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    12 July 2020, Volume 46 Issue 7
    • REVIEW
      Research advances on characteristics, damage and control measures of weedy rice
      CHEN Lei, JIN Man, ZHANG Wei-Le, WANG Cheng-Xu, WU Yong-Bin, WANG Zhi-Zhong, TANG Xiao-Yan
      Acta Agronomica Sinica. 2020, 46(7):  969-977.  doi:10.3724/SP.J.1006.2020.92064
      Abstract ( 1001 )   HTML ( 79 )   PDF (3059KB) ( 567 )   Save
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      Weedy rice (Oryza sativa f. spontanea) presumably originated from rice but has weedy characteristics. It is one of the malignant weeds in rice field that decreases rice production and grain quality severely. In this study, the biological characteristics of weedy rice were described from morphology, shattering, dormancy and stress tolerance. The process of weedy rice origination from de-domestication of cultivated rice was summarized briefly. We also introduced the worldwide distribution of weedy rice as well as its non-uniform distribution in China with the most severe occurrence in middle-south area of Jiangsu province and Zhanjiang of Guangzhou province. In addition, we analyzed the agricultural damage on rice yield, rice quality and paddy field ecology environment by weedy rice. To control the occurrence and spread of weedy rice, we further proposed comprehensive measures, including prevention and controlling measures, reasonable cultivation system, and scientific use of chemical herbicides.

      Establishment of an efficient genotyping technique based on targeted DNA endonuclease in vitro activity of CRISPR/Cas9 ribonucleoprotein
      WANG Nan,QI Xian-Tao,LIU Chang-Lin,XIE Chuan-Xiao,ZHU Jin-Jie
      Acta Agronomica Sinica. 2020, 46(7):  978-986.  doi:10.3724/SP.J.1006.2020.93064
      Abstract ( 809 )   HTML ( 35 )   PDF (3254KB) ( 275 )   Save
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      Establishing a rapid, accurate, high-throughput and easily implementable genotyping method is highly desirable for functional genomics, genetic improvement and mutant screening. Here, we describe a convenient and inexpensive technique for genotyping using the targeted DNA endonuclease activity of Cas9 or Cas9NG ribonucleoproteins complex (sgRNA/Cas9-RNP or sgRNA/Cas9NG-RNP). In this study, Cas9 and Cas9NG protein purified from E. coli extract was assembled with in vitro transcribed single guide RNA (sgRNA)or enhanced sgRNA (esgRNA) as an assembled ribonucleoprotein (RNP) complex to fulfill the targeted endonuclease activity on the PCR amplicons of ZmWx exon 7. The restriction profiles can be converted into genotyping results of wildtype, homozygous or heterozygous mutant, respectively. Our data showed that ZmWx gene-edited mutants can be genotyped rapidly and efficiently by the sgRNA-optimized system esgRNA/Cas9. The reaction component optimization data suggested that 500 ng of DNA substrates could be cleavaged completely by incubating with 1 μg 1:1 molar ratio of esgRNA/Cas9 ribonucleoproteins for 30 minutes at 37℃, or by 4 μg 1:1 molar ratio of esgRNA/Cas9NG ribonucleoproteins for 4 hours at 37℃. Expanding the targeting flexibility of mutant detection via esgRNA/Cas9NG indicated that Cas9NG variant might recognize relax NG PAM (protospacer-adjacent-motif, PAM) at the expense of decreasing restriction activity, which is necessary to improve the activity of esgRNA/Cas9NG by further optimization. Therefore, the establishment and application of esgRNA/Cas9 based PCR/RNP technique provides an easy, simple and low-cost approach to genotyping in functional genomics, molecular breeding and mutant screening. In addition, our in vitro data on esgRNA/Cas9NG has certain and significant reference value for developing it into in vivo genome editing studies.

