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28 August 2022, Volume 40 Issue 4
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  • Special Topics: Study on Food Legumes
    Study on Comparison of Regeneration Capacity of Different Varieties of Common Bean
    CHENG Yuan, MA Pengtao, WU Jing
    2022, 40(4):  465-471.  doi:10.16036/j.issn.1000-2650.202202080
    Abstract ( 344 )   PDF (14915KB) ( 149 )   Save
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    【Objective】 To select the appropriate regeneration genotypes of common beans,to build the construction of the common beans transformation system laid the foundation. 【Method】 Select 19 common beans, the embryonic axis of the cotyledons was used as explants, regenerative buds were induced on bud-inducing medium containing 2 mg/L 6-BA, 0.5 mg/L TDZ and 2 mg/L AgNO3. The germination rate, regeneration bud rate and the average number of regenerated buds were counted, and observed the status of the regeneration bud and the regeneration bud rate. Comprehensive screening of suitable regeneration materials. 【Result】 The regeneration bud rate of Xibaiyang Jiaodou was 94.4%, which is significantly different from other common beans. 【Conclusion】 It is preliminarily concluded that the Xibaiyang Jiaodou is more suitable to construct the genetic transformation system among 19 common beans.
    Path Analysis of Yield Related Traits and Selection of High Yield Germplasm in Mung Bean
    CAI Debao, DING Donghui, LIU Qing, CHEN Xuemiao, WANG Lanfen, CHEN Jibao
    2022, 40(4):  472-480.  doi:10.16036/j.issn.1000-2650.202201065
    Abstract ( 238 )   PDF (7386KB) ( 139 )   Save
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    【Objective】 In order to explore the key traits that affect mung bean yield and understand the main influencing factors of mung bean yield、 select germplasm with high yield. 【Method】 Using 294 germplasms from home and abroad as materials, 17 traits related to mung bean yield were evaluated through field experiments for 3 years. Correlation analysis, multiple regression analysis, passage analysis and other methods were used to explore the main influencing factors of mung bean yield, and cluster analysis was used to screen excellent germplasm. 【Result】 Correlation analysis showed that the yield per unit had the strongest correlation with 100-seed weight (0.67), pod length (0.56), seed diameter (0.63) and pod per plant (0.36), and had a significant positive correlation with plant height,number of branches per plant, maturity stage and other traits. The optimal regression equations of seed yield (SY), plant height (PH), number of branches per plant (BPP), pod per plant (PPP), pod length (PL), pod width (PW), seed per pod (SPP) and 100-seed weight (HSW) were established by stepwise multiple regression analysis:SY=-2 628.124+136.778HSW+13.436PPP+4.780MD+34.901SPP+22.469PL+42.851PW+1.545PH+249.033SD+19.176BPP+3.242RGD, equation determination coefficient R2 = 0.96, P= 0.000 1;Path analysis showed that pod per plant (0.63) and 100-seed weight (0.53) had the most direct effects on yield,while pod length (1.11) and maturity stage (1.00) had the most indirect effects; Cluster analysis showed that 294 materials were divided into 6 groups, and the yield, pod width, seed diameter and 100-seed weight of groups Ⅰ(2) and Ⅱ (25) were significantly higher than those of other groups, which could be used as the parent material for high yield mung bean introduction or cross breeding. 【Conclusion】 A total of 10 key traits affecting the yield of mung bean were identified and 27 germplasm with high yield were screened, which laid a foundation for further breeding with high yield.
    Genetic Diversity Analysis and Powdery Mildew Resistance Identification of Adzuki Bean Germplasm Resources in Chongqing
    LONG Juechen, DU Chengzhang, ZHANG Xiaochun, LIU Jianfei, WANG Qiang, GAO Feihu, TANG Keming, CHEN Hong, ZHANG Jijun
    2022, 40(4):  481-488.  doi:10.16036/j.issn.1000-2650.202206094
    Abstract ( 218 )   PDF (11097KB) ( 167 )   Save
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    【Object】 In order to study the rich diversity of adzuki bean germplasm resources, provide important material basis for genetic and breeding research and screening of powdery mildew resistant germplasm resources, the project team collected 59 adzuki bean germplasm resources from Chongqing area in 2 years. 【Method】 Genetic diversity analysis, principal component analysis and cluster analysis were used to identify the genetic diversity, and the powdery mildew resistance of the accessions for two consecutive years. 【Result】 The genetic diversity index of each characters were ranked as: plant height> maturing days> bottom pod height> number of pods per plant> pod length> 100-seed weight> flowering days> pod width> node number of main stem> number of seeds per pod> number of branches> Seed coat color> pod shape> seed shape> trilobate leaf color> growth habit> podding habit> flower color> trilobate leaf shape> main stem color> vein color> petiole color. The 59 accessions were divided into 5 groups by cluster analysis. The Ⅰ group contained 16 accessions, the Ⅱ group contained 4 accessions, the Ⅲ group contained 2 accessions, the Ⅳ group contained 31 accessions, and the Ⅴ group contained 6 accessions. In the three-dimensional scatterplot, 59 accessions were roughly distributed in two regions by the first three principal components. Accessions on the left side of the image were mostly erect, while accessions on the right side were mostly semi-erect. The results of resistance identification showed that the average resistance of adzuki bean germplasm resources in Chongqing was susceptibility to powdery mildew, and 6 highly resistant materials and 4 resistant materials were screened out from them. 【Conclusion】 The germplasm resources of adzuki bean in Chongqing were divided into 5 groups by cluster analysis. Six high resistant and four resistant accessions were screened out from 59 germplasm resources by field induced disease identification.
