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- Abstract：In order to clarify the effects of nitrogen fertilizer on the growth, dry matter accumulation, distribution and yield of winter wheat under different shading degrees, wheat cultivar ‘Xindong 20' was used as material under field conditions. Four degree shading treatments were no shading(S0), shading at the jointing to heading stage is 10%, and shading at heading stage to maturity stage 25%(S1), 20%-50%(S2)and 30%-75%(S3). Four levels of nitrogen fertilizer(pure nitrogen)treatments were no fertilizer(N0); jointing stage(after shading)nitrogen 103. 5 kg/hm2(N1); 138. 0 kg/hm2(N2)and 172. 5 kg/hm2(N3). The effects of nitrogen fertilizer on the growth rate(CGR), net assimilation rate(NAR), photosynthetic potential(PP), dry matter accumulation and the ratio of reproductive organs to vegetative organs(RVR)and yield of wheat under different shading conditions were analyzed. The results showed that: Shading significantly decreased CGR, NAR, dry matter accumulation, RVR and yield of wheat, and light shading significantly increased PP. CGR of N2 and N3 treatment at jointing to flowering stage were significantly higher than those at N1 and N0. CGR of N2 treatment at flowering to filling stage and filling to maturity stage and PP at jointing to flowering stage and flowering to filling stage were significantly increased respectively. The total dry matter accumulation increased by 52. 5%, 11. 2%, 16. 7% higher than other nitrogen fertilizer treatments, and RVR was 3. 6% and 11. 9% higher than that of N1 and N3, the yield increased by 39. 8%, 7. 9% and 6. 6%. Under moderate and severe shading conditions, CGR of N0 treatment was significantly higher than that of other fertilization treatments at jointing to flowering stage and flowering to filling stage, the CGR of N1 treatment was 28. 2%, 21. 8%, 33. 5% and 266. 7%, 32. 4%, 76. 1% higher than that of N0, N2, N3 treatment at flowering to filling stage and filling to maturity stage, respectively. PP was 153. 8%, 1. 0%, 6. 5% higher at jointing to flowering stage and 51. 4%, 5. 1%, 12. 8% higher at flowering to filling stage, respectively. NAR decreased with the increase of nitrogen application rate. Correlation analysis showed that yield was positively correlated with CGR at jointing to maturity stage, PP at flowering to filling stage, dry matter accumulation and RVR. Therefore, under light shading, nitrogen application could improve the crop growth rate and photosynthetic production capacity after flowering, which was beneficial to dry matter accumulation and grain distribution, and some extent compensated for the adverse effects of low light on wheat yield. Under moderate or severe shading conditions, the regulation effect of nitrogen fertilizer on wheat population growth and dry matter accumulation and distribution decreased, and the application rate of nitrogen should be moderately reduced.Keywords：shading;nitrogen fertilizer;crop growth;wheat;yield2|10|7<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to explore the effects of nitrogen topdressing amount on the yield and quality of wheat with different color-grained wheat varieties, four black-grained wheat varieties(‘Yunhei161', ‘Ziyou 5', ‘Donghei 1', ‘Linhei 131'), and seven white grain varieties(‘Pinyu 8012', ‘Jimai 44', ‘Jimai 23', ‘Jinmai 95', ‘Shinong 086', ‘Hannong 1412', ‘Zhongnong 175')were selected. Four nitrogen supplemental levels of 0(N0), 34. 5(N1), 51. 8(N2), 69. 0 kg/hm2(N3)at jointing stage were set. The grain yield, quality, nitrogen content, nitrogen absorption and selenium content of wheat were determined. The results showed that: 1)Nitrogen topdressing increased the wheat yield, and the degree of increment varied with wheat varieties. The highest yield of black-grained wheat varieties was obtained under N1, which was increased by 19. 4%-30. 8%. The highest yield of ‘Pinyu 8012', ‘Jimai 23', ‘Jinmai 95', ‘Jimai 44'and ‘Shinong 086' was achieved under N2, which was increased by 20. 8%-85. 1%. The yield of ‘Hannong 1412'and ‘Zhongnong 175' increased with the increase of nitrogen topdressing amount. 2)Nitrogen topdressing increased grain nitrogen content of the two color grain wheat, with an increase of 4. 2%-18. 3% under N3 for black-grained wheat and 3. 9%-18. 1% under N2 for white-grained wheat. Grain selenium content increased by 11. 3%-121. 8% for black-grained wheat and decreased by 6. 7%-83. 0% for white-grained wheat under topdressing nitrogen treatments. Nitrogen topdressing increased the protein contend of black-grained wheat and white-grained wheat by 0. 7%-16. 1% and 0. 8%-31. 7%, respectively. 3)Considering the yield and quality indexes, on the basis of 165 kg/hm2 basal nitrogen, the suitable nitrogen topdressing amount was 34. 5 kg/hm2 for black-grained wheat and 51. 8 kg/hm2 for white-grained wheat at jointing stage.Keywords：nitrogen topdressing amount;wheat;grain color;yield;quality;selenium5|9|2<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Conservation tillage is an important measure to reduce soil erosion in farmland. In order to explore the reasonable promotion of conservation tillage in spring maize farmland under the limitation of water and heat in Northeast China, based on 2 705 pairs of data collected from 44 published literatures, meta-analysis was performed to compare the differences in soil water content and temperature in the spring maize farmland under four conservation tillages(straw mulching(SM), no-tillage(NT), no-tillage+straw mulching(NM)and subsoiling(SN))with traditional tillage CK. The effects of different influencing factors in Northeast China were analyzed. The results showed that: conservation tillage had humidification and cooling effect on the maize farmland in the growing season. Soil water content was increased by 5. 93% and soil temperature was decreased by 2. 93%. The increasing effects of the soil water content of four treatments in descending order was SM>NM>SN>NT. The soil temperature decreased significantly under SM and NT. However, the temperature of NM and SN increased significantly, and the temperature increase range of NM was only 0. 