Welcome to Acta Agronomica Sinica,

Table of Content

    12 July 2022, Volume 48 Issue 7
      Characterization and genetic mapping of a classic-abortive-type recessive genic-male-sterile mutant ap90 in rice (Oryza sativa L.)
      CHEN Chi, CHEN Dai-Bo, SUN Zhi-Hao, PENG Ze-Qun, Adil Abbas, HE Deng-Mei, ZHANG Ying-Xin, CHENG Hai-Tao, YU Ping, MA Zhao-Hui, SONG Jian, CAO Li-Yong, CHENG Shi-Hua, SUN Lian-Ping, ZHAN Xiao-Deng, LYU Wen-Yan
      Acta Agronomica Sinica. 2022, 48(7):  1569-1582.  doi:10.3724/SP.J.1006.2022.12044
      Abstract ( 241 )   HTML ( 50 )   PDF (12430KB) ( 290 )   Save
      Figures and Tables | References | Related Articles | Metrics

      In this study, we obtained a stable male sterile mutant abortive pollen 90 (ap90) from the mutant library of Zhonghui 8015 (wild-type, WT), an indica restorer line, induced by Ethyl Methy Sulfone (EMS). Compared to the WT, the ap90 mutant displayed no significant differences in plant height, plant type, tiller number, heading date and other agronomic traits, but the anthers were thinner, light creamy yellow and pollen grains were completely abortive. Semi-thin sections observation of anther development at different stages showed that the ap90 mutant carried an abnormal development process of anther wall cells. Namely, the tapetum cell degradation was obviously abnormal, the microspore cells could not form a normal pollen wall structure during mitosis and the starch filling process was blocked which eventually resulted in the degradation of microspores into threadlets and failure of anther dehiscence. Scanning electron microscopic (SEM) observations of the anther surface and pollen exine suggested that the anther epidermis of mutant ap90 were shrunk and covered by more compactly arranged cuticles. The shape of Ubisch distributed on the inner surface of anther locule were irregular, closely arranged and disordered. The pollen grains were shriveled and the sporopollenin on the pollen exine were abnormally arranged. Genetic analysis showed that the ap90 phenotype was controlled by a pair of recessive nuclear genes. Gene preliminary mapping located the mutation site into a 491.73 kb interval between RM21421 and RM21435 on the long arm of rice chromosome 7. Further Mut-Map sequencing analysis confirmed that there was a 37 bp deletion and a following single base substitution in the second exon region of LOC_Os07g22850 in the ap90 mutant, which resulted in the shifted coding sequence, prematurely terminated transcription and translation, leading to the entire abortive pollen and sterile spikelet in the ap90 mutant. Expression pattern analysis results demonstrated that the OsAP90 gene was specifically expressed in anthers and the OsAP90 protein was mainly located in the endoplasmic reticulum (ER). The qPCR results suggested that the relative expression level of many male sterility-related genes in the ap90 mutant was affected by the mutation site, which further proved that OsAP90 played an important role during the formation of Ubisch and pollen wall in rice anther development.

      Analysis of drought responsive regulatory network in sugarcane based on transcriptome and WGCNA
      LI Pei-Ting, ZHAO Zhen-Li, HUANG Chao-Hua, HUANG Guo-Qiang, XU Liang-Nian, DENG Zu-Hu, ZHANG Yu, ZHAO Xin-Wang
      Acta Agronomica Sinica. 2022, 48(7):  1583-1600.  doi:10.3724/SP.J.1006.2022.14121
      Abstract ( 233 )   HTML ( 31 )   PDF (2398KB) ( 197 )   Save
      Figures and Tables | References | Related Articles | Metrics

      Drought is one of the important factors restricting the development of sugarcane industry. Previous studies have shown that E. arundinaceus has good resistance genes, which can be inherited through distant hybridization. In this study, we used YCE96-40, a F1 hybrid clone of E. arundinaceus and sugarcane, as material to analyze the transcriptome of leaves and roots after drought treatment for 0 and 24 hours at seedling stage. We compared the differences in response of roots and leaves to drought at transcriptional level, and identified 21,885 differentially expressed genes (DEGs) (DR vs CR: 10176, DL vs CL: 7907). The root response to drought stress was more intense. GO functional enrichment analysis showed that DEGs in roots and leaves were enriched in items related to dehydration response and hormone signal transduction process, such as “response to osmotic stress biological process” and “response to water shortage biological process”. Different from leaves, a large number of DEGs in roots were significantly enriched in the items related to cell membrane. Several lignin related DEGs were identified in roots, which indicated that lignin was involved in root drought response. Through WGCNA analysis of all DEGs, a total of 11 gene co-expression modules were identified, including five modules significantly related to root after drought treatment and two modules significantly related to leaf after drought treatment. Furthermore, 26 transcription factors were selected as candidate transcription factors for drought response in sugarcane, and the regulatory network was constructed. The results provide theoretical guidance for further understanding the molecular mechanism of sugarcane drought resistance and sugarcane drought resistance breeding.

      Expression characteristic and gene diversity analysis of ScHTD2 in sugarcane
      LI Xu-Juan, LI Chun-Jia, WU Zhuan-Di, TIAN Chun-Yan, HU Xin, QIU Li-Hang, WU Jian-Ming, LIU Xin-Long
      Acta Agronomica Sinica. 2022, 48(7):  1601-1613.  doi:10.3724/SP.J.1006.2022.14130
      Abstract ( 136 )   HTML ( 15 )   PDF (7328KB) ( 58 )   Save
      Figures and Tables | References | Related Articles | Metrics