    Genetic Diversity Analysis of Agronomic Traits in Vegetable Pea Germplasm Resources
    CUI Xiao, ZHANG Xiaoyan, HAO Junjie, QIU Shizuo, LYU Xianghua, SONG Fengjing
    2022, 40(4):  489-497.  doi:10.16036/j.issn.1000-2650.202204079
    Abstract ( 259 )   PDF (3252KB) ( 173 )   Save
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    【Objective】 This study was conducted to understand the genetic diversity of 144 vegetable pea genetic resources and evaluate the vegetable pea resources for improving the efficiency of vegetable pea breeding programs in China. 【Method】 A total of 34 agronomic traits of 144 vegetable pea resources were analyzed for genetic diversity by using cluster analysis and principal component analysis. 【Result】 The results showed a high level of genetic diversity among these vegetable peas which could be utilized as the major traits for excellent cultivar breeding. The coefficient variation (CV) of 34 traits of the tested germplasm ranged from 4.653% (growth period) to 79.115% (use), with an average coefficient variation of 34.896%. The variation range of qualitative traits was low, but the variation range of most quantitative traits was high. The average genetic diversity index of 34 traits was 1.218 2, of which layer numbers of main stem pod (2.065 2) was the highest and the lowest was leaf type (0.214 6). The coefficient variation, variation range and genetic diversity index were not related. In this study, the principal components of 18 quantitative traits were also analyzed and the results showed that the accumulation indices of the top six principal components was up to 72.971%. Cluster analysis showed that 144 vegetable pea resources were classified into 7 groups with significantly different traits. The resource numbers of each group were 2, 5, 17, 43, 24, 8 and 45,respectively. The group Ⅱ had high yield traits, providing useful resources for hybridization breeding. 【Conclusion】 The 34 agronomic traits of 144 vegetable pea resources showed extensive genetic variation and abundant genetic diversity. 35 germplasms were identified with bigger seed,more pods per plant, higher yield, longer and wider pod etc.. The excellent resources in our results will contribute innovative utilization in hybridization breeding of vegetable pea.
    Genetic Analysis and QTL Mapping of Initial Pod Node Position and Initial Pod Height in Vicia faba L.
    WU Xiaoyan, ZHOU Xianli, ZHANG Hongyan, PENG Xiaoxing, FAN Huiling, TENG Changcai, LIU Yujiao
    2022, 40(4):  498-504.  doi:10.16036/j.issn.1000-2650.202207095
    Abstract ( 191 )   PDF (7640KB) ( 92 )   Save
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    【Objective】 The initial pod node position and initial pod height are important mechanized production traits in faba bean. The development of relevant molecular markers for assisted breeding provides a basis for the innovation of faba bean germplasm suitable for mechanized production and new variety breeding. 【Method】 The study, a F2 population was constructed by crossing Qingchan 19 (female parent) and Qinghai 13 (male parent). The genetic characteristics of the initial pod traits were analyzed by using the mixed genetic model of major gene + polygene, and the QTLloci for the initial pod node and height of F2 population were located by SSR markers. 【Result】 The results showed that genetic basis for initial pod position trait of Vicia faba was accorded with two pairs of additive-dominant-epistatic major gene model (2MG-ADI), and that of the initial pod height trait was accorded with two pairs of additive-dominant major gene model (2MG-AD). 1 596 pairs of faba bean SSR primer, were used to screen the F2 population and 79 pairs of primer showed polymorphic; Furthermore, the genetic linkage map of Qingcan 19/Qinghai 13 F2 population was constructed. This map contained 6 linkage groups, the total length of the map was 1 804.59 cM, the average distance between two markers was 22.84 cM, the length of each linkage group was 26.34~1 389.89 cM, and the number of markers in the linkage group was 2~54. Based on the map, 5 QTL loci related to initial pod node and 8 QTL loci related to pod height. 【Conclusion】 The initial pod node position and initial pod height of faba bean are controlled by two pairs of main genes, and five molecular markers related to the initial pod node position and eight molecular markers related to the initial pod height have been excavated, which provided a theoretical basis for directional selection of good varieties with suitable initial pod node position and initial pod height.