006%. Meta-analysis of subgroups showed that: There was no difference in soil water content and soil temperature among subgroups under conservation tillage. There were significant differences in soil water content in some subgroups intragroup, and the order of significance were: soil texture>soil depth>growth period>average annual temperature>annual rainfall>straw mulching amount. A significant difference in soil temperature was only found in the subgroup of straw mulching amount. In addition, under(3 000, 6 000］ kg/hm2 straw covering conditions, the effect of water storage and water content conservation was the best. In conclusion, the implementation of four conservation tillages in the spring maize planting area with an average annual temperature of 0-10 ℃ has significant indigenous humidification and cooling effects in Northeast China.Keywords：meta-analysis;maize growth period;soil temperature;soil water content13|11|4<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to study the effect of the utilization priority of soil nutrient patches among competing plants and root mineral nutrient uptake of crops, the modern maize(Zea Mays)variety Xianyu 335 was selected as the study material and root-box experiment was conducted. A total of five delayed time were set up under homogeneous and heterogeneous nutrient supply patterns. The aboveground biomass, nutrient content, root-shoot ratio (T/R)and root length of maize under normally planted and delayed planted were determined. The results showed that: In one root-box, the aboveground shoot biomass of the delayed planted maize was significantly 28. 4%-74. 3% lower than that of normally planted maize in nutrient homogeneous environment, while the aboveground shoot biomass of the delayed planted maize was significantly 19. 2%-193. 0% lower than that of normally planted maize from 2-5 d in nutrient heterogeneous environment. The root biomass of the delayed planted maize had no significant changes with the time increasing in both nutrient homogeneous and heterogeneous environments, while the root biomass of normally planted maize exhibited a significantly increased with the delayed planting time increasing. Therefore, in one root-box, the root/shoot ratio of the delayed planted maize was significantly higher than that of the normally planted maize; The root length and volume exhibited similar trends with root biomass. In one root-box, there was no significant difference in the specific root length and root tissue density between normal and delayed corn planting under homogeneous environment; The root tissue density of maize planted only at the delayed 5th day planted maize was significantly lower than that of normal maize planted in the nutrient heterogeneity environment. In conclusion, the order of maize uptaking soil nutrient resources can cause the formation of competitive for aboveground nutrients, especially in nutrient heterogeneous environments, maize adapted to nutrient and competitive environment by adjusting itself.Keywords：nutrient patch;priority effect;root plasticity;root/shoot ratio;size-asymmetric root competition;competitive hierarchy2|9|3<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To study the biodegradation process of slow release fertilizer containing polymer urea-formaldehyde, the polymeric slow release fertilizer containing nitrogen, phosphorus and potassium(PSRF)was used in medium as sole carbon and nitrogen sources. Soil applied PSRF for two years was used to screen for the degrading microorganisms. Morphology, ITS gene sequence identification and phylogenetic analysis were used to identify the strain. SEM, laser particle size meter(LPSM), acetyl acetone spectrophotometry and ammonium molybdate spectrophotometry were used to estimate the degradation effect of insoluble pyrolytic resistant giant molecule PSRF(rPSRF)ultrasonic treated at 100 ℃. The results showed that: One PSRF degradable strain was isolated and was identified as Penicillium rubens with preservation number CGMCC 23229(P. rubens 23229). The results of SEM and LPSM showed that P. rubens 23229 could attach and grow on rPSRF and degrade it from a dense bulk grain structure of small pieces and smaller debris during co-culture with rPSRF. In the progress of degradation, the phosphorus contented in solution increased from 0 to 21. 52 μg/mL, and the formaldehyde content increased from 0 to 0. 213 mg/mL, which were significantly different to the control. Moreover, rPSRF could be degraded in the P. rubens 23229 fermentation broth after cultured in screening medium containing PSRF, indicating that the degradation enzyme produced by P. rubens 23229 was an extracellular enzyme and induced by PSRF. This study can provide reference to the biodegradation pathway and application of polymer urea-formaldehyde fertilizer.Keywords：polymeric urea-formaldehyde slow release fertilizer;degrading microorganisms;Penicillium rubens;biodegradation9|9|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To explore the expression of HvnANT1 gene in the process of purple-grain color development in Hulless barley, purple grain coat hulless barley ‘Nierumuzha' and white grain coat hulless barley ‘Kunlun 10' were taken as test materials. The gene of hulless barley purple grain was located by simplified genome GBS(genetic-by-sequencing), and the HvnANT1 gene was cloned for bioinformatics analysis. The results showed that: 1)A MYB transcription factor was obtained at 84. 30-86. 00 cM of chromosome 7H and named as HvnANT1. 2)The gene was 1 033 bp in length, and its complete open reading frame was 762 bp, encoding 253 amino acids. The molecular weight of HvnANT1 protein was 27. 14 kU, and it was an unstable hydrophilic basic protein with no transmembrane structure and no signal peptide. The secondary structure of the protein is mainly composed of random coil, α-helix, extended chain and β-rotation, and has two SANT domains(located at the 13th to the 63th; the 66th to the 114th amino acids). 3)The results of homology alignment and phylogenetic analysis showed that the sequence similarity between the HvnANT1 protein of hulless barley and the ANT1 protein of Hordeum vulgare, Triticum turgidum, Sorghum bicolor, Zea mays L, Dichanthelium oligosanthes, Setaria italica, Oryza rufipogon, Cephalotus follicularis, Trifolium affine, Morella rubra were 100. 00%, 88. 85%, 54. 64%, 60. 95%, 60. 82%, 58. 46%, 57. 61%, 37. 76%, 36. 05%, 36. 33%; these sequences all have two highly conserved SANT domains. The HvnANT1 protein of hulless barley had the closest relationship with H. vulgare, followed by Triticum urartu and the farthest relationship with Oryza sativa. 4)The results of subcellular localization showed that the gene was localized in the nucleus. 