      Tillering is one of the most important agronomic traits for sugarcane which is a vegetatively propagated economic crop. Mining these genes related to tillering trait and utilizing them form an ideal architecture are important to effectively increase cane yield of sugarcane varieties. In this study, qRT-PCR technology was used to explore the expression characteristics of a homologue of HTD2 related to rice tillering, which was named ScHTD2 previously obtained from sugarcane. The polymorphism of ScHTD2 gene in sugarcane germplasm resource population was analyzed, and the correlation between variation sites and tillering trait were also detected. The results showed that relative expression of this gene was tissue specific and highest in leaves. During the germination and development of axillary, the relative expression was the highest in the dormant buds. With the germination of sugar buds, the relative expression level first was significantly down-regulated, and the germination and development of sugar buds were negatively regulated. Treatments of phytokinin, auxin and strigolactone can significantly induce its expression in germinating axillary buds and tiller buds of seedling. By combining with the phenotypic changes after hormone treatment, the high expression of this gene induced auxin and strigolactone could inhibit the continued development of germinating axillary buds and delay the occurrence of tillers, but this inhibitory effect did not occur in the high expression of this gene induced by phytokines. Gene polymorphism analysis on 520 cloned sequences of HTD2 genomic DNA from 26 sugarcane germplasm resources showed that the genome sequence structure of this gene contained two exons and one intron, and the variation was the most abundant in the intron region, followed by the exon 1 region. Much higher nucleotide diversity in intron region was detected in main sugarcane variety population, while the origin species parent population had the higher nucleotide diversity in exon 1 and 2 regions. In terms of haplotype diversity in the coding region, the origin species parent population possessed the most abundant haplotype diversity, followed by the main variety population. In the genetic selectivity test, the original species parent population was subjected to positive selection, with high selection pressure and rapid gene evolution, while the backbone parents population and the main variety populations are subject to negative selection toward purification. Two haplotypes of code region located at radiating center of haplotype evolution map, indicating that they belonged to primitive types. The dose effect of mutation type from 23 SNP sites and 5 InDel sites in the code region was significantly related to the tillering rate of sugarcane germplasm resources, so more attention should be paid to the dose effect of mutation types in sugarcane molecular assisted-breeding plan in future. The present study lays a foundation for further analyzing the biological meaning of tillering related to key genes and the development of functional markers in sugarcane.

      Reference genes screening for expression analysis of secondary cell wall synthesis related genes in jute (Corchorus capsularis)
      YANG Xin, LI Yu, LIU Chuan-Bing, ZHANG Li-Lan, HE Qin-Yao, QI Jian-Min, ZHANG Li-Wu
      Acta Agronomica Sinica. 2022, 48(7):  1614-1624.  doi:10.3724/SP.J.1006.2022.14119
      Abstract ( 134 )   HTML ( 15 )   PDF (2757KB) ( 41 )   Save
      Figures and Tables | References | Related Articles | Metrics

      Selecting suitable reference genes for calibration and standardization can not only improve the accuracy of real-time quantitative PCR (qRT-PCR), but also lay the foundation for analyzing the expression pattern of genes related to secondary cell wall synthesis in jute. In the present work, 8 candidate reference genes were screened on the homologs of common reference genes by using available genomic and transcriptomic data of the research group. To evaluate the stability of candidate genes, we used different tissues (roots, stems and leaves) of ‘Huangma 179’ at the 14 days after germination (DAG) as materials for qRT-PCR. Then qRT-PCR data were analyzed by coefficient of variation (CV) of Ct value, the softwares of geNorm and NormFinder, respectively. The results showed that the most stablest reference gene was CcDnaJ, and the best combination of reference genes was ‘CcDnaJ + CcUBQ + CcUBI’. The expression patterns of secondary wall synthesis related genes were analyzed by transcriptomic data of hypocotyls at the 10 DAG, stem barks at the 60 DAG and 90 DAG. The electronic expression of lignin synthase genes, Cc4CL1 and CcCCoAOMT1, in stem barks at the 60 DAG were the highest, and then decreased at the 90 DAG. The expression of cellulose synthase genes, CcCesA4, CcCesA7, CcesA8, and xylan biosynthesis genes, CcIRX8, CcIRX9, CcFRA, in hypocotyls at the 10 DAG were the highest, and decreased in stem barks at the 60 DAG and 90 DAG. These findings indicate that these genes were involved in jute fiber development. Furthermore, the expression patterns of 5 secondary wall synthesis related genes, Cc4CL1, CcCCoAOMT1, CcCesA4, CcCesA7, and CcesA8, were analyzed by qRT-PCR using the reference gene combination of ‘CcDnaJ + CcUBQ + CcUBI’ at different stem developmental stages, i.e. hypocotyls at the 7 DAG and stems at the 14 DAG. The results revealed that relative expression of Cc4CL1, CcCesA4, CcCesA7, and CcesA8 genes in stems at the 14 DAG were higher than that in hypocotyles at the 7 DAG, suggesting that jute fiber formation starts at between 10 and 14 DAG, and the reference gene combination of ‘CcDnaJ + CcUBQ + CcUBI’ was available as well.

      Regulation of long non-coding RNA (LncRNA) in barley roots in response to Piriformospora indica colonization
      GUO Nan-Nan, LIU Tian-Ce, SHI Shuo, HU Xin-Ting, NIU Ya-Dan, LI Liang
      Acta Agronomica Sinica. 2022, 48(7):  1625-1634.  doi:10.3724/SP.J.1006.2022.11043
      Abstract ( 86 )   HTML ( 13 )   PDF (8332KB) ( 45 )   Save
      Figures and Tables | References | Related Articles | Metrics

      The molecular mechanism of biomass enhancement by Piriformospora indica in colonization plants needs to be further explored. LncRNA is a kind of long-chain non-coding RNA, which plays an important role in the regulation of plant growth and development. However, it remains unclear whether barley LncRNAs are responsive to Piriformospora indica colonization. It was found that barley roots exhibited fast development and large roots branched after P. indica colonization. Genome-wide high throughput RNA-seq and bioinformatical analysis showed that 752 and 932 differentially expressed LncRNAs were detected in responsive to P. indica at 3-day and 7-day after colonization, respectively. And 70 differentially expressed LncRNAs were found at 7-day compared to 3-day. Among these, 375 were up-regulated and 377 were down-regulated after 3 days’ colonization, and 459 were up-regulated and 473 were down-regulated after 7 days’ colonization, 39 were up-regulated and 31 were down-regulated in 7-day to 3-day comparison group. The qPCR results verified the validity of LncRNAs data in RNA-seq. GO and KEGG analysis indicated that a few LncRNAs might be involved in the molecular functions, cellular components, and biological processes upon P. indica colonization. This study provides a new theoretical basis and experimental basis for further understanding of the interaction between LncRNAs and coding sequences and regulatory functional networks, and provides new ideas and directions for crop shape improvement based on LncRNAs.