    Identification and Evaluation of Salt Tolerance of Pea Resources
    YA Xiuxiu, YANG Dongxu, ZHOU Guimei, CHEN Jian, LIU Zhenxing
    2022, 40(4):  505-511.  doi:10.16036/j.issn.1000-2650.202207096
    Abstract ( 261 )   PDF (11152KB) ( 111 )   Save
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    【Objective】 The current study was conducted to meet the needs of pea production in Hebei coastal area. 【Method】 32 pea germplasm resources were used as materials to identify and comprehensively evaluate the salt tolerance of pea germplasm under mixed sodium salt stress at germination stage. 【Result】 When the concentration of mixed salt solution increased to 150 mmol/L, the standard deviation of relative germination rate (RGR) among pea varieties (lines) reached the maximum,19.75. principal component analysis showed that the cumulative contribution rate of relative germination rate (RGR), relative shoot fresh weight (RSFW) and relative germination potential (RGP) reached 80.18%. The 32 pea germplasm resources were divided into four grades according to salt tolerance by cluster analysis,including 8 high salt tolerance varieties (lines), 3 salt tolerance varieties (lines), 7 medium tolerance varieties (lines) and 10 salt sensitive varieties (lines). 【Conclusion】 Pea has salt tolerance, and different pea varieties have different salt tolerance. 150 mmol/L mixed salt stress at germination stage was an effective method to identify the salt tolerance of pea. Relative germination rate (RGR),relative shoot fresh weight (RSFW) and relative germination potential (RGP) can constitute the evaluation index system of salt tolerance of pea. Eight highly salt-tolerant pea varieties (lines) could be used as parents to further develop excellent varieties of stress-tolerant pea or to conduct introduction test and demonstration promotion in coastal saline-alkali land.
    Analysis of Faba Bean Germplasms from Different Geographical Regions Resistance Characteristics to Callosobruc chinensis L.
    YANG Xin, YANG Feng, LYU Meiyuan, YU Haitian, HU Chaoqin, WANG Yubao, ZHENG Aiqing, DAI Zhengming, TANG Yongsheng, DAI Kuai, WANG Liping, HE Yuhua
    2022, 40(4):  512-518.  doi:10.16036/j.issn.1000-2650.202204093
    Abstract ( 182 )   PDF (2623KB) ( 138 )   Save
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    【Objective】 This study is explore the resistance to Callosobruc chinensis L. of faba bean for preliminary identification and screening of insect-resistant materials. 【Method】 The resistance of 874 faba bean germplasms from different geographic origin were evaluated by artificial infection and saturated infection method under storage condition. 【Result】 The results showed that the susceptibility (S) and high susceptibility (HS) materials accounted for 30.9% and 64.9% of the comprehensive resistance to Callosobruc chinensis L., respectively, however, the proportion of high resistant (HR) and resistant(R) materials were 3.1% and 1.1%, respectively. Significant differences in resistance to Callosobruc chinensis L. were observed in different seed color of faba bean germplasms. The resistant rate and weight of insect in cyan, motley and dark faba bean germplasms were 4.8% and 96.6 mg, 8.7% and 91.1 mg, 2.4% and 120.2 mg, respectively. The resistance rate and weight of insect in large-grain, mid-grain and small-grain germplasms were 2.5% and 154.7 mg, 3.8% and 109.7 mg, 8.1% and 56.7 mg, respectively. There was no significant difference in the resistance to Callosobruc chinensis L. between the domestic and foreign germplasms, however, there were significant differences in the resistance to Callosobruc chinensis L. of faba bean germplasms from different provinces, and the provinces with high resistance were Chongqing, Hunan, Zhejiang, Anhui and Jiangxi, while the germplasms from Yunnan, Sichuan, Shanxi and Guizhou had relatively low resistance. The comprehensive resistance of motley was better than that of cyan and dark germplasms. At the same time, the resistance to Callosobruc chinensis L. of faba bean germplasms decreased with the increase of hundred-grain weight, the comprehensive resistance of small-grain germplasms was significantly higher than that of mid- and large-grain germplasms. 【Conclusion】 In this research, the evaluation and screening of resistance resources of faba bean provided potential resistance sources and theoretical basis for breeding of resistance new varieties. However, further research is needed to explore the internal mechanism and related genes of resistance to Callosobruc chinensis L.
    Animal Science
    Transcriptomes Analysis Revealed the Molecular Mechanism about the Anti-S180 Tumor Activity of the Polysaccharide ME-X from Morchella esculenta
    LU Yan, HUANG Yao, YE Ziyu, ZHOU Liqian, LIU Xinlan, DING Xiang, HOU Yiling
    2022, 40(4):  519-528.  doi:10.16036/j.issn.1000-2650.202110086
    Abstract ( 196 )   PDF (10469KB) ( 114 )   Save
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    【Objective】 This study aims to explore the antitumor activity of a polysaccharides from Morchella esculenta (named ME-X) and its impact on gene expression, observing the potential effect molecules and main signaling pathways under ME-X, which had a phenotype of suppressing the growth of S180 tumor in mice. 【Method】 In this study, the S180 tumor bearing mice were used as a model and antitumor experiments in mice were performed at first, then RNA-Seq technology was combined to sequence the S180 tumor cells from those mice in the experimental groups with bioinformatics analysis of the obtained data. 【Result】 ME-X, like Mannatide, which could significantly (P<0.01) inhibit the growth of S180 tumor in mice, and the rate of inhibition reached 53.81%. Differential expression genes (DEGs) analysis suggested that the key genes mostly enriched in the PI3K-AKT signaling pathway including many significantly up-regulated genes, such as fibroblast growth factor 10 (Fgf10), fibroblast growth factor receptor 2 (Fgfr2), cytokine receptors (Prlr, Ghr, I12rb) and phosphoenolpyruvate carboxykinase (Pck1). 【Conclusion】 It was suggested that ME-X could regulate the metabolism, migration and cell cycle of S180 tumor cells through PI3K-AKT signaling pathway to inhibit S180 tumor.