      Development and verification of CAPS markers based on SNPs from transcriptome of jute (Corchorus L.)
      TAO Ai-Fen,YOU Zi-Yi,XU Jian-Tang,LIN Li-Hui,ZHANG Li-Wu,QI Jian-Min,FANG Ping-Ping
      Acta Agronomica Sinica. 2020, 46(7):  987-996.  doi:10.3724/SP.J.1006.2020.94158
      Abstract ( 658 )   HTML ( 21 )   PDF (1034KB) ( 320 )   Save
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      Developing CAPS markers can provide a new and effective tool for genetic diversity analysis, germplasm identification and marker-assistant selection of jute. The transcriptional sequence analysis was carried out by Illumina HiSeq 4000 with jute 179 and the wild species in Aidian. Furthermore, the SNP loci were screened and primers related to lignin synthesis genes 4CL, COMT and transcription factor MYB were developed. CAPS markers were screened based on above SNP primers using dCAPS Finder2.0 and their polymorphism was verified. A total of 72,674 unigene sequences were got in jute transcriptome by assembly, with a length of 29,705,997 bp, a number of SNP loci of 67,567, and an average of 1 SNP per 440 bp. Thirty-nine pairs of SNP primers related to 4CL, COMT, and MYB were designed by Oligo8, of which 26 pairs of CAPS primers were screened, with a developing rate of 66.7%. Among the 26 pairs of CAPS markers, 11 pairs were polymorphic, with a polymorphic ratio of 43.2%. The screened CAPS markers could effectively distinguish 12 different accessions of jute germplasm, indicating CAPS is an ideal molecular marker which can lie a reliable tool used in genetic research of jute.

      Fine mapping of Phytophthora resistance gene RpsZheng in soybean cultivar Zheng 97196
      ZHANG Xue-Cui,ZHONG Chao,DUAN Can-Xing,SUN Su-Li,ZHU Zhen-Dong
      Acta Agronomica Sinica. 2020, 46(7):  997-1005.  doi:10.3724/SP.J.1006.2020.94143
      Abstract ( 612 )   HTML ( 21 )   PDF (575KB) ( 139 )   Save
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      Phytophthora root rot caused by Phytophthora sojae, is a major disease in soybean production, which can cause serious yield losses. To date, the most effective way to control the disease is deployment of resistant soybean cultivars containing Phytophthora sojae (Rps) resistance genes. The previous study identified an Rps gene RpsZheng in soybean cultivar Zheng 97196, which was mapped on chromosome 3. The objective of this study was to confirm and finely map the resistance gene RpsZheng. The susceptible Williams and resistant Zheng 97196 were crossed and generated 188 F2:3 families, which were used as a mapping population. The genetic linkage map of RpsZheng was constructed using genetic and phenotypic data. RpsZheng was mapped between the flanking SSR markers SattWM82_39 (2.5 cM) and BARCSOYSSR_03_0269 (1.0 cM). Based on genome-wide resequencing data of parents, we developed and identified polymorphic InDel markers to further narrow the RpsZheng candidate region to 105.2 kb. Molecular detection among soybean cultivars was carried out using the co-segregation markers in the RpsZheng candidate region. The marker WZInDel11 could effectively distinguish RpsZheng from other Rps genes. This study identified specific genomic intervals of RpsZheng and developed co-segregation markers that can be effectively used for gene function studies and molecular assisted selection breeding.

      Screening of compatible maizeSNP384 markers and the construction of DNA fingerprints of maize varieties
      TIAN Hong-Li, YANG Yang, WANG Lu, WANG Rui, YI Hong-Mei, XU Li-Wen, ZHANG Yun-Long, GE Jian-Rong, WANG Feng-Ge, ZHAO Jiu-Ran
      Acta Agronomica Sinica. 2020, 46(7):  1006-1015.  doi:10.3724/SP.J.1006.2020.93048
      Abstract ( 879 )   HTML ( 11 )   PDF (3898KB) ( 139 )   Save
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      In order to improve the management of maize varieties and the protection of intellectual property rights, a compatible multiple platform loci combination maizeSNP384 was developed as a means of identifying varieties of maize. SNP-DNA fingerprints of 335 maize hybrids were constructed. All the 384 SNPs were located in the intra-genic region, showing good polymorphism. The average MAF, PIC, and DP of 384 loci were 0.39, 0.36, and 0.60, respectively. MAF in 88% of the 384 loci was most than 0.30, PIC in 98% was most than 0.30, and DP in 98% was most than 0.50. Pairwise comparative analysis of 335 maize hybrids using genetic similarity showed that the range of variation of GD (1-Nei genetic distance) was 0.60-0.99, and the ratios of GD value greater than or equal to 0.98, 0.95, and 0.90 were 0.10%, 0.38%, and 1.40%, respectively. The range of variation of GS (same allele ratio) was 0.50-0.99, and the ratios of GS value greater than or equal to 0.98, 0.95, and 0.90 were 0.03%, 0.11%, and 0.35%, respectively. The optimal locus combination was extracted from 384 SNPs, with the variety discrimination power of 0.99 when 12 SNPs were extracted; the combination of 20 SNPs was able to identify all 335 varieties. In summary, 384 core SNPs reported in this study are compatible with multiple platforms, highly stable, highly repeatable and having high variety discrimination power. SNP-DNA fingerprints of 335 maize hybrids were constructed based on these core SNPs, which provides key data support for molecular identification, fingerprint data construction, and molecular breeding of maize.

