Table of Content

    01 October 2022, Volume 55 Issue 19
    Maize Transcription Factor ZmEREB93 Negatively Regulates Kernel Development
    PANG HaoWan,FU QianKun,YANG QingQing,ZHANG YuanYuan,FU FengLing,YU HaoQiang
    Scientia Agricultura Sinica. 2022, 55(19):  3685-3696.  doi:10.3864/j.issn.0578-1752.2022.19.001
    Abstract ( 483 )   HTML ( 70 )   PDF (4112KB) ( 198 )   Save
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    【Objective】 Maize, a kind of crucial crop, is widely used in food supply, livestock feed, and industry. AP2/EREBP (APETALA2/ethylene response element-binding protein) transcription factor (TF) plays an important role in plant growth, development, and stress response. Previous study showed that ZmEREB93 might regulate seed size as a target gene of ZmBES1/BZR1-5 TF. ZmEREB93 was cloned and used to analyze its expression pattern and function, which lays foundation to clarify the function and mechanism of ZmEREB93 regulating seed size. 【Method】 The full length of ZmEREB93 was cloned from maize inbred line B73 by PCR. The characters of nucleotide and amino acid sequences were analyzed by informatic methods. Subsequently, the tissue expression specificity of ZmEREB93 was analyzed via quantitative real time PCR (qRT-PCR). The expression vector in plant and yeast was constructed and used for subcellular localization and transcription activation assay, respectively. ZmEREB93 was transformed into Arabidopsis mediated by agrobacterium transformation. The seed phenotype of transgenic lines was analyzed. Finally, the potential target genes of ZmEREB93 were screened by chromatin immunoprecipitation sequencing (Chip-seq) and co-expression analysis, and further confirmed by yeast one hybrid (Y1H). 【Result】 The ZmEREB93 gene was cloned by PCR. Sequence analysis showed that ZmEREB93 had no intron and a 618 bp ORF, encoding 205 amino acids with a highly conserved AP2 domain and belongs to the ERF subclade of AP2 family. The results of qRT-PCR showed that the ZmEREB93 gene highly expressed in kernels of 15 and 25 days after pollination (DAP), and slightly expressed in stem and root, but did not express in tassel, silk and bract. The expression level of ZmEREB93 was the highest in 25 DAP kernels reached 11 times of that in 15 DAP kernels. The results of transcriptional activation and subcellular localization assay exhibited that ZmEREB93 protein had no transcriptional activation activity in yeast cells and was localized in the nucleus, respectively. Compared to wild type, the seeds of transgenic lines were significantly smaller and showed lower thousand-seed-weight. Chip-seq and co-expression analysis suggested that the Zm00001d013611, Zm00001d006016, Zm00001d027448 and Zm00001d03991 genes were candidate target genes regulated by ZmEREB93 TF. The result of Y1H showed that ZmEREB93 directly bind to Zm00001d013611 promoter. 【Conclusion】 Maize ZmEREB93 TF specifically expressed in seeds and negatively regulated seed size.

    Cloning and Functional Analyses of MsCIPK2 in Medicago sativa
    SU Qian,DU WenXuan,MA Lin,XIA YaYing,LI Xue,QI Zhi,PANG YongZhen
    Scientia Agricultura Sinica. 2022, 55(19):  3697-3709.  doi:10.3864/j.issn.0578-1752.2022.19.002
    Abstract ( 382 )   HTML ( 72 )   PDF (5750KB) ( 141 )   Save
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    【Objective】 CIPKs are a group of important protein kinase involved in signaling pathway of plant in response to stress. They can form CBL-CIPK complex with CBL, to activate the expression of related responsive genes to cope with various abiotic stresses in cells. Exploration and study on the molecular mechanism of MsCIPK genes in alfalfa in response to abiotic stress will help to reveal the biological basis of stress resistance in alfalfa, and to provide new gene resources for alfalfa breeding with enhanced stress resistance. 【Method】 The MsCIPK2 gene was cloned by using PCR, the sequence was analyzed by bioinformatics tools, and the expression level of MsCIPK2, MsCBL2, MsCBL6, MsCBL7 and MsCBL10 genes in various tissues were analyzed by using qRT-PCR. The pCAMBIA1302-GFP-MsCIPK2 vector was transiently expressed in tobacco leaf epidermal cells, and the subcellular localization was observed under laser confocal microscope. Yeast two-hybrid assay was used to analyze interaction between MsCIPK2 and four MsCBLs proteins. Agrobacterium rhizogenes was used to generate alfalfa hairy roots over-expressing MsCIPK2. qRT-PCRs were used to analyze the expression levels of related genes in transgenic hairy root lines. 【Result】 The coding sequence of MsCIPK2 gene was obtained by using PCR, and it is 1 230 bp in length, encoding 409 amino acids. The deduced MsCIPK2 protein contained typical ATP binding site, activation loop, NAF motif and PPI motif as for the CIPK family genes. The expression level of MsCIPK2 gene was the highest in roots, and the lowest in the flowers of alfalfa. Subcellular localization results showed that MsCIPK2 protein was localized in the endoplasmic reticulum. Yeast two-hybrid assays showed that MsCIPK2 protein interacted with MsCBL2, MsCBL6, MsCBL7 and MsCBL10 proteins, showing stronger interaction with MsCBL10 than with other MsCBLs. The expression levels of MsCBL2, MsCBL6, and MsCBL10 were the highest in roots of alfalfa, and the expression level of MsCBL7 was the highest in pods. qRT-PCR results showed that the expression levels of abiotic stress-associated genes ATPase, P5CS, CYP705A5, COR47, HAK5 and RD2 were significantly up-regulated in hairy roots over-expressing MsCIPK2. Under the treatment of 200 mmol·L-1 NaCl and 20% PEG, when compared with the control hairy root line, hairy roots over-expressing MsCIPK2 had lower MDA content, and higher POD activity, proline content and soluble sugar content. 【Conclusion】 MsCIPK2 can interact with CBL protein, and responded to salt and drought stress in roots of alfalfa. Over-expression of MsCIPK2 can improve salt and drought stress resistance in alfalfa, and MsCIPK2 can be used as candidate gene for alfalfa breeding with improved abiotic stress resistance.