    Effects of Heat Stress on Serum Indexes of Stress, Antioxidant and Liver Function of Cows at Different Lactation Stages
    YAO Zhilan, CHENG Lijie, SHEN Liuhong, CAO Suizhong, WANG Shaoxi, FU Hongqing
    2022, 40(4):  529-535.  doi:10.16036/j.issn.1000-2650.202201070
    Abstract ( 186 )   PDF (570KB) ( 161 )   Save
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    【Objective】 To study serum stress, antioxidant and liver function related indexes of cows at different lactation stages during heat stress period. 【Method】 All cows, including 856 cows in the heat stress period and 896 cows in the non-heat stress period, were divided into four lactation stages according to days in milk: the late perinatal cows (0-21 d), the early lactation cows (22-120 d), the mid-lactation cows (121-200 d), and the late-lactation cows (201-305 d). 10 cows were randomly selected with similar body conditions, age and days in milk in the same lactation period (2-4 births) during mild heat stress and non-heat stress period from each lactation period, the test cattle were collected separately venous blood of bovine tail root and serum biochemical indexes include heat shock protein 70 (HSP70), cortisol (Cor), superoxide dismutase (SOD), total antioxidant capacity (T-AOC), malondialdehyde(MDA), non-esterified fatty acid (NEFA), haptoglobin(HP), glutamate dehydrogenase (GDH) were measured. 【Result】 Compared with cows at different stages in non-heat stress period, cows in mild heat stress period serum stress index HSP70, Cor concentration and antioxidant index SOD activity increased obviously significantly(P<0.01), T-AOC of late perinatal cows and early lactation cows was significantly obviously reduced (P<0.01), mid-lactation cows was significantly reduced (P<0.05). MDA of late perinatal cows increased significantly (P<0.05), MDA of early lactation cows and mid-lactation cows increased obviously significantly (P<0.01). GDH activity of each lactation cows was significantly obviously increased (P<0.01), NEFA concentration of late perinatal cows and early lactation cows was significantly extremely increased (P<0.01), significant improvement in middle lactation (P<0.05), HP concentration of late perinatal cows, early and middle lactation cows was significantly increased (P<0.01). 【Conclusion】 The cows at different lactation stages were affected by heat stress, all of them had different degrees of stress reaction and oxidative damage, and the liver function was damaged to different degrees. In particular, early lactation cows and mid-lactation cows were seriously affected by heat stress.
    Effects of Curcumin on Migration of Canine Bone Marrow Mesenchymal Stem Cells
    LI Weiyao, DENG Jiaqiang, ZHAO Fangfang, ZHU Xuerui, CAO Suizhong, SHEN Liuhong, YU Shumin
    2022, 40(4):  536-542.  doi:10.16036/j.issn.1000-2650.202111087
    Abstract ( 222 )   PDF (21880KB) ( 88 )   Save
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    【Objective】 This study aims to explore the effects of curcumin (Cur) on migration of canine bone marrow mesenchymal stem cells(cBMSCs). 【Method】 cBMSCs cultured in vitro were chosen as the experimental materials and divided into P3 group (P3-cBMSCs) and Cur group [P6-cBMSCS + Cur (0, 0.1, 1 and 10 μmol/L)]. The migration ability of cBMSCs was tested by wound healing assay, Transwell assay, microfilament green fluorescent staining, RT-qPCR, cell necrosis, apoptosis and relative telomere length detection after treated with Cur. 【Result】 Compared with the P3 group, the wound healing rate and the number of cells migrated to the surface of the Transwell chamber decreased with the increase of passage times in P6-cBMSCs (P<0.01). Rounded cells, decreased stress fibers and of migration-related genes (MMP-2 and MMP-9) mRNA expression were found in P6-cBMSCs as compared with the P3 group. The migration ability of P6-cBMSCs was promoted after treated with Cur. In addition, enhanced cell spreading area and the degree of stretching, increased stress fibers, the upregulation of migration-related genes (MMP-2 and CXCL8) mRNA expression, maintained viability, delayed apoptosis and necrosis and shortened cell relative telomere length were observed after treated with Cur. 【Conclusion】 Cur can enhance the migration capacity of cBMSCs and 1 μmol/L was optimum.
