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- Abstract：To study the paternal effect of maize kernel moisture, five hybrids and five inbred lines with low dehydration rate were used as female parents, and five early-maturing inbred lines with good dehydration performance were used as male parents. Pollinations were made between male and female parents, meanwhile, control groups were obtained by self-pollinating of parental lines. Kernels derived from both crossing- and selfing-pollination was sampled at 52 days after pollination(DAP, d), and then used for single-kernel moisture quantification. The result showed that the moisture of kernels derived from hybrids×early-maturing male parents decreased by 3. 04 percentage point, and was accompanied by 5. 63% increase in single-kernel weight compared with the selfing kernels of female hybrids; Similarly, the moisture of kernels derived from inbred lines×early-maturing male parents was reduced by 2. 85 percentage point, and was accompanied by 7. 18% increase in single-kernel weight compared with the selfing kernels of female inbred lines. In conclusion, strong positive correlation of moisture exists between crossed kernels and selfing kernels of male parents, and early-maturing male parents could reduce moisture of kernels when pollinating to female parents with low dehydration rate. This research provides a reference to develop methods and germplasms suitable for kernel mechanized harvesting of maize.Keywords：maize;kernel;moisture;nuclear magnetic resonance;genetic effect1|11|1<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：In order to explore the best combination of irrigation amount and drip irrigation frequency suitable for spring maize growth in Hexi area, ‘Xianke 858' was taken as the test material. Three different irrigation amounts, i. e. 60% ETc(W1), 80% ETc(W2)and 100% ETc(W3), and three different irrigation frequencies, i. e. 4 d(D1), 8 d(D2)and 12 d(D3)were designed and there were 9 treatments in total. The plant height, stem diameter, leaf area index(LAI), dry matter accumulation and yield of spring maize were measured during the growth period. The results showed that: The plant height, stem diameter, LAI and dry matter accumulation of W3 treatment were significantly higher than those of W1 and W2 treatments at the same drip irrigation frequency. The effects of irrigation amount on maize yield, water use efficiency(WUE)and irrigation water use efficiency(IWUE)were extremely significant. The yield of W3 was the highest, reaching 15 769 kg/hm2, which was 29. 68% and 8. 90% higher than that of W1 and W2 respectively, while the WUE of W3 was the lowest, which is 22. 17% and 12. 68% lower than W1 and W2. The irrigation amount displayed a significant impact on the water consumption of spring maize, and the water consumption of spring maize increased with the increase of irrigation amount; At the same irrigation amount, the growth index, yield, WUE and IWUE of D1 were the highest in deficit irrigation(W1 and W2). Under full irrigation level(W3), D2 had the highest yield, WUE and IWUE, which were 16 658 kg/hm2, 3. 16 kg/m3 and 4. 3 kg/m3, respectively. The interaction between irrigation amount and drip irrigation frequency had extremely significant effects on plant height, yield, WUE and IWUE of spring maize. The principal component analysis also showed that W3D2 had the highest score. The combination of W3D2(100% ETc, 8 d interval)not only had the greatest yield, but also had relatively higher WUE, meaning that it was the optimal combination for spring maize production in Hexi area.Keywords：Hexi area;irrigation amount;drip irrigation frequency;spring maize growth;yield;water use efficiency3|14|19<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：For QTL mapping of southern leaf blight resistance in maize, 200 F2 individuals of sweet corn combination ‘T8'בT33' were used as genetic mapping population to construct genetic linkage map. Image scanning was performed on the leaves of individual plants for resistance identification and for further QTL mapping. The results showed that: A linkage genetic map with a total length of 1 270. 2 cM was constructed by 214 SSR marker loci, and the average distance between individual markers was 5. 9 cM. A total of 11 QTL of southern leaf blight resistance were detected on chromosomes 3, 4, 5, 6 and 9 using composite interval mapping and lesion image recognition technology. A single QTL accounted for 5. 08%-19. 67% of phenotypic variation. The major QTL of three resistance indexes were detected simultaneously in the marker interval of umc1746-bnlg1523 on chromosome 3 and bnlg603-mmc0081 on chromosome 5, and the contribution rate of each major QTL was more than 10. 00%. In addition, QTL for leaf blight coefficient of three leaves nearest from ear and ear leaf were detected simultaneously in umc1399-umc1307 interval on chromosome 3, and the contribution rates were 5. 08% and 9. 49%, respectively.Keywords：sweet corn;southern leaf blight;lesion image recognition;QTL1|11|0<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：In order to find out the influence of pre-winter sowing period on the growth process, yield and quality of spring wheat varieties. From 2017 to 2019, three pre-winter sowing periods(mid-October, late October, early November)and spring sowing periods(at the end of March, CK)were set up in the field to study the growth process, stem number dynamics, yield composition and seeds quality of ‘Xinchun 6', ‘Xinchun 20', ‘Xinchun 27' and ‘Xinchun 43'. The results showed that the average seedling yield of winter sowing treatment(59. 13%)was 21. 57 percentage points lower than the average seedling average of spring sowing treatments(80. 