      Functional validation of Bna-novel-miR36421 regulating plant architecture and flower organ development in Arabidopsis thaliana
      DAI Li-Shi, CHANG Wei, ZHANG Sai, QIAN Ming-Chao, LI Xiao-Dong, ZHANG Kai, LI Jia-Na, QU Cun-Min, LU Kun
      Acta Agronomica Sinica. 2022, 48(7):  1635-1644.  doi:10.3724/SP.J.1006.2022.14106
      Abstract ( 139 )   HTML ( 13 )   PDF (3079KB) ( 165 )   Save
      Figures and Tables | References | Related Articles | Metrics

      MicroRNA is involved in the regulation of various biological processes such as development, stress response, and embryonic development in rapeseed, however, only few studies focused on the regulation of miRNA on the plant architecture and floral organ development of rapeseed. In this study, Bna-novel-miR36421 that differentially expressed between the high and low harvest index accessions of rapeseed was identified, whose biological function and regulation mechanism were further characterized through phenotype analysis in transgenic plants, target gene prediction, expression pattern comparison, and dual luciferase reporter system. The results showed that Bna-novel-miR36421 was highly homologous to miR167 family members, and might be a novel miR167 member in rapeseed. The qRT-PCR and dual luciferase reporter system results indicated that Bna-novel-miR36421 could inhibit the relative expression levels of Bna.C03ARF6, Bna.C06ARF8, Bna.A09PATL2, and Bna.C03DUF581. In the overexpressing Arabidopsis plants, the expression of Bna-novel-miR36421 was significantly increased, while the transcription levels of the Arabidopsis orthologs of its target genes were decreased significantly. Phenotypic observation showed that the plant height of overexpression Arabidopsis plants were reduced, with shortened stems and curled leaves. The development of floral organs was abnormal, with enlarged pistil, shortened stamen filaments, unbreakable anthers, and aborted pollens. Hence, it could be proposed that Bna-novel-miR36421 may regulate plant architecture and floral organ development by repressing Bna.C03ARF6, Bna.C06ARF8, Bna.A09PATL2, and Bna.C03DUF581. The results laid a solid foundation for understanding the molecular mechanism of miRNA-mediated plant architecture and flower organ development, and mining the key genes involved in plant developmental processes.

      Identification of regulatory genes related to flavonoids synthesis by weighted gene correlation network analysis in the panicle of foxtail millet
      HAN Shang-Ling, HUO Yi-Qiong, LI Hui, HAN Hua-Rui, HOU Si-Yu, SUN Zhao-Xia, HAN Yuan-Huai, LI Hong-Ying
      Acta Agronomica Sinica. 2022, 48(7):  1645-1657.  doi:10.3724/SP.J.1006.2022.14107
      Abstract ( 160 )   HTML ( 15 )   PDF (1508KB) ( 180 )   Save
      Figures and Tables | References | Related Articles | Metrics

      Flavonoids are important secondary metabolites in plants and play significant roles in plant growth and development. They have antioxidant activity and are beneficial to human health. Foxtail millet is rich in nutrients, making it a healthy grain and popular among consumers. The crop is gaining more and more attention as a C4 model plant. However, there are few studies on the metabolic regulatory mechanism of flavonoids in foxtail millet. In this study, the panicles of flavonoid-rich variety JG21 and flavonoid-less variety NMB were analyzed on the flavonoid metabolomic profiles. Transcriptome sequencing was performed on the panicles of JG21 at different developmental stages. Transcription factors involved in regulating flavonoid metabolism were identified by weighted gene correlation network analysis (WGCNA). The expression patterns of these genes were verified by qRT-PCR. The results showed that the main flavonoid components enriched in the spikelets of foxtail millet were apigenin, vitexin, and naringenin, accounting for more than 79% of the total flavonoids. The flavonoid-related network of JG21 contained 38,921 genes, which were divided into 32 modules. Among them, the turquoise module, green module, and magenta module were significantly correlated with flavonoid metabolism. A total of 27 transcription factor families related to the regulation of flavonoid metabolism were identified by using differentially expressed genes related to flavonoid metabolism pathway as the hubs, and 11 transcription factors were obtained through promoter binding motif analysis. Pearson correlation analysis showed that 7 out of the 11 transcription factors might be involved in flavonoid metabolism, which were WRKY38, MYB4a, PI, WRKY15, WRKY62, MYB46, and WRKY23, respectively. The above results provide new candidate genes for studying the transcriptional regulation mechanism of flavonoids and lay a foundation for further investigation of the flavonoid metabolism regulation mechanism in foxtail millet.

      Screening candidate genes involved in potato tuber development using WGCNA
      JIAN Hong-Ju, ZHANG Mei-Hua, SHANG Li-Na, WANG Ji-Chun, HU Bai-Geng, Vadim Khassanov, LYU Dian-Qiu
      Acta Agronomica Sinica. 2022, 48(7):  1658-1668.  doi:10.3724/SP.J.1006.2022.14115
      Abstract ( 158 )   HTML ( 13 )   PDF (8629KB) ( 145 )   Save
      Figures and Tables | References | Related Articles | Metrics

      Tuber is the main economic organ of potato. It is of great significance to illustrate its formation and development mechanism for high yield breeding of potato. Although some related genes have been reported, there are still a large number of genes involved in tuber production which need to be further excavated and identified. With the continuous innovation and development of sequencing technology, transcriptome data has become more abundant and complicated. The method of screening genes related to specific traits, tissues or developmental stages using Weighted Gene Co-expression Network Analysis (WGCNA) has been widely used. In this study, to construct co-expression networks and screen co-expression modules related to tuber development, WGCNA was used to analyze transcriptome data of potato DM 1-3516 R44 (DM) material and RH89-039-16 (RH) material from 15 tissues and organs, respectively. GO and KEGG pathway enrichment were performed on the genes in the screening expression module. The top 10 genes in the module were taken as the hub genes, annotated by PGSC database and NCBI, and verified by qRT-PCR. 13 co-expression modules were obtained in both DM and RH materials, among which the Cray module in DM material analysis and the Black module in RH material analysis were significantly correlated with tubers by WGCNA. The analysis showed that the genes of the two modules were significantly enriched in related processes such as hormone metabolism, starch and sucrose metabolism, and cell formation. In addition, gene StGA2ox1, which had been proved to be related to tuber development, was noted in Cyan, and StGA2ox1 was correlated with 10 hub genes in the module in the co-expression analysis. The qRT-PCR results of the hub genes were basically consistent with the results of RNA-seq. In this study, two co-expression modules related to tuber development were identified by WGCNA, and several candidate genes related to tuber development were screened out, which laid a foundation for high yield potato breeding.

