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- Abstract：In the absence of differential host system, this study is aimed to analyse the relative parasitic fitness and pathogenicity of southern corn rust collected from different regions. The resistance of maize varieties was evaluated. The Puccinia polysora Underw. strains obtained from Sanya Hainan, Heyuan Guangdong, Hechi Guangxi, Guilin Guangxi, Shaodong Hunan and Yuxi Yunnan were inoculated to 28 maize varieties to analyse the disease index and the relative parasitic fitness. The results showed that the varieties with the highest resistance to P. polysora was Denghai 605, and the most pathogenic strains came from Hechi, Guangxi. The relative parasitic fitness of P. polysora from different regions on the same maize variety was different. The relative parasitic fitness of the strains from the same regiron also had significant differences in different maize varieties. Different P. polysora strains had pathogenic differences. This study can provide basis for selection of resistant maize varieties to southern corn rust, the classification of pathogenic types and physiological races, and breeding of resistant varieties.Keywords：southern corn rust;Puccinia polysora;disease index;relative parasitic fitness5|15|2<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：To explore the suitable varieties and supporting agronomic measures of maize mechanical harvesting in the middle reaches of the Yangtze River, different maize varieties were selected and harvested at different times after grain maturity in 2018 and 2019 to analyze the changes in yield and quality of mechanical harvest. The key agronomic traits were further identified influencing the broken rate and loss rate in mechanical harvest. The results showed that the harvest time had significant effects on mechanical harvest yield and quality in spring maize. The delayed harvest by a week significantly increased the grain test weight, thus increased the mechanical harvest yield by 9. 72% averaged across varieties and two years. However, delayed harvest by 2 weeks would reduce the yield of mechanical harvest. In the two experimental years, the impurity rate was less than 3%, while the broken rate and loss rate of mechanical harvest were all higher than 5%, which were the major problem in maize mechanical harvest in this region. Grain thickness, grain moisture and 100-grain weight were the key traits affecting the grain broken rate in mechanical harvest, which showed a significant negatively quadratic curve relationship with the grain broken rate. The lodging rate, ear height and barycenter height were the key traits affecting the loss rate. The lodging rate is positively linearly correlated with the mechanical harvest loss, while the ear height and the barycenter height had a significant quadratic curve relationship with the loss rate. In conclusion, the delayed harvest by one week significantly decreases the grain moisture and thus reduces the grain broken rate. However, continuing to delay the harvest has the risk in increasing lodging rate. It is suggested that spring maize in the middle reaches of Yangtze river could be mechanically harvested 7-10 d after maturity, which could effectively reduce the grain moisture and the grain broken rate, thus increase the mechanical yield.Keywords：the middle reaches of the Yangtze River;spring maize;mechanical grain harvest;harvest time;broken rate;agronomic traits1|12|3<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：In order to explore the occurrence rules of different disasters during the growth period of winter wheat, the main wheat producing area of Hebei Province was taken as the research area, the disasters data from 1990 to 2018 were used to analyze the spatial and temporal characteristics of disasters and to estimate the major disaster damage ratio of winter wheat. The results showed that: 1)Winter wheat drought occurred frequently, the highest drought frequencies of winter wheat at jointing stage and heading stage were 0. 7 and 0. 6, respectively; during the study period, there were 54 times of wind-hail disasters mainly occurred in heading stage(21 times), milk-ripening stage(11 times)and ripening stage(19 times); freezing injury were 27 times in total, among which 10 times were at tillering stage and 14 times were at jointing stage; dry-hot wind mainly appeared in heading stage, milk-ripening stage and ripening stage; diseases and pests mainly appeared in the heading stage. 2)During the growth period of winter wheat from 1990 to 2018, the frequency of drought decreased, the wind-hail times and dry-hot wind days showed a growing trend, the number of freezing injury and the extent of diseases and pests continued to decline. 3)The frequency of drought in all regions was at high level, among which the central and southern regions were more prone to drought; wind-hail disaster moved from south to north with the growth period of winter wheat; the occurrence of freezing injury was more frequent in western region during the whole growth period and more frequent in southern region at jointing stage; the annual number of hot-dry wind days increased from north to south; the annual disaster rate of diseases and pests is higher in the south. 4)The contribution rate of drought reduction was the highest, the contribution rate of freezing injury was lower, and the reduction rate of winter wheat in central and southern regions were higher. The yield of winter wheat in both Shijiazhuang and Langfang reduced by more than 6%, and by about 5% in other areas. Therefore, to reduce the rate of winter wheat disaster damage, each region should pay more attention to the effects of wind-hail and dry-hot wind on winter wheat on the basis of the existing disaster reduction measurement according to the occurrence law of disasters.Keywords：winter wheat;growth period;natural disasters;disaster intensity6|13|3<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：To explore the effect of ‘Tribenuron-methyl' on the photosynthetic characteristics of different varieties of foxtail millet leaves, nine foxtail millet varieties were used as the test materials, and 10% ‘tribenuron-methyl' wattable powder was taken as the test drug. Three doses, 112. 