70%), with large differences between years, and significant differences in seedling emergence rate among the three pre-winter sowing treatments. In winter, seedlings were 9-15 d earlier than in spring sowing treatment, 8-11 d prematurely matured, and extended life. The breeding period was 6-18 d; the peak number of total stems will be reduced, and the peak number of total stems appeared ahead of schedule; the average output for two years of pre-winter sowing treatment(7 065. 99 kg/hm2)was 17. 10% higher than that of spring sowing, and the number of spikes and thousands of grain weight were increased by 30. 68% and 5. 59%. The mean difference in yield between pre-winter sowing treatments was not significant. Pre-winter sowing reduced the protein content, sinker value and wet gluten content of wheat grains. There was no significant difference in grain quality indexes between pre-winter sowing treatments. Among varieties in the same winter sowing period, the settlement value and wet gluten content were significantly different, with high in ‘Xinchun 43' and ‘Xinchun 6' respectively. In summary, the increase in yield of pre-winter sowning wheat compared with spring-sown wheat was mainly the result of the increase in the number of spike grains. All pre-winter sowing wheat significantly reduced the protein content, sinker value and wet gluten content compared with spring-sown wheat, and the difference in the effect on the grain quality index between different winter-sown treatments was significant. Under the conditions of this experiment, the combined yield and quality results showed that late October to early November was the suitable winter sowing period for spring wheat varieties in the North of Xinjiang Uygur Autonomous Region.Keywords：spring wheat sowing in winter;sowing date;growth characteristics;yield;quality1|11|13<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：To explore the correlation between the growth characteristics and functions(plant growth and nutrient absorption)of arbuscular mycorrhizal fungi(AMF), a two-compartment pot experiment containing seven different AMF species: Funneliformis mosseae, Glomus versiforme, Rhizophagus intraradices, Claroideoglomus etunicatum, Claroideoglomus claroideum, Acaulospora scrobiculata, Diversispora spurca and non-inoculated control(CK), were designed for tests with maize(Zea mays L. )and alfalfa(Medicago sativa L. )as host plants. The mycorrhizal colonization rates, hyphal length densities, shoot biomass, shoot P/Zn uptake, AMF gDNA abundance in plant roots and the relative expression of ZmPht1; 6 gene in maize roots were determined. The results showed that: F. mosseae, R. intraradices, G. versiforme and C. etunicatum had higher colonization rates in the roots and hyphal length densities in the rhizosphere of maize and alfalfa, and displayed a positive response on the plant growth, plant P and Zn uptake. C. claroideum, A. scrobiculata and D. spurca had lower colonization rates and hyphal length densities. C. claroideum had a promoting effect on growth and P uptake of alfalfa, but had an inhibitory effect on the growth, P and Zn uptake of maize. The latter two had no significant effect or even inhibitory effect on the plant growth, plant P and Zn uptake. Highly positive correlations were found between AMF growth indices(total colonization rate and hyphal length density)and the mycorrhizal growth response and mycorrhizal P and Zn uptake response. Total colonization rate of maize contributed 79. 0% variations of mycorrhizal biomass response, 77. 6% of mycorrhizal phosphorus uptake response and 74. 1% of mycorrhizal zinc uptake response, respectively. The hyphal colonization rate of AMF in alfalfa roots contributed 76. 5% variation of mycorrhizal biomass response, 72. 6% of mycorrhizal phosphorus uptake response and 74. 0% variation of mycorrhizal zinc uptake response. In addition, a significant positive correlation was found between AMF gDNA abundance and total colonization rate of alfalfa roots. There was also a significant positive correlation between the relative expression of ZmPht1; 6 genes and mycorrhizal phosphorus uptake response in maize. In conclusion, the infection indices of AMF are the main factors affecting mycorrhizal growth and the nutrient uptake response of host plants. AMF gDNA abundance can be used as an indicator of AMF growth, but it varies with plants. To a certain extent, the relative expression of ZmPht1; 6 of maize roots can reflect the P absorption function of AMF.6|12|16<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：In order to explore the feasibility of the application of biodegradable film in the production of fresh corn and sweet potato, 3 biodegradable films BF1(PBAT materials produced in China), BF2(mainly imported PBAT materials)and BF3(PPC materials produced in China)produced by 3 companies were used as experimental materials to analyze their performance, degradability and effects on soil temperature, soil moisture, crop growth, yield and economic benefit on fresh corn and sweet potato production in Beijing. PE(ordinary polyethylene)and LD(bare land)were taken as contrast. The results showed that the temperature and moisture retention of biodegradable film was lower than that of PE film, but higher than that of LD. They could make fresh corn and sweet potato mature earlier and improve their yield, appearance and quality. Among them, the yields of fresh corn covered with BF1 and BF3 were 18 652. 66 and 18 125. 73 kg/hm2, the yields of sweet potato covered with BF1 and BF3 were 31 586. 16 and 29 933. 