5)The results of qRT-PCR showed that the expression of HvnANT1 gene in the soft dough stage was extremely significantly up-regulated in ‘Nierumuzha' compared with the early milk stage and late milk stage. The expression level of ‘Kunlun 10' was lower and the difference was not significant in each period; and the expression of HvnANT1 gene in the grains of ‘Nierumuzha' at soft dough stage was significantly higher than that of ‘Kunlun 10'(P<0. 01). The anthocyanin synthesis-related structural genes HvnCHI, HvnANS and HvnDFR were similar to the gene expression patterns. In conclusion, the SANT domain in the HvnANT1 protein structure of hulless barley is relatively conserved in the evolution of species. The gene is located in the nucleus, which is consistent with the characteristics of transcription factors, and the expression pattern of HvnANT1 gene is related to the structural genes HvnCHI, HvnANS and HvnDFR. Similarly, the expression level is significantly increased in the soft dough stage of grain color formation, which provids a theoretical basis for in-depth study of the regulation of hulless barley HvnANT1 gene on grain color formation.Keywords：tibetan hulless barle;HvnANT;1;HvnCHI;HvnANS;HvnDFR;gene expression2|8|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to explore the physiological function of silicon in oat seedlings' resistance to stem rust, the oat variety ‘Bayou 1', which is highly susceptible to stem rust, was used as experimental material. The nutrient solutions containing different K2SiO3 concentrations(0, 0. 5, 1. 0, 1. 5, 2. 0, 2. 5 and 3. 0 mmol/L, respectively)were irrigated into pot. The resistance of oat seedlings to stem rust, photosynthetic performance, antioxidant enzyme activity and osmotic regulation substance content of leaves were measured. The results show that: Under the condition of inoculation with stem rust, 1. 5 mmol/L K2SiO3 significantly increased the resistance of oat seedlings to stem rust, photosynthetic characteristics, antioxidant enzyme activity and osmotic regulation ability of leaves. Compared with 0 mmol/L(CK), the dry weight and fresh weight of oat seedlings increased by 90. 91% and 74. 71%, respectively. Leaf chlorophyll content increased by 18. 67%, net photosynthetic rate(Pn), transpiration rate(Tr), stomatal conductance(Gs)and intercellular CO2 concentration(Ci)increased by 51. 47%, 285. 71%, 285. 71% and 27. 78%, respectively. The maximum fluorescence(Fm), photochemical efficiency(FV/Fm)and photosynthetic performance index(PIABS)were increased by 19. 62%, 7. 69% and 5. 84%, respectively. The activities of superoxide dismutase(SOD)and peroxidase(POD)were increased by 35. 66% and 28. 88%, respectively. The contents of malondialdehyde(MDA), soluble protein and proline were decreased by 50. 00%, 27. 45% and 16. 62%. In conclusion, the exogenous application of silicon can improve the resistance of oat to stem rust, and 1. 5 mmol/L is the optimal concentration of silicon.Keywords：silicon;oats;stem rust;disease resistance;photosynthesis4|9|2<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to clarify the function of TCP family related genes in Chinese kale in leaf development, based on cabbage genome data, this study identified 40 members of TCP gene family in Chinese kale. Referring to the annotation of homologous TCP genes in Arabidopsis and the relative expression of genes in Arabidopsis database, BoTCP21 and BoTCP25 genes were preliminarily selected and analyzed by qRT-PCR experiment. The results showed that BoTCP21 and BoTCP25 were widely expressed in leaves, but their expression patterns were different in different parts of true leaves. In order to find out the genes involved in leaf development in TCP gene family, the BoTCP family was comprehensively analyzed by bioinformatics and qRT-PCR experiment. The results showed that 40 BoTCP were non-secreted hydrophilic proteins, which were located on 8 chromosomes respectively. The members of BoTCP in Chinese kale are classified into three categories by phylogenetic tree construction and phylogenetic analysis, among which there are nineteen members in PCF subfamily, eight members in CYC subfamily and thirteen members in CIN subfamily. The results of qRT-PCR showed that BoTCP21 and BoTCP25 had higher expression levels in true leaves and bolting leaves, BoTCP14 had higher expression levels in the roots of flowering and podding plants, while BoTCP16 had the highest expression levels in the roots of bolting plants, which indicated that the expression of BoTCP family members in the tissue parts was spatio-temporal specific and widely participated in the morphogenesis and organ development of plants.Keywords：Chinese kale;TCP;gene family;whole genome identification;bioinformatics;expression analysis6|9|3<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to explore the effects of LED pulse light on crop photosynthetic characteristics, and explore how to further reduce energy consumption and improve lighting efficiency without affecting the normal growth of crops. Lactuca sative L. was selected as experimental material in this research. Five duty ratio levels(20%, 40%, 60%, 80% and 100%)and 14 frequency levels(1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1 024, 2 048, 4 096 and 8 192 Hz)were set and a total of 70 processes were performed were used to investigate the effects of different forms of pulse light on the net photosynthetic rate(Pn)of leaves with duty ratio of 100%(continuous light)as the control. The response model between duty ratio and frequency of pulse light and net photosynthetic rate was established. Through the analysis of marginal effect interaction and light use efficiency(LUE), it was concluded that both the duty ratio and frequency of pulse light promoted leaf Pn. With the increase of duty ratio and frequency, Pn also increased and finally tended to a stable state until there was no significant difference with the net photosynthetic rate under continuous light treatment. The higher the duty ratio, the lower the frequency of Pn saturation of lettuce leaves. When Pn reaches saturation state, LUE under pulse light is significantly higher than that under continuous light. To sum up, the duty ratio is 20% and the frequency is 512 Hz is the optimal combination of duty cycle and pulse light frequency. The study could provide theoretical support for optimizing the design and development of LED plant energy saving supplementary light source parameters.Keywords：pulsed light;duty ratio;frequency;photosynthetic response model;light use efficiency6|10|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：This