5(T1), 225. 0(T2, recommended dose)and 450. 0 g/hm2(T3), were respectively set, and the same amount of water was used as control(CK). At 21 d after treatment, the photosynthetic fluorescence parameters in the 2nd leaf from top of foxtail millet were measured. The results showed that: 1)T1 treatment did not affect the photosynthetic system of various foxtail millet varieties. 2)Under T2 treatment, The net photosynthetic rate(Pn)of ‘Zhangzagu 10', ‘Zhangzagu 13', ‘Huangjingu' and ‘Longgu 39' were not significantly different from the CK; The Pn ‘Jingu 5', ‘Jingu 21', ‘Zhonggu 9', ‘Yugu 18', and ‘Jigu 35' decreased by 50. 64%, 60. 91%, 43. 74%, 49. 62% and 54. 82%, respectively. 3)Under T3 treatment, the photosynthetic fluorescence parameters of ‘Zhangzagu 13' and ‘Longgu 39' were not significantly different from those of CK. The quantum yields of non-regulated energy dissipation(Y(NO))of ‘Yugu 18' and ‘Jingu 21' were significantly increased than CK by 129. 17% and 60. 87%, respectively. The quantum yields of regulated energy dissipation(Y(NPQ))of ‘Jingu 5', ‘Huangjingu' and ‘Zhangzagu 10' increased by 13. 73%, 10. 00% and 12. 28% respectively. The proportions of non-photochemical reaction dissipation(Ex)of ‘Jingu 21' and ‘Zhonggu 9' were increased 48. 39% and 113. 33%, while the PSII actual photochemical efficiency(Y(II)), the relative electron transfer rate of PSII(ETR(II)), the photochemical quenching coefficient(qP), the share of light energy absorbed for photochemical reactions(P)and Pn were significantly decreased than CK. The non-photochemical quantum yield due to PSI donor side limitation(Y(ND))of ‘Jigu 35' and ‘Longgu 39' were significantly higher than that of CK by 300. 00%. The PSI actual photochemical efficiency(Y(I))and the relative electron transfer rate of PSI(ETR(I))of ‘Jingu 21' were reduced than CK by 45. 95% and 45. 26%, respectively. The Y(I)and ETR(I)of ‘Huangjingu' were reduced by than CK 43. 59% and 43. 13%, respectively. In summary, T1 treatment had little effect on the photosynthetic system of all tested varieties. Under T2 treatment, all tested varieties could dissipate excess excitation energy through heat dissipation. Under T3 treatment, the photosynthetic system of ‘Zhangzagu 13' and ‘Longgu 39' were basically normal; the photosynthetic system of ‘Jingu 21' and ‘Yugu 18' were more severely damaged. Although the other varieties were relatively lightly damaged, the photosynthetic pigment content of their leaves decreased, electron transfer was blocked, energy distribution was unbalanced, which affected the photosynthetic rate of foxtail millet leaves.3|11|3<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：In order to achieve the accurate quantitative detection of the composition in genetically modified herbicide-tolerant soybean variety ‘ZH 10-6', 5′ flanking sequence of the genetically modified soybean ‘ZH 10-6' was used as the target sequence, PCR amplification primers and TaqMan probes were designed, and the primer probe concentration was optimized. After specific testing, a droplet digital PCR detection method for the herbicide-tolerant soybean variety ‘ZH 10-6' was established. The results show that: 1)The specificity was good. Only when the genetically modified herbicide-tolerant soybean ‘ZH 10-6' genome was used as a template, will there be amplification signals; 2)The sensitivity was high. When the relative standard deviation was ≤25%, the detection limit of this method(LOD)is 13 copies, and the limit of quantification(LOQ)was 66 copies; 3)The results of PCR amplification reaction displayed a linear correlation coefficient between template content and sample copy number is R2>0. 99, The linear range of DNA content is 0. 08%-100. 00%. In conclusion, the quantitative detection method for transgenic soybean ‘ZH 10-6' transformants established in this study has strong specificity, good stability, high accuracy and sensitivity, and can be used for the quantitative detection of genetically modified soybean ‘ZH 10-6' strains quickly, simply and efficiently.Keywords：droplet digital PCR;genetically modified soybean ‘ZH 10-6';event specific;transformant specificity1|11|4<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：To study the effect of a stay-green mutation on the expression of sucrose metabolism-related genes during leaf senescence, taking Zhilv No. 1(Z1)and one of its parents Jinda No. 74(JD74)as experimental materials, the change trend of soluble sugar content in soybean leaves from flowering to maturity was determined and the expression differences of sucrose metabolism-related genes were compared. The results indicated that: 1)The soluble sugar content of two soybean varieties fluctuated, increased and then decreased during the period from anthesis to maturity. From 14 to 42 days after flowering, the content of soluble sugar was much higher in Z1 than that in JD74. 2)From 29 to 42 days after anthesis, the expression levels of sucrose phosphate synthase gene SPS4, invertase iso-genes CInv, CWInv2 and sucrose synthase iso-genes SS1 and SS2-2 in Z1 were significantly higher than those in JD74. The expression levels of hexokinase and fructokinase genes Hxk and Frk were also much higher than that in JD74. 3)Except for SUT4-1, sucrose transporter iso-genes SUTs showed obvious variety-specific expression patterns. From 29 to 42 days after anthesis, the expression levels of SUTs in Z1 were higher. In summary, the stay-green mutation in soybean had a significant impact on the expression of sucrose metabolism-related genes, especially in the key periods of soybean grain formation such as the early and middle stage of pod filling, the expression of source metabolism related genes in Z1 was more transcriptionally active.Keywords：soybean;stay green;sucrose metabolism;gene expression2|10|0<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：To further investigate the function and value of endophytes in sugarcane cultivars and wild resources of Saccharum related species, and screened the microbial strains with the functional activity of promoting plant growth, in the hope of increasing sugarcane income and production. In this study, a total of 589 endophytic bacteria strains separated and purified previously were taken as research material. We