Loading...

Table of Content

    01 January 2021, Volume 54 Issue 1
    CROP GENETICS & BREEDING·GERMPLASM RESOURCES·MOLECULAR GENETICS
    Relationship Between Phytohormones and Male Sterility of BNS and BNS366 in Wheat
    LIU HaiYing,FENG BiDe,RU ZhenGang,CHEN XiangDong,HUANG PeiXin,XING ChenTao,PAN YinYin,ZHEN JunQi
    Scientia Agricultura Sinica. 2021, 54(1):  1-18.  doi:10.3864/j.issn.0578-1752.2021.01.001
    Abstract ( 648 )   HTML ( 77 )   PDF (803KB) ( 361 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】 In order to provide more information about pollen fertility regulation in thermo-photo-sensitive genic male sterile (TGMS) wheat BNS and BNS366, the relationship between male sterility and the changes of endogenous hormones during microsporogenesis was analyzed.【Method】BNS and BNS366 were used as experimental materials, and Aikang58 and Zhengmai366 (Near-isogenic line of BNS366) were used as controls, respectively. Four different types of wheats were sowed at October 10th (normal sowing) and December 2nd (late sowing). I2-KI method was used to measure the frequency of fertile pollen grains. National and international methods were used to determine self-seeds rate. Indirect enzyme-linked immunosorbent assays (ELISA) method was used to detect 6 kinds of endogenous hormone contents in leaves from the pistil and stamen differentiation stage to the trinuclear stage, young panicles from the pistil and stamen differentiation stage to the tetrad stage and anthers from the uninucleate stage with small-vacuole to the trinuclear stage.【Result】Under normal sowing conditions, the frequency of fertile pollen grains, the national and international rate of self-seeds in both BNS and BNS366 wheats were zero that were completely male sterility, while under late sowing conditions, the three indexes were 34.74%, 43.12% and 48.48% in BNS that was partial male sterility, as well as 92.63%, 55.37 % and 67.94% in BNS366 that was normal fertility. However, the three indexes in Aikang58 and Zhengmai366 wheats under normal and late sowing conditions were 82.56%-94.00%, 73.90%-82.31% and 96.54%-139.26%, respectively, that were normal fertility and no significant difference were found between the two sowing conditions. Moreover, the increased frequency of fertile pollen grains-∆ [(frequency under normal conditions-frequency under late sowing conditions)×100%/ frequency under late sowing conditions] in BNS and BNS366 were lower than those in Aikang58 and Zhengmai366. Multiple comparisons of the hormone’s levels were carried out in the two experiment groups, respectively. We found that the increased hormones levels [(hormones levels under normal conditions - hormones levels under late sowing conditions)×100%/hormones levels under late sowing conditions] differed in all four different varieties. The correlation analytic method was carried on the statistical analysis to the endogenous hormone content and the frequency of fertile pollen grains, and to the endogenous hormone content-∆ and the frequency of fertile pollen grains-∆. For both of BNS and BNS366, there were common characters in dynamic changes of endogenous hormone contents during developmental stages of wheat young panicles in sterile lines. The IAA (indole-3-acetic acid) contents were insufficient in the leaves of the tetrad (BNS) and the pistil primordia differentiation stage (BNS366), and insufficient in the anthers of the uninucleate stage with small-vacuole (BNS) and the uninucleate stage with big-vacuole (BNS366), too, but sufficient in the anthers of the binucleate stage. The gibberellic acid (GA) contents were insufficient in young panicles of the tetrad stage and in anthers of the uninucleate stage with small-vacuole. There were no differences of the zeatin riboside (ZR) contents among the materials. The abscisic acid (ABA) contents tilted towards short supply (BNS) and that was inadequate really (BNS366) in young panicles of the tetrad stage. There were also no differences among the materials in the brassinosteroid (BR) contents. The methyl jasmonate (MeJA) contents were generally insufficient in leaves of the pistil and stamen differentiation stage, the tetrad stage, the uninucleate stage with small-vacuole or the uninucleate stage with big-vacuole, and the trinucleate stage, and in young panicles at the pistil and stamen differentiation stage (BNS) or at the tetrad stage (BNS366), respectively, and in anthers at the uninucleate stage with big-vacuole.【Conclusion】Under normal sowing conditions,the lack of IAA, GA, ABA, especially MeJA before the uninucleate stage with big-vacuole in BNS and BNS366 might promote the occurrence of male-sterility.

    Chilling Tolerance Identification and Response to Cold Stress of Gossypium hirsutum Varieties (Lines) During Germination Stage
    ZHANG LongYan,CHENG GongMin,WEI HengLing,WANG HanTao,LU JianHua,MA ZhiYing,YU ShuXun
    Scientia Agricultura Sinica. 2021, 54(1):  19-33.  doi:10.3864/j.issn.0578-1752.2021.01.002
    Abstract ( 574 )   HTML ( 74 )   PDF (2038KB) ( 454 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】In this study, the purpose was to study the response of cotton seeds to chilling stress, and to identify the chilling tolerance of different test varieties during the germination period in Gossypium hirsutum. We were also committed to analyzing the cold-tolerance characteristics of tolerant and sensitive varieties at the physiological levels, and to provide a reference for further research on the molecular mechanism of cold tolerance during the germination period. 【Method】Fifty-three upland cotton varieties were used to determine the imbibition rate and relative imbibition rate under chilling stress. In addition, we also measured the cold tolerance indexes such as germination index, vigor index, mean germination time, average germination speed, germination potential, germination rate, seed germination coefficient, radicle fresh weigh, radicle dry weight, embryo fresh weight, embryo dry weight, productive efficiency and material growth rate under chilling stress. We used correlation analysis, principal component analysis, membership function analysis and cluster analysis to comprehensively evaluate the 15 morphological indexes in the imbibition and germination stage. We also measured the changes in antioxidant enzyme activities, osmotic adjustment substance concentration and the expression of antioxidant enzyme genes between different cold-tolerant varieties under chilling stress. 【Result】Under chilling stress, the relative water absorption and water absorption rate of cotton seeds showed a downward trend, and the cold tolerance indexes of 53 cotton varieties showed significant differences. There was a strong correlation between imbibition rate and relative imbibition rate during the imbibition stage, and their correlations with other germination indicators were not significant or negatively correlated. In addition, the correlation analysis also found that indicators such as radicle fresh or dry weigh, vigor index, average germination speed and mean germination time could better reflect the cold tolerance of different varieties. Principal component analysis showed that three principal components could be obtained through simplification, with contribution rates of 55.17%, 18.27% and 8.79%, respectively. The results of membership function and clustering analysis showed that the 53 varieties could be divided into four categories according to comprehensive evaluation value: high tolerant (5 varieties), tolerant (13 varieties), null-tolerant (26 varieties) and sensitive (9 varieties), of which Xinluzhong4 and Zhong103026 are the most resistant and sensitive variety to cold stress, respectively. After chilling treatment, the activity of SOD, POD and CAT in the seeds of Xinluzhong4 could be restored to the level close to or exceeding the control in a short time, the soluble protein concentration in Xinluzhong4 was significantly higher than that in Zhong103026. Gene expression analysis showed that the expression of GhPrx53 and GhCSD1 tended to be consistent with the changes of POD and SOD enzyme activity, respectively. 【Conclusion】The identification indexes of cold tolerance in upland cotton at the germination stage are diversified. The radicle fresh weight, radicle dry weight and vigor index can be used as positive indicators for cold tolerance, while the mean germination time and average germination speed can be used as negative indicator for cold tolerance during the germination period. Soluble protein concentration and the enzyme activities of POD, SOD and CAT can be used as physiological indicators for cold tolerance identification during cotton germination.