study aimed to clarify the changes of bacterial community composition and the structural differences of related networks in three different varieties of Chinese chives endophytes and five ecological compartments of phylloplane and rhizosphere. Based on 16S rRNA gene sequencing and analysis. The diversity of microbial communities with different functions were discussed. The abundance of functional microorganisms in each ecological compartment and the microbial co-occurrence network of aboveground compartment, underground compartment and various varieties were analyzed. The results showed that: 1)The content of Pseudomonas related to pathogen defense in phylloplane of ‘Jiuxing 16' leek variety resistant to gray mold was significantly higher than that of other varieties; 2)Ecological compartments had significant effects on the relative abundance of microbial community composition at phylum level and genus level. Sphingomonas gradually decreased from top to bottom in plants; 3)The microbial co-occurrence network of underground ecological compartment was more complex and anti-interference than that of aboveground compartment. There were microbial co-occurrence networks with similar network diameters but different central nodes among Chinese chives varieties. There were more negative connections between Proteobacteria, Acidobacteria and Chloroflexi, because ‘Jiuxing 16' and ‘Jiuxing 18' displayed different dormancy characteristics. In summary, the effect of ecological compartment on the microbial structure distribution and interaction network of leek was higher than that of leek varieties, and different leek varieties would recruit specific microorganisms according to their own characteristics.Keywords：ecological compartment;endophyte;phylloplane;rhizosphere;Chinese chives;co-occurrence networks2|14|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to identify high-quality disease-resistant cherry tomato resources, the PARMS method was used in this research to analyze the distribution of eleven resistant(R)genes in 696 tomato materials of 59 cherry tomato germplasm resources. The results showed that: Most resources contain Ty-1 or Ty-2 gene, encompassing about 35. 3% and 17. 8% plants, respectively. On the contrary, the distribution of I-2, I-3 and Sw-5 genes are rare, which only present in 5. 9%, 3. 2% and 5. 2% of the total plants, respectively; A total of 25 resources with more than three R genes were selected as multiple resistant resources. Furthermore, the nutritional, flavor, and storage qualities of the selected multiple resistant resources were analyzed. According to disease resistance, their total soluble solid(TSS)content, total acid content, sugar-acid ratio, and appearance quality, six high-quality resources with multiple resistance were identified, including 180-4, 179-7, 176-6, 165-6, 205-10 and 168-5. Meanwhile, based on their disease resistance, lycopene content, and appearance quality, six resources with high lycopene content and multiple resistance were selected, which were 177-9, 219-11, 192-2, 202-3, 214-4 and 216-5. In conclusion, the identified resources in this research provide materials for the breeding of new cherry tomato varieties with multiple resistance and high quality.Keywords：cherry tomato;resistant genes detection;quality analysis;screening5|8|2<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：An infectious disease characterized by eyelid swelling, respiratory symptoms and acute egg-laying rate decline in chicken flocks in multiple provinces of China. In order to explore the pathogen, epidemiological survey, virus isolation and identification, sequence analysis, and chicken infection experiment were analyzed. The results indicated: 1)In December 2021, this disease was firstly found in Three-yellow chicken flock in Guangdong Province, and then occurred in Fujian, Anhui, Jiangsu, Henan and other provinces, the chicken flocks that were exhibit high morbidity and easy to infection bacterial, the mortality rates range from 1% to 10%. 2)The pathogen was diagnosed as H3N8 subtype AIVs. 3)Sequence analysis showed that the novel H3N8 AIVs were evolving as a triple reassortment event with Eurasian avian H3 gene, North American avian N8 gene and G57 genotype H9N2 internal genes. 4)The new H3N8 AIVs were highly susceptible to SPF chickens. Infected chickens showed eyelid swelling and hyperemia, and mild respiratory symptoms. The pathological changes were necrosis and abscission of Harderian glands mucosa, necrosis of ciliated epithelial cells of turbinate and trachea, infiltration of inflammatory cells in submucosa, and bronchopneumonia of lungs. The virus can be detected from the oropharynx and cloaca for 5-7 days, and replicate efficiently in the concha nasalis, trachea and lungs, also in extra pulmonary organs such as Harders glands. In conclusion, the novel reassortment H3N8 virus was adapted to chickens and caused pathogenic in chickens. Therefore, comprehensive surveillance of the H3N8 AIVs in domestic poultry is imperative and control of the virus endemic is needed.Keywords：H3N8;avian influenza virus;Genetic reassortment;chicken;pathogenicity11|13|4<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to analyze the distribution and protection of nucleic acid vaccine related patent applications, promote the research and development of nucleic acid vaccine in China, and strengthen protection and utilization of intellectual property in this field, the study analyzed its patent application trend through keyword and IPC classification code in Incopat database, which based on public information. Then the patent application, regional distribution and technological distribution were analyzed, and two typical enterprises, BioNTech and Inovio were researched about their patent strategy. The results showed that: A total of 12 746 related patent applications were obtained, and the number of patent application for nucleic acid vaccines maintained at a high level in recent years, and the major technology source and target market countries or areas include America, China and other developed countries. The main patent applicants were American or European R&D organization. The patent strategy of BioNTech and Inovio presented multi-level, long-term, and wide-area. The study provided intellectual property strategies including adaption to the new patent law, strengthened layout and flexible operation for Chinese vaccine research and development enterprises, and also hoped to provide reference for the development of nucleic acid vaccine technology in China.Keywords：nucleic acid vaccine;DNA vaccine;RNA vaccine;patent layout;patent protection4|8|1<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The objective of this study was to analyze the characteristics of the lactation curves and the influencing factors of 305 d milk yield in Jersey cattle, and compare the differences of the lactation curves between Jersey and Holstein. The continuous records of daily milk yield from 1 721 Jersey cattle and 6 093 Holstein cattle were collected in a large-scale daily farm in Hebei from January 2017 to January 2021. Wood model was used to fit the individual lactation curves, and peak yield, peak day, rate of change in daily milk yield and milk yield in different lactation stage were determined to analyze the characteristics of the lactation curve. The GLM procedure in SAS 9. 