48 kg/hm2, respectively. There were no significant differences among the yields of BF1, BF3 and PE, and they were significantly higher than that of LD. The economic benefit of biodegradable mulch film on fresh corn and sweet potato was higher than that of LD, but lower than that of PE film. The benefit order from high to low was BF1>BF3>BF2. Based on the analysis of comprehensive economic and ecological benefits, BF1 should be the first choice in the production of fresh corn and sweet potato in Beijing. The application of biodegradable plastic film can replace PE film gradually and realize the application of plastic film pollution-free.Keywords：biodegradable film;fresh corn;sweet potato;yield;benefit3|12|8<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：In order to understand the LBD gene family of Amaranthus tricolor, this study screened and identified the members of the LBD gene family by transcriptome data and named the members AtrLBD. The results showed that: 1)A total of 16 AtrLBD were identified from the transcriptase of Amaranth, all of them were unstable proteins, and the amino acid length ranging from 91 to 351 aa, relative molecular mass ranging from 9. 396-38. 250 ku. The secondary structure of AtrLBD proteins mainly consisted of Alpha helix and random coil. Subcellular localization analysis predicted that AtrLBD were mainly localized in nucleus, chloroplast and mitochondria. The results of MEME analysis showed that 16 AtrLBD proteins had 10 conserved amino acid sequences. 2)The phylogenetic tree displayed that 16 AtrLBD and AtLBD were divided into Class I and Class II, and could be subdivided into Class Ia, Ib, Ic, Id, Ie and Class IIa, IIb. MiRNA prediction results reveled that four AtrLBD were miRNA target genes. 3)qRT-PCR results showed that except AtrLBD4, AtrLBD5, AtrLBD10 and AtrLBD16, AtrLBD were induced by blue light. This study provided a foundation for verifying the function and evolution of the LBD gene family in Amaranthus tricolor L.14|12|3<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：In order to understand the parasitism and pathogenicity of Pratylenchus coffeae to tomato plants, the parasitism and pathogenicity of five different geographical populations of P. coffeae to tomato and the difference of pathogenicity among different nematode populations were tested via pot experiment in green house. Tomato rhizosphere nematodes were isolated using a modified Baermann funnel method. The results showed as follows: 1)Seventy five days post inoculation, all the five different populations of P. coffeae could infect tomato roots, and the reproductive factors(Rf)in tomato rhizosphere were greater than 1, indicating that tomato was a suitable host plant for the tested five different nematode populations. 2)After inoculation with P. coffeae, the plants were growing poorly and had chlorotic leaves, and the tomato roots showed distinct brown spots and heavily rot. 3)The three growth parameters of tomato plants inoculated with P. coffeae were significantly lower than that of the healthy control groups(CK). 4)The tested five nematode populations of P. coffeae have strong pathogenicity to tomato. However, the pathogenicity differed among five P. coffeae populations from different hosts. The population of HN-K1 from corn in Henan Province had the most pathogenic to tomato and the population of AH-015A2 from wheat in Anhui Province had the least pathogenic to tomato. In conclusion, the five different geographical populations of P. coffeae were parasitic and pathogenic to tomato, but there were significant differences in pathogenicity among different populations.Keywords：Pratylenchus coffeae;tomato;parasitism;pathogenicity;Baermann funnel method2|15|2<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：Seed quality is an important foundation for the stable and high yield of zucchini(Cucurbita pepo L. ). It is an effective way to improve the seed quality of zucchini by establishing appropriate comprehensive seed treatment technology. In this study, soft X-ray imaging technology was used to analyze the structure of zucchini seeds, and the effects of specific gravity selection and priming treatment on the germination characteristics of seeds were studied. The results show that the normal, abnormal and dead seeds could be distinguished based on the morphology of seeds by soft X-ray imaging which reached correct recognition rate of 98. 2%, 27. 3% and 65. 9%, respectively, and the correct recognition rate of all seeds was 86. 0%; Grain separation by specific gravity improved the germination rate of zucchini seeds from 83% to 90%. Seed priming treatment improved seed germination speed and uniformity, and the germination potential was increased from 75% to 90% and 7 days treatment had the best effect; After the specific gravity selection and seed priming treatment for 7 days, not only the emergence rate of seeds was significantly increased, but also several physiological indicators related to seedling growth were improved. In summary, the soft X-ray imaging technology can be used to distinguish the types of zucchini seeds, and the specific gravity selection and seed priming technology can be used to improve the seed quality of zucchini. These technologies can be used for the industrialization application in seed companies.Keywords：zucchini;seed;soft X-ray;morphology;specific gravity selection;priming1|13|0<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：In order to screen for broad bean variety with better quality, especially with high L-dopa yield, six broad bean varieties, Lincan No. 2, Qidou No. 1, Haimen Daqingpi, BeiDouQiXing, Black Broad Bean and HongXiangJiao were tested for quality comparison. Four harvesting periods(3rd, 6th, 9th and 12th days)were set to investigate the most suitable harvesting period for sprouts. The growth index and nutrition index of sprout vegetables were measured and analyzed. The results showed that with the extension of the harvesting period, the height and edible fresh weight of broad bean sprouts increased, reaching the maximum at the 12th day of harvest, and the yield of L-dopa also reached the highest at this time. The edible fresh weight of Black Broad Bean was the largest when harvested on the 12th day, the content of soluble protein, free amino acid and total flavonoids were the best, and the yield of L-dopa was the highest, which was 1 392. 