    Analysis on the Characteristics of Soluble Sugar Components in Sweetpotato Storage Root and Its Relationship with Taste
    SHEN ShengFa,XIANG Chao,WU LieHong,LI Bing,LUO ZhiGao
    Scientia Agricultura Sinica. 2021, 54(1):  34-45.  doi:10.3864/j.issn.0578-1752.2021.01.003
    Abstract ( 495 )   HTML ( 52 )   PDF (479KB) ( 353 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】The soluble sugar content in sweetpotato storage root is an important indicator of edible quality and processing performance. The study on the characteristics of soluble sugar components and their relationship with edible quality can help to understand the changes of soluble sugar components and their influence on taste during processing, providing a basis for the selection of varieties for table use and processing, and breeding and utilization of germplasm resources for special use. 【Method】 The content of soluble sugar components in raw and steamed storage roots of 102 sweetpotato germplasm were determined by high performance liquid chromatography with evaporative light scattering detector (HPLC-ELSD). The characteristics were analyzed according to dry matter content types, and correlation and stepwise linear regression were used to analyze the relationship between soluble sugar components and taste and their contribution to edible quality. 【Result】 There were four soluble sugars of fructose, glucose, sucrose and maltose in both raw and steamed storage roots. In the raw storage root, the sucrose content was the highest, with an average content of 25.79 mg·(g·FW)- 1, accounting for 45.31% of the soluble sugar. The fructose and glucose content were similar and closely related, and the fitting equation for fructose content (y) and glucose content (x) was y = 0.807x + 1.275. The maltose content was the lowest, with an average content of 6.79 mg·(g·FW)-1, which only accounts for 11.92% of the soluble sugar. The content of soluble sugar in raw storage root mainly depended on the fructose and glucose content. Generally, the varieties with low dry matter content had higher content of soluble sugar and fructose in raw storage root, and the biochemical sweetness was better. During the process of steaming, the changes of soluble sugar content were mainly due to the production of a large number of maltose, which increased from 0.96-24.67 mg·(g·FW)-1 of raw root to 14.80-136.16 mg·(g·FW)-1. The content of soluble sugar in steamed storage root was determined by the maltose content, and the variety types with medium or high dry matter content had higher content of soluble sugar and maltose. The improvement of taste quality mainly attributed to the increasing soluble sugar content during the process of steaming. Maltose, fructose and sucrose were the important factors affecting the taste quality, and maltose contributed nearly 50% to the increase of taste quality, particularly to the flavor and texture. Fructose content contributed the most to the viscosity while sucrose contributed more to the texture than fructose. 【Conclusion】 The content of soluble sugar and fructose in raw storage root was an important indicator to evaluate the sweetness of raw sweetpotato. The content of soluble sugar and maltose in steamed storage root was an important indicator to evaluate the edible quality of sweetpotato. Maltose, fructose and sucrose were the important soluble sugar components that determined the edible quality and processing performance of sweetpotato. In this study, 11 sweetpotato germplasm with specific soluble sugar in storage root was selected.

    TILLAGE & CULTIVATION·PHYSIOLOGY & BIOCHEMISTRY·AGRICULTURE INFORMATION TECHNOLOGY
    Relationship Between Growth and Development Characteristics and Yield Formation of Summer Maize Varieties Differing in Maturities
    ZHAO JiYu,REN BaiZhao,ZHAO Bin,LIU Peng,ZHANG JiWang
    Scientia Agricultura Sinica. 2021, 54(1):  46-57.  doi:10.3864/j.issn.0578-1752.2021.01.004
    Abstract ( 736 )   HTML ( 62 )   PDF (659KB) ( 649 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】 This study was expected to explore the relationship between growth and development characteristics and yield formation of summer maize varieties differing in maturities, providing theoretical references for the selection of new maize varieties with early maturity, high yield and adaptability to grain mechanical harvesting. 【Method】 In 2017, the early maturity hybrids Denghai 518 (DH518), Hengzao 8 (HZ8) and the mid-late maturity hybrids Denghai 605 (DH605) and Zhengdan 958 (ZD958) were used as test materials. In 2018, the early maturity hybrids Denghai 518 (DH518), Jingnongke 728 (JNK728), and the mid-late maturity hybrids Denghai 605 (DH605) and Zhengdan 958 (ZD958) were used as test materials. The planting density was 75 000 plants/hm2. The leaf establishment law, ear development characteristics, and the difference in solar radiation and accumulated temperature requirements at different growth stages were analyzed. 【Result】 The solar radiation and accumulated temperature requirements of different maize varieties at various growth stages were: R1-R6>VE-R1>sowing-VE. The demand for accumulated temperature of different varieties after flowering was higher than that before flowering. The difference in demand for accumulated temperature of mid-late maturity hybrids and early-maturing varieties was mainly in V6-R1, which was specifically manifested in the 9-16th leaf establishment period; There was no significant difference in the demand for accumulated temperature after flowering. Correlation analysis showed that the yield of summer maize varieties at different maturity stages had extremely significant positive correlations with spike height and spike height coefficient. The development characteristics of tassel in summer maize cultivars at different maturity stages were different. The length of tassel in late-maturing cultivars was significantly lower than in early-maturing cultivars, but the number of tassel branches, total tassel spikelet, spikelet abortion rate and effective spikelet of late-maturing varieties were significantly higher than those of early-maturing varieties; The differentiation of female ears to grains was greatly affected by the genotype of the variety. 【Conclusion】The growth and development characteristics of summer maize varieties differing in maturities were significantly different, and the yield of the mid-late maturity hybrids was significantly higher than that of the early maturity hybrids. The typical characteristics of early-grain mechanical harvesting corn varieties were fewer total leaves, shorter V6-R1 time and faster dehydration rate.

