increasing trend reached 631. 5×103 hm2/a. The correlation coefficient between the effective irrigated area and the total grain output reached 0. 96(P<0. 001). 2)The effective irrigated area in most provincial regions in China showed an increasing trend. The northeast region increased the most significantly. Heilongjiang province had the most obvious increase in effective irrigated area in China. The effective irrigated area of Hebei, Inner Mongolia, Shandong, Jiangsu, Anhui, Henan, Hubei, Hunan, Xinjiang, Guizhou and Yunnan Provinces increased also obviously. 3)The effective irrigated area in some developed provinces and cities showed a decreasing trend. The effective irrigated area in Beijing, Tianjin and Shanghai showed a significant decrease trend after 2000. 4)From 1978 to 2020, Beijing, Tianjin and Xinjiang were the regions with the highest effective irrigation ratio in China. The proportion of effective irrigation in the south was generally lower than that in the north. Northeast region had the most obvious increase of effective irrigation ratio in China. In conclusion, in the past nearly 43a the growth of grain production in China and the stable increase of effective irrigated area had close relationship. The effective irrigated area of Beijing, Tianjin, Shanghai, Zhejiang, Guangdong and Shaanxi had reduction growth trend, while other provincial administrative regions had growth trend. The effective irrigated area of Heilongjiang and Inner Mongolia increased the most obvious. It is suggested that the relevant departments should keep the red line of cultivated land and increase the policy investment in agricultural irrigation facilities of cultivated land continuously. Finally, the strategy maker should imply and promote the construction of high-standard farmland to ensure the stable growth of effective irrigated area in China and the safety of food production in China.Keywords：China;effective irrigated area;inter-annual variation;interdecadal variation4|19|2<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：In order to study the development process and level of agricultural and rural modernization in Beijing, entropy method, GIS technology and obstacle degree model were adopted in this study. Based on the two target layers of agricultural modernization and rural modernization, a comprehensive evaluation index system of agricultural and rural modernization was constructed to analyze the overall development level of agricultural and rural modernization in Beijing from 2015 to 2020, development level of agricultural and rural modernization in each district, spatial pattern characteristics and obstacle factors. The results show that: 1)The agricultural and rural modernization development level of Beijing increased from 0. 591 4 in 2015 to 0. 719 2 in 2020, which is in the early stage of basically realizing agricultural and rural modernization. The two target levels and nine criteria levels have also been significantly improved, but the rural modernization development level is far lower than the agricultural modernization development level. 2)The overall development level of agricultural and rural modernization in all districts of Beijing is on the rise. The development level of high-value areas is steadily improved, and the development momentum of low-value areas is insufficient. Only Shunyi district is in the late stage of the beginning, other districts are in the early and middle stages. 3)The spatial distribution is obviously uneven, from sporadic distribution to cluster distribution, high level and low level regions appear the trend of diffusion at the same time and gradually formed a “low in northwest and high in southeast” spatial distribution pattern, and the spatial differentiation kept increasing year by year; 4)The modernization of agricultural industrial system and the modernization of rural infrastructure and public services are the key constraints for the development of agricultural and rural modernization in Beijing. In conclusion, this study the paper proposes to adhere to the two bottom lines of ensuring stable production and supply important agricultural products, narrow the income gap between urban and rural areas, give demonstration and leading role to high-level areas, develop rural characteristic industries in lower-level areas, and accelerate the construction of livable and professional-friendly rural areas.Keywords：agricultural and rural modernization;index system;comprehensive evaluation;the entropy method;handicap model3|22|0<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：To explore the correlation between land use structure and industrial structure, Quzhou County in Hebei Province was taken as the study case, and the land use and socio-economic data from 2011 to 2017 were used. An industry-based land use classification system was constructed, the information entropy, structure change rate, deviation coefficient, land occupation rate per unit output value, Pearson correlation coefficient were adopted in this study to analyze current situation and change situation of land use structure and industrial structure, and the correlation between the two. The results showed that: 1)Quzhou County as a large agricultural county in the transitional stage of early and middle industrialization, its primary industry land and secondary industry led the change of land use structure and industrial structure, respectively. However, there were some problems such as the increasingly acute contradiction between supply and demand of land use and the unbalanced development of industrial structure. 