48 mg/10 plants. Haimen Daqingpi and Qidou No. 1 ranked second and third respectively. Taken together, the best broad bean variety suitable for L-dopa extraction is Black Broad Bean, and the optimal harvest period is the 12th day. This study provides a theoretical basis for the subsequent mass production of medicinal ingredients in broad bean sprouts.Keywords：broad bean;sprout vegetable;variety comparison;harvest time;L-dopa1|11|1<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：The purpose of this study was to investigate the changes of nutrient components and material digestion rate of the dried corn stalks in the dairy cows rumen after instant catapult steam explosion(ICSE)pretreatment. ICSE pretreatment of dried corn stalks was carried out under conditions of 2. 0 MPa 150 s, 1. 8 MPa 200 s, and 1. 2 MPa 200 s, with 4 repetitions in each group. Corn stalks were pretreated by ICSE, inoculated with Lactobacillus, and then stored under anaerobic conditions for 60 days. After that, amino acid composition, main nutrient components, and mycotoxin content of the corn silage were analyzed. The nylon bag method was used to evaluate the dry matter(DM)reduction rate in dairy cow rumen. The results showed that quality of the corn silage was excellent in the condition of 1. 8 MPa 200 s pretreatment containing 10. 85% crude protein, which was significantly(P<0. 05)two-folds higher than that in the 2. 0 MPa 150 s pretreatment group(5. 99%). Further, the crude protein of 1. 8 MPa 200 s pretreatment group was higher than that in control(8. 38%)and 1. 2 MPa 200 s pretreatment(10. 46%)groups. Further, 1. 8 MPa 200 s pretreatment group exhibited the superior DM degradation rate(77. 36%), which was extremely significantly(P<0. 01)higher than that of control and 1. 2 MPa 200 s pretreatment, while it also presented significantly(P<0. 05)higher DM degradation rate than 2. 0 MPa 150 s pretreatment group. Therefore, the dried corn stover product has preferable quality by combining ICSE pretreatment and silage associated with lactic acid bacteria, which will have a promising application value in ruminant breeding area.Keywords：silage;ICSE;corn stover;rumen digestibility6|14|1<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：In order to keep bedding materials dry and clean, a self-draining beds were constructed to increase the lying time of buffalo, and improve the level of their health and welfare. Thirty healthy buffaloes with similar body condition and body weight were randomly assigned to barns covered with river sand and sand/wood shavings to study their effects on standing and lying behavior preference in summer. The results demonstrated that: buffaloes lay 7. 55 h/d in 15 cm thick sand bed(S-15), which was significantly higher than 4. 58 h/d in 20 cm thick sand bed(S-20)and 0. 42 h/d in 10 cm thick beds(S-10a)(P<0. 01), and lay only 0. 03 h/d in the feed alley. Compared with the three types of river sand bed, the standing time of buffalo on the feeding alley was significantly higher(P<0. 05). On the sand/wood shavings bed, dairy buffaloes preferred to lie on the 10 cm thick sand bed(S-10b, 8. 63 h/d), followed by the 15 cm(WS15)and 20 cm(WS20)wood shavings beds. And the daily lying time was 2. 01 and 1. 26 h, respectively. Daily amount of feces in the feed alley was significantly greater than that of the other three beds(S-10a, S-15 and S-20; S-10b, WS-15 and WS-20)(P<0. 01). In conclusion, in summer, sand is more suitable as bedding material than wood shavings in summer. Laying 15 cm thick sand above the self-draining beds increased the lying time of buffalo. A special feed alley for feeding and defecation can keep bedding material dry and clean to increase lying comfort for dairy buffaloes.Keywords：dairy buffaloes;self-draining beds;bedding materials;behavior2|10|4<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：In order to explore the effects of a new type of amino acid complex iron additive chelated by two amino acids in broiler diets on broiler growth performance, organ index, blood index, tissue antioxidant performance and iron content, 960 1-day-old AA broiler male chicks were selected and randomly divided into 6 treatments with 8 replicates for each treatment and 20 chicks for each replicate. In the experimental treatment group, 0, 20, 40, 80 and 120 mg/kg Fe of new complex amino acid complex iron(ZprFe)and 80 mg/kg Fe of ferrous sulfate(FeSO4)were added to the corn-soybean meal basal diet, respectively. The results showed that: 1)The addition of ZprFe in the broiler diet had no significant difference in the average daily feed intake, average daily gain, and feed-to-weight ratio of broilers(P>0. 05). 2)The addition of ZprFe to the diet significantly increased the liver and spleen indexes of 42-day-old broilers(P<0. 05), and increased linearly and quadratically with the addition of dietary iron(P<0. 05). 3)The addition of ZprFe significantly increased the serum iron content of 21-day and 42-day-old(P<0. 05); significantly reduced the 21-day-old serum total iron binding capacity(P<0. 05), but had no significant effect on the 42-day-old serum total iron binding capacity Influence(P>0. 05). The addition of ZprFe significantly increased the activity of 21-day-old serum manganese superoxide dismutase(Mn-SOD)and 42-day-old serum copper and zinc superoxide dismutase CuZn-SOD activity(P<0. 05). 4)The addition of ZprFe had no significant effect on the total superoxide dismutase(T-SOD)and total antioxidant capacity(T-AOC)of the liver(P>0. 05), but it can significantly increase the T-SOD activity and T-AOC capacity of chest muscles(P<0. 