      Changes of anthocyanins and expression analysis of synthesis-related genes in potato during storage period
      LI Jie-Ya, LI Hong-Yan, YE Guang-Ji, SU Wang, SUN Hai-Hong, WANG Jian
      Acta Agronomica Sinica. 2022, 48(7):  1669-1682.  doi:10.3724/SP.J.1006.2022.14111
      Abstract ( 186 )   HTML ( 15 )   PDF (4108KB) ( 247 )   Save
      Figures and Tables | References | Related Articles | Metrics

      Researches on the biosynthesis mechanism of anthocyanins have been widely done in plants, while little information is available on the mechanism of anthocyanins degradation and compositions in anthocyanins. The storage period affects the quality of potatoes. During storage period, the changes in anthocyanins content and composition of colored potato tubers remains unclear. In this study, the contents and components of anthocyanins and reducing sugar content were measured during storage period. Additionally, the relative expression of anthocyanins metabolism related genes (StPAL, StC4H, St4CL, StF3H, StDFR, StUFGT, StF35H, StAN1, and StbHLH1) were analyzed using qRT-RCR. The results showed that with the extension of storage period, the total contents and components of anthocyanins decreased. The relative expression levels of anthocyanins metabolism-related genes were down-regulated, but not StDFR in Heijingang. During storage period, the elevated reducing sugar might affect the anthocyanin content. Overall, these results indicated that a high level of anthocyanin during storage contributed to the high-quality colored potato, providing theoretical basis for breeding new colored potato varieties and manufacture products in future.

      Identification and expression analysis of uncoupling protein gene family in sweetpotato
      CHEN Lu, ZHOU Shu-Qian, LI Yong-Xin, CHEN Gang, LU Guo-Quan, YANG Hu-Qing
      Acta Agronomica Sinica. 2022, 48(7):  1683-1696.  doi:10.3724/SP.J.1006.2022.14126
      Abstract ( 118 )   HTML ( 15 )   PDF (8716KB) ( 93 )   Save
      Figures and Tables | References | Related Articles | Metrics

      The objectives of this study are to identify and analyze the uncoupling protein (UCPs) gene family members in sweetpotato (Ipopoea batatas (L.) Lam) and to investigate its expression specificity in different tissues of sweetpotato and its response to low temperature (4℃), high salinity (NaCl) and drought (PEG-6000) stresses. The results showed that the UCP (IbUCP) gene family of sweetpotato included five genes, which were named IbUCP1 (GenBank accession number: MW753000), IbUCP2 (GenBank accession number: MW753004), IbUCP3 (GenBank accession number: MW753001), IbUCP4 (GenBank accession number: MW753002), and IbUCP5 (GenBank accession number: MW753003), respectively. IbUCP contains 261-375 amino acid residues with the theoretical isoelectric point from 8.53 to 9.86. IbUCP were mainly located in mitochondria. IbUCP was a hydrophilic protein belonging to the superfamily of mitochondrial. The secondary structure of IbUCP was mainly composed of α-helix and random coils, which was consistent with the prediction of tertiary structure. IbUCP did not contain transmembrane helix structure and signal peptide. IbUCP family members were divided into five branches, which were closely related to Ipomoea triloba and Ipomoea nil, and was conserved to a certain extent. Promoter prediction revealed that IbUCPs family genes not only has basic transcription elements, but also some signal response elements, transcription factor recognition binding elements, and stress response cis-acting elements. Expression analysis showed that the IbUCPs gene family were tissue-specific. The IbUCP4 expressed the highest in stem, and the other IbUCPs genes were found expressed the highest in tuberous root. IbUCP1, IbUCP4, and IbUCP5 responded to low temperature stress.All members of the IbUCPs gene family all responded to high salinity stress. Additionally, under drought stress, IbUCP1, IbUCP4, and IbUCP5 all responded and reached the peak at different time, respectively. Various stresses can regulate the expression of IbUCPs, and this study provides a theoretical basis for the function mining of UCP gene in sweetpotato and the selection of sweetpotato stress-resistant varieties.

      Functional analysis of GmTGA26 gene under salt stress in soybean
      KE Dan-Xia, HUO Ya-Ya, LIU Yi, LI Jin-Ying, LIU Xiao-Xue
      Acta Agronomica Sinica. 2022, 48(7):  1697-1708.  doi:10.3724/SP.J.1006.2022.14123
      Abstract ( 180 )   HTML ( 18 )   PDF (6101KB) ( 94 )   Save
      Figures and Tables | References | Related Articles | Metrics

      TGA transcription factors are a subfamily of bZIP, which play important roles in pathogen and abiotic stress responses. A TGA transcription factor family gene GmTGA26 was screened and cloned from soybean in this study. Homologous protein comparison showed that GmTGA26 had a conserved leucine zipper domain and had the highest homology with wild soybean. The analysis of gene expression characteristics revealed that GmTGA26 gene was induced by salt stress in soybean. In addition, GmTGA26 gene encoded nuclear localization protein and had transcriptional activation activity. The “complex” soybean plants overexpressing GmTGA26 were obtained through Agrobacterium rhizogenes-mediated hairy root transformation of soybean. The growth state of “complex” soybean plants was better than the empty vector control under salt stress. Meanwhile, the MDA content and relative plasma membrane permeability decreased significantly (P < 0.05), while the chlorophyll content and root activity increased significantly (P < 0.05). The qRT-PCR results indicated that overexpression of GmTGA26 in soybean hairy roots under salt stress could significantly up-regulate the expression of stress response genes. The above results showed that overexpression of GmTGA26 significantly enhanced the salt tolerance of “complex” soybean plants. It is speculated that GmTGA26 participates in the regulation of soybean salt stress response by regulating a series of downstream stress response genes.