4 was used to analyze the impacts of parity and calving season on 305 d milk yield and the differences of the lactation curves between two breeds. The results showed: 1)The Wood model had a good fitting effect on the lactation curve of Jersey cattle, and its R2 reached 0. 86; 2)The 305 d milk yield of Jersey cattle was significantly(P<0. 05)influenced by the parity and calving season; the 305 d milk yield of Jersey cattle with higher parity and calving in spring was higher; 3)The lactation curve of Jersey cattle and Holstein cattle was significantly(P<0. 05)different in terms of peak yield, peak day and rate of change in daily milk yield. The peak day of Jersey cattle was 39. 84 d earlier than that of Holstein cattle, and the proportion of peak yield in total milk yield was 0. 036% higher than that of Holstein cattle. The milk production of Jersey cattle was mainly concentrated in the early lactation(1-99 days)and the milk production decreased significantly in the late lactation(200-305 days)(P<0. 05). In conclusion, this study comprehensively revealed the lactation characteristics of Jersey cattle using continuous records of daily milk yield, provided information for exploring breed differences between Jersey and Holstein cattle and provided a reference for genetic selection and precise management of dairy farm using continuous records of daily milk yield.Keywords：Jersey;Holstein;lactation curve;daily milk yield;305 d milk yield15|8|5<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：The study explored the effects of three different oil and fat diets on inguinal subcutaneous fat deposition and macrophage typing in mice under two kinds of fat energy supply conditions. A total of 90 C57BL/6 J male mice were randomly divided into 6 groups, and fed with low-fat lard(Lar-10%), low-fat rapeseed oil(Rap-10%), low-fat olive oil(Oli-10%), high-fat lard(Lar-30%), high-fat rapeseed oil(Rap-30%), and high-fat olive oil(Oli-30%). After 16 weeks, the inguinal subcutaneous adipose tissues were dissected and stained by hematoxylin-eosin staining, reactive oxygen species(ROS)content was detected. M1and M2 macrophage markers(CD11c, CD206)were double stained with fluorescence, and their contents were detected by ELISA. The results showed that: 1)Under the condition of low-fat diet, the three kinds of oil/fat diets had no significant differences on inguinal subcutaneous adipose tissues weight, its cross-sectional area, and ROS content in subcutaneous adipose tissues(P>0. 05); 2)With the increase of fat energy supply, inguinal subcutaneous fat deposition increased significantly(P<0. 05). Under the condition of high-fat diet, the weight of inguinal subcutaneous adipose tissue in Lar-30% group was significantly higher than that in Rap-30% and Oli-30% groups(P<0. 05), and the content of ROS in inguinal subcutaneous adipose tissue in Oli-30% group was significantly lower than that in the other two groups(P<0. 01); 3)High-fat diet increased content of CD11c and CD206, macrophage markers, in adipose tissue, but the ratio of CD206/CD11c in mice fed olive oil was significantly higher than that in mice fed lard and rapeseed oil(P<0. 05). In brief, reducing the level of fat energy can effectively reduce fat deposition. Compared with lard and rapeseed oil, olive oil diet may reduce fat accumulation by increasing the ratio of CD206/CD11c, inhibiting the transformation of macrophages to M1 type, reducing the production of ROS in adipose tissue to reduce inflammation.Keywords：lard;olive oil;rapeseeds oil;macrophage2|8|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In response to the problem of low soil temperature in the marginal area on the southern side of the greenhouse during winter in the cold and arid regions of the northern China, experiment and simulation method was used, non-insulation zone was set, polystyrene foam board insulation zone(insulation material buried depth 30 and 60 cm)and cement brick insulation zone(insulation material buried depth 30 cm)in the middle of the greenhouse were extruded. The changes of soil temperature and moisture contents of 5, 15, 25 and 55 cm from the ground surface in the test area were studied. The results showed that: 1)The soil temperature at the distance of 5 cm from the ground surface was mainly affected by the soil moisture content, and had a negative relationship with the moisture content; 2)The soil temperature of 15-55 cm from the ground surface was greatly affected by the effect of the insulation structure, the soil temperature of the non-insulation group was always lower than the soil temperature of the insulation group, and the maximum soil temperature difference was 1. 2 ℃; 3)Under the same burial depth, the thermal insulation performance of extruded polystyrene foam board was better than that of cement brick, the maximum soil temperature difference in the southern marginal area of the greenhouse with two types of thermal insulation structures was 0. 3 ℃; 4)The simulation was solved by the transient method, the minimum fit between the simulated value and the measured value on the y=x function line was 0. 961, and the maximum mean square error was 0. 