2)The change degree of industrial structure was greater than that of land use structure in Quzhou County, and the development of land use structure and industrial structure were not synchronized and coordinated. The use efficiency of primary and tertiary industry land, and intensity of land use needed to be further improved. The development of secondary industry and the change of land use structure had an internal relationship. It is concluded that Quzhou County should comprehensively improve the land use efficiency of primary industry, promote high-quality development of secondary industry and the intensive use of its industrial space, accelerate industrial restructuring and transforming, arrange the layout of tertiary industry land and reserve industry land reasonably, strengthen the connection of land use policy and industrial development policy to promote the collaborative optimization of the two.Keywords：land use structure;industrial structure;correlation;Quzhou County2|22|0<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：Given the problems of weir-flume combination facilities such as slope foot erosion and bank slope collapse caused by flood, a certain slope is set on the weir top on both sides of the facility to form a crest slope which inclined to the flume, so that the water is concentrated in the middle of the facility and the erosion on both sides of the bank slope reduced. With the hydraulic performance experiment, the mid-vertical water depth, the variation of Froude number, the influence of three crest slopes(0, 1/16 and 1/8)on the discharge capacity of the facility and the flow formula were studied under twelve kinds of discharges(6-61 L/s). The results show that: 1)The water depth of the weir-flume combination facilities with the three crest slopes has similar changes along the flume. With the increase of the crest slope, the water level upstream of the mid-vertical line increased. The water depth on the weir near the bank slope is reduced, which can reduce the erosion of water flow on both sides of the bank slope. 2)The crest slope had little influence on the location of the critical flow section, which mainly occurs in the second half of the trapezoidal section of the drainage flume. Under the same discharge, the discharge coefficient of the combination facility decreased with the increase of crest slope. Under the same crest slope, the discharge coefficient of the facility decreased with the increase in discharge. 3)When the relative hydraulic head was small, the discharge coefficient varied greatly. When the relative hydraulic head was large, the discharge coefficient was stable. The discharge coefficient was divided into two parts: the variable discharge coefficient and the stable discharge coefficient, and the discharge calculation formulas under different crest slope conditions were fitted respectively. Compared with the measured discharge, when the crest slope was 0, 1/16 and 1/8, the maximum absolute value of relative errors was 2. 22%, 2. 37% and 2. 21%, respectively, and the average relative errors were 0. 88%, 0. 95% and 1. 15%, respectively. In addition, when the discharge was 11 L/s and 21 L/s, the increase in crest slope made the relative error of the flow formula decrease from -2. 22% to -0. 44% and from 2. 35% to -0. 24%. Therefore, the existence of the crest slope can reduce the erosion of water flow on both sides of the bank slope and has little impact on the critical flow section. The increase in crest slope also improves the measurement accuracy of weir-flume combination facilities under the small discharge.Keywords：weir-flume combination;crest slope;flow measurement formula;discharge capacity2|23|1<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：Aiming at the problem of the low drinking water temperature for dairy cows leading to reduced milk yield, an air-source heat pump water heater was introduced to design the drinking water heating system of large-scale dairy farms. Milk yield of dairy cows in the two groups was continuously monitored under different drinking water heating modes at environmental temperature >15 ℃, 4 ℃≤ environmental temperature ≤15 ℃, and environment temperature <4 ℃. The curve of daily milk yield of dairy cows in the two groups was analyzed. The results showed that: After supplying 22-25 ℃ hot water to the dairy cows in a low temperature environment, the average milk yield of dairy cows did not change significantly with the ambient temperature(P>0. 05), while the average dairy cow after drinking the water after drinking the milk at a temperature of 12-15 ℃. The lactation volume changed significantly with environmental temperature changed(P<0. 01), indicating that long-term drinking of 22-25 ℃ hot water in a low-temperature environment can generally enhance the production performance of dairy cows. After excluding the effects of the lactation period, the average milk yield of the experimental group and the control group was compared. The average daily milk yield of dairy cows with a drinking water temperature of 12-15 ℃ under low air temperature decreased by 0. 45 kg every 7 days, and after raising the drinking water temperature to 22-25 ℃, the milk yield of dairy cows remained stable. It was particularly effective in enhancing the milk yield and production stability of dairy cows in the middle of lactation. In conclusion, the new system constructed in this study can supply 22-25 ℃ drinking water for dairy cow under environment temperature <4 ℃ and are beneficial to increase milk yield and production stability.Keywords：dairy cows;drinking water system;water temperature;environmental temperature;milk yield5|16|1<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