    Effects of Elevated Temperature and CO2 on the Photosynthetic Characteristics of Intercropping Maize
    WANG Fei,SUN ZengGuang,YIN Fei,GUO BinBin,LIU Ling,JIAO NianYuan
    Scientia Agricultura Sinica. 2021, 54(1):  58-70.  doi:10.3864/j.issn.0578-1752.2021.01.005
    Abstract ( 413 )   HTML ( 42 )   PDF (657KB) ( 394 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】The aim of this study was to clarify effects of elevated temperature and CO2 concentration on the photosynthetic characteristics of maize under intercropping with peanut, so as to provide the theoretical basis for the green high-yield and high-efficient cultivation of maize intercropping peanut (maize||peanut) under the condition of climate change in the future.【Method】In this study, maize intercropping peanut 2﹕4 pattern was taken as the research object. In 2018, ambient temperature ambient CO2 concentration (TC) and elevated temperature and CO2 (+T+C) were set up in the experiment, and elevated temperature ambient CO2(+TC) was added in 2019 to conduct the experiment, under two phosphorus levels of P0 (0) and P180 (180 kg P2O5·hm-2), respectively. The effects of elevated temperature and CO2 on photosynthetic pigment content, SPAD value, and photosynthetic response curves to light intensity and CO2 concentration and the related parameters of intercropped maize were studied.【Result】 (1) Compared with TC, +TC increased the content of chlorophyll b and chlorophyll a+b of intercropping maize at 34 days after seedlings, while this treatment reduced the chlorophyll a/b value. Under the condition of phosphorus application at 55 days after seedling, SPAD value, AQY, CE, Amax, Vc,max, Jmax, and TPU of maize were increased by 7.80%, 18.18%, 18.86%, 13.34%, 13.33%, and 20.14%, respectively, and maize grain yield increased by 19.2% to 28.1%. Compared with +TC, +T+C improved the AQY, but reduced LCP of intercropping maize at 55 and 65 days after seedling; The CE, Amax, Vc,max, Jmax, and TPU of intercropping maize were increased by 13.58%-32.96%, 21.31%-11.61%, 9.35%-14.5%, 9.52%-15.13% and 8.82%-26.16% at 55 days after seedling, respectively; The yield were increased by 5.25%-18.70%. All reached significant difference levels (P<0.05). (2) Compared with TC, +T+C increased the SPAD value of intercropping maize at big bell mouth and filling stages, which were increased by 4.68%-12.91% and 7.88%-18.37%, respectively, while decreased by 8.63%-12.72% at dough stage; chlorophyll a, b, and a+b of intercropping maize increased by 17.58%-19.54%, 52.55%-59.55%, and 26.08%-28.47%, respectively, at 35 days after seedlings; chlorophyll a/b were decreased by 23.04%-25.18%; AQY and LSPn were increased by 30.30%-75.76% and 16.87%-19.44%, respectively, at 55 days after seedlings; CE, Amax, Vc,max, Jmax and TPU increased by 15.72%-36.78%, 24.91%-32.66%, 20.77%-29.83%, 20.93%-30.48%, and 27.16%-30.74%, respectively; The yield increased by 7.24%-52.0%. All reached significant difference levels. (3) Compared with no phosphorus application, phosphorus application increased the content of chlorophyll b of intercropping maize under TC, +TC and +T+C by 24.15%, 18.64% and 22.04%, respectively, at 85 days after seedling; LSPn was increased by 13.30%, 17.0% and 9.86%, respectively, at 34 days after seedling; and the yield was increased by 24.2%-67.2%, 55.6% and 27.8%-38.0%, respectively. All reached significant difference levels. 【Conclusion】 Elevated temperature or elevated temperature and CO2 could increase chlorophyll content and net photosynthetic rate of intercropping maize at early growth stage, showing a positive synergy, while elevated CO2 could alleviate the negative effects of elevated temperature at the middle and late growth stage. Elevated temperature and CO2 could increase the yield of intercropping maize, the key lies in the improvement of chlorophyll content, carboxylation efficiency, maximum electron transfer rate and triose phosphate utilization rate at the early and middle growth stage. The supply of phosphorus had an obvious positive effect.

    PLANT PROTECTION
    Identification of Major Pathogenic Fungi of Soybean in Hebei Province and Screening of Control Fungicides
    BI QiuYan,DANG ZhiHong,ZHU WeiQi,GAO ZhanLin,HAN XiuYing,ZHAO JianJiang,WANG WenQiao,LU Fen,WU Jie
    Scientia Agricultura Sinica. 2021, 54(1):  71-85.  doi:10.3864/j.issn.0578-1752.2021.01.006
    Abstract ( 529 )   HTML ( 57 )   PDF (3153KB) ( 390 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】The objective of this study is to identify the fungal pathogens causing the main diseases of soybean plants in Hebei Province, screen the fungicides which can effectively inhibit the identified pathogens, and to provide a basis for chemical control of soybean disease in Hebei Province.【Method】The main pathogens of soybean collected from Hebei Province were isolated and purified according to the disease symptom. The morphology of colony, mycelium and spore was observed and identified by using 3D ultra depth of field digital microscope and Olympus Microscope. The rDNA-ITS regions of five pathogenic strains were amplified by PCR and sequenced by universal primers ITS1-ITS4. Neighbor-joining method of software MEGA 7.0 was used to construct phylogenetic trees and analyze the relationship among different pathogens. The pathogens with specific primer sequences were identified and verified. The main pathogen kinds of soybean plants in Hebei Province were identified by the combination of macromorphology, microscopic characteristics and molecular biology techniques. The method of mycelium growth rate and the control effects of different fungicides on the major diseases in vitro leaves or young stems of soybean were used to screen the fungicides.【Result】Based on the analysis of macromorphology, microstructure and sequence, the pathogens isolated from the main soybean producing areas in Hebei Province were Fusarium equiseti, Colletotrichum chlorophyti, Phoma herbarum, Alternaria alternata and Exserohilum rostratum. The corresponding diseases were soybean root rot, anthracnose, leaf spot of P. herbarum, black spot and leaf spot of E. rostratum. The results of virulence test showed that the above pathogens were all sensitive to the triazole fungicides, such as difenoconazole, triflumizole, metconazole and Qoi fungicide pyraclostrobin. F. equiseti was sensitive to Qoi fungicide trifloxystrobin, the pathogens except F. equiseti were sensitive to amide succinate dehydrogenase inhibitors fluopyram, C. chlorophyti and E. rostratum were sensitive to alkyl polyamines fungicide xinjunan, C. chlorophyti was sensitive to organic sulfur bionic fungicide ethylicin, the EC50 values of the inhibitors were less than 10 μg·mL -1. The control results of different fungicides on the major soybean diseases showed that the fungicides of difenoconazole, triflumizole, metconazole, pyraclostrobin, trifloxystrobin significantly inhibited above diseases, fluopyram significantly inhibited the diseases except soybean root rot, xinjunan and ethylicin significantly inhibited anthracnose and leaf spot of E. rostratum, the control effects were above 90%.【Conclusion】Five kinds of pathogen and disease of soybean in Hebei Province are identified. The triazole sterol biosynthesis inhibitors difenoconazole, triflumizole, metconazole and Qoi respiration inhibitor pyraclostrobin were recommended as the optimal fungicides for soybean fungal diseases in Hebei Province.