      Research on the grain production pattern and heat resource utilization efficiency based on temperature zone division in China
      WANG Kai-Cheng, ZHAO Jiong-Chao, HAN Tong, SHI Xiao-Yu, GAO Zhen-Zhen, BO Xiao-Zhi, CHEN Fu, CHU Qing-Quan
      Acta Agronomica Sinica. 2022, 48(7):  1709-1720.  doi:10.3724/SP.J.1006.2022.13042
      Abstract ( 110 )   HTML ( 6 )   PDF (5419KB) ( 82 )   Save
      Figures and Tables | References | Related Articles | Metrics

      It is of great significance to reveal the changes of grain production pattern and natural resource utilization efficiency for rational utilization of natural resources, security of national food security, and sustainable development. Base on the data of county-scale grain production and 683 meteorological stations from 1985 to 2015 in China, ArcGIS spatial analysis method was adopted to analyze the grain production pattern changes and heat resource utilization characteristics considered temperature zone division. Studies had shown that about 90% of Chinese total grain output was produced in mid temperate, warm temperate, northern subtropical, and mid subtropical zones from 1985 to 2015, accounting for 18.6%, 25.6%, 21.6%, and 25.9%, respectively. In the past 30 years, the proportion of grain production in the single cropping region had increased by 13.8%, while it had decreased by 2.7% and 11.2% in the double and triple cropping region, respectively. The proportion of grain production had increased by 13.9% in the mid temperate zone of the single cropping region which was drove by the advance of planted acreage and yield, while the proportion decreased by 13.9% in the subtropical zones of the triple-cropping system. Over the past 30 years, the annual accumulated temperature above 10℃ had continued to increase in different temperature zones, and that was more evident in southern region than northern region. However, the increased magnitude of heat utilization efficiency for grain production in southern temperature zones was lower than northern region. There was a “dislocation phenomenon” between the changes of Chinese grain production pattern and the distributions of heat resources. Therefore, it was necessary to consider the coordination of grain production and natural resources matching as well as the characteristics of resource utilization for improving resource utilization efficiency when optimizing the layout of regional grain production and formulating strategies in China.

      Identification on sensitivity of wheat to low temperature at reproductive stages
      WANG Juan, LIU Yi, YAO Dan-Yu, ZOU Jing-Wei, XIAO Shi-He, SUN Guo-Zhong
      Acta Agronomica Sinica. 2022, 48(7):  1721-1729.  doi:10.3724/SP.J.1006.2022.11045
      Abstract ( 135 )   HTML ( 5 )   PDF (5207KB) ( 160 )   Save
      Figures and Tables | References | Related Articles | Metrics

      Spring freezing injury caused by the low temperature at the reproductive stage is one of the natural disasters that seriously threaten the safety of wheat production in China. Spring wheat cultivar Zhongmai 8444 was employed to accurately determine the correlation between low-temperature damage and the sensitive stages of plant development under the controlled condition. Yield loss and the symptoms of frostbite were observed when plants were treated with freezing stress during the spike differentiation stage. The results showed that the developmental leaf age is relevant to the young spike differentiation stage in wheat plants. In addition, the degree of frost damage to the stems and leaves of wheat plants increased with the decrease of temperature and the developmental processes. In contrast, the plant height, spike length, and seed setting rate declined with a decrease in temperature and developmental processes. The late double ridge phase (S2.25) to floret primordia differentiation phase (S3.5) and the anther connective tissue formation phase (S5) to stigma branches protuberance phase (S7) are the two stages that change significantly to low-temperature sensitivity during the young spike development. Based on the tolerance of stems, leaves, spikes, and other organs to low temperature, the meiotic stage can be used to comprehensively evaluate the resistance level of wheat to frost in spring.

      Combined effects of panicle nitrogen fertilizer amount and shading during grain filling period on grain quality of conventional japonica rice
      TAO Yu, YAO Yu, WANG Kun-Ting, XING Zhi-Peng, ZHAI Hai-Tao, FENG Yuan, LIU Qiu-Yuan, HU Ya-Jie, GUO Bao-Wei, WEI Hai-Yan, ZHANG Hong-Cheng
      Acta Agronomica Sinica. 2022, 48(7):  1730-1745.  doi:10.3724/SP.J.1006.2022.12039
      Abstract ( 121 )   HTML ( 10 )   PDF (445KB) ( 98 )   Save
      Figures and Tables | References | Related Articles | Metrics

      Panicle nitrogen fertilizer amount and shading during grain filling period directly and obviously regulated the relationship between carbon and nitrogen metabolism of rice grains by affecting leaf photosynthesis and plant nitrogen nutrition, which would be benefit to forming different characteristics of rice quality. In order to investigate the combined effect between panicle nitrogen fertilizer amount and shading during grain filling period on quality of conventional japonica rice, field experiments were carried out with three panicle nitrogen application treatments of 40.5 kg hm-2 (N1), 81.0 kg hm-2 (N2) and 121.5 kg hm-2 (N3) at the same amount of basal and tilling fertilizers, and two artificial shading treatments of 100% natural light (S0) and 50% natural light (S50) during grain filling period in 2019 and 2020. The quality characteristics of conventional japonica rice Huaidao 5, Nanjing 9108, and Yangnongxiang 28 were determined under different light and nitrogen conditions during grain filling period. Results showed that with the increase of panicle nitrogen fertilizer amount, the brown rice rate, milled rice rate, and heading rice rate firstly increased and then decreased under S0 and decreased under S50. The brown rice rate, milled rice rate and heading rice rate of S0 were significantly higher than S50, while the processing quality of S0N2 with higher heading rice rate was the best among all treatments. The chalkiness grain percentage and chalkiness degree of rice had a trend of S50N3 > S50N2 > S50N1 > S0N3 > S0N2 > S0N1. Therefore, the increase of panicle nitrogen fertilizer amount and the shading during grain filling period had a cumulative effect on the increase of chalkiness grain rate and chalkiness degree of rice. Both the increase of panicle nitrogen fertilizer amount and shading during grain filling period decreased the amylose content and gel consistency, but increased the protein content. And the variation coefficient of glutelin was higher than other protein components among treatments. The rice taste value was decreased with the increase of panicle nitrogen fertilizer amount and the shading during grain filling period, while the direct influence of taste characteristic value on taste value was different among rice varieties. The peak viscosity and breakdown viscosity of rice starch decreased with the increase of panicle nitrogen fertilizer amount and the shading during grain filling period, while the setback viscosity increased. And the combination of light and nitrogen increased the difference of the above viscosity indexes among treatments. Based on the ratio of amylose content to protein content under different treatments of panicle nitrogen fertilizer amount and shading during grain filling period, the carbon and nitrogen metabolism ability of plants at grain filling stage were changed. In addition, the amylose content and protein content were significantly negatively correlated with taste value, while the correlation coefficient of protein was bigger than amylose content. Thus, an appropriate reduction of panicle nitrogen application fertilizer amount was beneficial to the improvement of rice processing quality, appearance quality and cooking and eating quality at grain filling stage with shading. The reduction of amylose content and especially the reduction of protein content might be an effective way to improve rice taste. The results would provide scientific support for the innovation of high yield and good taste rice cultivation techniques.