    Effects of Several Factors on inVitro Hatchability of Fertilized Eggs of Cherax quadricarinatus
    SUN Lihui, LI Qian, CHEN Jianming, JIANG Jianhu, GAO Lingmei, GUO Jianlin
    2022, 40(4):  543-549.  doi:10.16036/j.issn.1000-2650.202202098
    Abstract ( 316 )   PDF (23545KB) ( 83 )   Save
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    【Objective】 This study was conducted to optimize the hatching conditions of Australian freshwater crayfish. 【Method】 Four single factor experiments were conducted to investigate the effects of water temperature, waterflow, development period and hatching density on in vitro hatching rate of fertilized eggs of Australian freshwater crayfish. 【Result】 The results showed that the incubation time decreased with the increase of water temperature, the highest in vitro hatching rate was observed at 28 ℃(P<0.05), the hatchability of fertilized eggs was significantly higher at 26 ℃ and 30 ℃ than that at 24 ℃ and 32 ℃(P<0.05), the accumulative temperature was 9 375 ℃·h. The in vitro hatching rate of fertilized eggs under different waterflow was 5 L/min>2 L/min>8 L/min (P<0.05); The hatching rate of fertilized eggs in the embryo with eye pigments and prepare-hatchling stage was significantly higher than that in the egg-nauplius stage (P<0.05); The hatching rate of fertilized eggs was significantly higher at density 500 eggs/L and 1 000 eggs/L than that at density 1 500 eggs/L(P<0.05), however, there was no significant difference in in vitro hatchability between 500 eggs/L and 1 000 eggs/L(P>0.05). 【Conclusion】 In summary, the fertilized eggs of Australian freshwater crayfish were stripped in the embryo with eye pigments, at the density 1 000 eggs/L, at water temperature 28 ℃ and waterflow 5 L/min could obtain a higher hatching rate.
    Crop Nutrition
    Study on the Effect of Nitrogen Fertilizer Application on Maize Yield in North China Based on Meta-Analysis
    ZHANG Lingchun, ZHANG Xinyue, GAO Qiang, YAN Li
    2022, 40(4):  550-557.  doi:10.16036/j.issn.1000-2650.202202084
    Abstract ( 221 )   PDF (1108KB) ( 157 )   Save
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    【Objective】This research is to quantitative analyze the effects of different field management measures on maize yield under nitrogen application conditions in North China, so as to clarify the effects of nitrogen application under different conditions on maize yield, and provide data reference for optimizing the comprehensive management measures of maize in North China and exerting the effect of nitrogen fertilizer on yield.【Method】In this study, the meta-analysis method was used to search and screen the published literatures about the effect of nitrogen fertilizer application on maize yield in Chinese and English databases. The database included 62 studies and 583 pairs of experimental data are to be analyzed.【Result】The results showed that nitrogen application had a significant effect on maize yield (P<0.001; lnR++=0.331 6), and the average yield increase reached 39.32%. The most important factor affecting nitrogen fertilizer effect in North China was nitrogen application rate, followed by cropping system, nitrogen fertilizer type and irrigation method. If the basic fertility of the soil is high, the input of nitrogen fertilizer should be reduced; The yield-increasing effect reached the maximum when the mean nitrogen application was around 161 kg N/hm2 in North China. Adopting a crop rotation system could significantly improve the yield-increasing effect, among, which the cotton-wheat-maize rotation had the highest increasing effect reaching 82.74%, which was 56.77% higher than that of maize continuous cropping; the combined application of organic fertilizer and inorganic fertilizer can increase the yield by 79.48%, the mean yield-increasing under drip irrigation reached 42.90%, which was 18.8% higher than that under traditional irrigation.【Conclusion】Nitrogen application rate and cropping systems were important explanatory variables for the effect of nitrogen application on maize yield. In order to realize the high yield and high efficiency of maize modern agricultural in North China, we should consider the soil fertility conditions comprehensively, and adopt a reasonable nitrogen rate, crop rotation system, organic fertilizer return and drip irrigation mode.