    Cloning and Expression Analysis of Light Harvesting Chlorophyll a/b Protein Gene CcLhca-J9 in Conyza canadensis
    LI ZuRen,LUO DingFeng,BAI HaoDong,XU JingJing,HAN JinCai,XU Qiang,WANG RuoZhong,BAI LianYang
    Scientia Agricultura Sinica. 2021, 54(1):  86-94.  doi:10.3864/j.issn.0578-1752.2021.01.007
    Abstract ( 403 )   HTML ( 61 )   PDF (1164KB) ( 277 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Background】Conyza canadensis, a pernicious weed, is harmful and lack of the effective management strategy. The caprylic acid can efficiently inhibit the photosynthesis of C. canadensis, which is a potential bio-herbicidal compound. Light harvesting chlorophyll a/b-binding protein (LHC) is the key complex protein in PSI, and plays an important role in photosynthesis.【Objective】The objective of this study is to explore the LHC gene in response to caprylic acid, and to provide a theoretical basis for the development of bio-herbicide.【Method】The open reading frame (ORF) of CcLhca-J9 was cloned from C. canadensis leaf by homologous PCR and RACE. The nucleotide sequence was analyzed by DNAMAN. The phylogenetic tree was constructed with the high similarity nucleotide from NCBI by neighbor-joining method and MEGA software. The molecular weight, isoelectric point and protein structure were analyzed using SWISS-MODEL and ExPaSy websites. Using homologous modeling results as a model, the affinity of caprylic acid and CcLhca-J9 protein was analyzed using AutoDock 4.2 software. RT-qPCR was used to analyze the difference of CcLhca-J9 expression level of caprylic acid, water and ferulic acid treatments.【Result】The CcLhca-J9 ORF is 744 bp, encoding 247 amino acid residues with a molecular weight of 26.766 kD and theoretical pI of 6.43, which belongs to Chloroa b-bind family protein. The phylogenetic analysis showed that the CcLhca-J9 had the most closed relationship with the Lhca protein of Tanacetum cinerariifolium (GEW73959.1) and Artemisia annua (PWA35049.1), and was in the same branch of Asteraceae group, with consistency of more than 85%, indicating that the gene family was conserved. The second structure of CcLhca-J9 protein had alpha helix, random coil, extended strand, beta turn. The homologous three-dimensional model of CcLhca-J9 protein was compared by 4y28.1.O (2.80Á), the tertiary structure was a monomolecular object with six chlorophyll a ligands, which was a typical light harvesting chlorophyll a/b-binding protein. Molecular docking result showed that hydrogen and p-π bond interaction were produced between caprylic acid and CcLhca-J9 amino acid residues Gly68, Phe67, Phe69 and Arg197. The result of RT-qPCR showed that the expression level of CcLhca-J9 was significantly decreased after 0-8 h caprylic acid treatment. Compared with ferulic acid control and water treatment, caprylic acid treatment inhibited the expression of CcLhca-J9.【Conclusion】CcLhca-J9 has the typical function of light harvesting chlorophyll a/b-binding protein, which may be involved in the process of inhibiting the growth of C. canadensis leaves and is a herbicidal target with the potential to develop herbicides.

    SOIL & FERTILIZER·WATER-SAVING IRRIGATION·AGROECOLOGY & ENVIRONMENT
    Nutrient Resource Quantity of Main Crop Straw and Utilization Potential Under Straw Returning in Anhui Province
    CHAI RuShan,XU Yue,CHENG QiPeng,WANG QingYun,MA Chao,YE XinXin,ZHANG LiGan,GAO HongJian
    Scientia Agricultura Sinica. 2021, 54(1):  95-109.  doi:10.3864/j.issn.0578-1752.2021.01.008
    Abstract ( 432 )   HTML ( 21 )   PDF (1120KB) ( 440 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】 Anhui is a national major grain production province. Clearance of the nutrient resource quantity of main crop straw and utilization potential under straw returning in Anhui province could provide reference data for reasonable utilization of straw nutrient resources and synthetic fertilizers reduction. 【Method】 Based on statistical data and literature review, the capacity of main crop straw, the nutrient resource quantity of straw and potential for straw incorporation to substitute nutrient inputs were estimated for different cities and regions of Anhui province in this research. 【Result】 The amounts of crop straw from rice, wheat, maize and rapeseed were 17.58, 22.51, 7.12 and 2.75 million tons per year in Anhui province during the period of 2016-2018, respectively. The crop straws were mainly produced in North area of Huai River, and Area between Yangtze River and Huai River, accounting for 47.0% and 33.6% of the total provincial crop straw yields, respectively. The main crop straws contained 0.40 million tons of N, 0.13 million tons of P2O5 and 0.85 million tons of K2O, respectively. The straw nutrient resources from rice, wheat, maize and rapeseed accounted for 44.6%, 34.4%, 13.9% and 7.1% of the total provincial main crop straw nutrient resources, respectively. In the main crop-cultivating areas of Anhui province, the amounts of synthetic fertilizers substituted by rice straw incorporation per unit area of arable land were N 29.5-35.0 kg·hm-2, P2O5 13.6-16.2 kg·hm-2 and K2O 132.9-157.5 kg·hm-2. The amounts of synthetic fertilizers substituted by wheat straw incorporation were N 24.1-33.5 kg·hm-2, P2O5 8.4-11.7 kg·hm-2 and K2O 83.5-115.8 kg·hm-2. For maize, straw incorporation could substitute N 24.7-32.7 kg·hm-2, P2O5 12.5-16.5 kg·hm-2 and K2O 59.7-79.0 kg·hm-2. In the main rapeseed-planting areas, rapeseed straw incorporation could substitute N 24.1-34.0 kg·hm-2, P2O5 11.2-15.8 kg·hm-2 and K2O 101.3-142.7 kg·hm-2. 【Conclusion】 Using crop straws properly could satisfy the basic potassium requirement for crop production and partly substitute the inputs of synthetic nitrogen and phosphorus fertilizers. Making full use of nutrient resources from main crop straws may provide an effective solution for synthetic fertilizers reduction under straw returning in Anhui province.

    SOIL & FERTILIZER·WATER-SAVING IRRIGATION·AGROECOLOGY & ENVIRONMENT
    Environmental Safety Risk for Application of Anaerobic Fermentation Biogas Slurry from Livestock Manure in Agricultural Land in China
    WANG XiaoBin, YAN Xiang, LI XiuYing
    Scientia Agricultura Sinica. 2021, 54(1):  110-139.  doi:10.3864/j.issn.0578-1752.2021.01.009
    Abstract ( 1078 )   HTML ( 36 )   PDF (1467KB) ( 318 )   Save
    Figures and Tables | References | Related Articles | Metrics