screened and identified some functional strain which has ability of nitrogen fixation, uptake of insoluble phosphorus, potassium and other growth-promoting characteristics. On this basis, the organic acids, indole acetic acid(IAA)and siderophore produced by the strains were also quantitatively determined and classified. The results showed that the twelve endophytic bacteria strains were selected out, and these strains were numbered temporally as B7, B9, C9, D5, E12, F5, G3, H5, J8, L9, M3 and O9, respectively. Among them, most strains have biological activities such as nitrogen fixation, phosphorus dissolution and potassium solubilisation. Twelve strain were identified as belonging to six generas including Pantoea, Pseudomonas, Enterobacter, Serratia, Acinetobacter and Bacillus. Notably, the strain G3 and the C9 had the strongest ability to dissolve inorganic phosphorus and organic phosphorus, following tested, the concentration of soluble phosphorus in the medium were(1 386. 97±331. 96)mg/L and(2 523±68. 17)mg/L, respectively. The strain M3 had strong potassium-resolving ability and the concentration of soluble potassium in the culture solution was 8. 59±0. 08 mg/L. The organic acids produced by the strain mainly tartaric acid, and the rest were malic acid, acetic acid, lactic acid and citric acid. Twelve functional strains generally have the ability to produce IAA and siderophore, while the types of siderophore produced vary from strain to strain. Some strains can promote the growth of sugarcane seedling bud and root length when co-cultivation with sugarcane seedlings, among which E12, C9 and G3 treatment perform better. This research laid a material foundation for the subsequent development of microbial fertilizer in the future, and also provide reference for related research.Keywords：sugarcane;endophytic bacteria;growth-promoting;phytohormone;organic acid14|10|10<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：The aim of this study was to provide a biomechanical basis for the enrichment of evaluation index system of the sand-fixing ability of plant and the development of sand willow stubble machines. The branches of Salix psammophila, a pioneer tree species for sand fixation in the arid and semi-arid desert areas of Inner Mongolia, was taken as study object, and the mechanical properties of its tensile, shear and flexural properties during winter dormancy were studied. The effects of the length, diameter and chemical composition of the branches on their mechanical properties were analyzed. The results show that the ultimate tensile strength was(14. 05-52. 02 N), shear strength(16. 26-80. 04 N)and flexural strength(1. 02-3. 54 N)of the branchesin the test diameter range within the range of 0. 5-2. 5 mm. With the increase of the branch diameter, the stress-diameter increasing function is different. The ultimate tensile strength(8. 96-66. 19 MPa), shear strength(8. 04-39. 87 MPa)and bending strength(1 566. 46-46. 71 MPa)increased with the decreasing of diameter. The stress intensity-diameter decreasing function was different. It shows that diameter is an important factor affecting the mechanical properties of branches. As the length of the branches grows, the flexural strength tends to increase, while the tensile strength and shear strength have no obvious changes. The average ultimate tensile strength of the branches of S. sylvestris is(36. 19±3. 29 N)is stronger than the average shear strength of(50. 04±4. 54 N), and the average ultimate tensile strength of the branches is(31. 01 MPa±2. 81 MPa), which is stronger than the average shear strength of(16. 98±1. 54 MPa), indicating that the branch is easily damaged by the external force type of shear force. The tensile strength, shear strength and flexural strength of Salix branches are significantly(P<0. 05)and extremely significant(P<0. 01)positively correlated with cellulose and hemicellulose content, and were significantly positively correlated with lignin content(P<0. 05). In conclusion, the tensile, shear and flexural strength of the branches play a major role in which cellulose and hemicellulose followed by the lignin content.Keywords：Salix psammophila;branche;mechanical property;tensile strength;shear strength;cellulose6|9|2<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：To evaluate the phytosanitary status of pear orchards and characterize the prevalence of viruses and viroids in pear plants in Beijing area, 157 pear samples collected from main pear-growing districts were detected for the presence of apple stem grooving virus(ASGV), apple stem pitting virus(ASPV), apple chlorotic leaf spot virus(ACLSV)and apple scar skin viroid(ASSVd)by RT-PCR. The results showed that all samples were tested positive for virus(es), among which 91. 1% of the samples were tested positive for ASGV, 59. 2% for ASPV and 54. 8% for ASSVd. In contrast, the infection rate of ACLSV(35. 7%)was relatively low. Up to 84. 7% of the samples showed mixed infections, among which the mix-infection of ASGV+ASPV+ASSVd was the most common. It accounted for 25. 5% of the samples, followed by the mix-infection of ASGV+ASPV 11. 5% or ASGV+ACLSV 11. 5%. Virus(including viroid)species detected in different pear plants of same cultivar ‘jingbaili' in the same orchard were not exactly the same. In conclusion, the prevalence of viruses and viroid in pear plants in Beijing area was determined in this study, which could provide a reference for controlling of pear viral diseases.0|11|1<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：In this study, to solve the problems of low rooting rate of Pyrus betulifolia somaclone and low survival rate of transplanting, in vitro shoots of Pyrus betulifolia were used to optimize the rooting medium for adventitious root induction and root growth, and training methods of plantlets. The results showed that: 1)Ninety-six percent of in vitro shoots regenerated adventitious roots when the robust shoots were cultured on the NN69 medium supplemented with 1. 0 mg/L IAA and 1. 