05). The addition of ZprFe had a significant effect on liver iron content. With the increase of dietary iron content, liver iron content increased significantly(P<0. 05). In summary, adding new complex amino acid complex iron ZprFe in the diet is beneficial to the growth and development of broiler's organs, and could improve the antioxidant performance and tissue iron deposition of broilers. The appropriate addition range of ZprFe 40-80 mg in the AA broiler diet under the experimental conditions is recommended/kg Fe. This study provides a theoretical basis for the actual production.Keywords：broiler;amino acid chelated iron;Iron deposition;anti-oxidation ability;suitable addition amount4|11|3<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：The aim of the study was to investigate the effects of epigallocatechin gallate(EGCG)on antioxidant capacity in serum and organs of acute heat-stressed broilers. A total of 144 10-day-old male Huainan partridge chickens were randomly divided into 3 groups(control(group Ⅰ), acute heat stress(group Ⅱ)and acute heat stress+EGCG(group Ⅲ))with 6 replicates in each group and 8 birds in each replicate. The basal diet was fed in group Ⅰ and group Ⅱ, and the basal diet supplemented with 400 mg/kg EGCG was fed in group Ⅲ. At the age of 94 days, the ambient temperature of group I was maintained at(22±1)℃, and that of group Ⅱ and group Ⅲ was raised to(33±1)℃ for 12 hours. And then serum, spleen, liver and jejunum samples were collected. The antioxidant indexes were detected by colorimetry. The expression levels of Nrf2 signaling pathway-related genes were determined by qRT-PCR. The results showed as follows: 1)Compared with group I, the spleen index, total superoxide dismutase(T-SOD)and catalase(CAT)activities in serum and spleen, T-SOD and glutathione peroxidase(GSH-Px)activities and nuclear factor E2 related factor2(Nrf2), NAD(P)H quinone oxidoreductase 1(NQO1), CAT, GSH-Px mRNA expression levels in liver were significantly decreased(P<0. 05). The content of malondialdehyde(MDA)in the jejunum, the contents of MDA and PC and the mRNA expression level of Kelch-like epichlorohydrin-related protein 1(Keap1)in liver were significantly increased(P<0. 05). 2)Compared with group Ⅱ, CAT activity in spleen, GSH-Px activities and CAT mRNA expression levels in liver in group III were significantly increased(P<0. 05), while MDA contents in jejunum and liver were significantly decreased(P<0. 05). In summary, dietary EGCG supplementation can improve antioxidant capacity of acute heat-stressed broilers and then alleviate the oxidative damage caused by acute heat stress. The mechanism may be related to EGCG activating the expression of key antioxidant genes in the Nrf2 signaling pathway. This study provided theoretical foundation for the application of EGCG in broiler production.Keywords：epigallocatechin gallate;broiler;acute heat stress;antioxidant2|27|5<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：Arming at solving the problem of poor segmentation effect of diseased ear images in the method of wheat scab intelligent identification, the median filter method was used to denoise the image of wheat ear disease pre-processing, and the maximum between-class variance algorithm(OTSU)based on threshold and k-means algorithm based on clustering were adopted to segment the wheat ear images infected with wheat scab in the RGB, HSV and Lab color spaces from the flowering stage to the yellow ripening stage, and the diseased parts of the wheat ears were extracted. A total of 200 images of wheat ears affected by wheat scab from flowering stage to ripening stage were used for segmentation experiment. The results showed that the best segmentation effect was obtained by transforming the image from RGB color space to Lab color space and using OTSU algorithm to segment the a component, and the difference ratio was only 1. 11%.Keywords：wheat scab;image processing;color spaces;threshold segmentation;clustering algorithm4|13|10<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：In order to achieve rapid detection of selenium content in multiple samples of foxtail millet, 93 foxtail millet samples with different genetic backgrounds were used as the research object, and the samples were divided into a calibration modeling set(sample size n=51)and an external verification set(n=42). The NIRSTMDS2500 desktop near-infrared spectrometer produced in Denmark was used to collect spectral information, and the SNV and Detrend spectral preprocessing method and PLSR(Partial Least Squares)modeling method were used to establish the determination model of the total selenium content of shelled foxtail millet through variable standardization. The workflow call the model was used to realize the rapid detection of the total selenium content of foxtail millet; the total selenium content of foxtail millet was determined by by the national standard, and the results were used as the chemical reference value of the prediction model of the total selenium content of foxtail millet. The result showed that: The internal cross-validation correlation coefficient of the total selenium content of foxtail millet is 84. 5%; The root mean square error of the calibration set and the root mean square error of the verification set are 0. 039 6 and 0. 089 2 respectively, indicating that the near-infrared predicted value of the total selenium content of foxtail millet is close Chemical reference value; The performance deviation ratio is 5. 478, which is greater than the quality control standards proposed by the American Association of Cereal Chemists and International Association for Cereal Science and Technology. The ratio of the standard errors of the prediction set and the modeling set in the model established in this study is 1. 073 0, which is less than 1. 