      Fine mapping of a major QTL qMES20-10 associated with deep-seeding tolerance in maize and analysis of differentially expressed genes
      REN Meng-Meng, ZHANG Hong-Wei, WANG Jian-Hua, WANG Guo-Ying, ZHENG Jun
      Acta Agronomica Sinica. 2020, 46(7):  1016-1024.  doi:10.3724/SP.J.1006.2020.93054
      Abstract ( 631 )   HTML ( 15 )   PDF (1693KB) ( 265 )   Save
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      Drought stress is a major threat to maize (Zea mays L.) yield. Deep-seeding tolerant maize variety can absorb water in deep soil and thus have strong drought tolerance. Therefore, it is of great theoretical and practical importance to study the genetic mechanism of deep-seeding tolerance. In our previous work, we identified a major QTL qMES20-10 controlling maize deep-seeding tolerance on chromosome 10 using an F2:3 population derived from a deep-seeding tolerant inbred line 3681-4 and a common inbred line X178. In this study, a BC3F3:4 population was constructed through background and foreground selection using X178 as the recurrent parent. The major QTL, qMES20-10, was firstly verified in this BC3F3:4 population. Furthermore, advanced backcross population was constructed through marker-assisted selection, and qMES20-10 was fine-mapped within the interval of 133.3-136.0 Mb on chromosome 10. Moreover, RNA-Seq analysis of two near-isogenic lines screened from the BC3F3:4 families identified the differentially expressed genes, mainly involved in chemical stimulus response, oxidation reduction, and oxidative stress response. These results lay a foundation of further cloning the major QTL qMES20-10.

      Cloning and functional analysis of GmNRT1.2a and GmNRT1.2b in soybean
      LI Guo-Ji, ZHU Lin, CAO Jin-Shan, WANG You-Ning
      Acta Agronomica Sinica. 2020, 46(7):  1025-1032.  doi:10.3724/SP.J.1006.2020.94152
      Abstract ( 612 )   HTML ( 24 )   PDF (1848KB) ( 272 )   Save
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      Nitrate transporters (NRTs) have been found to be involved in nitrate uptake, transport and allocation in Arabidopsis. The role of GmNRT1.2s in soybean (Glycine max) symbiotic nitrogen fixation process has been speculated by bioinformatics analysis, however, its biological function has not been explored yet. In this study, we mainly focused on analyzing the expression pattern and biological function of GmNRT1.2a and GmNRT1.2b in soybean. The relative expression levels of GmNRT1.2a and GmNRT1.2b were higher in leaves, which induced by nitrate and up-regulated with increasing nitrate concentration. GmNRT1.2a and GmNRT1.2b expressions were also induced by rhizobial inoculation and nod factor (NF) treatment. Overexpression of GmNRT1.2a or GmNRT1.2b caused dramatic increment of nodule number. The results provide some data for further investigating the molecular mechanism of GmNRT1.2a and GmNRT1.2b in regulating the symbiotic nitrogen fixation process of soybean.

      Identification of drought-related co-expression modules and hub genes in potato roots based on WGCNA
      QIN Tian-Yuan, SUN Chao, BI Zhen-Zhen, LIANG Wen-Jun, LI Peng-Cheng, ZHANG Jun-Lian, BAI Jiang-Ping
      Acta Agronomica Sinica. 2020, 46(7):  1033-1051.  doi:10.3724/SP.J.1006.2020.94130
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      Weighted gene co-expression network analysis (WGCNA) is a research method in systematic biology. It is widely used to identify gene modules related to target traits in multi-sample transcriptome data. In order to further explore the molecular mechanism of potato response to drought stress, two cultivars (C16: CIP 397077.16 and C119: CIP 398098.119) introduced from the International Potato Center were used as experimental materials, and five drought stress gradients were treated for 0 h, 2 h, 6 h, 12 h, and 24 h, with the untreated material as a control. A total of 30 samples of root system were used for transcriptome sequencing, with three biological replicates. Based on the above transcriptome data, we constructed a co-expression network of weighted genes associated with stress-resistant physiological traits by WGCNA, and obtained 15 gene co-expression modules closely related to root drought resistance. In addition, a number of hub genes involved in drought stress regulation pathways were discovered from the four modules with the highest correlation with target traits. These results provide clues for further study on the molecular genetic mechanisms of potato root drought resistance.