0 mg/L NAA under the darkness for 7 days, and then transferred to the same basic medium without auxins under lightening conditions; 2)More than 90% of the rooted plantlets survived when hardened in closed jars or hydroponic for 3 weeks and transplanted in the greenhouse. In conclusion, the two-step rooting method including utilization of high concentration of auxins in culture medium combined with dark culture at the beginning and auxin-free medium with light culture at the second step is suitable to induce rooting of in vitro cultured P. betulifolia. Optimizing the rooting techniques of plantlets provided a technical support for commercially producing clonal rootstocks of P. betulifolia.6|13|5<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：Catechins and caffeine are the key indicators of tea quality. In order to explore the feasibility of visible/near infrared spectroscopy(Vis/NIR)combined with convolutional neural network(CNN)for nondestructive and rapid detection of catechins and caffeine of fresh tea, this study used high performance liquid chromatography to determine the content of catechins and caffeine in tea, and established a corresponding relationship with the spectral information of the sample. Regression analysis and CNN modeling were used to construct the quantitative relationship between the spectrum and contents of tea. In addition, the competitive adaptive reweighted sampling(CARS)and successive projections algorithm(SPA)were used to select the characteristic wavelengths for the development of simple models. The result showed that: The contents of four catechins and caffeine displayed a gradual decrease trend from the first leaf position to the sixth leaf position. The extracting characteristic wavelengths not only reduced the number of spectral variables, but also obtained models performance that were better or close to that of the full spectrum. CNN performed well in the regression analysis and feature extraction, the coefficient of determination(R2)and residual prediction deviation(RPD)of optimal models for predicting catechins and caffeine reached 0. 93 and 3. 28, respectively. Therefore, the convolutional neural network combined with visible/near infrared spectroscopy could quickly and non-destructively detect contents of catechins and caffeine.Keywords：convolutional neural network;visible/near infrared spectroscopy;fresh tea;catechin;caffeine2|13|6<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：In order to improve the water solubility and emulsifying stability of Pinus tabulaeformis needle essential oil, the nano emulsion was prepared by the swirling mixer and microfluidic apparatus. By using the volume fraction of the emulsion and the area of the emulsion in three phase diagram, the best conditions for the preparation of nano emulsion were determined and the structure, particle size and multiple fractions of the nano emulsion Km, PDI and stability were analyzed. The results showed that: 1)The optimal formula of P. tabulaeformis needle essential oil nanoemulsion was 16. 14% of essential oil, 10. 45% of compound surfactant(4∶1 of absolute alcohol and Tween 80), and 73. 41% of distilled water; 2)P. tabulaeformis needle essential oil nanoemulsion had light blue microemulsion, and the droplets were spherical and distributed evenly, with a diameter of 35 nm, PDI is 0. 165; 3)The stability experiment showed that the average particle size and PDI of nanoemulsion had no obvious change under the condition of storing 60 days at room temperature and in pH=7 aqueous phase environment, which showed better storage stability. The best storage time was 30 days. The thermal stability test showed that the temperature of the pine needle essential oil nanoemulsion was 80 ℃, which had good thermal stability; 4)The antibacterial stability experiment results showed that the pine needle essential oil nano emulsion had better antibacterial activity compared with the non-emulsified essential oil. In conclusion, the P. tabulaeformis needle essential oil nanoemulsion prepared in this study had good water solubility and stability, and its bacteriostatic ability was enhanced compared with essential oil.Keywords：Pinus tabulaeformis;essential oil;nanoemulsion;stability.0|10|1<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：In order to investigate the differences among the placenta products of trypsin, pepsin and papain, placenta hydrolysates were obtained by enzyme hydrolysis of the three enzymes under the optimal conditions. Each enzyme was repeated 3 times. LC-MS/M technology was used to identify the proteins and peptides in the products, and the BIO-PEP database was used to match and calculate the antioxidant peptides below peptides. The results showed 541, 137, 86 proteins and 2 766, 1 170, 128 peptides were identified in trypsin group, pepsin group and papain group, respectively. The number of identified proteins and peptides in the trypsin group was significantly higher than the other two groups(P<0. 01), and the number of identified proteins and peptides in the papain group was significantly lower than the other two groups(P<0. 05). The potential antioxidant peptides of decapeptide and below accounted for 39. 14%(256/654), 32. 80%(81/247)and 53. 33%(16/30). The proportion of papain group was significantly higher than the other two groups(P<0. 05). The common features of three kinds of antioxidant peptides were EL, LY, MM, LK, IR, MY, VY, HL, LK, TY, HH, El and LK, IR, EL. In summary, the biological information of cow placenta hydrolyzed by trypsin is the richest, and its reliability and accuracy are the highest in proteomics. Papain has the most thorough enzymatic hydrolysis of cow placenta, and its products have the strongest potential antioxidant activity. The antioxidant activity of dairy cow placenta comes from Y, M, H, K. In summary, according to the qualitative and quantitative analysis of enzymolysis products by LC-MS/M technology, the biological information of cow placenta hydrolyzed by trypsin is the most abundant, and its reliability and accuracy are the highest in proteomics. Papain hydrolyzes cow placenta most thoroughly, and its products have the strongest potential antioxidant activity. This study provides a theoretical basis for the selection of enzymes and the development and utilization of antioxidant peptides in cow placenta by proteomics.Keywords：dairy cow;placenta;protease;LC-MS/MS;antioxidation.6|10|2<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：In order to study the protective effect of Lactobacillus casei on jejunal mucosal epithelial injury in Salmonella infected chicks, 450 SPF healthy chicks just hatched were randomly divided into normal control group, Salmonella group, Lactobacillus casei group, prevention group, treatment group and preventive treatment group, with 5 replicate in each group and 15 chickens in each replicate. The changes of intestinal mucosal structure and the expression of inflammatory factors in chicks were detected by HE staining and ELISA. The results showed that: 1)Compared with the Salmonella group, feeding L. casei could make the columnar cells of intestinal villi arranged orderly and prevent maintain the integrity of intestinal villi. 