    Effects of Nitrogen Application Rate on Nitrogen Use Efficiency and Apparent Nitrogen Balance of Direct Seeding Rapeseed in Chengdu Plain of Sichuan Province
    ZHANG Fangfang, HU Yue, LIU Shishan, YANG Yunfei, YAN Hongmei, WU Yongcheng
    2022, 40(4):  558-564.  doi:10.16036/j.issn.1000-2650.202108081
    Abstract ( 165 )   PDF (577KB) ( 181 )   Save
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    【Objective】 This study was conducted to explore a reasonable nitrogen (N) application rates for high yield and high use efficiency of nitrogen fertilizer of direct seeding rapeseed in Chengdu plain of Sichuan province. 【Method】 Field experiment, consisting of five different N application rates (0, 135, 180, 225, 270 kg N/hm2) was conducted on Xigao town, Guanghan county of Sichuan province for two consecutive years (2015—2017). The content of soil inorganic N of 0-20 cm topsoil, seed yield and plant N absorption were determined at the maturity stage of rapeseed to analyze the effects of N application rates on yield, N use efficiency and apparent N balance of direct seeding rapeseed. 【Result】 Compared with N0 treatment, plant height, branch position, number of primary branches, number of pods per plant and grain yield of adding N fertilizer treatment were improved significantly in rapeseed. However, there was no significant difference in plant height, branching position and grain yield among four fertilizer treatments (135, 180, 225, 270 kg N/hm2). N agronomic efficiency and N partial productivity decreased with the increase in N application, and there were significant differences among different treatments. Under the N application rates(135-180 kg N/hm2) , there was low apparent N loss, low N surplus and little difference between total amount of N output and total amount of N input, with the N surplus was mainly soil inorganic N residues. The apparent N loss and N surplus in the second year were higher than that in the first year under the same N application treatment due to accumulative effect. There was a trend of first increase and then decrease in N apparent efficiency and N apparent residual rate with the increase of N application rates. Overall, the apparent N losses decreased with the increase of N rates. 【Conclusion】 Considering the rapeseed yield, efficient utilization of N fertilizer, and apparent balance of farmland N, the reasonable N application rate of direct seeding rapeseed was 180 kg N/hm2 in Chengdu plain of Sichuan pProvince.
    Effect of Foliar Application of Potassium Dihydrogen Phosphate and Ethephon on the Synchronous Maturation and Quality of Upper Leaves of Flue-Cures Tobacco
    ZENG Shuhua, WU Runsheng, GUO Shiping, XIA Chun, LIU Lei, LEI Xiao, CHEN Xiangjun, ZHANG Yonghui, LIU Yajie
    2022, 40(4):  565-573.  doi:10.16036/j.issn.1000-2650.202111048
    Abstract ( 1009 )   PDF (6434KB) ( 122 )   Save
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    【Objective】 This study aims to study the effects of the concentration and spraying time of potassium dihydrogen phosphate and ethephon on the synchronous maturity and quality of upper tobacco leaves. 【Method】 The Box-Behnken method of the response surface optimization design was used to carry out the experimental design, intending to investigate three factors and three levels of spraying concentration of potassium dihydrogen phosphate (0、3.4、6.8 g/L), ethephon (0、0.05、0.1 g/L) and spraying time (20、25、30 days after topping). A total of 16 spray treatments and the indexes related to the mature state of tobacco leaves from top to bottom 1-3 pieces and top 4-6 pieces were measured. The appearance quality and chemical composition of flue-cured tobacco were also evaluated. 【Result】 Spraying potassium dihydrogen phosphate and ethephon could promote the synchronous maturity of the upper tobacco leaves, and the effect of treatment T2 (20 days after topping, combined with spraying 3.4 g/L potassium dihydrogen phosphate and 0.1 g/L ethephon) was the best. The appearance quality score increased by 0.45-7.7 points compared with control, the Comprehensive evaluation score of flue-cured tobacco was 0.82-6.33 points higher than control, and the score of T2 was the highest (79.60). It can be predicted that when the spraying time is 20 days after topping, the concentration of potassium dihydrogen phosphate is 3.808 g/L and the concentration of ethephon is 0.081 g/L, the synchronous maturity of upper tobacco leaves is the best and the quality of flue-cured tobacco leaves is the best. 【Conclusion】 Synchronous maturity of upper tobacco leaves was advanced and tobacco quality was enhanced by spraying appropriate concentration of potassium dihydrogen phosphate and ethephon at 20 days after topping.
    Biology and the Environment·Food Engineering
    Characterization of Complete Chloroplast Genome and Phylogenetic Analysis of Camellia trichosperma Chang
    ZHENG Qian, TONG Yihan, KONG Qingbo, FENG Shiling, ZHOU Lijun, DING Chunbang, CHEN Tao
    2022, 40(4):  574-582.  doi:10.16036/j.issn.1000-2650.202202074
    Abstract ( 159 )   PDF (10656KB) ( 351 )   Save
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    【Objective】 This paper is to identify the taxonomic status of Camellia trichosperma by analyzing sequence characteristics of the chloroplast genome and constructing phylogenetic tree. 【Method】 The chloroplast genome of Camellia trichosperma was sequenced, assembled, annotated; sequence feature analyed and phylogenetic tree constructed by high-throughput sequencing technology. 【Result】 Camellia trichosperma chloroplast genome length was 156 605 bp, with typical tetrad structure, and its GC content in IR region was the highest (40.5%). 87 protein-coding genes, 36 tRNA genes and 8 rRNA genes were predicted by annotation. Simple repeat sequence (SSR) analysis showed that the chloroplast genome contained 68 SSR loci, in which the number of mononucleotide, dinucleotide, trinucleotide, tetranucleotide and hexanucleotide were 48, 4, 1, 3 and 12, respectively. Codon bias analysis showed that leucine codon utilization rate was the highest and tryptophan was the lowest. 【Conclusion】 Phylogenetic analysis showed that Sect. Camellia was closely related to C. japonica and C. Chekiangoleosa. However, it was relatively distantly related to C. reticulata and C. semiserrata in the same group.