      Photo-thermal interaction model under different photoperiod-temperature conditions and expression analysis of SiCCT gene in foxtail millet (Setaria italica L.)
      JIA Xiao-Ping,YUAN Xi-Lei,LI Jian-Feng,WANG Yong-Fang,ZHANG Xiao-Mei,ZHANG Bo,QUAN Jian-Zhang,DONG Zhi-Ping
      Acta Agronomica Sinica. 2020, 46(7):  1052-1062.  doi:10.3724/SP.J.1006.2020.94144
      Abstract ( 587 )   HTML ( 24 )   PDF (1313KB) ( 325 )   Save
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      Photoperiod and temperature are two important environmental factors that affect growth and development, ecological adaptability and yield of crops. Uncovering the effect of interaction between photoperiod and temperature on crop growth and development and the molecular mechanism for this interaction has important influence on breeding practice and theoretical research. In this study, four photo-thermal treatments (long-day and high temperature, long-day and low temperature, short-day and high temperature, short-day and low temperature) were designed to investigate heading stage, plant height, leaf number and panicle length of ‘Huangmaogu’. The photoperiod played a key role on growth of foxtail millet, while changes in temperature had no more effect on delaying reproductive growth by long-day treatment compared with that by short-day treatment. The effect of temperature differed with the difference of photoperiod, high temperature shortened vegetative growth period and low temperature prolonged vegetative growth period under short-day condition, while it was opposite under long-day condition. The effect on reproductive growth was short-day and high temperature treatment > short-day and low temperature treatment > long-day and low temperature treatment > long-day and high temperature treatment. Furthermore, a CCT-motif gene named SiCCT was cloned from leaf of ‘Huangmaogu’ by RT-PCR technology, which encodes 286 aa and belongs to CMF subfamily. Phylogenetic analysis based on aa sequences of CCT-motif genes showed that there existed a close relationship among foxtail millet, sorghum and maize. Real-time PCR analysis showed that the expression level of SiCCT was higher in leaf than in young panicle and leaf sheath. The SiCCT showed a circadian expression pattern under both long-day and short-day conditions. The expression level of SiCCT was the highest at 7-leaf stage, and decreased rapidly at 8-leaf stage (heading) and after heading under short-day condition. The expression of SiCCT maintained high level from 7-leaf stage to 10-leaf stage under long-day condition, during which ‘Huangmaogu’ was at vegetative growth phase. No matter high temperature or low temperature, the expression level of SiCCT at different leaf stages was totally higher in long-day treatment than in short-day treatment, and lower in low temperature than in high temperature under long-day condition. The general expression level of SiCCT was positively correlated with vegetative growth period of ‘Huangmaogu’. In summary, SiCCT is regulated by both photoperiod and temperature, suggesting that SiCCT participates in photoperiod pathway and thermosensory pathway, and regulates the whole vegetative and reproductive growth process of foxtail millet through interaction between the two pathways.