    The biogas slurry (BS) is a kind of residue liquid of biogas produced by anaerobic fermentation with livestock and poultry manure as the main raw materials. The biogas project in China began in the 1970s. With the development of livestock and poultry farming, and anaerobic digestion technology of livestock manure, the production of anaerobic fermentation BS from livestock manure has greatly increased. The BS from livestock and poultry manure is also a kind of sewage, thus its safe disposal or treatment has become an issue that must be faced and solved to prevent from environmental pollution resulted from agricultural waste in China. At present, the BS has been mainly returned to agricultural land directly without any harmless treatment, as a main disposal method of BS. However, several harmful pollutants (including heavy metals and antibiotics) in livestock manure can still remain in the BS in the process of anaerobic fermentation, and to some extent, even exceed the limits of national water quality standards, endangering farmland ecological environment safety. In this paper, a large number of research data published in the last decade were collected, and the concentrations of heavy metals and antibiotics in animal feeds and manure (including pig, cattle, and chicken) were analyzed, and the impacts of the BS returned into the farmlands on soil quality, water environment and agricultural product safety were evaluated. The research results were showed as follows. (1) The BS was at a risk of seriously exceeding the limits for water quality standard. For example, the concentrations of pollutants (including Hg, Cd, As, Pb, Cr, Cu, Zn and Cl) detected in BS mostly exceeded the limits of the Standards for Irrigation Water Quality (GB 5084—2005), and exceeded the limits (Class IV-V) of the Standards for Groundwater Quality (GB/T 14848—2017). In addition, several antibiotic residues were detected in BS, in which tetracycline antibiotics were higher than other antibiotics, exceeded the threshold value for water quality (10 ng·L-1) set by European Medicines Agency (EMEA). (2) The BS was at a risk of agricultural land pollution. For example, the concentrations of pollutants (including Cd, As, Pb, Ni, Cr, Cu and Zn) detected in the soils applied with BS exceeded the Risk Screening Values for Soil Contamination of Agricultural Land in the Soil Environmental Quality Risk Control Standard for Soil Contamination of Agricultural Land (GB 15618—2018). In addition, it was reported that several antibiotic residues (such as tetracyclines and quinolones, with the concentration of 3.9 and 14.3 mg·kg-1, respectively) were detected in the soils applied with BS for 6 years, exceeding the allowable limit of soil antibiotic residues (0.1 mg·kg-1) stipulated by the Steering Committee of the Veterinary International Committee on Harmonization (VICH). (3) The BS was at a safety risk of agricultural products. As some field experiments reported, several pollutants detected in crops applied with BS (such as Cd, Pb, Ni, Cr, Zn and As in vegetables) exceeded the Safety Qualification for Agricultural Product-Safety Requirements for Non-environmental Pollution Vegetable (GB/T 18406.1—2001), and Maximum Levels of Contaminants in Food (GB 2762—2017). The results indicated that because the rates of BS in agricultural land were usually high, a large amount of BS directly used into farmlands by waste disposal method might lead to the risk of excessive pollutants accumulated in the soils, even exceeding GB 15618—2018 limits in a short term. In order to ensure the safety of soil, water and agricultural products, it is imperative to make pre-treatments for removal of pollutants (including heavy metals and antibiotics) in BS, not exceeding the limit standards for BS returning in farmlands. Therefore, the further research and application on BS treatment technologies for removal of heavy metal and antibiotic pollutants are still needed to strengthen to ensure BS safe utilization in agricultural land.

    SOIL & FERTILIZER·WATER-SAVING IRRIGATION·AGROECOLOGY & ENVIRONMENT
    Effects of Rainfall Intensity and Underground Hole (Fracture) Gap on Nutrient Loss in Karst Sloping Farmland
    YAO YiWen,DAI QuanHou,GAN YiXian,GAO RuXue,YAN YouJin,WANG YuHong
    Scientia Agricultura Sinica. 2021, 54(1):  140-151.  doi:10.3864/j.issn.0578-1752.2021.01.010
    Abstract ( 251 )   HTML ( 14 )   PDF (994KB) ( 235 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】 The ways and laws of soil nutrient loss and surface loss in slope farmland in karst area under different rainfall intensities and underground holes (fissures) were studied in order to provide a theoretical basis for the control of soil nutrient loss and agricultural non-point source pollution control in karst slope farmland. 【Method】 Taking the slope farmland with a slope of 15° in the karst area as the research object, the surface morphology and underground pore (fissures) characteristics of karst slope farmland were simulated under different rain intensities (30, 50, 70, and 90 mm·h-1) and underground pore (fissures) gap degrees (1%, 3%, and 5%), with a total of 36 rainfalls in the cross-test, in order to explore the characteristics of surface and underground nutrient loss. 【Result】 (1)Rain intensity had a significant effect on runoff and sediment production on slope farmland in karst area (P<0.05). Surface and underground runoff and sediment production increased with the increase of rain intensity, and its critical rain intensity might be between 30 and 50 mm·h-1, when the runoff and sediment production were from the underground to the ground; with the increase of the underground pore (fissures) gap, the amount of underground runoff and sand production increased, and the surface was in the opposite pattern. (2)The loss of runoff nutrients in karst slope farmland was mainly through the surface form, which was through the form of underground pores (fissures) under the light rain intensity; the loss and modulus of TN, TP and TK in runoff increased with the increase of rain intensity, and the effect of rain intensity on the nutrient loss concentration of each runoff was not obvious. In addition, the amount of nutrient loss and the loss modulus of the ground surface decreased with the increase of the underground pore (fissures) gap, and vice versa and the increase of underground pore (fissures) gap made the proportion of underground runoff nutrient loss gradually increase. (3)Nutrients would be lost through the form of attachment to the sediment, of which the surface sediment was mainly lost. The average loss concentration, loss amount and loss modulus of each sediment nutrient on the surface and underground increased with the increase of rainfall intensity, and the average concentration and loss amount of TK loss were significantly higher than TN and TP under different rainfall intensities. Under the same rain intensity, the average loss concentration, loss amount and loss modulus of surface nutrients showed a decreasing trend with the increase of pore (fissures) porosity, and the opposite was underground, but the loss amount was mainly from the surface to the surface and underground. Both were equally important. (4)Correlation analysis showed that rainfall intensity had a significant positive correlation with runoff and sediment loss. The impact of rain intensity on nutrient runoff was higher than sediment, and surface runoff was most affected by rain intensity. The effect of underground pore (fissures) gap on the loss of sediment nutrients was higher than that of runoff. Among the sediment nutrients, the loss of underground sediment nutrients was greatly affected by it. 【Conclusion】The surface was the main form of nutrient loss in karst slope farmland, and the effect of underground pores (fissures) on nutrient loss could not be ignored. In the prevention and control of nutrient loss on slope farmland, the surface could slow down the runoff and sediment yield of slope farmland by increasing vegetation coverage and adding litter, etc. The underground soil was fixed by the roots of the vegetation, thus reducing the leakage of nutrients to the underground through the fissure, thereby reducing the soil nutrient loss of the slope farmland.

    HORTICULTURE
    Cloning and Functional Analysis of BraERF023a Under Salt and Drought Stresses in Cauliflower (Brassica oleracea L. var. botrytis)
    LI Hui,HAN ZhanPin,HE LiXia,YANG YaLing,YOU ShuYan,DENG Lin,WANG ChunGuo
    Scientia Agricultura Sinica. 2021, 54(1):  152-163.  doi:10.3864/j.issn.0578-1752.2021.01.011
    Abstract ( 374 )   HTML ( 36 )   PDF (2728KB) ( 457 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】In our previous study, Ethylene-responsive factors (ERFs) involved in abiotic stress responses in cauliflower were identified. In the present study, one of these ERF transcription factors with unknown function, named BraERF023a, was cloned. The expression profiles and function of BraERF023a under salt and drought stresses were further explored. 【Method】BraERF023a was cloned by RT-PCR in cauliflower. The sequence characteristics of BraERF023a were analyzed by biosoftwares such as MEGA 6. The expression profiles of BraERF023a under salt and drought stresses were explored by qRT-PCR. BraERF023a overexpression vector was then constructed and genetically transformed into Arabidopsis. The phenotypes and survival rate of overexpression BraERF023a transgenic Arabidopsis under salt and drought stresses were observed and analyzed.【Result】Sequence analysis confirmed that BraERF023a coding region was 597 bp in length and encoded a protein containing 198 amino acids with an AP2 conserved domain. BraERF023a was highly conserved in Brassica. The expression level of BraERF023a significantly increased under both salt and drought stresses in cauliflower. Functional analysis indicated that comparative with the wild-type controls, overexpression BraERF023a transgenic Arabidopsis lines exhibited better growth vigor and higher plant survival rate under salt or drought stress.【Conclusion】 BraERF023a played important roles in positive response to salt and drought stresses in cauliflower. Overexpression of BraERF023a in Arabidopsis could significantly improve the tolerance of transgenic lines to salt and drought stresses.