2)After feeding L. casei, the levels of IL-17, IFN-γ and TNF-α were significantly decreased(P<0. 05), and the expression of anti-inflammatory factor IL-10 was significantly higher than that in Salmonella infection group(P<0. 05). In conclusion, feeding L. casei could protect the intestinal health of chickens, reduce the damage of Salmonella on jejunal mucosa and strengthen the immune function of intestinal tract. This study provides a theoretical basis for the application of L. casei in the prevention of Salmonella infection in livestock and poultry.0|9|1<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：To investigate the effects of spore powder of Ganoderma lucidum(GI)and soybean isoflavone(SI)on the growth performance, meat quality and antioxidant capacity of Wenchang Chicken, a total of 540 110-day-old Wenchang Chickens were randomly allocated into 3 groups with 6 replicates and 30 birds per replicate. The test period was 30 days. The control group was fed with basal diet, and the treatment groups were supplemented with 500 mg/kg spore powder of(GI)or 300 mg/kg(SI)in the basic diet, respectively. At the end of the experiment, the growth performace of birds was measured, and plasma and breast muscle were collected to determine the antioxidant variables, meat quality, sensory evaluation and indicators for shelf life in meat. The results showed that: 1)Compared with the control group, supplementation with SI increased the final weight and ADG of birds(P<0. 05), and decreased the feed/gain ratio(P<0. 05); 2)The spore powder of GL significantly increased pH(P<0. 05)and decreased shear force(P<0. 05)of breast muscle 24 h after slaughter; SI significantly decreased the a* value of breast muscle 45 min after slaughter(P<0. 05)and increased the L* value and pH of breast muscle 24 h after slaughter(P<0. 05); 3)The score of broth taste of meat in spore powder of GL group was significantly increased(P<0. 05); 4)Spore powder of GL significantly reduced the content of malondialdehyde(MDA)in breast muscle 24 h after slaughter and volatitle basic nitrogen in breast muscle 45 min after slaughter(P<0. 05); SI significantly reduced the MDA content of breast muscle 45 min and 24 h after slaughter(P<0. 05); 5)The supplementation with spore powder of GL and SI significantly reduced the content of MDA in plasma of birds(P<0. 05), and spore powder of GL also increased the content of glutathione(P<0. 05). In conclusion, 500 mg/kg spore powder of GL or 300 mg/kg SI improved the antioxidant capacity and muscle quality of Wenchang Chicken. And the effects of 500 mg/kg spore powder of GL were better than 300 mg/kg SI.11|12|8<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：To analyze the complete genome sequence and genetic variation of canine parainfluenza virus strain CPIV-BJ01 isolated in laboratory, the full length of CPIV-BJ01 strain was amplified and sequenced. The nucleotide and amino acid of the whole genome and envelope glycoproteins(F, SH and HN)of 27 parainfluenza virus type 5 strains from GenBank database were compared. The genetic and evolutionary relationships were analyzed. The results showed that CPIV-BJ01 strain had the closest genetic relationship with canine PIV5 1 168-1, with nucleotide similarity of 99. 9% and amino acid similarity of 99. 8%. The F and HN gene sequences of CPIV-BJ01 were relatively conservative. Their changes of nucleotide and amino acid were within 4%, among which the amino acid of F protein formed a new O-glycosylation site. The SH gene sequence of CPIV-BJ01 was significantly different from that of other evolutionary branches with nucleotide similarity of 84. 4%-97. 0% and amino acid similarity of 31. 8%-95. 6%. In summary, compared with the previously reported strains, the genomic sequence of CPIV-BJ01 strain had nucleotide or amino acid sequence changes in F, HN gene and some non-coding genes, and there are glycosylation modifications in F protein, which were unique of the CPIV-BJ01 strain. These results enriched the genome information of Chinese CPIV epidemic strains.Keywords：canine parainfluenza virus;genome sequencing;sequence analysis;envelope glycoprotein gene0|9|0<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：The aims of this study were to investigate the effects of kitchen waste compost on the growth and yield of rice and soil nutrient content and provide a theoretical basis for the rational application of kitchen waste compost in rice fields. Field experiments were conducted. No-fertilier treatment was used as control. Under the condition of equal nitrogen, four treatments including chemical fertilizer, food waste biochemical integrated machine for processing tailings composting products(kitchen waste compost), pig manure organic fertilizer and chicken manure organic fertilizer were set up. The growth indexes, and yield of rice and the soil nutrient content at different developmental stages were determined. The results showed that: The kitchen waste compost and chemical fertilizer treatments significantly increased the plant height, above-ground biomass and actual yield of rice. Among them, the yield of rice under the kitchen waste compost treatment reached 9 379. 63 kg/hm2, which was significantly higher than that of the control and pig manure organic fertilizer treatment and it was increased by 19. 40% and 12. 