    Effects of High Temperature Stress in Different Periods on Dry Matter Production and Grain Yield of Summer Maize
    ZHANG Chuan,LIU Dong,WANG HongZhang,REN Hao,ZHAO Bin,ZHANG JiWang,REN BaiZhao,LIU CunHui,LIU Peng
    Scientia Agricultura Sinica. 2022, 55(19):  3710-3722.  doi:10.3864/j.issn.0578-1752.2022.19.003
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    【Objective】 Frequent, recurrent and prolonged high temperature stress had significant effects on grain yield of summer maize in Huang-Huai-Hai region. In this study, we investigated the effects of high temperature stress at the V12 stage and VT stage on leaf photosynthetic characteristics, carbon assimilate accumulation, distribution and grain yield of maize varieties with different heat tolerance. 【Method】 In this study, heat resistant maize variety Zhengdan 958 (ZD958) and heat sensitive maize variety Xianyu 335 (XY335) were used as materials. The normal temperature treatments (day 32℃12 h /night 22℃12 h) were set as the control at the same time. High temperature greenhouse equipped with automatic temperature and humidity control facilities was used to simulate the effect of natural field high temperature, the high temperature stress treatments (day 38℃12 h/night 28℃12 h) were set at V12 and VT stage, respectively. The dynamic characteristics of leaf area index (LAI), carbon metabolism enzyme activities, photosynthetic rate and carbon assimilate accumulation and allocation were compared after high temperature stress, aimed to determine the response mechanism of dry matter production performance and grain yield to high temperature stress. 【Result】 After high temperature stress, LAI, carbon metabolism enzyme activities, net photosynthetic rate and dry matter accumulation of two cultivars were significantly decreased. LAI, RuBP carboxylase activity, PEP carboxylase activity, net photosynthetic rate and dry matter accumulation of ZD958 and XY335 decreased by 2.98%-4.21%, 40.38%-54.46%, 16.88%-30.60%, 18.14%-25.49%, 12.83%-19.38% and 3.80%-5.07%, 56.56%-76.16%, 26.33%-33.66%, 22.37%-34.62%, 22.07%-26.72%, respectively. The decrease range of high temperature stress in VT stage was larger than that in V12 stage. After high temperature stress, transpiration rate of summer maize leaves increased, while leaf water use efficiency decreased significantly. Under high temperature stress, 13C assimilation of ZD958 and XY335 decreased by 18.48% and 22.82%, respectively, and the proportion of 13C assimilation in grains decreased. The high temperature stress significantly decreased grain number per spike and grain yield, although 1000 grain weight increased slightly. Compared to the optimum temperature, after V12 high temperature stress, the grain number per spike and yield of ZD958 decreased by 62.53% and 45.87%. After VT high temperature stress, grain number per spike and yield decreased by 70.53% and 66.89%. After V12 high temperature stress, the grain number per spike and yield of XY335 decreased by 70.50% and 62.87%. After VT high temperature stress, grain number per spike and yield decreased by 85.41% and 80.61%. The decrease range of high temperature stress in VT stage was larger than that in V12 stage, and XY335 decreased more than ZD958. 【Conclusion】 The high temperature stress reduced LAI, RuBP carboxylase and PEP carboxylase activities, and significantly reduced photosynthetic rate and dry matter production performance of summer maize. Under high temperature stress, the grain number per spike decreased significantly, which inhibited the transportation of carbohydrate from leaf and stem to grain, resulting in lower grain yield. The effects of high temperature stress on dry matter performance and grain yield of summer maize in VT stage was significantly greater than that in V12 stage. The decrease of heat sensitive variety XY335 was significantly greater than that of heat resistant variety ZD958 in two periods.

    Analysis of American Soft Wheat Grain Quality and Its Suitability Evaluation According to Chinese Weak Gluten Wheat Standard
    LIU Feng,JIANG JiaLi,ZHOU Qin,CAI Jian,WANG Xiao,HUANG Mei,ZHONG YingXin,DAI TingBo,CAO WeiXing,JIANG Dong
    Scientia Agricultura Sinica. 2022, 55(19):  3723-3737.  doi:10.3864/j.issn.0578-1752.2022.19.004
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    【Objective】 The consumption of biscuits in China is increasing yearly, but soft wheat, the material for making biscuits, has been in shortage for a long time. American soft wheat is of stable quality and excellent processing performance, and is welcomed by Chinese processing enterprises. This study on the interannual dynamic change of grain quality and the relationship between quality indexes of American soft red winter and soft white wheat in multiple years could provide the reference for Chinese weak gluten wheat production. 【Method】 Based on the quality data of soft wheat published by American Wheat Association from 1999 to 2019, the correlation analysis and cluster analysis were used to analyze the relationship among wheat grain, flour, dough and baking quality, and the fitness of American soft wheat quality to the existing weak gluten wheat standard in China was also analyzed. 【Result】 For grain quality, the mean value of grain protein content (GPC, %), hardness (H), test weight (TW, g·L-1) and 1000-grain weight (TKW, g) of soft red winter wheat was lower than that of soft white wheat. The annual variation of quality indexes showed: H>TKW>GPC>TW. For flour quality, the wet gluten content (WG, %) of two kinds of soft wheat were about 22%. Four kinds of solvent retention capacity (SRC, %) of soft red winter wheat were higher than or similar to soft white wheat, while the WG, sedimentation value and four kinds SRC of soft red winter wheat had lower variation coefficients. For dough quality, the development time, stability time (ST, min), alveograph P, L, W value and extensograph parameters of soft red winter wheat were lower than those of soft white wheat, and their water absorption (WA, %) was about 52%. The variation coefficients of farinograph, alveograph and extensograph parameters of soft red winter wheat were lower. According to Chinese weak gluten wheat standard GB 17320-2013, the reaching rate of GPC, WG and ST in soft red winter wheat were 100%, 100% and 57.1%, respectively. The reaching rates of GPC, WG and ST in soft white wheat were 90.5%, 95.2% and 38.1%, respectively. Under GB 17893-1999, GPC, WG and ST of two kinds of soft wheat were as follows: GPC