    Effects of Low Temperature Storage on Monoterpenes in Table Grape
    WANG HuiLing,YAN AiLing,SUN Lei,ZHANG GuoJun,WANG XiaoYue,REN JianCheng,XU HaiYing
    Scientia Agricultura Sinica. 2021, 54(1):  164-178.  doi:10.3864/j.issn.0578-1752.2021.01.012
    Abstract ( 369 )   HTML ( 26 )   PDF (1216KB) ( 362 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】The content and composition of free and glycosidically-bound monoterpenes during low temperature storage were investigated, and the changes of aroma components for Muscat flavor from the perspective of more comprehensive metabolites were interpreted, so as to provide a theoretical basis for the better study of the change of grape flavor quality and the establishment of the best storage condition.【Method】Two new grape varieties RuiduHongmei and RuiduZaohong were used as materials. The healthy fruits were precooled to -1 - 0℃ firstly, and then were transferred into PE grape fresh-keeping film. The film was subsequently sealed and put into cold storage ((2±1)℃, 90% RH). The samples were taken every 15 days. The physical, chemical and appearance quality indexes of the fruits were determined by conventional methods. The contents of free and glycosidically-bound monoterpenes in grape berries were determined by headspace solid phase microextraction combined with gas chromatography and mass spectrometry (SPME-GC-MS).【Result】In the process of low temperature storage, the content of soluble solids showed a decreasing trend, while the changes of titratable acid showed slightly different in two grape cultivars; the berry weight loss, percentage of the decayed, berry drop ratio and the browning index were increased with the extension of low temperature storage time, but berry retention force exhibited a decrease; the compounds analysis results showed that the main free monoterpenes in the two grape varieties included linalool, β-Myrcene, β-cis-Ocimene, limonene, cis-furan linalool oxide and geraniol; and the major glycosidically-bound monoterpenes included linalool, β-Myrcene, geraniol, geranial, β-cis-Ocimene, nerol oxide and so on. During low temperature storage, the content of total free monoterpenes decreased significantly; the change patterns of 28 free monoterpenes were grouped into four types; compared to the initial storage stage, the content of most of the free type compounds was decreased sooner or later in the process of storage. Principal component analysis showed that free monoterpenes, such as geranic acid, nerol oxide, linalool and 4-Terpineol (M17) could be used as the major contributions for different storage time samples. Each glycosidically-bound monoterpene also showed different change trends during low temperature storage in two grape cultivars. The content of the total glycosidically-bound monoterpenes showed opposite trends to that of free monoterpenes. The glycosidically-bound rose oxides could be used as marker monoterpenes to distinguish the two grape varieties.【Conclusion】RuiduHongmei had a better low temperature storage characteristics than RuiduZaohong. The contents of free monoterpenes decreased significantly in low temperature storage, the free geranic acid, nerol oxide and linalool could be used as the main components for different storage time, and the bound oxidized rose could be used as the marker for variety differentiation.

    FOOD SCIENCE AND ENGINEERING
    Water-Holding Capacity and Water Migration of Lamb Gigot During Dry Aging
    WANG Xu,ZHANG DeQuan,ZHAO YingXin,BAI YuQiang,LI Xin,HOU ChengLi,ZHENG XiaoChun,CHEN Li
    Scientia Agricultura Sinica. 2021, 54(1):  179-189.  doi:10.3864/j.issn.0578-1752.2021.01.013
    Abstract ( 335 )   HTML ( 28 )   PDF (536KB) ( 160 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】 Dry aging meat is popular among consumers because of its unique product characteristics. Thus, the objective of this study was to clarify the regularity of water migration in meat during dry aging by exploring the effects of dry aging on the water-holding capacity of lamb gigot and water migration in it, thereby provide a theoretical foundation for high quality meat production.【Method】The hind legs of twenty-six Small-tail Han sheep (male, carcass weight (23.4±1.09) kg, 6-7 months old) were obtained and assigned into three groups randomly which were wet aging group, relative humidity (80±5) % dry aging group (RH80 dry aging group) and relative humidity (60±5) % dry aging group (RH60 dry-aging group) at (2±2)℃. The drying loss, water content, cooking loss, water distribution and protein secondary structure of lamb gigots were measured at aging 0, 7, 14, 21, and 28 d.【Result】The drying loss of gigots in dry-aging groups was significantly higher than that in wet-aging group (P<0.05). The water content of RH60 dry-aging gigots was significantly lower than that of wet-aging gigots after aging 7 days (P<0.05), and no significant difference of water content was observed between RH80 and RH60 dry-aging group (P>0.05). According to the results of the water-holding-capacity (WHC) test, the cooking loss in dry-aging groups was significantly lower than that in wet-aging group (P<0.05), except RH80 dry-aging group at aging 14 d. Additionally, at aging 14 d, the cooking loss of samples had no difference from that at 0 d (P>0.05), which indicated that the WHC of dry-aging groups was better than that of wet-aging group and the WHC of the sample was improved at dry-aging 14 d. The results of protein secondary structure of gigots demonstrated that compared with that at aging 7 d, the disordered structure of protein in wet-aging group, RH80 dry-aging group and RH60 dry-aging group reduced by 9.2%, 14.1%, and 17.26% at aging 14 d, respectively, which indicated a better protein stability and WHC of gigots at aging 14 d. According to the results of low-field nuclear magnetic resonance (LF-NMR), at aging 21 d, transverse relaxation time of free water (T22) in gigots of three aging groups increased significantly compared with that at aging 14 d, which indicated an increase in the freedom degree of water and a decrease in WHC. In all of the three aging groups, immobilized water (P21) had the largest proportion among the total water in gigots. At the early stage of aging, the proportion of P21 decreased at the beginning and then increased while the proportion of bound water (P2b) increased first and then decreased. This indicated that immobilized water transferred to bound water first and then bound water transferred back to immobilized water at the later stage of aging, the P21 decreased while proportion of free water (P22) increased, which meant that immobilized water converted into free water at this aging stage with a decrease of WHC.【Conclusion】Dry aging gigots was lower in water content and higher in WHC, compared with wet aging gigots. During dry aging of gigots, there was a conversion relationship between bound water and immobilized water, and between immobilized water and free water. Besides, the increase of immobilized water meant an increase in WHC of gigots, while an increase of free water indicated the decrease of gigots WHC. During a long aging time of gigots, the different relative humidity had a significant effect on drying loss and cooking loss of dry-aging gigots, however, which did not significantly affect its water content and water migration.