      Wheat yield estimation from UAV platform based on multi-modal remote sensing data fusion
      ZHANG Shao-Hua, DUAN Jian-Zhao, HE Li, JING Yu-Hang, Urs Christoph Schulthess, Azam Lashkari, GUO Tian-Cai, WANG Yong-Hua, FENG Wei
      Acta Agronomica Sinica. 2022, 48(7):  1746-1760.  doi:10.3724/SP.J.1006.2022.11053
      Abstract ( 118 )   HTML ( 9 )   PDF (7779KB) ( 84 )   Save
      Figures and Tables | References | Related Articles | Metrics

      Crop yield estimations are important for national food security, people, and the environment. Timely and accurate estimation of crop yield at the field scale is of great significance for crop management, harvest and trade. It ultimately enables farmers to optimize inputs and economic return. We selected an irrigated wheat field in a region near Kaifeng, Henan province, for this study. The terrain in that region is undulating and spatial differences. We used a low-altitude unmanned aerial vehicle (UAV) remote sensing platform equipped with a multi-spectral camera, thermal infrared camera, and RGB camera to simultaneously obtain different remote sensing parameters during the key growth stages of wheat. Based on the extracted spectral reflectivity, thermal infrared temperature, and digital elevation information, we calculated the spatial variability of remote sensing parameters, and growth indices under different terrain characteristics. We also analyzed the correlations between vegetation indices, temperature parameters and wheat yield. By means of four machine learning methods, including multiple linear regression method (MLR), partial least squares regression method (PLSR), support vector machine regression method (SVR), and random forest regression method (RFR), we compared the yield estimation capability of single-modal data versus multimodal data fusion frameworks. The results showed that slope was an important factor affecting crop growth and yield. We observed significant differences in remote sensing parameters under different slope grades. Soil water content, water content of plants, and above-ground biomass at the three growth stages were significantly correlated with slope. Most of the vegetation indices and temperature parameters of three growth stages were significantly correlated with yield as well. Based on the strength of their correlation with yield, seven vegetation indices (NDVI, GNDVI, EVI2, OSAVI, SAVI, NDRE, and WDRVI) and two temperature parameters (NRCT, CTD) were selected as the final input variables for the model. For the single-modal data framework, the model constructed with the vegetation indices was better than the yield model constructed with the temperature parameters, and the highest accuracy was obtained with a RFR model based on vegetation indices at filling stage (R2 = 0.724, RMSE = 614.72 kg hm-2, MAE = 478.08 kg hm-2). For the double modal data fusion approach, the highest accuracy resulted at flowering stage, using the temperature parameters combined with the vegetation indices of RFR model (R2=0.865, RMSE=440.73 kg hm-2, MAE=374.86 kg hm-2). Even higher accuracies were obtained, using the multimodal data fusion approach with a RFR model based on vegetation indices, temperature parameters and slope information at flowering stage (R2 = 0.893, RMSE = 420.06 kg hm-2, MAE = 352.69 kg hm-2), and the highest validation model (R2 = 0.892, RMSE = 423.55 kg hm-2, MAE = 334.43 kg hm-2) for fusion of the flowering stage. The results revealed that by using a multimodal data fusion framework of terrain factors combined with RFR, we can fully exploit the complementary and synergistic roles of different remote sensing information sources. This effectively improves the accuracy and stability of the yield estimation model, and provides a reference and support for crop growth monitoring and yield estimation.

      Characteristics of cadmium accumulation and distribution in different organs of wheat with different cadmium-accumulating type
      FENG Ya-Juan, LI Ting-Xuan, PU Yong, ZHANG Xi-Zhou
      Acta Agronomica Sinica. 2022, 48(7):  1761-1770.  doi:10.3724/SP.J.1006.2022.11046
      Abstract ( 102 )   HTML ( 6 )   PDF (461KB) ( 84 )   Save
      Figures and Tables | References | Related Articles | Metrics

      The study of cadmium accumulation and distribution characteristics in different organs of wheat with low Cd accumulation is helpful to clarify the mechanism of low Cd accumulation in grain, which is of great significance for cultivating wheat varieties with Cd safety. A pot experiment was conducted to clarify the characteristics of Cd accumulation and distribution in different organs of different Cd accumulating wheat materials at the late growth stages. The physiological characteristics of the key organs, namely node I and glume, were further explored. The results showed that there was significant difference of Cd accumulation and distribution between the two wheats at maturity stage. Cd concentrations in node I and glume of Mianmai 37 were significantly higher than those of Kangxiu 3816. The stage of from filling to maturity was the key period for Cd accumulation in node I and glume of the accumulation of Mianmai 37. In subcellular level, Cd in node I and glume of both wheat was mostly distributed in the cell wall, accounting for 70%-80%. The distribution ratio of the soluble fraction of Mianmai 37 node I was 18%, and that of Kangxiu 3816 was 15%. The distribution ratio of the soluble fraction of Mianmai 37 glume was 19%, which was 2.7 times that of Kangxiu 3816. More Cd was found to distribute in soluble faction in node I and glume of Mianmai 37 compared with Kangxiu 3816. There was no significant difference of GSH concentration in node I of the two wheats at filling stage. The PC1 and PC2 concentrations in node I of Mianmai 37 were significantly lower than those of Kangxiu 3816, while the PC3 and PC4 concentrations were significantly higher. The concentrations of GSH, PC1, PC2, PC3, and PC4 in the glume of Mianmai 37 were significantly higher than those of Kangxiu 3816. Cd retention in node I and the soluble fraction of glumes, as well as the great increase of NPT concentrations, contributed to low Cd accumulation in Mianmai 37. The present study investigates the mechanism of Cd retention in the key organs of wheat, which is of great significance to clarify the mechanism of Cd accumulation in wheat grains.