2. Therefore, the use of PLSR to establish a model has a high prediction accuracy and a high degree of robustness, which can achieve rapid detection of the total selenium content of foxtail millet.Keywords：total selenium content of foxtail millet;near-infrared spectroscopy analysis technology;quantitative model;rapid detection0|10|3<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：As a kind of reactive volatile sulfur compound, dimethyl sulfur(DMS)plays a vital role in global sulfur cycle and has a negative greenhouse effect in climate change. This study summarized domestic and foreign research progress of DMS in atmospheric environment and retrieved 1 997 literatures published from 1900 to 2020 in Web of Science core collection for bibliometric analysis, with the keywords of “dimethyl sulfide” and “air”, “dimethyl sulfide” and “atmosphere”, “dimethyl sulfide” and “atmospheric”, respectively. The results showed that: 1)Studies over past decades was focused on the formation and environmental impact of DMS in marine areas, including DMS production by marine phytoplankton and bacteria, model estimation of global DMS sea-air flux, ways to eliminate DMS and radiation effect of its oxidation products. 2)The impact of global warming on DMS emission has gradually become a focus of attention. 3)The sources and emissions flux of DMS in non-marine areas were not very clear. The contribution of non-marine sources of DMS and its environmental impact with the development of economy. The impact of global warming on DMS release process and the quantifying of the contribution of non-marine sources DMS are issues worthy of further attention in the future.Keywords：dimethyl sulfur;environmental impact;sources;bibliometrics3|10|2<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：In order to compile the load spectrum of the tractor propeller shaft under actual working conditions for the characteristics of single peak and multi-peak of tractor propeller shaft load and the limitation of parameter extrapolation, the rule-of-thumb(ROT)method was used to calculate the bandwidth. An improved load extrapolation method based on kernel density estimation(KDE)was proposed in this study. By building a set of wireless torque test system for tractor propeller shaft and conducting field tests, the propeller shaft load data under ploughing conditions were obtained, the optimal bandwidth of the From-To rain flow matrix was obtained based on ROT, and the kernel density estimation threshold was calculated from the rain flow matrix. The non-parametric method based on KDE was used to extrapolate the loads larger than the threshold, and the loads smaller than the threshold were extrapolated proportionally. Finally, the rationality of the extrapolated loads was verified. The results showed that: Compared with the traditional non-parametric method, when using the extrapolation method based on KDE, the calculation time was shortened by 54. 16%; Compared with the measured load, the extrapolated mean, standard deviation, and maximum error were respectively 2. 2%, 0. 87% and 6. 3%, which were within the allowable error range of engineering application. The cumulative frequency curves of extrapolated load and test load were drawn, respectively, Both the goodness of fit R2 and the pseudo-damage ratio were greater than 0. 99. This method was used to extrapolate the load of other working conditions of the propeller shaft, and good results were also obtained. In conclusion, the extrapolation method based on KDE is helpful to compile the load spectrum reflecting the actual loading condition of the tractor propeller shaft. This study provides references for the extrapolation of mechanical parts with similar load distribution characteristics.Keywords：tractor;propeller shaft;load extrapolation;non-parameter method;kernel density estimation;rule-of-thumb2|14|5<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：The aims of this study are to understand the current situation, characteristics and shortcomings of agricultural machinery operation service research, explore the development law of agricultural machinery operation service, and provide a basis for improving agricultural machinery operation service research. The relevant research on agricultural machinery operation services is systematically sorted out from the aspects of concept definition, development history, supply and demand status, and impact effects. The theoretical basis and internal mechanism of agricultural machinery operation services development are summarized. The results show that the rapid development of agricultural machinery operation services benefited from the combination of effective markets and effective government, the demand caused by labor constraints, capital constraints, technical constraints and land constraints faced by farmers, and the supply caused by natural, economic, political and social factors, The role of supply and demand has formed a mechanized development path with Chinese characteristics. At present, the research of agricultural machinery operation services mainly focuses on the analysis of the demand side and the impact effect, and insufficient attention is paid to the supply side. In addition, there are few researches on the allocation of production factors of farmers in agricultural machinery operation services. The empirical analysis shows that the issue of heterogeneity and endogenousness of farmers is not discussed enough. Future research should focus on the reform of the agricultural supply side and the high-quality development of agriculture, organically integrate the requirements of rural revitalization with the development of agricultural machinery operation services, and enhance the strategic nature of research.Keywords：agriculture machinery operational services;supply and demand;factors allocation;research review2|10|3<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：Using the method of bibliometrics, this study drew the knowledge map by CiteSpace software, and maked a visual analysis of the related literature of rural industrial integration development included in CNKI. The results showed that: 1)The earliest research on China's rural industrial integration was in 2005, and after 2015, the number of published papers showed an explosive growth. 