Route optimization of rural low-carbon logistics based on improved multi-objective genetic algorithm
Abstract：Aiming at the practical problems of high cost, insufficient demand coverage and high carbon emissions existed in the logistics distribution of counties, townships and villages in China, a rural logistics distribution routing optimization model considering demand uncertainty and carbon emissions constraints was constructed. an improved multi-objective genetic algorithm suitable for multiple vehicles was proposed. Combined with the rural logistics distribution data, MatlabR2014a software was used to carry out simulation experiments, and the optimal distribution route scheme of rural logistics under the demand uncertainty and carbon emission constraints was finally obtained. The simulation results show that: The proposed improved multi-objective genetic algorithm has better effectiveness and applicability for solving the rural logistics distribution routing problem; Under the demand uncertainty and carbon emission constraints, the improved multi-objective genetic algorithm can effectively reduce the cost of rural logistics distribution and improve the demand coverage rate; Compared with the single-vehicle distribution scheme, the multi-vehicle distribution scheme has more advantages in rural logistics distribution.Keywords：improved multi-objective genetic algorithm;rural logistics;route optimization;demand uncertainty;carbon emission constraints10|21|1<HTML><L-PDF> <Meta-XML>Updated：2023-12-22- Abstract：In view of the urgent need for continuous improvement of the quality of cultivated land and the problem of the low sustainability of farmers' adoption of organic fertilizer technology in China, this study analyses the effect of information competence and the mediating effect of income uncertainty on farmers' continuous adoption of organic fertilizer from the theoretical and empirical levels. The negative binomial regression and non-parametric Bootstrap methods are adopted to analyze 1 667 original data from six main vegetable-producing provinces in China. The results show that: 1)Information competence has a significant positive impact on farmers's continuous adoption of organic fertilizers at the 1% level, with a marginal effect of 0. 740; 2)Information competence has the greatest impact on the continuous application of organic fertilizers of farmers with age ≤52 years old(the 50th percentile)and who have been educated ≥9 years, with marginal effects of 0. 808 and 0. 789, respectively; 3)Income uncertainty has a significant mediating effect on the influence of information competence on farmers' continuous adoption of organic fertilizer, with marginal effect coefficient of 0. 035. Therefore, to improve the sustainability of farmers' adoption of organic fertilizers, the government should update the form of agricultural technology promotion, improve the information technology infrastructure facilities, and provide targeted information training services and so on to improve their information competence.Keywords：continued adoption of organic fertilizer;information competence;Bootstrap method;income uncertainty6|21|6<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：Based on the survey data of 364 residents in Dashanbao, Zhaotong, Yunnan Province, the impact of climate change perception on farmers' livelihood strategies is analyzed using partial least square structural equation model to clarify the path and internal logic of climate change perception affecting farmers' livelihoods. The results show that: 1)Climate change perception has a significant negative impact on agricultural livelihood strategies and a significant positive impact on non-agricultural strategies. 2)Climate change perception influences livelihood strategies through adaptive behavior, which makes farmers' livelihoods turn to non-agricultural strategies. 3)Individual factors of farmers and agricultural production environment play significant moderating roles in the relationship between climate change perception and livelihood strategies. Groups with risk-loving and high information acquisition ability are more inclined to adjust livelihood strategies. Farmers tend to adhere to agricultural livelihood strategies when agricultural subsidies and agricultural infrastructure are relatively complete. This study can provide some reference for the government to formulate more targeted climate change policies and improve the sustainable livelihood ability of rural residents.Keywords：rural households;perception on climate change;adaptive behavior;livelihood strategy;structural equation model4|23|5<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：To further explore the correlation between individual information allocation and agricultural e-commerce, and to improve the effective strategies to enhance the overall information gain. From the perspective of information sharing, based on the assumption of bounded rationality, an evolutionary game model of “producer and consumer” two-in-one of agricultural products is constructed. The strategic interaction between different subjects and the influence of main parameters under the three scenarios of free trade, platform supervision and interest connection are discussed. According to the phase diagram, system simulation is used to simulate the moving trajectory of the model equilibrium point under different scenarios. The results show that: 1)The “interest connection” scenario can accelerate the realization of the stable state of the participating players' information allocation strategy for agricultural e-commerce and improve the overall information income of the society more than the “free trade” and “platform supervision” scenarios. 