      Effects of 5-aminolevulinic acid and ethephon compound on carbon balance of source-sink of spring maize in Northeast China
      LI Rui-Jie,TANG Hui-Hui,WANG Qing-Yan,XU Yan-Li,WANG Qi,LU Lin,YAN Peng,DONG Zhi-Qiang,ZHANG Feng-Lu
      Acta Agronomica Sinica. 2020, 46(7):  1063-1075.  doi:10.3724/SP.J.1006.2020.93065
      Abstract ( 638 )   HTML ( 16 )   PDF (1576KB) ( 175 )   Save
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      In order to explore the mechanism of 5-aminolevulinic acid (5-ALA) and ethephon (ETH) compound for alleviating chilling damage, and to establish a chemical controlled cultivation technique for cold tolerance, dense planting and stable production of spring maize (Zea mays L.) in Northeast China, we conducted a field experiment at Gongzhuling Experiment Station (43o9'55"N, 124o48'43"E) of Jilin province, China, in 2018 and 2019. The maize (cv. Zhongdan 909) plants were treated with mixture of 5-ALA and ETH at different concentrations by foliar spraying at the jointing stage (V6). The source-sink metabolism, grain filling rate and yield of spring maize were evaluated. The yield of plants treated with 22.50 g hm-2 5-ALA combined with 450 g hm-2 ETH (A2E1) was significantly increased by 4.8% compared with the control. A2E1 promoted the synthesis of sucrose in functional leaf before anthesis. The sucrose phosphate synthase (SPS) activity and sucrose content in functional leaf were increased by 5.4% and 7.9% by A2E1 treatment, in comparison with the control, respectively. A2E1 treatment promoted the transport of sucrose from leaf to kernel during the first 20 days after anthesis, showing that the sucrose content decreased by 14.4% in the ear leaf, but increased by 41.4% in kernel. In addition, A2E1 also promoted sucrose degradation in grain. Sucrose synthase (SS) activity in the direction of decomposition was increased by 12.5% compared with the control, and the activities of acid invertase (AI) and neutral invertase (NI) were increased by 52.8% and 24.1%, respectively, during early grain-filling stage (about 10 days after anthesis). In this case, spring maize under A2E1 treatment had a relatively higher maximum grain-filling rate than the control treatment. At harvest, ear length and kernel number per ear were 4.7% longer and 8.6% higher, respectively, and the bare tip length was 58.3% shorter than those of the control. In conclusion, 5-ALA-ETH can effectively improve the transportation of sucrose between source and sink of spring maize in Northeast China, accelerate the kernel filling and alleviate the effect of chilling damage during the growing period, which is of great guarantee to a high and stable yield of spring maize in this region.

      Biological characteristics and cytological studies on anther abortion of male sterile Camellia crassocolumna
      JIANG Hui-Bing,YANG Sheng-Mei,LIU Yu-Fei,TIAN Yi-Ping,SUN Yun-Nan,CHEN Lin-Bo,TANG Yi-Chun
      Acta Agronomica Sinica. 2020, 46(7):  1076-1086.  doi:10.3724/SP.J.1006.2020.94159
      Abstract ( 817 )   HTML ( 21 )   PDF (16191KB) ( 236 )   Save
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      The purpose of this study was to explore the flower morphology, anther and pollen abortion time and its cytological characteristics in male sterile plants of C. crassocolumna. The flowering process, floral morphology, anther structure, meiosis and microsporogenesis of male sterile (M350) and fertile plants (M352) of C. crassocolumna were observed by stereomicroscopy, paraffin section, chromosome preparation and DAPI staining. The results showed that the wild tea plant had a perfect flower, its anthers were tetrasporangiate shaped like a butterfly, with an anther wall development of basic type. It tapetal cells were binuclear, forming secretory cells at the tetrad stage, and degrading during mononuclear pollen stage. After the meiosis I, meiosis II and cytokinesis, pollen mother cells developed into tetrahedral tetrads. Microspores were triangular, and mature pollen was two-celled. The stamens of male sterile flowers developed normally in the early stage of flower bud development, and there was no difference between sterile and fertile flowers, while in the late stage of flower bud development, filaments were curved, anthers adhered and shriveled, anthers could not release pollen. The tapetal cells of male sterile flowers were proliferation abnormally and disordly at the meiosis of stage pollen mother cells, and the degradation of tapetum was delayed during the mononuclear and binucleate pollen periods. During meiosis of pollen mother cells of male sterile flowers, there were some abnormal appearances, such as chromosome ring, lagging chromosomes, chromosome bridges, chromosomal deletion, scattered chromosomes, unequal separation, micronucleus and abnormal tetrad. In sterile plants, the microspore cytoplasm was disorder, pollen grains adhered to each other at the mononuclear stage, pollen wall crumpled and deformed, cytoplasm and nucleus of pollen were blurred, the mature pollen cells were hollow and sunken. Taken together, the floral organ morphology of male sterile plants in C. crassocolumna belongs to stamen collapse type and anther abnormality type. The development of anthers is blocked from meiosis of pollen mother cells to uninucleate pollen stage, belonging to pollen mother cell abortion type and uninucleate pollen abortion type. Mononuclear period is the main period of anther abortion. Tapetum degradation delayed, chromosomal abnormalities of pollen mother cells in meiosis, and abnormal development of microspores and pollens, might be the main reasons for anther abortion in male sterile plants of C. crassocolumna.