2)The development of rural industrial integration mainly focused on the six aspects: the participants of industrial integration, the mode of industrial integration, the influencing factors of industrial integration, the effect of industrial integration, industrial integration and modern agriculture, industrial integration and Rural Revitalization. The current research frontier was the relationship between industrial integration and Rural Revitalization. 3)At present, there were three problems that needed to be solved urgently: Firstly, the research was mainly concentrated in the field of economics and management science, lack of other disciplines perspective; Secondly, the evaluation standard of industrial integration was not unified, and there were few empirical studies; Thirdly, the research on rural employment, rural ecology, and farmers' social life was less. In view of the above problems, relevant suggestions aiming at improving and deepening the research on the integration of rural industry were put forward.Keywords：rural;industrial integration;CiteSpace;research progress;knowledge map5|13|8<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：In order to explore the spatial dispersion distribution of rural settlements in the hilly region of southern China, Yingtan City of Jiangxi Province was taken as the research object. Based on land use data in Yingtan City in 1996, 2009 and 2018, the landscape pattern index and principal component analysis method were adopted to construct the index of rural settlements dispersion, and spatial-temporal evolution characteristics of rural settlements dispersion and its influencing factors during the recent two decades in Yingtan city were explored by using the spatial autocorrelation and geodetector method. The results showed that: 1)The average annual of rural residential areas respectively increased was 183. 35 and 204. 14 hm2/a from 1996 to 2009 and from 2009 to 2018. The total scale of rural residential areas in Yingtan City kept growing, however, there was descending in aggregation degree and increasing in fragmentation level. 2)In 1996, 2009 and 2018, the mean values of the rural settlements dispersion degree in each township were 0. 41, 0. 42, and 0. 45, respectively. The total number of townships, whose rural settlements were classified as level I, accounted for 41. 18%, 35. 29% and 26. 47%. The townships of level II accounted for 35. 29%, 44. 12%, and 50. 00%, and the townships with level III accounted for 23. 53%. The rural settlements dispersion of townships were increased overall and regional rural settlements dispersion had obvious spatial aggregation. 3)From 1996 to 2018, the influence of topographic position index and population density on rural settlements dispersion first increased and then decreased, and the influence of distance to towns and roads on rural settlements dispersion first decreased and then increased. The relationships between the influencing factors were one factor wanes, the other waxes. In conclusion, the topographic index, distance to roads and population density are the dominant factors for rural settlements dispersion. The distance to towns, distance to rivers, and GDP per area are important factors for rural settlements dispersion. Each dominant factor can enhance the explanatory power of other influencing factors for rural settlements dispersion in different periods. This study provides a scientific basis for the planning and coordination of rural settlements in the hilly region of South China.Keywords：rural settlements;composite index of dispersion;impact factor;geodetector;Yingtan City2|29|12<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：To explore the impacts of animal husbandry industry agglomeration on county economic growth, Heilongjiang Province was taken as an study case. The panel data of 66 counties(cities, districts)in Heilongjiang Province from 2008 to 2017 were adopted and the location entropy index method was used to measure the situation of animal husbandry industry agglomeration in Heilongjiang Province. The feasible generalized least square method(FGLS)was used to empirically test the impact of animal husbandry industry agglomeration on county economic growth. The results showed that: 1)The overall agglomeration degree of animal husbandry industry in pastoral, semi pastoral and non-pastoral areas showed a downward trend, the average values of industrial agglomeration were 3. 27, 2. 49 and 1. 54, respectively; 2)The overall regression results showed that there was an obvious “U” type relationship between animal husbandry industry agglomeration and county economic growth, and the sample regression of different production areas confirmed the existence of “U” type relationship between animal husbandry industry agglomeration and county economic growth; 3)The capital investment, labor input, informatization level, financial development level, capacity of enterprises above designated size, county fiscal revenue, traffic facilities construction, basic education level, etc. also had an important impact on county economic growth. Therefore, this study puts forward some policy suggestions, such as reasonable planning of the main production area of animal husbandry, encouraging and promoting the agglomeration of animal husbandry industry, strengthening the subsidy policy of animal husbandry, guiding the development of animal husbandry according to local conditions, increasing the input of resource allocation, and optimizing the development environment of county economy.Keywords：rural revitalization;animal husbandry industry;industrial agglomeration;county economy;Heilongjiang Province0|11|2<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：In order to study the impact of rural hollowing on agricultural technology progress, this study takes the panel data of 66 counties in Hubei Province from 1997 to 2017 as study object to analyze the impact direction and trend of rural hollowing on agricultural technology progress by using generalized least square method and quantile regression. The results show that: 1)The rural hollowing leads to the development of labor-saving technologies. When the degree of hollowing is about 0. 