037, indicating that the model constructed in this study has a high simulation accuracy.Keywords：double-layer solar greenhouse;southern margin;thermal insulation structure;soil water and heat coupling;soil temperature1|9|1<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Aiming at the problem of uneven soil covering on the film caused by uneven soil extraction from the rotary tillage soil borrowing device of a flax planter in the northwest region of China, a flax precision hole-seeding combined operation machine with a soil storage device is designed. The machine consists of one rotary tillage device, one mulching film covering device, one drip irrigation belt laying device, one mulching film laying device and one seeding device. According to the requirements of agronomic planting, a theoretical analysis is carried out and the power of the key devices of the machine is calculated, and the linear speed of the soil belt, the speed of the two-way screw conveyor, the radius of the double-row seed scoop-type seeder and the power of the tractor for the whole machine are determined. EDEM software is used to simulate the soil covering process of the mulching soil covering device to verify the feasibility of the soil storage device. Field test results show that when the machine advancement speed is 0. 6 m/s, the cavity rate is 1. 2%, the qualification rate of the number of holes is 89. 3%, the qualification rate of seeding depth reaches 86. 5%, the film hole dislocation rate is 5. 1%, and the qualification rate of film edge covering soil thickness is 95. 7%, and the pass rate of adjacent row spacing is 92. 4%. In conclusion, the relevant indexes of the field planting performance test all meet the requirements of the operation quality of the film-mulched hole planter, and the results of the field test and the simulation results are basically consistent.Keywords：flax;full film coverage;precision hole seeding;soil storage tank0|9|2<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to understand the latest research hotspots and development trends in the field of water-saving agriculture in China, with the help of the Web of Science(WOS)core collection database and using “water-saving agriculture” as the theme, 3 775 published documents in total by Chinese scholars from 1990 to 2021 were selected. Quantitative analysis was carried out about the indicators of annual publication volume, discipline distribution, publication journals, research scholars, main research hotspots and their developing trend by using CiteSpace, VOSviewer and HistCite visual analysis software. The results showed that: 1)From 1990 to 2021, the number of documents in the field of water-saving agriculture in China showed an upward trend as a whole; 2)The subjects involved were mainly water resources, accounting for 28. 9% of the total number of documents; 3)The top three academic journals with the largest publications were Agricultural Water Management, Water, and Journal of Cleaner Production; 4)The Chinese Academy of Sciences, China Agricultural University, and Northwest A & F University were the main research institutions; 5)Reclamation, North China Plain, Furrow irrigation, Aerated irrigation were among the most important research hotspots in recent five years based on the results of sudden detection of keywords. In summary, there are plenty of foundations about the researches of water-saving agriculture in China, and some promising progresses have been made in the mechanism of efficient water use for crops, precise allocation and control of agricultural water use, water and fertilizer integration. However, the research on the intelligent control of water and fertilizer integration and its comprehensive effects on soil, crop, environment, and society still needs to be strengthened. With the development of science and technology and the progress of society in China, the future researches about water-saving agriculture probably will develop towards a more intelligent and precise integration of water and fertilizer, which integrates information technology, improves the scientific nature of water and fertilizer application to create smart agriculture.Keywords：water-saving agriculture;bibliometrics;co-occurrence network;CiteSpace;VOSviewer4|12|2<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Aiming at the problem that it is difficult to determine the irrigation timing and amount in the tea plantation irrigation system, Houkui tea plantation in Taiping area of Huangshan is taken as the research object. The CART algorithm is used to analyze the correlation between environmental factors and irrigation and compared with logistic regression and support vector machines prediction models. The Penman-Monteith formula was used to calculate the irrigation amount accurately and the irrigation method obtained in this study is then verified by field experiments. The results showe that: 1)The correlation between soil moisture and irrigation is the largest at 20 cm, 40 cm and 60 cm underground, they are 40. 66%, 12. 74% and 12. 25%, respectively. Therefore, soil moisture is the most critical environment factor in judging irrigation timing; 2)Using the CART algorithm of Taiping Houkui, The accuracy, precision, recall and F1 value by using the CART algorithm to predict the irrigation timing areincreased by 12%-16%, 1. 3%-1. 4%, 12%-16% and 7%-9% than those of the Logistic Regression and the support vector machine models, respectively; 3)The the irrigation amount calculated by Penman-Monteith formula on shows that the annual irrigation amount of Houkui tea tree in Taiping area of Huangshan is 200-500 mm, and the summer shoot irrigation amount is the largest, accounting for more than 70% of the annual irrigation amount. Field experiments verifies that the water-saving rate of this irrigation method reaches 30% to 35%. Therefore, the irrigation strategy obtained by the CART algorithm and the Penman-Monteith formula has certain references for the precise irrigation of tea plantations in this area.Keywords：irrigation timing;irrigation quantity;CART algorithm;precision irrigation16|11|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：Aiming at the problems of too many sensors and too large data redundancy in the layout of soil moisture sensors in tea plantations, an improved K-medoids method was used to optimize the number and deployment location of soil moisture sensors in tea plantations. On the basis of ensuring full coverage of sensing network in tea plantations, the data of each sensing node were collected in real time. The time series data of each sensor under different weather conditions were constructed, and the cubic spline interpolation method was used to synthesize the continuous function. The Euclidean distance in K-medoids was replaced by the distance function of new time series data defined by profile alignment method, and the clustering centers were used as the final sensor placement. This study randomly selected the location and collected the soil relative moisture content to verify the representativeness of the cluster centers as the sensor distribution. Soil moisture data collected from 2018-07 to 2018-08(experiment I)and 2020-12(experiment II)were clustered using the pre-improved and post-improved K-medoids methods. The results show that: 1)The improved K-medoids reduces the number of sensors from 32 to 4. Comparing the relative bias between the soil moisture value in the centers of the cluster and the cluster mean value before and after the improvement, experiment I decreased from 2. 