    Changes Surrounding Soil Nutrients of Salix psammophila Sand Barriers in Different Setting Years
    ZHAO Chen, GAO Yong, DANG Xiaohong, WANG Ruidong, YANG Xiaojie, WANG Hao
    2022, 40(4):  583-590.  doi:10.16036/j.issn.1000-2650.202111083
    Abstract ( 154 )   PDF (2136KB) ( 164 )   Save
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    【Objective】 This study aims to explore the effects of increasing the years of Salix psammophila sand barriers soil carbon (C), nitrogen (N), phosphorus (P) content and ecological stoichiometric ratio of surrounding soil. 【Method】 Taking Salix psammophila sand barriers setting for 1-7 laid on either side of highway in Kubuqi Desert as the research object, the variation of soil C, N, P and ecological stoichiometric ratio characteristics of surrounding soil with setting years were analyzed. 【Result】 ①There were significant differences in soil nutrient contents between 1-7 years' Salix psammophila barrier (P<0.05), soil pH was weakly alkaline and soil water content decreased year by year with the barrier year. ②Significant differences were detected in SOC (soil organic matter) and TN (total nitrogen) (P<0.05), SOC, TN and TP (total phosphorus) were all moderately variable. ③SOC and TN were significantly or extremely significantly correlated with C∶N and C∶P, which indicated that SOC and TN were the main factors affecting ecological stoichiometric ratio of Salix psammophila sand barriers soil. 【Conclusion】 The Salix psammophila sand barriers setting for three and five years are important turning point of nutrient change, thus suggested to pay more attention to the maintenance during these periods to prevent nutrient flow caused by sand barriers damage.
    Ant Community and Distribution Pattern of Terraced Field Forest Ecosystem in Yuanyang, Yunnan Province
    YANG Rui, HE Qiuju, XU Zhenghui, WU Binian, DU Hong, ZHANG Xinmin
    2022, 40(4):  591-600.  doi:10.16036/j.issn.1000-2650.202111088
    Abstract ( 266 )   PDF (672KB) ( 226 )   Save
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    【Objective】 This paper aims to reveal the relationship between ant species diversity and environmental factors in terraced field forest ecosystem. 【Method】 Ant community and distribution pattern of Yuanyang terraced field forest ecosystem were investigated by adopting plot-sampling method. 【Result】 A total of 101 species belonging to 47 genera and 10 subfamilies of Formicidae were recorded, including three new record species in China: Kartidris matertera Bolton, Pheidole planifrons Santschi and Pseudolasius zamrood Akbar et al. Technomyrmex albipes (Smith), Tapinoma melanocephalum (Fabricius) and Carebara affinis (Jerdon) are the dominant species of the ant community. The main indices of ant community showed multiple peaks with the increase of altitude, which mainly affected by air temperature and human disturbance. Species composition of communities at different altitude was significantly different. Most ant species have narrow vertical distribution range, limited habitats, foraging places and nesting sites, and show fragility in the environment. 【Conclusion】 It is concluded that the terraced field forest ecosystem in Yuanyang plays an important role in maintaining ant species diversity. Ant communities at different altitudes have differential ecological functions and protection values. Affected by human disturbance, the stability of ant communities at some altitudes is reduced, most ant species have limited habitats and show fragility. It is necessary to strengthen the protection of forest vegetation so as to maintain the vitality of forest-terraced field ecosystem and its biodiversity.
    Effect of Land Use on Water Environment Quality in Urban Wetland Park
    LI Nian, JIANG Tao, CHEN Qibing
    2022, 40(4):  601-609.  doi:10.16036/j.issn.1000-2650.202207099
    Abstract ( 211 )   PDF (14115KB) ( 83 )   Save
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    【Objective】 This study aims to analysis the effect of urban wetland park land uses on water environment quality to provide reference and basis for the land use planning and optimizing of urban wetland parks and parks with large water bodies. 【Method】 Based on GIS spatial analysis technology, this study calculated the land uses of wetland park and the corresponding landscape development index representing the land use intensity. The Pearson correlation analysis is used to explore the impact of land use on water environment. 【Result】 ① The road area has positive influence on the COD index of water environment. ② Woodland has a great influence on the DO value and has a certain buffer and purification effect on water quality. ③ The buffer radius has a positive correlation with the land development intensity. Land development intensity within a certain range has positive effect to the water environment quality. 【Conclusion】 To build a buffer radius at any point at the edge of the water body,when the buffer radius is between 164.8 and 244.8 m, the use of the land (LDIindex) is controled between 3 and 4.2 will be the most advantageous to the water environment in the wetland park.