      Effects of filming and supplemental nitrogen fertilizer application on plant growth and population quality of late sowing winter wheat before winter
      LIU A-Kang, MA Rui-Qi, WANG De-Mei, WANG Yan-Jie, YANG Yu-Shuang, ZHAO Guang-Cai, CHANG Xu-Hong
      Acta Agronomica Sinica. 2022, 48(7):  1771-1786.  doi:10.3724/SP.J.1006.2022.11057
      Abstract ( 138 )   HTML ( 9 )   PDF (780KB) ( 107 )   Save
      Figures and Tables | References | Related Articles | Metrics

      In order to solve the actual problem of weaker wheat seedlings before overwintering due to the delayed sowing date in the winter wheat area of northern China, a late sowing experiment was carried out at the Beijing Experimental Base of the Chinese Academy of Agricultural Sciences from 2019 to 2021. Three sowing dates were set: sowing at the appropriate time on October 5th (S0), appropriate late sowing on October 15 (S1), and too late sowing on October 25 (S2). To study the effects of film mulching and supplemental application of nitrogen fertilizer on the population quality, individual traits and stems and tillers growth of late-sown wheat before winter, the late sowing S1 and S2 were treated with film mulching and nitrogen fertilizer regulating measures. The results showed that late sowing was not conducive to the formation of wheat population and individual quality before winter, and the growth of stems and tillers. Late sowing and mulching to increase temperature can increase the total number of stems and tillers in the population before winter. Compared with the treatment without mulching, mulching can increase the growth rate and relative growth rate of wheat before winter under the conditions of appropriate late sowing and too late sowing. The total number of stems and tillers in the population increased by 42.9% and 148.4%, respectively. The leaf age of the plant before winter increased, and the number of individual tillers increased on average by 1.6 and 2.0, respectively. Film mulching to increase the temperature prolonged the vegetative growth process of the first tiller to the third tiller on main stem, promoted cell growth, increased the soluble sugar content in the stems and leaves, tillering node, roots, and the ratio of IAA/ZR in leaves, and increased the total number of stems and tillers in population before winter. Evaluation of the seedling situation of each treatment for late sowing showed that under the condition of suitable sowing time, it was beneficial to improve the comprehensive quality of two different tillering ability cultivars before winter. Among them, Zhongmai 8 had better seedling situation under the condition of late sowing + film mulching, while Hangmai 501 also had better seedling situation under the condition of proper late sowing, proper late sowing + supplementary nitrogen fertilizer, proper late sowing + film mulching, and too late sowing + film mulching. Meanwhile, there were differences in the responses of two different tillering ability wheat cultivars to the temperature increase under the condition of late sowing + film mulching. It was more beneficial for Zhongmai 8 to improve the overall population quality before winter under the conditions of suitable sowing or late sowing + film mulching, while under the conditions of the appropriate sowing, appropriate late sowing and too late sowing + film mulching, it was beneficial to improve the quality of late sowing seedlings for Hangmai 501. Supplementary application of nitrogen fertilizer had no significant regulatory effects on population quality, individual traits and stems, and tillers growth of late-sown wheat before winter. In summary, under the condition of late sowing, film mulching can effectively improve the overall quality of wheat populations and individuals before winter, and further promote the growth of stems and tillers.

      Characteristics of farmland water consumption under two-year wheat-maize interannual rotation patterns in Heilonggang Plain
      ZHAO Ying-Xing, WANG Biao, LIU Qing, SONG Tong, ZHANG Xue-Peng, CHEN Yuan-Quan, SUI Peng
      Acta Agronomica Sinica. 2022, 48(7):  1787-1779.  doi:10.3724/SP.J.1006.2022.11030
      Abstract ( 109 )   HTML ( 8 )   PDF (656KB) ( 60 )   Save
      Figures and Tables | References | Related Articles | Metrics

      In order to solve the contradiction of water and grain about the traditional continuous winter wheat (Triticum aestivum L.) and summer maize (Zea mays L.) double-cropping system (W-M→W-M, CK) in the groundwater funnel area of Heilonggang Plain, the new rotation patterns with two-year cycle of “one-year traditional W-M + one-year other crops” were designed, trying to find out a water-saving and green stable cropping system suitable for this region. The field experiment was carried out in Wuqiao, Hebei province from October 2018 to September 2020. Setting spring maize→W-M (Ms→W-M), winter wheat→W-M (W→W-M), spring sweet potato (Dioscorea esculenta (Lour.) Burkill)→W-M (Psw→W-M), spring peanut (Arachis hypogaea Linn.)→W-M (As→W-M), winter wheat-summer peanut→W-M (W-A→W-M) and potato (Solanum tuberosum L.)-silage corn→W-M (P-C→W-M) six rotation patterns with two years cycle, we tried to analyze the characteristics of farmland water consumption. The results showed that: (1) Compared with CK, the annual water consumption of rotation patterns reduced by 3.1%-15.2%, expect W-A→W-M. The annual average water consumption of Ms→W-M, P-C→W-M, As→W-M and Psw→W-M decreased by 6.1%, 7.2%, 9.2%, and 15.2%, respectively, and the annual average net groundwater consumption of the four patterns also decreased by 9.0%, 10.3%, 16.2%, and 32.9%, respectively. (2) The combination of crops at different water consumption levels could achieve water complementary spatially. Winter wheat mainly consumed 0-160 cm soil moisture, which was reduced by 20% compared with sowing. Potato mainly consumed 0-100 cm soil moisture, which was reduced by 12% compared with sowing. Spring peanut mainly consumed 20-80 cm soil moisture, which was reduced by 4% compared with sowing. (3) Partial rotation patterns could reduce the demand for irrigation water and increase soil water storage. In 2019 rotation year, when the irrigation amount of Ms→W-M and As→W-M patterns were 145 mm and 175 mm less than CK, the soil water storage of 2 m increased by 27.2 mm and 12.6 mm compared with the start of rotation year, respectively. When the irrigation amount of W-M→W-M was 300 mm, the soil water storage of 2 m increased by 18.4 mm compared with the start of rotation year. (4) Partial rotation patterns had better economic water use efficiency (EWUE), which were 1.2-1.5 times of CK. The EWUE of As→W-M and W-A→W-M were 1.5 times and 1.2 times significantly higher than that of CK, respectively. Based on the characteristics of farmland water consumption and EWUE, the two-year rotation patterns of As→W-M, Psw→W-M, P-C→W-M, Ms→W-M could reduce the farmland water consumption, meanwhile, maintain and improve the economic water use efficiency, and could be implemented to partially replace the winter wheat and summer maize double-cropping system in Heilonggang Plain.