95%, respectively. In addition, the results of rice test showed that the effective panicle number and the number of grains per panicle of rice in the kitchen waste compost treatment were higher than those of other treatment groups. The thousand-grain weight and seed setting rate were slightly lower than those of pig manure and chicken manure organic fertilizer treatment, but they did not reach significant differences. The results of soil data measurement showed that the kitchen waste compost treatment was better than the pig manure and chicken manure organic fertilizer. The soil organic matter and soil available nitrogen were all improved. The soil organic matter content was higher than that of pig manure and chicken manure organic fertilizer treatment and it was increased by 19. 87% and 11. 64%, respectively. The content of soil available nitrogen was higher than other fertilization treatments from tillering stage to yellow maturity stage, and was significantly higher than that of pig manure organic fertilizer treatment at tillering stage, heading stage and yellow maturity stage. In summary, the kitchen waste compost can ensure the growth and yield of rice, which is superior to pig manure organic fertilizer in terms of soil organic matter and available nitrogen and has the potential for promotion and application.Keywords：kitchen waste;composting;rice;growth;yield;soil nutrient content5|13|12<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：The initial moisture content(MC)of raw materials has a significant effect on the temperature change and nutrient transformation during composting. In order to evaluate the effects of initial moisture on nitrogen convertion during composting, this study was carried out in an industrial silo composting reactor, using sewage sludge and rice chaff as raw materials. The initial MC(mass ratio)of the feedstocks were adjusted to 57%(MC57), 60%(MC60), 63%(MC63)and 66%(MC66), respectively, and the temperature, germination index(GI)and different forms of nitrogen were investigated. The results demonstrated that when the MC of raw material is between 60% and 63%, the fermentation temperature increases rapidly in silo reactor which can reach above 60 ℃ and is evenly distributed in different layer, the germination index values are higher than 80% that have met the requirements of composting standard. With the increasing MC of raw materials, the contents of total nitrogen and nitrate nitrogen increased firstly then decreased, the contents of ammonium nitrogen decreased gradually, and the contents of organic nitrogen, amide and cyanamide nitrogen increased gradually during the sewage sludge composting in silo reactor. At the end of composing, the total nitrogen content of the MC63 reached 14. 20 g/kg, which is higher than other treatments. On the other hand, the treatment of MC60 has the highest available nitrogen content(9. 53 g/kg). The results of this study suggest that an initial MC of raw materials between 60% and 63% is beneficial to improve the nitrogen content of the compost products.0|11|8<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：In view of the problems of environmental pollution and crop damage of traditional soil disinfection methods, the feasibility of using ozone water in greenhouse soil disinfection was studied. The effects of ozone water mass concentration(ρ(O3))and irrigation cycle on the removal rates of bacteria, fungi, Actinomycetes and nematodes in greenhouse soil(0-30 cm in thickness)were investigated with lime nitrogen as control. The results showed that: 1)Soil disinfection with ozone water reached a depth of 15 to 20 cm, which covered the rhizosphere of common greenhouse horticultural crops and is expected to reduce rhizosphere disease infection; 2)The reduction rate of microorganisms in the soil(0-30 cm)treated with ρ(O3)=5 mg/L for three times was higher than that in the soil treated with ρ(O3)=20 mg/L for once; 3)The optimum effect of soil microorganism reduction achieved by irrigating ozone water ρ(O3)=10-15 mg/L 3 times with intervals of 7 days, and covering with PE agricultural mulch. The reduction rates of soil bacteria, fungi, actinomycetes and nematodes under this method were 44. 6%, 53. 5%, 46. 1% and 48. 6%, respectively. The reduction rates of soil bacteria, fungi and Actinomycetes under this irrigation method were all higher than those under the control group except for the nematodes, which was slightly lower than that under the control group; 4)The proportion of nitrobacteria, nitrite, bacillus and streptomyces in the original soil was 5. 3%, which increased to 7. 4% after ozone water treatment, and the proportion of beneficial microorganisms in the soil was slightly increased. In conclusion, the application of ozone water in greenhouse soil disinfection can achieve a good subtractive effect of soil microorganisms and nematodes, without producing harmful by-products compared with traditional chemical disinfectants. Therefor, the ozone water can be used to control soil-borne diseases in greenhouses.Keywords：greenhouse soil disinfection;ozone water;soil borne pathogen;the disinfection rate;suitable irrigation method4|15|1<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：Aiming at the problems such as large sensor interference from the environment, complicated installation and high cost existed in current automatic adjustment system for the header height of the rice-wheat combine harvester, an indirect measurement method of header height based on vehicle body inclination and header inclination is proposed. Related mathematical model is established and an adaptive adjustment system of header height based on inclination sensor is developed on this basis. The mathematical model verification test is performed to compare the calculated header height with the actual header height to verify the accuracy of the mathematical model. The header height control accuracy test, the system response speed test and the simulated field crossing test are used to verify the control effect of the adaptive adjustment system of header height based on inclination sensor. The results show that: 1)The correlation coefficient between the calculated header height and the measured header height change curve is 0. 97, which verifies the accuracy of the mathematical model. 2)The maximum error of the header height control is 18 mm. 3)The average ascent speed of the header is 0. 22 m/s and the average descent speed is 0. 