    Theoretical Calculation and Experimental Study on Suspension Velocity of Walnut and Its Main Components after Mechanical Shell Cracking
    ZHU Zhanjiang, KANG Min, LIU Kui, MA Wenqiang, SHEN Xiaohe
    2022, 40(4):  610-618.  doi:10.16036/j.issn.1000-2650.202107030
    Abstract ( 184 )   PDF (4426KB) ( 151 )   Save
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    【Objective】 In order to provide a basis for the design of walnut cleaning device and walnut shell-kernel air separation device,the suspension velocity of walnut and its main components shell,kernel and distractor after mechanical shell cracking was studied. 【Method】 The basic physical parameters of each component after mechanical cracking of walnut shell were measured,and the suspension velocity was calculated by selecting the appropriate deformation coefficient according to the material geometry.The single particle suspension velocity, particle group suspension velocity and separation wind speed of each material were measured by the material suspension velocity test bench. 【Result】 The suspension velocity of each material was distributed in a certain range,and the suspension velocity ranges of original walnut and hollow walnut were 17.37-21.15,11.65-13.73 m/s respectively;The suspension speed ranges of 1/2,1/4,1/8 and 1/16 grades of walnut kernel were 11.71-13.16,11.51-12.72,10.68-11.97 and 9.21-11.11 m/s respectively,and the suspension speed ranges of four grades of walnut shell were 6.33-9.33,6.36-8.29,5.50-7.64 and 5.19-6.85 m/s respectively,and the suspension speed range of distractor was 1.76-4.55 m/s. 【Conclusion】 Theoretical calculation and experiment could be used as important methods to obtain the suspension velocity of walnut materials. From the suspension velocity data obtained,walnut materials were suitable for pneumatic separation, and the separation difficulty of different grades of shell and kernel was different. The suspension velocity of particle group was positively correlated with the number of particles,which was a cubic fitting function;The separation wind speed of each material was 1.1-1.2 times of the average suspension speed of hollow walnut or walnut shell of corresponding light material.
    Agricultural Economy
    Measurement and Evolution Characteristics of Agricultural Total Factor Productivity in China: Based on the Empirical Evidence of 283 Prefecture Level Cities in China
    DU Lei, TIAN Minghua, MA Shuang, WANG Fang, LIU Dan
    2022, 40(4):  619-624.  doi:10.16036/j.issn.1000-2650.202202091
    Abstract ( 235 )   PDF (1033KB) ( 138 )   Save
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    【Objective】 This study aims to China's agricultural total factor productivity and its growth source to provide a scientific basis for improving China's agricultural total factor productivity and promoting high-quality agricultural development. 【Method】 Based on the panel data of 283 prefecture-level cities in China from 2001 to 2018, the total factor productivity of agriculture was measured and decomposed by the Metafrontier-Malmquist index. 【Result】 ①From 2001 to 2018, China's agricultural total factor productivity was 6.60%, and its growth was mainly driven by agricultural technological progress. The contribution of agricultural technological efficiency was small. The growth law showed an "inverted U-shaped" growth trend of first rising and then falling.②The agricultural total factor productivity of priority development areas, moderate development areas, and protected development areas are 6.00%, 8.70% and 10.01%, respectively. ③The prefecture-level cities in the priority development area have high agricultural technology efficiency, and the prefecture-level cities in the moderate development area have rapid agricultural technology progress. 【Conclusion】 Improving the efficiency of agricultural technology, promoting the coordinated development of regional agriculture, and improving the quality of agricultural growth are found to be the effective ways to improve China's agricultural total factor productivity.
    Research on Social Network , Risk Preference and Adoption Behavior of Water-Saving and Drought-Resistant Rice Technology: Empirical Analysis Based on Heckman’s Sample Selection Model
    MAO Xiangdong, CHEN Peizhe, ZHANG Lixia
    2022, 40(4):  625-632.  doi:10.16036/j.issn.1000-2650.202106062
    Abstract ( 182 )   PDF (729KB) ( 135 )   Save
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    【Objective】 This study was conducted to explore the factors affecting farmers' decision and adoption time of water-saving and drought-resistant rice technology, and to provide reference for the publicity and promotion of water-saving and drought-resistant rice technology. 【Method】 Based on the perspective of social network and risk preference, Heckman sample selection model was used as the research method of this study to empirically analyze the impact of social network and risk preference on farmers' adoption decision and adoption time of water-saving and drought-resistant rice technology. 【Result】 ①Social network and risk preference had significant effects on the decision and adoption time of water-saving and drought-resistant rice technology, in which social network was positive and risk preference was negative.②Among the four dimensions of social network, three dimensions of network trust, network learning and network interaction had a significant positive impact on farmers' decision making and adoption time of water-saving and drought-resistant rice technology, while network reciprocity had no significant positive impact.③Farmers' decision and adoption time of water-saving and drought-resistant rice technology were also affected by risk preference type, participation in technology training, technology publicity intensity and technology knowledge. 【Conclusion】 Attention should be paid to the construction and cultivation of farmers’ social network to reduce the risk perception of risk-averse farmers on the adoption of water-saving and drought-resistant rice technology, promote their acceptance of water-saving and drought-resistant rice technology, and improve the adoption rate and adoption time of water-saving and drought-resistant rice technology.