1, the preference coefficient of agricultural technology selection is close to 1, and both labor-saving technologies and land-saving technologies are adopted. With the deepening of rural hollowing, the progress of agricultural technology tends to be labor-saving technology, but when the proportion exceeds 50%, the impact on agricultural technology progress is not significant; 2)Under different terrain conditions, the rural hollowing has different impacts on agricultural technology progress. Mountainous areas are more inclined to adopt labor-saving technologies whereas hilly areas tend to adopt land-saving technologies, but the regression results of plains are not robust; 3)The larger the average sown area per household is, the more labor per unit area of arable land is and the further away from the central market is, and the more favorable it is to promote the development of labor-saving technologies. Regions with higher net income per capita are conducive to innovation in land-saving technologies. Based on this, some relevant policy suggestions are put forward.Keywords：rural hollowing;agricultural technology progress;labor-saving technology;land-saving technology9|9|4<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：To investigate non-agricultural employment and whether different basic social insurance choices will affect the willingness of rural households to transfer homesteads, this study is based on 2017 data from China rural household tracking survey(CRHPS). The Logit model applied to empirically test the specific impact of non-agricultural employment, basic social insurance and the interaction between these two variables on the transfer of homestead. The results show that the farmers' non-agricultural employment significantly promotes farmers' homestead transfer, and the increases in both non-agricultural employment time and non-agricultural employment intensify farmer's willingness to transfer. Farmers' participation in different basic social insurances has different effects on the circulation of homesteads; Farmers who participate in the new rural cooperative pension insurance or the new rural cooperative medical insurance are locked in the agricultural operation and production under the “yoke effect” of the new rural cooperative or new rural insurance, and thus their circulation of homesteads is inhibited. Farmers who participate in the urban pension insurance or urban medical care prefer to transfer homesteads, and that finding is proved by the positive results. The interaction between non-agricultural employment and basic medical insurance reveals that the increase in non-agricultural employment time or the increase in non-agricultural employment will alleviate the “yoke effect” of the new rural cooperative or new rural insurance on farmers. Finally, suggestions of paying attention to the quality of rural labor transfer, and the compatibility of farmers and non-agricultural employment are put forward to guarantee the welfare of farmers' non-agricultural employment.Keywords：non-agricultural employment;basic social insurance;homestead transfer5|13|3<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
- Abstract：In order to solve the challenges in tracing the frequently contaminated food cold chain, the problems of source locating and diffusion tracking of contamination in food cold chain is investigated. Based on Bayesian inference model, an efficient identification method by considering batches information is proposed, and a food cold chain tracing and tracking system is developed. By using the open data set of food cold chain provided by Rapid Alert System for Food and Feed, the processes and results of contamination source locating and tracking analysis are demonstrated. The results indicate that: The diffusion of contamination in food cold chain has many characteristics such as isolation of contamination propagation, sparsity of observation samples, path diversity and time uncertainty, which lead to the weak applicability of the traditional risk source identification and spread methods. By considering the batches information of traceable food cold chain, contamination source locating model is more efficient in calculation, which can not only reduce the complexity of food cold chain contamination traceability, but also improve the accuracy. According to the contamination source locating algorithm, the food cold chain tracing and tracking system can directly identify the contamination source node and mark out the path of risk propagation. Therefore, accelerating the construction of traceability system and improving the ability of contamination source locating and diffusion tracking in food cold chain are suggested to eliminate the risk from the origination, quickly block the risk diffusion and effectively ensure food safety in cold chain.Keywords：food cold chain;food traceability;source locating of contamination;risks tracking;cold chain logistics2|10|0<HTML><L-PDF> <Meta-XML>Updated：2023-12-22