85% to 1. 91%, and experiment II decreased from 2. 01% to 1. 43%. 2)The relative moisture content of the cluster centers obtained by improved K-medoids are close to the average value of the test area, and the relative bias is less than 2%; 3)The clustering centers obtained by the improved K-medoids algorithm as the starting points of the distribution path length is 82. 4 m, using eight sensors, better than the original 106. 5 m and ten sensors. In conclusion, the layout method based on improved K-medoids can optimize the number and location of sensors and is applicable under different weather conditions.Keywords：soil moisture;sensor layout;relative moisture content;time series data;K-medoids9|10|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To explore the supporting path for regional ecological protection and optimization of urban layout, taking the migration of Beijing administrative center as the background, based on the land use survey and natural and socio-economic data of Tongzhou District from 2009 to 2017, Dyan-CLUE model is used to simulate the spatial distribution of land use in Tongzhou District under different scenarios in 2035. The results show that: 1)The simulation results of year 2017 show that the kappa coefficient is 0. 95, which indicates that the simulation results are almost consistent with the reality, and can be applied to scenario simulation. 2)The main change characteristics of the natural growth scenario are that cultivated land, garden(grassland)and water area turn to construction land. The most obvious change under the ecological protection scenario is that cultivated land, garden(grassland)and facility agricultural land turn to forest land, while the government planning scenario is that garden(grassland)and facility agricultural land turn to forest land. 3)Compared with natural growth and government planning scenario, ecological protection scenario strengthens the protection of forest land and inhibits the growth of construction land; Compared with the natural growth scenario, the government planning scenario emphasizes the protection of cultivated land and inhibits the growth of construction land. In terms of space, the difference mainly lies in Shexian Town in the southeast and Songzhuang Town in the north. According to the research results, the following policy suggestions are put forward: 1)Cultivated land protection needs to pay attention to the marginal areas of urban sub centers and towns in the east of Tongzhou District; 2)Garden(grassland)protection needs to focus on Songzhuang Town in the north and Xiji Town in the east of Tongzhou District; 3)New forest land planning can focus on Shexian Town in the southeast of Tongzhou District, Zhangjiawan Town in the middle and Songzhuang Town in the north of Tongzhou District, while water area planning can focus on towns around the urban area of Tongzhou District and Shexian Town in the southeast.Keywords：LUCC;Dyan-CLUE model;Tongzhou District;scenario simulation6|9|2<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to explore the influencing factors on farmers' willingness to recover residual film in Yunnan Province, a questionnaire survey was carried out, and 900 valid questionnaires were empirically studied based on structural equation model. The results show that: The livelihood capital, ecological cognition and policy perception have a significant positive impact on farmers' willingness to recover residual film. According to the influence path coefficient, the desending order of above three factors is policy perception>ecological cognition>livelihood capital. At the same time, the intermediary effect of livelihood capital through policy is greater than its direct effect. The effect of policy guiding farmers to recover residual film is better than other methods. In addition, farmers with high livelihood capital pay more attention to policies and have a higher degree of acceptance and recognition than those with low livelihood capital. Based on this, this study puts forward a series of relevant policy suggestions, such as strengthening subsidies and vigorous publicity, as well as step advancing gradually in due order.Keywords：willingness to recover residual membrane;influencing factors;structural equation model6|11|1<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to explore the impact of non-agricultural employment and ownership cognition on farmers' withdrawal from contracted land, based on the 1 006 survey data of rural households from nine provinces in China, this study analyzes the cost and benefit of farmers' withdrawal from contracted land. Probit model and grouped regression are used to investigate how non-agricultural employment and ownership cognition affect the farmers' willingness to withdraw from contracted land. The results show that: There is a mismatch between farmers' ownership cognition and the ownership regulation. About 39. 