      Individual and combined effects of air temperature at filling stage and nitrogen application on storage protein accumulation and its different components in rice grains
      HAN Zhan-Yu,GUAN Xian-Yue,ZHAO Qian,WU Chun-Yan,HUANG Fu-Deng,PAN Gang,CHENG Fang-Min
      Acta Agronomica Sinica. 2020, 46(7):  1087-1098.  doi:10.3724/SP.J.1006.2020.92062
      Abstract ( 595 )   HTML ( 23 )   PDF (3708KB) ( 391 )   Save
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      Air temperature during grain-filling stage and application amount of nitrogen fertilizer are two of most important factors affecting rice grain quality, which largely related to grain protein content and cooking palatability. In this paper, the difference in grain protein content and its composition was investigated using different rice varieties, with different temperature treatments under artificial controlled condition and three nitrogen application levels in a long-term experiment field. Meanwhile, another experiment of two factors (temperature and nitrogen) in pot condition was conducted to clarity the interaction effects of temperature and nitrogen on grain protein content and its components. The higher temperature (HT) and heavier N application (HN) significantly enhanced the total protein content and glutelin accumulation in rice grain. However, HT differed obviously from HN in their impact on grain prolamin. HT significantly decreased grain prolamin concentration and markedly enhanced the ratio of glutelin to prolamin in rice grains, while HN increased in grain glutelin and prolamin contents had smaller effects on ratios of glutelin to prolamin and the proportion of subunit compositions in grain storage proteins. Furthermore, HT had a marked impact on the glutelin composition in rice grains, with the significant increase in 57 kD pro-glutelin amount. However, the effect of HT on 37 kD α-glutelin and 22 kD β-glutelin was greatly variable among different rice varieties. The varying extent of grain protein amount per grain (mg grain-1) affected by HT was much smaller than that of grain protein content (%). The combined effect of HT and HN on the total storage protein and glutelin accumulation in rice grain was much greater than the individual effect of HT and HN. The dropping extent of grain prolamin content under HT appeared to be smaller for HN relative to LN, suggesting that appropriate N application was beneficial to keep the relatively stable content of grain prolamin composition under the fluctuating temperature for rice growth.

      Extraction of crop acreage based on multi-temporal and dual-polarization SAR data
      Gulnur ISAK,Mamat SAWUT,MA Chun-Yue
      Acta Agronomica Sinica. 2020, 46(7):  1099-1111.  doi:10.3724/SP.J.1006.2020.94134
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      It plays a vital role in agricultural production management and agricultural policy formulation to acquire spatial distribution information and planting area of crops timely and accurately. In this paper, according to the phenological characteristics of crops, the back scattering coefficients (Sigma) and normalized back scattering coefficients (Gamma) of cotton, corn and orchard in different growth periods were extracted by using multi-temporal Sentinel-1A images (April 17, May 5, June 16, July 22, August 27, and September 2). The time-series change curves of the scattering characteristics were established and the characteristics were analyzed by using backscattering coefficients of crops with different polarizations and different time phases. Artificial neural network (ANN), support vector machine (SVM), and random forest (RF) were used to classify and identify cotton, corn and orchard. On this basis, the classification results were compared and analyzed, and the accuracy was verified. The backscattering coefficient of cotton increased significantly in June and July with the highest value in August, of which the changes were most obvious and easily distinguished from other crops. The backscattering coefficients of corn and fruit trees were significantly different from those of other land objects in September. The optimal classification was obtained by using random forest (the overall accuracy was up to 88.97%) than by using neural network and support vector machine. The classification accuracy for cotton and orchard was 90.88% and 93.17%, and the classification effect of corn is the worst, only 71.6%. In conclusion, multi-temporal and dual-polarization SAR data has certain application potential in the identification and area extraction of different crops.