2)Measures such as reducing the misjudgment rate of inferior agricultural products, reducing the cost of high-quality information processing, appropriately increasing the amount of platform rewards, and enhancing future cooperation benefits can encourage producers to actively release high-quality information and consumers to use information in an orderly manner, thus forcing the platform to upgrade information quality.Keywords：agricultural e-commerce information;individual;configuring strategy;evolutionary game;simulation8|20|0<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：In order to clarify whether the participation of village collective as an intermediary help to optimize the agricultural land transfer market, literature review, theoretical analysis and multi-case comparison are used to study the realistic predicament of the agricultural land transfer market, the causes behind it and the measures to solve it. Based on constructing the theoretical framework and combining it with the practice in Guangdong, the study puts forward the idea that village collectives as an intermediary to participate in the agricultural land transfer will help solve the dilemma and optimize the development of the agricultural land transfer market. The results show that: Firstly, the historical lock, market failure, and institutional arrangement lead to the real dilemma of rural land transfer. Secondly, under the legal rights and social responsibilities, the village collective has the characteristics of governance, independence, and representativeness, which are helpful to solve the current practical predicament of the agricultural land transfer market, to optimize the market. Thirdly, there are various modes of village collectives' participation in the transfer of agricultural land. In conclusion, it is necessary to accurately define the role of village collectives in the transfer of agricultural land according to the actual situation of rural land, to highlight the role and advantages of village collectives in the transfer of agricultural land, and realize the transfer of agricultural land with high efficiency, high benefit, and high effect.Keywords：farmland circulation;village collective;distress6|21|0<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：In order to enhance consumers' participate willingness and promote the localization development of community supported agriculture(CSA), based on the questionnaires of 820 consumers, the impact of green cognition on consumers' participate willingness in CSA, the mediation of perceived value between green cognition and consumers' participate willingness in CSA by constructing the multiple regression model were investigated. The results showed that: 1)The agricultural pollution cognition, green agricultural product cognition and green policy cognition had the significant positive impact on consumers' participate willingness in CSA, among which the green agricultural product cognition displayed the most obvious impact. 2)The functional value, service value and environmental value had the significant positive mediation between agricultural pollution cognition, green agricultural product cognition, green policy cognition and consumers' participate willingness in CSA, among which the functional value's mediation was the highest. Therefore, promotion of the coordinated development of multiple subjects would not only improve consumers' green cognition level, help them to form green consumption awareness, and then enhance their initiative to participate in CSA, but also promote the producers to improve the operation and management of CSA farm, establish mutual trust relationship with consumers, and then improve consumers' perceived value for CSA. In conclusion, green cognition could enhance consumers' willingness to participate in CSA and build the solid social foundation for the localization development of CSA.Keywords：community supported agriculture;green cognition;perceived value;participate willingness6|19|3<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：In order to explore the impact of rural digitization on agricultural resilience, this study uses the panel data of 30 provinces(municipalities and autonomous regions)in China from 2011 to 2020(Data do not include those of Tibet, Hong Kong, Macao and Taiwan regions. The same below), and adopts entropy method to estimate the development level of agricultural resilience and rural digitization in China. The coupling coordination degree model and the intermediary effect model are used to analyze the coordination degree of agricultural resilience and rural digitization, and the mechanism of rural digitization on agricultural resilience is explored. The results show that: The level of agricultural resilience, level of rural digitization development and degree of their coupling and coordination are on the rise. The rural digitization can improve agricultural resilience by narrowing urban-rural income gap and improving rural human capital. The rural digitization is more effective in areas with low agricultural resilience.Keywords：agricultural resilience;rural digitization;urban-rural income gap;rural human capital;coupling coordination degree analysis9|22|14<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