07% of the farmers believe that the contracted land belongs to themselves, and the private cognition of the contracted land ownership reduces their willingness to withdraw from contracted land. The increase of the proportion of non-agricultural income will reduce farmers' dependence on land, which will not only help to improve farmers' willingness to withdraw from contracted land, but also alleviate the negative effect from private cognition of contracted land ownership on farmers' willingness to withdraw from contracted land. After controlling endogeneity, non-agricultural employment has a stronger effect on withdrawal from contracted land. Therefore, in order to improve farmers' willingness to withdraw form contracted land, it is necessary to guide them to form correct recognition of contracted land ownership and improve farmers' non-agricultural employment level. In addition, the urban and rural social security system should be strengthened to relieve the worries of farmers, who will withdraw from contracted land, should be strengthened too.Keywords：non-agricultural employment;cognition of contracted land ownership;withdrawal from contracted land2|8|5<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to explore the impact and mechanism of industrial collaborative agglomeration and digital economy on agricultural total factor productivity, based on China's provincial panel data from 2013 to 2019, SBM-GML index is used to measure agricultural total factor productivity, and the system GMM method is used for empirical tests. The results show that: 1)The collaborative agglomeration of agriculture, secondary and tertiary industries has significantly promoted the improvement of agricultural total factor productivity, and the collaborative agglomeration of primary and tertiary industries has a more obvious promotion effect on agricultural total factor productivity. The results hold true after a series of robustness tests. 2)Digital economy not only has a significant positive impact on agricultural total factor productivity, but also plays a significant positive moderating role in the impact of collaborative agglomeration of primary and secondary industries, and collaborative agglomeration of primary and tertiary industries on agricultural total factor productivity. 3)The regional heterogeneity study shows that the collaborative agglomeration of agriculture and secondary and tertiary industries has a more obvious promoting effect on agricultural total factor productivity in western China and northeast China; Digital economy plays a more significant role in promoting agricultural total factor productivity in the eastern and central regions. To this end, this research puts forward countermeasures and suggestions to improve agricultural total factor productivity, such as strengthening the exchanges and cooperation between agriculture and the secondary and tertiary industries, and strengthening the construction of the digital economy.Keywords：industrial synergy and agglomeration;digital economy;agricultural total factor productivity;SBM-GML index4|8|6<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：To study the influence of financial agglomeration on the efficiency of agricultural technology innovation, based on the innovation value chain perspective, the study used the data from 30 provinces, cities and autonomous regions from 2000 to 2019(Data do not include those of Tibet, Hong Kong, Macau and Taiwan regions. The same below). Firstly, the financial agglomeration of each region in different years was measured by industry using the locational entropy method. Secondly, the level of efficiency of agricultural research output and efficiency of results transformation were measured using a two-stage DEA method. Finally, the impact of agglomeration of different financial industries on the efficiency of agricultural technology innovation in two stages was analyzed empirically with the help of spatial Durbin model. The results show that: There are obvious spatial correlation characteristics of the two-stage efficiency values, and there are 28% and 30% differences between the two-stage technological innovation efficiency values and the optimal frontier surface in 2019, respectively; Further partial differential decomposition of the spatial Durbin model reveals that financial agglomeration has a significant promoting effect on agricultural scientific research output efficiency, there is spatial spillover from the agglomeration of securities and banking industries. The agglomeration of insurance industry has a transforming effect on agricultural results. There are the spatial spillover of securities and banking industry agglomeration, and the insurance industry agglomeration has the inhibitory effect on the efficiency of agricultural output transformation.Keywords：financial agglomeration;agricultural technology innovation efficiency;spatial effect;two-stage2|10|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to investigate the influencing factors of the formation of agricultural production agglomeration between counties, this study adopts the spatial Durbin model, and uses the county agricultural production data obtained from five provinces in the Bohai Rim region to analyze the formation of the agricultural production spatial agglomeration based on the perspective of the county. The results shows that: Firstly, the spatial agglomeration of agricultural production has a positive spatial spillover effect, which is manifested in the promotion of the agglomeration of neighboring counties by the agglomeration of agricultural production at the county level. Secondly, The input of agricultural production factors promotes the agglomeration of the region, and the agricultural capital investment of neighboring counties has a depressing effect on the local county. Finally, market demand, regional economic development level and traffic conditions dispaly significant impact on the agglomeration of agricultural production.Keywords：agricultural production;spatial agglomeration;spillover effect1|8|3<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
- Abstract：In order to study the impact of the institutional quality and infrastructure of countries along “the Belt and Road Initiatives” on China's agricultural exports, based on an extended gravity model, this study uses the panel data of China's agricultural export trade during 2005-2019 from the 50“the Belt and Road”countries or regions to explore the influence of institutional quality and infrastructure of “the Belt and Road” countries on China's agricultural export with static effect. The samples are divided into high urbanization rate and low urbanization rate group, and high institutional quality group and low institutional quality group. The results showed that: The high-quality institution and perfect infrastructure of“the Belt and Road”countries have a significant positive impact on China's agricultural exports. The improvement of institutional quality can indirectly promote the export of China's agricultural products through infrastructure; The impact of institutional quality and infrastructure along the Belt and Road countries on China's agricultural export trade is more significant in the high urbanization rate group and the high institutional quality group.Keywords：institutional quality;infrastructure;agricultural exports;“the Belt and Road”3|8|0<HTML><L-PDF> <Meta-XML>Updated：2024-02-27