    Effects of Germination and Extrusion on Volatile Flavor Compounds in Brown Rice
    CHEN YanFang,ZHANG MingWei,ZHANG Yan,DENG YuanYuan,WEI ZhenCheng,TANG XiaoJun,LIU Guang,LI Ping
    Scientia Agricultura Sinica. 2021, 54(1):  190-202.  doi:10.3864/j.issn.0578-1752.2021.01.014
    Abstract ( 321 )   HTML ( 24 )   PDF (1177KB) ( 251 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】The objective of this study was to investigate the effects of germination and extrusion process on volatile flavor compounds of brown rice by analyzing changes of the volatile flavor compounds of brown rice, so as to provide a reference for evaluating and improving the volatile flavor of brown rice. 【Method】The volatile flavor compounds of raw brown rice (RBR), extruded brown rice (EBR), germinated brown rice (GBR) and extruded germinated brown rice (EGBR) were analyzed by headspace solid phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS). The qualitative and relative quantitative analyses of the volatile flavor components were carried out by NIST14 database, retention index (RI), and internal standard. Gas chromatography olfactory (GC-O) was used to analyze the composition spectrums of the active odor compounds and their overall flavor profile as well as the volatile flavor characteristics of brown rice samples. 【Result】 A total of 28 volatile flavor compounds were identified, including aldehydes, alcohols, terpenes, esters, heterocycles and arenes. After extrusion, the contents of aldehydes, heterocycles and arenes in brown rice were increased significantly, while the contents of alcohols and terpenes decreased significantly; moreover, new esters were detected after extrusion. After germination treatment, the content of alcohols was increased, while the contents of aldehydes, terpenes, heterocycles and arenes decreased; however, esters were undetected after germination treatment. After extrusion, the content of aldehydes, terpenes, heterocycles and arenes in germinated brown rice were increased, furthermore, while the content of alcohols decreased; moreover, new esters were detected. What’s more, the contents of aldehydes, terpenes, esters and heterocyclic compounds in germinated brown rice were significantly higher than those in brown rice after extrusion. The principal component analysis showed that the increases of the contents of compounds, such as heptanal, nonanal, benzaldehyde, D-limonene, toluene and 2-AP, were highly correlated with extrusion, while the increases in contents of 2-ethyl-1-hexanol and 3-methylbutanol were highly correlated with germination, and the increases in contents of ethyl acetate, butyl acetate, dimethyl sulfide and pyridine were highly correlated with germination-extrusion treatment. GC-O results showed that 19 kinds of active odor compounds were detected, with the odor intensity value (OIV) of some compounds’ over ≥ 3, such as hexanal, heptanal, hexanol, 1-octene-3-ol, 2-acetyl-1-pyrroline and p-xylene. The flavor profile analysis showed that the odor intensity of wax was the highest in brown rice, followed by those of grass and nut, while those of floral and fruity odor were the lowest. After extrusion, the nutty, grassy and fruity odor intensities of brown rice were increased significantly, in contrast, the waxy odor intensity decreased significantly. After germination, the waxy, nutty, grassy and floral odor intensities of brown rice were decreased, however, the fruit odor intensity did not change. After extrusion, the nutty, waxy, grassy and fruity odor intensities of germinated brown rice were increased significantly. 【Conclusion】Germination could improve the production of alcohols in brown rice, while it could decrease the contents of other volatile compounds to some extent, resulting in the decline of overall flavor intensity. However, during the process of germination, brown rice could produce volatile flavor precursors through biochemical action, which could promote the formation of more volatile flavor compounds by extrusion in germinated brown rice. Extrusion could have a positive effect on the formation of aldehydes, terpenes, esters, heterocycles and arenes in brown rice as well as germinated brown rice. Moreover, the volatile flavor compounds content in extruded germinated brown rice were significantly higher than those in extruded brown rice. The overall flavor intensities of both raw brown rice and germinated brown rice were increased after extrusion, with the most significant increase in the nutty and fruity odor intensities.

    ANIMAL SCIENCE·VETERINARY SCIENCE·RESOURCE INSECT
    Effects of Dietary Energy Levels on Production Performance, Blood Index, Slaughter Performance and Meat Quality of Holstein Steers
    ZHANG MeiQi,LI Yan,LI ShuJing,GAO YanXia,LI JianGuo,CAO YuFeng,LI QiuFeng
    Scientia Agricultura Sinica. 2021, 54(1):  203-212.  doi:10.3864/j.issn.0578-1752.2021.01.015
    Abstract ( 320 )   HTML ( 32 )   PDF (477KB) ( 365 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】The effects of dietary energy level on the production performance, blood index, slaughter performance and meat quality of Holstein steers were studied in this study, so as to provide a theory basis for fattening of Holstein steers.【Method】Thirty-nine healthy Holstein steers weighing about 650 kg were selected and randomly divided into 3 groups(n=13). The trial period was 255 d (the preparation period for 10 days and formal experiment period for 245 days). In the early stage of trial (from day 1 to 87), the three groups were low energy group (LE), medium energy group (ME), and high energy group (HE). The NEmf were 6.10, 6.30, and 6.50 MJ·kg-1, respectively, and the CP levels were 11.6%; the late stage of the test (from day 88 to 245) was divided into three stages, I (from day 88 to 130), II (from day131 to 188) and III (from day189 to 245). The dietary energy and CP level of each experimental group was the same in different stages, NEmf was 6.7, 7.20, and 7.29 MJ·kg-1, respectively, and CP level was 11.5%.The production performance and other indicators were measured at the end of the early and later period of the feeding experiment. Six steers in each group were randomly selected to collect blood for blood biochemical indicators measurement and to slaughter for slaughtering performance and meat quality measurement.【Result】Compared with LE group and ME group, the average daily gain(ADG) of HE group were increased by 21.50% (P<0.05) and 17.12% (P<0.05) , respectively, but there was no significant effect of dietary energy level on the ADG and feed to weight ratio of Holstein steer in the late and whole period (P>0.05).In the early stage of trial, the serum TG content increased significantly, the high and low order was HE group >ME group>LE group, the LPL content in HE group was the highest, which was 35.17% (P<0.05) and 9.92% higher than that in LE group and ME group, respectively; the NEFA content in HE group was the highest, which was 13.16% (P<0.05) higher than that in LE group, and there was no significant difference with that in ME group. At the later stage of trial, the LPL content of LE group was significantly increased by 18.47% (P<0.05) and 26.17% (P<0.05) compared with ME group and HE group.The carcass weight of Holstein steers was significantly increased by different dietary energy levels, the highest in HE group, which was 6.26% and 5.26% higher than that in LE group and ME group; the slaughter rate in HE group was 4.86% (P<0.05) and 4.10% (P<0.05) higher than that in LE group and ME group, but there was no significant difference in eye muscle area and marbling grade (P>0.05). The dietary energy level had no effect on pH, drop loss, shear force, dehydration rate and colorimetric values (P>0.05); the content of fat in the longissimus dorsi muscle of HE group was the highest, which was significantly increased by 52.54% (P<0.05) and 57.45% (P<0.05) compared with LE group and ME group, respectively.【Conclusion】Under the conditions of this experiment, it was better to adopt the straight-line high-energy fattening mode for Holstein steer. In the stage of body weight 650-770 kg, the level of NEmf was 6.50 MJ·kg-1, and the level of CP was 11.6%.