    Prediction of Soil Organic Carbon Content in Jiangxi Province by Vis-NIR Spectroscopy Based on the CARS-BPNN Model
    WU Jun,GUO DaQian,LI Guo,GUO Xi,ZHONG Liang,ZHU Qing,GUO JiaXin,YE YingCong
    Scientia Agricultura Sinica. 2022, 55(19):  3738-3750.  doi:10.3864/j.issn.0578-1752.2022.19.005
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    【Objective】 This study explored the roles of spectral variable selection and stratified calibration based on soil type in visible-near-infrared (Vis-NIR) spectroscopy for predicting soil organic carbon (SOC) content on a large spatial scale. 【Method】 A total of 490 samples were collected in Jiangxi province (Southeast China) and used for modeling with partial least squares regression (PLSR), support vector machine (SVM), random forests (RF), and back-propagation neural network (BPNN). The competitive adaptive reweighted sampling (CARS) procedure was used to select the feature bands of different soil types and total samples (i.e., sum of red soils and paddy soils). The prediction accuracy of models incorporating full bands or feature bands was evaluated for the different soil types. Further, the prediction accuracy of these models based on their global and stratification calibration was compared for the total samples. 【Result】 (1) The feature bands of red soils were 484, 683-714, and 2 219-2 227 nm, while those of paddy soils were 484, 689-702, and 2 146-2 156 nm. The CARS-BPNN model showed the best prediction performance for red soils (validation set R2 = 0.82), being 0.07 higher than that of BPNN with full bands. The CARS-RF model also had the best prediction performance for paddy soils (validation set R2 = 0.83), being 0.13 higher than that of RF with full bands. (2) Based on the stratified calibration, the best prediction performance was obtained using the CARS-BPNN model (validation set R2 = 0.82), which was 0.06 higher than that of the model based on global calibration. 【Conclusion】 The CARS-BPNN model combined with stratified calibration based on soil type could accurately predict SOC content in the study area.

    Genome-Wide Identification and Analysis of CC-NBS-LRR Family in Response to Downy Mildew and Powdery Mildew in Cucumis sativus
    KANG Chen,ZHAO XueFang,LI YaDong,TIAN ZheJuan,WANG Peng,WU ZhiMing
    Scientia Agricultura Sinica. 2022, 55(19):  3751-3766.  doi:10.3864/j.issn.0578-1752.2022.19.006
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    【Objective】 The bioinformatics and expression pattern analysis of the CC-NBS-LRR (CNL) gene family of the whole cucumber (Cucumis sativus) genome was carried out to provide a reference for further study of the functions of the CsCNL gene family in growth, development and disease stress response. 【Method】 Taking the CNL gene sequence of Arabidopsis thaliana as the reference, the genome of cucumber ‘9930’ was searched by local Perl language and Pfam software, and the members of CsCNL gene family were identified. CsCNL gene family was analyzed by some bioinformatics tools, such as ExPASY, GSDS2.0, MEGA, MEME, Tbtools and Mev. Transcriptome data, inoculating with downy mildew and powdery mildew pathogens (Pseudoperonospora cubensis and Podosphaera xanthii) and real-time quantitative PCR (qRT-PCR) were used to evaluate the expression of the genes. 【Result】 A total of 17 CsCNL genes were identified from cucumber genome. CsCNL genes are distributed on 6 chromosomes except chromosome 1. The encoded proteins are similar in structure to other plant CNLs. All CsCNL proteins contain conserved domains of CC, NBS and LRR. The amino acid sequence size ranged from 197 to 1 148 aa, with a molecular weight (MW) of 22.6 to 131.3 kD, and a protein isoelectric point (PI) ranged from 5.71 to 8.38. Collinear analysis showed that there were no segmental duplication and tandem duplication genes, and the multi-species phylogenetic relationship showed that CNL gene family members had high structural and functional similarities among Cucurbitaceae plants. There were many cis-acting elements related to disease resistance in the promoter of CsCNL genes. The expression of CsCNL genes was tissue-specific. At 2 d and 5 d after inoculation with P. cubensis, Csa3G815400, Csa3G822360 and Csa7G420890 were all significantly up-regulated in resistant variety, Csa4G015850 was down-regulated in resistant variety, and significantly different in susceptible variety. At 2 d and 5 d after P. xanthii inoculation, Csa2G008000 and Csa3G684170 were significantly up-regulated in susceptible variety and significantly down-regulated in resistant variety. Csa4G016360, Csa7G420890 and Csa7G425940 were significantly up-regulated in resistant variety, while unchanged or significantly down-regulated in susceptible variety. 【Conclusion】 CsCNL gene family has specific expression pattern in different tissues, and most of the CsCNL genes were induced by P. cubensis and P. xanthii. It is speculated that the increased expression of Csa3G815400, Csa3G822360 and Csa7G420890, and the decreased expression of Csa4G015850 can induce downy mildew resistance in resistant cucumber varieties. The increased expression of Csa4G016360, Csa7G420890 and Csa7G425940, and the decreased expression of Csa2G008000 and Csa3G684170 can induce the resistance to powdery mildew in resistant cucumber varieties, while the increased expression of Csa7G420890 can simultaneously induce disease resistance to downy mildew and powdery mildew in resistant cucumber varieties.