17 m/s. 4)In the simulated field crossing test, under the same obstacle conditions, turning on the system can reduce the coefficient of variation of the high stability of the header from 10. 77% when the system is not turned on to 2. 79%, and the robustness is good. This system meets the operational requirements of the combine harvester, and is suitable for a relatively flat working environment with small obstacles. The system can realize low-cost, real-time adaptive adjustment and is easy installation.Keywords：combine harvester;inclination sensor;header height;adaptive adjustment3|20|5<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：To improve the grading accuracy of fruit tree diseases and pests and better guide the prevention and control of orchard diseases and pests, the Transfer Learning technology and GoogLeNet model were combined to recognize and grade the damage degree of 25 kinds of pests and diseases from 6 kinds of orchard crops. At the same time, the impact of different data set sizes and optimization algorithms on model performance was studied. A visual pest recognition and grading system was designed based on the MATLAB platform. The results showed that: 1)The GoogLeNet model based on Transfer Learning had an up to 99. 35% accuracy in recognizing pests and diseases, and an accuracy of 92. 78% in the grade of damage; 2)Under the same training parameters, the verification accuracy of this research model was 2. 38% to 11. 44% higher than that of AlexNet, VGG-16, ResNet-18, SqueezeNet, the original GoogLeNet and MobileNet-v2 models, and the convergence speed was the fastest; 3)The recognition accuracy of this research model enhanced with the increase of the data set; Among the three optimization algorithms, the SGDM algorithm took the shortest time and had the highest accuracy, which was more suitable for this research model. By taking images of the diseased area of fruit tree leaves, the system designed in this study can accurately recognize the name of fruit trees, type of diseases and grade of damage within 0. 43 s.Keywords：fruit trees;diseases and pests;recognition system;transfer learning;GoogLeNet38|13|10<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：By combing the theory of cost analysis model with sensitivity analysis method, the lowest average cost calculation, machinery operation of critical size, relative to traditional practices, on average, cost savings and the influence factors of critical mass, seven aspects of orchard production process, e. g. flower thinning, picking, plant protection, weeding, pruning, fertilization & deep digging and irrigation machinery economic benefit, in Yejia pear orchard in Jiangsu were investigated for the economic evaluation of orchard mechanization. The results showed that: 1)The mechanical equipment operation after a certain size can obviously save more than the traditional way. The handheld thin flower implement in the planting area of more than 0. 11 hm2 became the most economical mode of operation. The irrigation link planting area of more than 34. 33 hm2 was the most economical way of operation system; 2)The fixed cost of machinery and the odd jobs cost were the important factors affecting the critical scale. If the fixed cost increased by 20%, the critical scale would increase by about 20%. And when the odd jobs cost increased by 20%, the critical scale would decrease by more than 15%; 3)The cost per hm2 of pear orchard in the study was saved by 11 536. 87 yuan. With the decrease of fixed cost and the increase of labor wage, the critical scale of mechanical equipment operation to replace the traditional way of operation became smaller, and the scope of economic application of mechanical equipment in orchard became larger.Keywords：orchard mechanization;cost analysis;sensitivity analysis;critical mass2|10|2<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：The aims of this study were to promote the national land use layout optimization, and sustain a continuous supply of food security and ecological services. Based on the perspective of food security, the clarification of the theoretical logic and compensation standard calculation for interprovincial arable land ecological compensation, the ecological compensation standard of food security in cultivated land area in 2019 were quantitatively studied by using the opportunity cost loss and ecological surplus value. The results showed as follows: 1)A total of 17 provinces were in the cultivated land ecological deficit area(payment area), and 14 provinces were in the surplus area(compensation area). After the later provinces met their own food demand, about 30% of the cultivated land's grain yield and ecological services was supplied to each ecological deficit area. 2)The total amount of compensation standard of the compensated areas is about 2 467. 34 billion Yuan, among which the highest three provinces are Henan, Shandong and Anhui, and the lowest three provinces are Ningxia, Gansu and Xinjiang. In conclusion, a compensation mechanism and supporting system, which includes the compensation subject, the target responsibility, the compensation mode and the source of funds, is put forward in this study to further ensure the long-term implementation of ecological compensation.Keywords：food security;ecological compensation;standard quantification;mechanism construction3|10|20<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：The aims of this study were to understand the impact of wool imports on domestic wool production and the reliance of different import source countries of Chinese wool. Firstly, the Armington model was introduced to measure the import substitution elasticity of China's wool import source countries from 2000 to 2019. The export output elasticity measurement method was then applied to analyze the dependence of different wool import source countries. The results show that: The homogeneity between domestic wool and imported wool is low, and the substitutability is small; From the perspective of import sources, New Zealand wool import has less substitution elasticity for domestic wool, while Uruguay and other imported source countries have greater substitution elasticity for domestic wool. However, the substitution elasticity of imported wool