    Effect of the Heterozygous Sex-Linked Dwarf Gene on Fat Deposition in Normal Type Chickens
    ZHU XingHao,CHEN Qing,SHAO BingHao,GUO YuJun,ZHANG XiangLi,DU PengFei,ZHU Yao,HUANG YanQun,CHEN Wen
    Scientia Agricultura Sinica. 2021, 54(1):  213-223.  doi:10.3864/j.issn.0578-1752.2021.01.016
    Abstract ( 268 )   HTML ( 22 )   PDF (846KB) ( 214 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】 The aim of this study was to to investigate the effect of the heterozygous sex-linked dwarf gene on fat deposition of chickens, so as to provide a theory base for producing quality chicken and local chichen by using dwarf gene. 【Method】 In this study, the normal size Gushi chicken and Guangxi Yao chicken rooster (ZDWZDW) were chosen to cross with the normal type hens (ZDWW) and the dwarf hens (ZdwW), respectively, and their offspring were raised under the same condition. 100 chickens (half male and half female) were randomly selected from each hybrid at the ages of 60 days, 90 days and 120 days for body measurement index, respectively. 10 chickens (half male and half female) were randomly selected from the hybrid populations of Gushi chickens to determine the dynamic change of body fat at 60 days and 90 days, respectively. In addition, 10 chickens (half male and half female) were selected from the hybrid populations of Gushi chickens and Guangxi Yao chickens at 120 days to determine the body fat deposition of different populations. The serum biochemical indexes were measured by using automatic biochemical analyzer, the content of intramuscular fat in breast muscle and leg muscle was determined by the Soxhlet extraction method, and the diameter and density of muscle fibers were measured by the paraffin section. 【Result】 The results showed that the offspring were normal in body size, and the male and female offspring from the normal type of female parent presented different characteristics of fat deposition with age. The female body fat indexes including abdominal fat weight, percent of abdominal fat, subcutaneous fat thickness and intermuscular fat width, which were all kept at a low level at 60 days, and increased significantly at the age of 120 days, while the male body fat maintained at low levels. In the meantime, the male and female offspring the dwarf type of female parent presented a similar dynamic change of fat deposition with age, and the body fat levels of the male and the female offspring at 120 days were significantly higher than that at 60 days and 90 days. However, the body fat change of the male offspring from the dwarf type of female parent (the heterozygote of dw) was different from that of the normal type of female parent (the homozygous of DW), whose abdominal fat weight, percent of abdominal fat, subcutaneous fat thickness and intermuscular fat width were significantly higher than that of the normal type of female parent at 90 and 120 days. Combining the data of body fat between Gushi chickens and Guangxi Yao chickens for 120 days, the result showed that population factor was significant for abdominal fat weight, percent of abdominal fat, intermuscular fat width and subcutaneous fat thickness. The abdominal fat weight, percent of abdominal fat, intermuscular fat width and subcutaneous fat thickness of the males from the dwarf type of female parent were significantly higher than that of the normal type of female parent (P<0.01). There was no significant difference in total cholesterol, triglyceride, low-density lipoprotein, and high-density lipoprotein between the population (from the normal type of female parent and the dwarf type of female parent). There was no significant difference in the IMF content of the breast muscle in the female offspring from the normal type of female parent and the dwarf type of female parent. The breast muscle IMF content of male from the dwarf type of female parent was significantly higher than that from the normal type of female parent (P<0.01). There was no significant difference in muscle fiber characteristics, including muscle fiber density, muscle fiber area and muscle fiber diameter between the offspring of the normal type of female parent and the dwarf type of female parent. 【Conclusion】The results showed that the heterozygous dwarf gene changed the characteristics of fat deposition in the males, and it could significantly increase the deposition of abdominal fat, subcutaneous fat, intermuscular fat and breast IMF content in the male. The heterozygous dwarf gene had no significant effect on blood lipid index and the characteristics of muscle fibers.

    Regulatory Function of Long Non-Coding RNAs in Ascosphaera apis
    ZHOU DingDing, FAN YuanChan, WANG Jie, JIANG HaiBin, ZHU ZhiWei, FAN XiaoXue, CHEN HuaZhi, DU Yu, ZHOU ZiYu, XIONG CuiLing, ZHENG YanZhen, FU ZhongMin, CHEN DaFu, GUO Rui
    Scientia Agricultura Sinica. 2021, 54(1):  224-238.  doi:10.3864/j.issn.0578-1752.2021.01.017
    Abstract ( 306 )   HTML ( 18 )   PDF (6524KB) ( 158 )   Save
    Figures and Tables | References | Related Articles | Metrics

    【Objective】Long non-coding RNAs (lncRNAs), a kind of RNAs with highly conserved secondary and tertiary structures and a length of more than 200 nt, have no protein-coding potential. LncRNAs are widely involved in transcriptional and post-transcriptional regulations, such as dosage compensation, cell differentiation and growing development. The study aimed to perform analyses of cis regulation, antisense lncRNA regulation and competing endogenous RNA (ceRNA) regulation as well as related discussion based on previously obtained high-quality lncRNA omics dataset from mixed samples of Ascosphaera apis mycelia and spores, and further reveal the putative regulatory role of lncRNAs in A. apis.【Method】Protein-coding genes located at 100 kb upstream and downstream of A. apis lncRNAs were predicted on basis of the position of lncRNA genes; these upstream and downstream genes were annotated to GO and KEGG databases using Blast to gain function and pathway annotations. Target mRNAs of lncRNAs were identified using LncTar software and then annotated to KEGG and eggNOG databases. Target miRNAs of lncRNAs and target mRNAs of miRNAs were predicted using TargetFinder, followed by visualization of regulatory networks using Cytoscape v3.7.1. The expressions of partial lncRNAs, target miRNAs and target mRNAs within regulatory networks were validated using RT-PCR.【Result】A total of 5 852 upstream and downstream genes of A. apis lncRNAs were predicted. These upstream and downstream genes could be annotated to 48 functional terms such as cellular process, metabolic process and stress response, as well as 121 pathways including metabolic pathways, biosynthesis of secondary metabolites and biosynthesis of antibiotics, which indicated that part of A. apis lncRNAs could regulate the expression levels of upstream and downstream genes via cis-acting function, thus participating in regulation of basic cell activities including material and energy metabolisms. Seven lncRNAs were found to have sequence complementary pairing relationship with seven target mRNAs. Among them, five targets were annotated to hypothetical proteins in eggNOG database, while gene3444 could be annotated to nuclear pore complex protein An-Nup120 and hypothetical protein in KEGG database, suggesting that the aforementioned one antisense lncRNA might be involved in regulating biological processes including biosynthesis of nuclear pore complex protein. Additionally, 227 lncRNAs were predicted to have target binding relationship with 73 miRNAs; majority of these lncRNAs (79.02%) could only link to 1-2 miRNAs and partial miRNAs could be targeted by several lncRNAs. Furthermore, lncRNA-miRNA-mRNA regulatory networks associated with oxidative phosphorylation pathway and MAPK signaling pathway were constructed and analyzed, the results showed that 222 lncRNAs related to oxidative phosphorylation pathway could target 78 miRNAs and 50 mRNAs; as for MAPK signaling pathway, 222 associated lncRNAs could target 76 miRNAs and 46 mRNAs; the results suggested that part of A. apis lncRNAs were likely to regulate these two pathways via ceRNA mechanism, hence affecting energy synthesis, environmental adaptation as well as growth and development.【Conclusion】Partial lncRNAs may regulate a series of biological processes such as growth and development, material and energy mechanisms as well as environmental adaptation of A. apis; MSTRG.5393.1 as an antisense lncRNA may regulate biosynthesis of nuclear pore complex protein in A. apis.