    Effects of Calcium on Growth and Development of Poncirus trifoliata and Resistance to Citrus Canker
    XIAO GuiHua,WEN Kang,HAN Jian,HAO ChenXing,YE RongChun,ZHU YiChi,XIAO ShunYuan,DENG ZiNiu,MA XianFeng
    Scientia Agricultura Sinica. 2022, 55(19):  3767-3778.  doi:10.3864/j.issn.0578-1752.2022.19.007
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    【Background】 Citrus canker is a bacterial disease caused by Xanthomonas citri subsp. citri (Xcc), which can infect branches, leaves and fruits, and affects almost all major citrus varieties. The results of a previous survey of 39 citrus orchards in Hunan Province showed that soil acidification and exchange calcium deficiency in citrus orchards were serious and calcium deficiency existed in all leaves. Calcium is one of the elements required by plants in large quantities, and calcium deficiency causes nutritional imbalance, reduced growth potential and compromised plant immunity level. However, the effect of calcium element on the process of citrus infection with canker is not clear. 【Objective】 The objective of this study is to analyze the pathogenic differences after inoculation with Xcc in Poncirus trifoliata (sensitive to citrus canker) leaves under different calcium concentrations, and to explore the role of calcium in Xcc infection of P. trifoliata leaves. 【Method】 The seedlings of P. trifoliata were sand cultured with calcium concentrations of 0, 0.75, 3, and 30 mmol·L-1. During the growth period of P. trifoliata, the biomass, chlorophyll a and b concentrations, and calcium content in roots and leaves were determined, as well as the formation of reactive oxygen species (ROS) in roots and callose deposition. The effects of Xcc inoculation on cell wall synthesis-related genes and immune-related genes in P. trifoliata leaves were investigated. 【Result】 Compared with 3 mmol·L-1 calcium treatment, 0, 0.75 and 30 mmol·L-1 calcium treatments inhibited the growth and development of aboveground and underground parts of P. trifoliate, and chlorophyll a and b concentrations decreased. The calcium content in roots and leaves was proportional to the amount of exogenous calcium. ROS and callose deposition were generated in roots after treatment with different calcium concentrations, reaching the maximum at 3 mmol·L-1. After inoculation with Xcc, the leaf symptoms gradually decreased with the increase of calcium concentration, but the growth of Xcc had no significant difference. Compared with 3 mmol·L-1 treatment, PtCESA4, a gene involved in cell wall synthesis, was up-regulated and then down-regulated by Xcc under 0 mmol·L-1 treatment, and up-regulated by Xcc under 30 mmol·L-1 treatment. PtPME and PtFLA were down-regulated by Xcc under 0 mmol·L-1 treatment, and up-regulated by Xcc under 30 mmol·L-1 treatment. The expression levels of immune pathway related genes PtGSL, PtGST1 and PtWRKY22 induced by Xcc at 30 mmol·L-1 were higher than those at 0 and 3 mmol·L-1 after inoculation with Xcc at 0, 2, 4 and 6 dpi. 【Conclusion】 The growth and development of P. trifoliate is affected by calcium deficiency and excess, resulting in leaf chlorosis, and ROS production and callose deposition in roots decreased. The sensitive symptoms on the leaf surface caused by Xcc were greatly attenuated after calcium application, but the bacterial content was not significantly different from that of the control. Calcium may promote cell wall thickening by regulating genes related to cell wall synthesis, thereby inhibiting Xcc from breaking through leaf epidermis and forming typical symptoms.

    The Variation Characteristics of Soil Organic Carbon Component Content Under Nitrogen Reduction and Film Mulching
    WANG ChuHan,LIU Fei,GAO JianYong,ZHANG HuiFang,XIE YingHe,CAO HanBing,XIE JunYu
    Scientia Agricultura Sinica. 2022, 55(19):  3779-3790.  doi:10.3864/j.issn.0578-1752.2022.19.008
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    【Objective】 The aim of this study was to clarify the effects of long-term optimized fertilization (nitrogen reduction) and nitrogen reduction plus film mulching on the characteristics of soil organic carbon (SOC) and its components content, and their contribution to winter wheat grain yield, so as to provide the theoretical support for dryland fertility and crop productivity in the Loess Plateau. 【Method】 Based on a 7-year location experiment, the undisturbed soil samples from 0-20 cm under different management measures were collected. The variation characteristics of winter wheat grain yield, SOC and its components content were explored, including particulate organic carbon (POC), mineral organic carbon (MOC), light-particulate organic carbon (Light-POC) and heavy-particulate organic carbon (Heavy-POC), and the relationship between SOC and its component content as well as their quantity contribution to the winter wheat grain yield were clarified. The organic carbon components were grouped by continuous physical grouping method, and their contribution for wheat yield was analyzed by redundancy analysis. The experiment set four treatments, including farmer’s practice fertilization (FP), monitoring fertilization (MF), monitoring fertilization plus ridge mulching-furrow planting (RF), and monitoring fertilization plus whole field filming (FH). 【Result】 The average yield of winter wheat was the lowest under FP treatment, which was 3 070 kg·hm-2. Compared with FP, the wheat yield under MF showed no significant difference, while wheat grain yield under RF and FH could achieve a significant increase by 27.0% and 46.4%, respectively; compared with the initial year of the experiment (2012), the SOC content showed a significant increase under different management measures during seven consecutive years, and the increase rate from low to high was 11.8% (MF), 22.4% (RF), 25.5% (FP), and 36.1% (FH), respectively. The improvement of SOC under MF was the slowest in calcareous cinnamon soil, when MF combining with plastic film mulching showed a significant improvement. The observed SOC components under different treatments showed, compared with FP and MF, RF and FH significantly increased the content of POC, Light-POC and the proportion of Light-POC in SOC. Based on the cooperation of the redundancy analysis, sensitivity index analysis and correlation analysis between SOC and its component, POC contributed the most to the improvement of wheat yield (up to 71.0%) and was the most sensitive to SOC content change and different management measures. Therefore, the improvement of crop yield and soil fertility by FH was mainly achieved by increasing POC content in soil organic carbon. 【Conclusion】 The monitoring fertilization plus whole field filming treatment was benefit to increase soil organic carbon and active organic carbon content in the cinnamon soil in the southeastern of the Loess Plateau, and achieve a sustainable increase in winter wheat yield.