from Australia and South Africa for domestic wool is not significant. From the perspective of the dependence of different import source countries, among the main import source countries, Australia, New Zealand, the United Kingdom, and South Africa are relatively rich in wool production resources, and the current wool export output elasticity of New Zealand and South Africa is greater than 1. The supply potential is great, but the current wool export output elasticity of Australia, the United Kingdom and other countries is less than 1; Among the non-main import source countries, Argentina's wool production resources are relatively abundant and the wool export output elasticity value has been increasing in recent years, and Peru's wool production. Although the resources are relatively general, the output elasticity of wool export is greater than 1. To ensure the safety of wool supply, China should actively expand new wool import channels while maintaining good cooperative relations with traditional wool importing countries, establish diversified import channels, increase protection of high-quality sheep breeds, and increase domestic wool production and quality.Keywords：wool;import dependence;substitution elasticity;export output elasticity1|9|1<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：The aims of this study are to improve the performance of agricultural film recycling policy, guide farmers to actively recycle agricultural film. Based on the survey data of 1 057 cotton farmers in Xinjiang, combined with the Smith policy process model, a Probit model is constructed to explore the satisfaction evaluation and influencing factors of policy implementation on agricultural film recycling. The results show that the cotton farmers' satisfaction on the implementation of agricultural film recycling policies is generally low, and the proportion of satisfaction on the content, intensity and effect are 27. 25%, 23. 27% and 22. 80%, respectively; Farmers' understanding of the policy on polluting plastics recycling, the government reasonable rewards and punishment degree to improve the satisfaction of polluting plastics recycling policy execution has significant positive influence. In addition to professional cooperatives, the number of family labor force, recycling agricultural films of the time it takes to polluting plastics recycling policy execution satisfaction have positive influence. The education level of farmers, and recycling agricultural films cost have negative effect on the satisfaction degree of the policy implementation. In conclusion, four suggestions, e. g. improving agricultural film recycling policy reward and punishment mechanism, developing the role of professional cooperatives, innovating the methods of publicity on agricultural film recycling policies and constructing of grass-roots environmental protection supervision system, are put forward in this study.Keywords：cotton farmers;agricultural film recycling;satisfaction;policy evaluation;influencing factors1|9|1<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：Based on the survey data of 718 residents in Shanghai, a negative binomial regression model was constructed, and the effect of waste sorting on the quantity reduction and quality upgrade of fresh agricultural products was investigated. The results showed that there are more than 50 percent of residents have changed to reduce the amount and improve quality in the purchase of green leafy vegetables and solanaceous vegetables. Since the implementation of the regulations on domestic waste sorting, 34. 82 percent of residents have bought fresh-cut agriculture products. In contrast, about 60 percent of residents have remained the previous consumption behavior of meat, aquatic product, fresh melons and fruit. Factors such as the age and gender of the head of household, and number of members in need of care have significantly affected consumption of fresh-cut agriculture products. The difficulty in domestic waste sorting has a significant negative impact on consumption fresh-cut agriculture products, and the waste output of agriculture products has a significant positive impact on the purchase of fresh-cut agriculture products, but they both have less marginal effect. The purchase of fresh-cut agriculture products is significantly correlated with the consumers' tolerance to its price, and the marginal effect is greater. Some policy suggestions, such as further reducing the cost of fresh-cut agriculture products and charging with waste quantity are put forward in this study.Keywords：waste sorting;fresh-cut agriculture products;reduction;negative binominal regression4|11|1<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：Village urbanization is not only an important progressive stage but also an important way to realize rural revitalization. This study investigates the development history and deductive mechanism of traditional village urbanization through case analysis, comparison and deductive induction. It is found that there are essential differences between the new village urbanization and the traditional village urbanization: The guiding ideology should be changed from economic development to people-oriented. The development power must adhere to the endogenous power, and the development mode should be changed from “passive” to ”active”; The evaluation standard should be increased from the level of urbanization to the quality of urbanization, and the evaluation index system should be changed from the population and land quantitative indicators of population and land to the qualitavie incator of urbanization Infrastructure to meet the needs of a better life. Therefore, to innovate the development mode of village urbanization, build “beautiful China” and “beautiful countryside”, and realize the strategic goal of Rural Revitalization, the new village urbanization should be the new “active” urbanization of “agricultural modernization mode of production, the concept of rural planning and construction and the quality of life of farmers” rather than the traditional “passive” urbanization.Keywords：rural urbanization;deductive mechanism;innovative development;rural revitalization;path design8|9|0<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