      A comparison of photogrammetric software packages for mosaicking unmanned aerial vehicle (UAV) images in agricultural application
      CHEN Peng-Fei,XU Xin-Gang
      Acta Agronomica Sinica. 2020, 46(7):  1112-1119.  doi:10.3724/SP.J.1006.2020.91066
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      Unmanned aerial vehicle (UAV) remote sensing technology provides a new tool for precise agricultural management. High precision automatic stitching of UAV images is the basis for application of UAV remote sensing technology. At present, there exist researches to compare the performance of stitching software packages on their spatial precision, but few researches on the evaluation of their spectral precision, which is very important for quantitative remote sensing inversion. The objective of this study was to compare the influence of the two most popular UAVs orthomosaic-processing software packages, Pix4D and Photoscan, on the spectral information of original single image when stitching the image in agricultural application and to recommend the better one for users. For this purpose, multispectral sensor was carried on a UAV to acquire images over a winter wheat fertilization experiment. The acquired images were processed by Pix4D and Photoscan software packages to produce mosaicked image. In the meanwhile, single multispectral images were also produced using the method released by sensor manufacturer. Based on above data, randomly placed samples in the fertilization treatment, extracted spectral information of each point in the three types of images individually, and compared their reflectance value and image contrast. Although there were significant correlations in reflectance values between the mosaicked images proceed by Pix4D and Photoscan and the single image for each band, the reflectance value and its coefficients of variation from Photoscan mosaicked image were closer to the corresponding values of single image, compared with Pix4D mosaicked image. It means Photoscan retains more spectral information of the original image during stitching image. Considering the geometric accuracy results and software package prices from existing studies, Photoscan is suggested as the better package for users.

      Cloning and functional analysis of the sweet potato sucrose transporter IbSUT3
      WANG Dan-Dan, LIU Hong-Juan, WANG Hong-Xia, ZHANG Peng, SHI Chun-Yu
      Acta Agronomica Sinica. 2020, 46(7):  1120-1127.  doi:10.3724/SP.J.1006.2020.94173
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      Sucrose, as the main transporter of photosynthate, is transported by sucrose transporters. In this study, we cloned IbSUT3 gene from sweet potato (Ipomoea batatas Lam. GenBank accession number MN233361), by RACE technique. The full-length sequence of the gene is 1607 bp and the complete open reading frame is 1518 bp, encoding 505 amino acids. The predicted protein has the molecular weight of 53.82 kD and isoelectric point of 9.19, containing 12 transmembrane domains. Multiple sequence alignment analysis indicated the protein, belonging to Group I, was significantly different from Group IV in evolution and shared high similarities with SUTs from other plant species. IbSUT3 had the function of transporting sucrose verified by SUSY7/ura3 system. Subcellular localization showed that IbSUT3 protein was located in the tobacco protoplasts plasma membrane. The qRT-PCR results showed that IbSUT3 highly expressed in leaves and induced by drought, high salt, low temperature and exogenous abscisic acid, suggesting that IbSUT3 is involved in response to various abiotic stresses, including abscisic acid.

      Evaluation of matrix reference material of Fumonisins FB1 in corn flour
      NIU Xin-Ning,WANG Bu-Jun
      Acta Agronomica Sinica. 2020, 46(7):  1128-1133.  doi:10.3724/SP.J.1006.2020.93056
      Abstract ( 475 )   HTML ( 8 )   PDF (345KB) ( 121 )   Save
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      To fill the gap of matrix reference material of fumonisins in our country, we developed a reference material of Fumonisins FB1 in corn flour. The homogeneity and stability of corn samples were tested by UPLC-MS/MS after screening, labeling, freeze-drying, grinding, mixing and sealing it. The content of Fumonisins FB1 in corn flour was determined by several laboratories, and the uncertainty of samples was analyzed. The homogeneity of the sample was calculated, with 1.42 of F which was less than the critical F0.05, and there was no significant change in the content of Fumonisins FB1 within the limited time for six months. The results showed that the uniformity and stability fulfill the requirements of reference material. The determined value of the sample was 1475.56 μg kg-1, and the uncertainty was 169.98 μg kg-1. The reference material can be used to calibrate the instrument, control laboratory quality and evaluate the testing quality of operators during the testing process of Fumonisins.

the Crop Science Society of China
the Institute of Crop Science, CAAS
China Science Publishing & Media Ltd.
Published: Science Press
Editor-in-chief: Wan Jian-min
Associate Editors-in-Chief:
Chen Xiao-ya Yang Jian-chang Zhang Xian-long Wang Jian-kang Xu Ming-liang Liu Chun-ming Wang Dao-wen Sun Chuan-qing Ding Yan-feng Jin Wei-wei Chu Cheng-cai Cheng Wei-hong
Director of the editorial department:
Cheng Wei-hong
CN 11-1809/S
ISSN 0496-3490
Post subscription code: 82-336

  • Started in 2013
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Editor in chief: Wan Jian-min
CN 10-1112/S
ISSN 2095-5421, 2214-5141(online)
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