    Effects of Reduced Phosphorus Application on Crop Yield and Grain Nutritional Quality in the Rice-Wheat Rotation System in Chaohu Lake Basin
    ZHANG XinYao,ZHANG Min,ZHU YuanPeng,HUI XiaoLi,CHAI RuShan,GAO HongJian,LUO LaiChao
    Scientia Agricultura Sinica. 2022, 55(19):  3791-3806.  doi:10.3864/j.issn.0578-1752.2022.19.009
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    【Objective】 The aim of this study was to explore the effects of reduced phosphorus (P) application on crop yield and nutritional quality, so as to provide a theoretical basis for increasing the P use efficiency and producing high grain quality of crops under the rice-wheat crop rotation system in the Chaohu Lake Basin. 【Method】 A field trial of reduced P application rates was conducted from 2017 to 2019 with five treatments in the Chaohu Lake Basin, which were contrast (CK, No phosphorus), farmers’ application rate (P1, 90 kg P2O5·hm-2), 10% P reduction (P2, 81 kg P2O5·hm-2), 20% P reduction (P3, 72 kg P2O5·hm-2), and 30% P reduction (P4, 63 kg P2O5·hm-2). The effects of reduced P application rates on rice and wheat grain yield and its components, grain protein and fraction content, micronutrients and their bioavailability were analyzed. 【Result】 Compared with no P application, the P application significantly increased the grain yield of rice and wheat by 9.8% to 28.3% and 56.6% to 89.7%, respectively. The 10% and 20% P reduction treatments for rice and wheat grain yield were not significantly different from the farmers’ P fertilizer application (P>0.05). However, the rice yields under the 30% P reduction treatment were significantly decreased by 14.4%. Compared with the farmers’ P application rate, the P reduction treatments significantly affected the crop protein, gliadin and glutenin content, while which had no significant effect on structural protein (albumin and globulin); the P reduction of 20% reduced rice grain protein and glutenin content by 2.7% and 32.3%, respectively. Compared with farmers’ P application rate, the grain protein and glutenin content of rice and wheat under the 30% phosphorus reduction treatment reduced by 6.8% and 21.9%, 48.4% and 31.6%, respectively. Phosphorus application also significantly affected the micronutrients content and bioavailability in rice and wheat grains. Compared with the farmers’ P application rate, P reduction treatments increased iron (Fe), copper (Cu) and zinc (Zn) concentration in rice and wheat grains by 21.2% and 19.3%, 11.9% and 15.8%, 14.5% and 19.9%, respectively; meanwhile, P/Fe, P/Cu and P/Zn molar ratios also reduced by 21.6% and 26.3%, 20.6% and 27%, 17.7% and 21.3%, respectively. The grain zinc concentration of rice and wheat increased linearly with decreasing P application, while the iron, manganese (Mn) and Cu concentrations were no significant differences among the P reduction treatments. P/Zn molar ratio of rice reduced with lower P application, but the P/Fe, P/Mn and P/Cu molar ratios had no significant differences among P reduction treatments. The P/Fe, P/Mn, P/Cu and P/Zn molar ratios in wheat grains reduced with lower P application, and then increasing the bioavailability of Fe, Cu and Zn in wheat grains. 【Conclusion】 In the rice-wheat crop rotation area of the Chaohu Lake Basin, reduced P application by 20% (from 90 kg P2O5·hm-2 reduction to 72 kg P2O5·hm-2) could still ensure stable crop yields. The reduced application of P fertilizer significantly increased the micronutrients concentration and its bioavailability in rice and wheat grains, although the grain protein and glutenin content lower than the farmers’ P application rate. In conclusion, the P3 (20% reduction in P fertilizer application based on the farmers’ P application rate) was the recommended P fertilizer rate to achieve P use efficiency and double high (yield and quality) of crop production in the rice-wheat rotation areas of the Chaohu Lake Basin.

    Genome-Wide Identification of DIR Family Genes in Tomato and Response to Abiotic Stress
    CHEN FengQiong, CHEN QiuSen, LIN JiaXin, WANG YaTing, LIU HanLin, LIANG BingRuoShi, DENG YiRu, REN ChunYuan, ZHANG YuXian, YANG FengJun, YU GaoBo, WEI JinPeng, WANG MengXue
    Scientia Agricultura Sinica. 2022, 55(19):  3807-3821.  doi:10.3864/j.issn.0578-1752.2022.19.010
    Abstract ( 465 )   HTML ( 62 )   PDF (7744KB) ( 193 )   Save
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    【Objective】 The aim of this study was to identify all members of tomato DIR gene family, and to predict and analyze their gene structures, physicochemical properties of proteins, phylogenetic relationship, chromosome location, collinearity analysis, promoter elements, expression pattern, prediction of interacting transcription factors and endogenous competitive RNA, so as to provide a reference for exploring the role of DIR in tomato growth and development and response to environmental stresses. 【Method】 The family members of DIR were identified in the whole genome level by bioinformatics methods. The chromosome location, conserved motif, cis-acting element, transcription factors, miRNA and circRNA were analyzed with Phytozome, MEME, PlantCARE, opsRNATarget and plantcircnet, respectively. Chromosome location map, evolutionary tree, relationship map between DIR and transcription factors, ceRNA network, and etc., were drown using Maptea, TBtools, Cytoscape and Omicshare. The expression level of DIR under environmental stresses was studied by NCBI gene database, transcriptome sequencing and qRT-PCR. 【Result】 27 members of DIR family were identified from the whole genome of the tomato, which were named SlDIR1-SlDIR27, and DIR genes of the tomato were located on 12 chromosomes, most of which were located at the end of chromosomes. The gene structures, motifs and domains were relatively conservative, and the classical structure of one exon existed in 22 SlDIR genes. The collinear relationship of DIR genes between tomato and Arabidopsis was much higher than that of rice and soybean. Based on the phylogenetic relationship, 27 DIR members of tomato were divided into three different subfamilies. The tissue specific expression analysis revealed that transcription levels of DIR members of tomato were higher in root. In addition, the promoter region of these genes contained multiple cis-acting elements related to abiotic stress, including drought, low temperature, and hormone induction, such as MeJA, ABA and SA. Hormone, growth and abiotic stress related to transcription factors (ERF, E2F / DP and MYB) were also predicted. Combined with our transcriptome data of pesticide stress and published transcriptome data analysis, the expression level of 5, 10, 10 and 13 SlDIR genes was significantly up-regulated after pesticide, drought, salt and cold stress. And SlDIR23 was induced by all the four stresses, while SlDIR8, SlDIR13 and SlDIR20 were specifically responded to the induction of cold stress, and SlDIR17 specifically responded to salt stress. Finally, the ceRNA regulation of tomato DIR showed that miR-156 might interacted with the target gene SlDIR8 to regulate tomato against stresses. 【Conclusion】 A total of 27 DIR gene family members were identified from the tomato genome and unevenly distributed on 12 chromosomes, with high expression in roots. The expression of SlDIR1, SlDIR13, SlDIR14 and other genes was included by MeJA, ABA and SA and other hormone response elements, among which SlDIR6 only contained MeJA element, and SlDIR27 only contained SA response element. In addition, SlDIR2, SlDIR14, SlDIR23 and other genes were participated in drought, salt, low temperature and other stresses. Especially for SlDIR23, it could be activated under different stress treatments. In addition, DIR genes interacted with transcription factors and noncoding RNA to regulate the responses of tomato plants under stresses.

    Differences in Nutrient Absorption and Utilization of 87-1 Grape Variety Under Different Rootstock Facilities
    MA YuQuan,WANG XiaoLong,LI YuMei,WANG XiaoDi,LIU FengZhi,WANG HaiBo
    Scientia Agricultura Sinica. 2022, 55(19):  3822-3830.  doi:10.3864/j.issn.0578-1752.2022.19.011
    Abstract ( 268 )   HTML ( 39 )   PDF (458KB) ( 125 )   Save
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    【Objective】 In order to screen high-efficiency grape rootstocks with different nutrients, the nutrient uptake and utilization efficiencies of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg) in 87-1 grape variety grafted with 12 rootstock varieties were studied, which was beneficial to provide a theoretical basis for the selection of rootstocks and the improvement of fertilizer utilization in grape production. 【Method】 From January 2020 to November 2021, the whole grape plants sampled from 87-1 grape variety grafted with 12 rootstock varieties at the key growth stages, such as germination stage, initial flowering stage, end bloom stage, seed development stage, veraison stage, maturation stage and deciduous stage, were carried out for two consecutive years, respectively. Based on mineral element content of N, P, K, Ca, and Mg in plants, the element accumulation per plant, dry matter production efficiency (DMPE), fruit production efficiency (FPE) and harvest index (HI) of each combination were calculated. And then, the differences between each indexes were analyzed, and the effects of different rootstocks on the absorption and utilization of nitrogen, phosphorus, potassium, calcium and magnesium were compared. 【Result】 The significant differences in the accumulation of N, P, K, Ca, and Mg per plant among different stock were found, 87-1/34EM of which had the highest accumulation of N, P, K, Ca, and Mg. Using DMPE and FPE as indicators, the biological and economic utilization efficiencies of nutrients (BUE and EUE) were evaluated. N and K of 87-1/420A combination had the highest DMPE, and 87-1/Beta and 87-1/101-14 combinations had higher DMPE of P and Ca. DMPE of Mg in 87-1/5BB combination performed better. The FPE of K was the best within 1103P rootstock, while the 101-14 rootstock had the highest FPE of N, P, Ca and Mg. The HI reflected the absorption and distribution of nutrients in the fruit. Under different rootstock treatments, the Beta rootstock had the highest HI of P and K, and the HI of N, while Ca and Mg was the highest within SO4, 5BB and Huapu No. 1 rootstock, respectively. 【Conclusion】 The grape absorptions of N, P, K, Ca, and Mg within different rootstocks were significantly different, and the absorption capacity and utilization efficiency showed inconsistency. Beta and 101-14 rootstocks had higher BUE and EUE of P and Ca. The BUE and EUE of K within 1103P rootstock was higher. 420A and 5BB rootstocks performed the best BUE in terms of N and Mg, respectively, while 101-14 rootstocks performed best EUE in terms of those. In addition, The Beta rootstocks promoted the distribution of P and K to fruits. SO4, 5BB and Huapu No. 1 rootstocks promoted the distribution of N, Ca and Mg to fruits, respectively.

    Starch Physicochemical Properties and Expression Levels of Anabolism Key Genes in Sweetpotato Under Low Temperature
    CUI Peng,ZHAO YiRen,YAO ZhiPeng,PANG LinJiang,LU GuoQuan
    Scientia Agricultura Sinica. 2022, 55(19):  3831-3840.  doi:10.3864/j.issn.0578-1752.2022.19.012
    Abstract ( 280 )   HTML ( 45 )   PDF (493KB) ( 173 )   Save
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    【Objective】Starch is the main component of sweetpotatoe, and the main use of tuberous roots is directly determined by the physicochemical properties of starch. Sweetpotato is a typical temperature-preferred tropical crop and sensitive to the storage temperature. Therefore, it is very important to study the effects of low temperature on starch physicochemical properties for the safe storage of sweetpotato. 【Method】 The starch average granule size and distribution, heat enthalpy, gelatinization properties, moisture absorption and swelling power were investigated in an experiment conducted by using Yanshu 25 and Shangshu 19 with storage of 13℃ (CK) and 4℃ (Low temperature, LT) for 14 days. 【Result】 The results demonstrated that the significant differences were observed in amylose/amylopectin content between the two sweetpotato varieties. The amylose content of Shangshu 19 (31.47%) was significantly higher than that of Yanshu 25 (25.86%), while the amylopectin content showed an opposite trend. The average particle size, volume and surface area of Yanshu 25 and Shangshu 19 ranged from ≤2.50 μm, 2.50-5.00 μm to 5.00-25.00 μm, respectively. The average particle size, volume and surface area of starch particles, moisture absorption and swelling power were decreased under LT stress. The starch initial temperature (T0), peak temperature (Tp) and heat thermal value (△H) of Yanshu 25 and Shangshu 19 during gelatinization process were decreased significantly as compared with CK. The change in starch △H of Yanshu 25 was higher than that of Shangshu 19, which indicated that the effect of low temperature on thermal properties of Yanshu 25 starch was more serious than that of Shangshu 19. Under low temperature storage conditions, the peak viscosity (PKV), disintegration value (BDV) and recovery value (CSV) of Yanshu 25 and Shangshu 19 were decreased significantly, while the gelatinization temperature (PT) was not significantly affected by temperature. The differences between the two varieties were significant. The expression levels of IbAGPa, IbAGPb, IbSBEI and bSBEII genes were decreased significantly under LT condition, while Ibα-amylase and Ibβ-amylase increased significantly. 【Conclusion】 In conclusion, the temperature played an important role in the starch physicochemical properties of sweetpotato, and the change of which was closely related to the storage temperature.

    Characterization of Chilled Mutton by ATP from Different Sources
    SU YuanYuan,ZHANG DeQuan,GU MingHui,ZHANG ChunJuan,LI ShaoBo,ZHENG XiaoChun,CHEN Li
    Scientia Agricultura Sinica. 2022, 55(19):  3841-3853.  doi:10.3864/j.issn.0578-1752.2022.19.013
    Abstract ( 259 )   HTML ( 35 )   PDF (679KB) ( 86 )   Save
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    【Objective】 In order to explore a new method for predicting the freshness of chilled mutton, the changes of adenosine triphosphate (ATP in meat, microbial ATP and ATP of meat surface) from different sources during storage were systematically studied, then the ATP that could characterize the change of chilled mutton was screened, and finally the prediction models for the total viable counts and volatile base nitrogen were established. 【Method】 The longissimus dorsi muscle of Small Tailed Han sheep was stored in air sealed packaging at 0℃ for 0, 1, 3, 5, 7, 9, 11, 13, 15, 17, and 21 days, respectively. The freshness indexes (pH, color, volatile base nitrogen, and total viable counts) and ATP from three sources (ATP in meat, microbial ATP, and ATP of meat surface) of chilled mutton were analyzed during storage. The changes of ATP from different sources were evaluated, and the predictive models of freshness indicators were built. 【Result】 The freshness index of total viable counts and volatile base nitrogen in chilled mutton showed an upward trend during storage, and both of them exceeded the national standard limit after 17 days; the ATP in meat showed a decreasing trend, while the microbial ATP and the ATP of meat surface were increased, which was consistent with the change trend of the freshness index; the correlation coefficients (R) between ATP in meat, microbial ATP, ATP of meat surface and total viable counts, total volatile base nitrogen were -0.399, 0.910, 0.943 and -0.357, 0.725, 0.907, respectively. The optimal model for predicting the total viable counts in chilled mutton by ATP of meat surface was Boltzmann, which the formula was TVC (lg cfu/g)=7.649-4.069/(1+exp(x-5.807)/0.632), (R2 =0.903, P<0.001); the optimal model for predicting total volatile base nitrogen in chilled mutton by ATP of meat surface was Expedc1, which the formula was TVB-N (mg/100 g)=2.493*exp(x/3.745)+ 3.057 (R2=0.888, P<0.001). 【Conclusion】 The results showed that the ATP of meat surface of chilled mutton had the significant positive correlations with the total viable counts and volatile basic nitrogen, and then confirmed that the ATP of meat surface could be used as an indicator to characterize the freshness of chilled mutton. The optimal prediction model of the total viable counts and volatile base nitrogen could provide a new idea for rapid detection of chilled mutton freshness.

    Analysis of Indirect Genetic Effects on Body Weight of 42 Day-Old Rugao Yellow Chickens
    GUO Jun,WANG KeHua,HAN Wei,DOU TaoCun,WANG XingGuo,HU YuPing,MA Meng,QU Liang
    Scientia Agricultura Sinica. 2022, 55(19):  3854-3861.  doi:10.3864/j.issn.0578-1752.2022.19.014
    Abstract ( 244 )   HTML ( 37 )   PDF (617KB) ( 87 )   Save
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    【Background】 In addition to regulating its own phenotype, the genotype of an individual animal also affects the performance of other animals within a social group through resource allocation or behavioral interaction, and this phenomenon is called an indirect genetic effect. In the animal breeding, if the genetic model harbored the indirect genetic effects, it will not only improve the social relationship between individuals, but also obtain more genetic gains. 【Objective】 In this study, Rugao Yellow Chickens raised in group cages were used as the test animals, and the indirect genetic model was used to evaluate body weight data, aiming to provide a flexible model to select the Rugao Yellow Chickens. 【Method】The body weight data was collected from the breeding group of Rugao Yellow Chickens. The fowls were weighed at the age of 42 days-old, and 11 983 raw data were collected. The data cleaning procedure included: i. removing outlier beyond three standard deviations either side of the mean; ii. eliminate the fowl without marker; iii. get rid of unknown sexed fowls; iv. the fowls with less than 4 records within a social group were also excluded. The pedigree data consisted of 12 208 fowls, including 11 735 chickens with body weight records and 473 chickens without records, 10 560 chickens without progeny and 1 648 with progeny, and the progeny of them included 208 male breeders and 1 440 female breeders. With SPSS software packages, ANOVA was used to test the influence of environmental factors on body weight and determine the factors included in the fixed effects. The classic animal model and indirect genetic model were used to analyze the variance components and genetic parameters of Rugao Yellow Chickens, and to test whether there was a dilution effect on the indirect genetic variance. The genetic model included the general fixed effects, fixed regression terms, additive genetic effects, indirect genetic effects, common environmental effects and residuals. In this study, the fixed regression term included cage sizes, and random terms included additive genetic effects, indirect genetic effects and common environmental effects. The initial value of the dilution parameter was set to 0, and it was step increased to 1.0 in increments of 0.1. After evaluating with AIC and BIC standard, the dilution parameter should be set to 0. Accounting for heterogeneous errors did not alter the estimates of genetic parameters and variance components. Therefore, the homogeneous error was assumed. Using WOMBAT software, estimates of variance components and genetic parameters converged for both classic and indirect genetic models (with or without dilution effect). 【Result】The fixed effects included the combination of laying batch-row-sex level. The significant indirect genetic variance for body weight of 42-day-old Rugao Yellow Chickens was found, for the additive heritability was 0.54±0.02, and the total heritable variation was 0.66±0.06. The corporation relationship between individuals presented in the same cage of Rugao Yellow Chickens. The direction of additive genetic and indirect genetic selection was the same, and the genetic correlation coefficient was 0.41. There was no dilution effect in the indirect genetic variance of Rugao Yellow Chickens. The indirect genetic variances were distinguished between sexes, and so on heritability and genetic correlation coefficient. 【Conclusion】Indirect genetic model could be used for the genetic evaluation and selection of body weight during the rearing period. Compared with those classic animal models, the indirect genetic models could achieve an additional genetic gain.

    Study on Seasonal Grazing Management Optimal Model in Alpine Desert Steppe
    HU ZhiQiang,SONG XiaoYu,QIN Lin,LIU Hui
    Scientia Agricultura Sinica. 2022, 55(19):  3862-3874.  doi:10.3864/j.issn.0578-1752.2022.19.015
    Abstract ( 218 )   HTML ( 38 )   PDF (1202KB) ( 105 )   Save
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    【Objective】In order to protect the ecological environment of China’s alpine desert steppe and guide the comprehensive and sustainable development of grassland pastoral areas, this study took the alpine desert steppe as the research object, and the optimization simulation calculation and dynamic balance analysis of grassland and livestock were carried out. 【Method】In this paper, based on the characteristics of seasonal rotational grazing and livestock production rhythms, the spatial and temporal segregation of grassland resources and the dynamic changes in livestock numbers were considered, and the two pasture grazing time periods of warm season and cold season were refined. On the basis of the existing reasonable livestock carrying capacity calculation method, the maximum livestock carrying capacity was the goal, the dynamic grass-livestock balance was the constraint, and the turnout time and slaughter rate were the optimization parameters. A grazing-management optimization model was established, and the Ulan County Pastoral area of Qinghai Province was selected as the typical representative of alpine desert seasonal pastoral area. Based on the genetic algorithm optimization, the optimal grazing conditions under the three precipitation scenarios of wet, normal and dry in the pastoral area of Ulan County were determined, a simulation to optimize the forage-livestock balance and dynamic forage-livestock balance analysis was carried out, and then the results with those before optimization were compared. 【Result】 The simulation results of the grazing-management optimization model were better for different precipitation scenarios in the grazing area. Based on the lowest amount of unutilized forage, the optimal grazing conditions under the three precipitation scenarios of wet, normal and dry in the pastoral area of Ulan County were determined to be the transition of livestocks on November 1 with a slaughter rate of 43.4%, the transition of livestocks on November 3 with a slaughter rate of 38.2% and the transition of livestocks on November 3 with a slaughter rate of 36.7%, respectively. The optimal proper carrying capacity was 1.099 million sheep unit, 0.961 million sheep unit and 0.836 million sheep unit in high, normal, and low flow years, respectively, which were 11.75%, 10.44% and 10.43% higher than the proper carrying capacity before optimization, respectively. In addition to the livestock slaughter rate and the transition time, the precipitation was also an important factor affecting the proper carrying capacity in pastoral areas. Before and after optimization, the proper carrying capacity of Ulan County’s pastoral area in wet years was 0.983 and 1.099 million sheep unit, respectively, which was 30% higher than the proper carrying capacity of 0.757 and 0.836 million sheep unit in dry years, respectively. Through the analysis of pasture grass production process and livestock dynamic grass demand process, the dynamic grass-livestock balance calculation for the normal flow year in the pasture area of Ulan County was found that the available forage in the cold season pasture before optimization could not be fully utilized, the grazing process was unreasonable, and the surplus grass amount was more than 61.3 million kg, while after optimization, the problem of underutilization of available forage was effectively solved and the forage resources were efficiently utilized. For the whole grazing area of Ulan County, the adjusting grazing turnout time and livestock slaughter rate was a reliable way to improve the grazing system. The grazing-management optimization model was used to optimize the grazing process in the grazing area, which could ensure the high proper annual carrying capacity in the grazing area while being able to achieve a dynamic grass-livestock balance in the seasonal grazing area. 【Conclusion】The grazing-management optimization had the good applicability to alpine desert seasonal pasturing areas and had the certain superiority in the regulation of grazing management process and the optimization of forage-livestock balance in rotating pastoral areas. The grazing-management optimization model could effectively regulate the livestock carrying capacity of a grazing area, and its optimization results could provide reference for the development of a reasonable grazing system. Therefore, the model could be used to optimize the grazing process of a single herding household or ranch, to obtain the optimal grazing conditions for a single herding household or ranch, so as to develop the corresponding grazing system, which was more practical guidance and operability for the production practice of a single herding household or ranch.