      Screening of low nitrogen tolerant cultivars based on low nitrogen tolerance comprehensive index at seeding stage in cotton
      ZHU Ling-Xiao, SONG Shi-Jia, LI Hao-Ran, SUN Hong-Chun, ZHANG Yong-Jiang, BAI Zhi-Ying, ZHANG Ke, LI An-Chang, LIU Lian-Tao, LI Cun-Dong
      Acta Agronomica Sinica. 2022, 48(7):  1800-1812.  doi:10.3724/SP.J.1006.2022.14085
      Abstract ( 96 )   HTML ( 10 )   PDF (2185KB) ( 104 )   Save
      Figures and Tables | References | Related Articles | Metrics

      In cotton production, excessive application of nitrogen fertilizers leads to the increasing cost of agricultural production and a large amount of nitrogen loss, causing damage to the environment. Screening cotton cultivars with low nitrogen tolerance is one of the most effective approaches to solve this problem. In this study, 21 cotton cultivars mainly planted in cotton regions were used as the experimental materials, and 23 agronomic traits were measured. The low nitrogen tolerance was evaluated by means of principal component analysis, the fuzzy membership function, cluster analysis, and correlation analysis under normal nitrogen treatment (N 138 mg kg-1) and low nitrogen treatment (N 0 g kg-1) using soil culture experiment at seeding stage. The results showed that the coefficient variation of most indexes were greater than 10%, which indicated that the selected varieties had good representativeness. Based on principal component analysis and correlation analysis, seven traits including root length, root surface area, root volume, shoot dry weight, total dry weight, actual photochemical efficiency, and maximum photochemical efficiency were used as evaluating indices for low nitrogen tolerance of cotton cultivars. Based on the low nitrogen tolerance comprehensive index, four low nitrogen tolerance cultivars (Luwu 403, Xinhai 12, Zhongmiansuo 64, and Xinluzao 23) and five low nitrogen sensitive cultivars (Fengkangmian 1, TM-1, Nongda 601, Zhongmiansuo 35, and Xinluzao 53) were screened out. The low nitrogen tolerance comprehensive index of the four low nitrogen tolerance cultivars ranged from 0.5723 to 0.6817, while the low nitrogen tolerance comprehensive index of five low nitrogen sensitive cultivars ranged from 0.2914 to 0.3962. In summary, the screening method based on the low nitrogen tolerance comprehensive index provided a new reference for the selection of crop cultivars with low nitrogen tolerance.

      Genome-wide association analysis and candidate gene selection of yield related traits in rice
      YANG Fei, ZHANG Zheng-Feng, NAN Bo, XIAO Ben-Ze
      Acta Agronomica Sinica. 2022, 48(7):  1813-1821.  doi:10.3724/SP.J.1006.2022.12047
      Abstract ( 186 )   HTML ( 20 )   PDF (4541KB) ( 323 )   Save
      Figures and Tables | References | Related Articles | Metrics

      Rice is the most important food crop for more than half of the world’s population, and the cultivation of rice varieties with high and stable yield is crucial for solving the world’s food problems. In this study, 226 rice core materials with relatively consistent growth stage were selected from “3K Rice Genome Project” and 2429 kb of high density genotype and 10 agronomic traits including growth period, plant height, effective panicle number, panicle length, spikelet density, seed setting rate, thousand-grains weight, yield per plant, spikelet per panicle, and grains per panicle were investigated by genome-wide associate study combined with 2429 kb of high-density genotype data. A total of 43 loci significantly associated with main agronomic traits were identified, including seven known loci, such as qRGP7.2, qPH12, qPL6.2, qSD6.2, qTGW1.1, qGP1, and qGP5.2. Six candidate genes were screened out, including LOC_Os12g18760 related to plant height, LOC_Os03g33530 related to effective panicle number, LOC_Os06g30940 related to panicle length, LOC_Os01g49810 related to thousand grains weight, LOC_Os09g25260 related to yield per plant, and LOC_Os09g32620 related to spikelet density and spikelet per panicle. These results provide important gene resources and the theoretical reference for genetic improvement of rice yield.

      Comparison of grain heavy metal concentration between main and ratoon seasons of ratoon rice
      YUAN Shen, PENG Shao-Bing
      Acta Agronomica Sinica. 2022, 48(7):  1822-1831.  doi:10.3724/SP.J.1006.2022.12021
      Abstract ( 115 )   HTML ( 11 )   PDF (2130KB) ( 62 )   Save
      Figures and Tables | References | Related Articles | Metrics

      Cadmium (Cd) and arsenic (As) pollution in rice has caused global concern. Ratoon rice has been traditionally practiced and is becoming more attractive to farmers. However, information on grain heavy metal concentration of ratoon rice is limited. Therefore, the objective of this study was to evaluate grain Cd and As concentrations of ratoon rice and to explore the differences in grain Cd and As concentrations between main and ratoon seasons. In this study, we determined Cd and As concentrations of rice grain in main and ratoon seasons, which were collected from farmers’ fields in 12 sample plots of Hubei province in 2016. In comparison with that of main season, grain Cd of ratoon season increased and decreased in 5 and 3 out of 12 sample plots, respectively, whereas there was no significant difference in grain Cd between main and ratoon seasons in the rest of 4 sample plots. Rice ratooning significantly reduced grain As contamination of ratoon season compared with main season in all sample plots. Grain As of ratoon season across 12 sample plots was between 68.6-147.4 μg kg-1, which was 36.5%-77.4% lower than that of main season. Notably, grain As of ratoon season in 12 sample plots were lower than that of the corresponding national standard (GB2762-2012). Overall, these results indicated that grain heavy metal contamination might occur in both main and ratoon seasons of ratoon rice. This study suggested that more research on the effects of rice variety, environment, crop management especially water management and/or their interactions on grain heavy metal concentration needs to be conducted for reducing grain heavy metal concentration of ratoon rice.

      Physiological characters and gene mapping of a precocious leaf senescence mutant ospls7 in rice (Orzo sativa L.)
      HUANG Fu-Deng, HUANG Yan, JIN Ze-Yan, HE Huan-Huan, LI Chun-Shou, CHENG Fang-Min, PAN Gang
      Acta Agronomica Sinica. 2022, 48(7):  1832-1842.  doi:10.3724/SP.J.1006.2022.12028
      Abstract ( 112 )   HTML ( 11 )   PDF (4730KB) ( 74 )   Save
      Figures and Tables | References | Related Articles | Metrics

      Leaf senescence is the final stage of leaf development, however, premature aging of leaves, especially functional leaves, leads to reduction of yield and quality. Thus, it is very important for developing novel crop germplasms with delayed leaf-senescence characteristics through investigating the molecular and physiological mechanism of leaf senescence. In this study, a stable precocious leaf senescence mutant ospls7 was obtained from 60Co γ-radiated upland rice cultivar Monolaya, and its morphology, physiological characteristics of leaf senescence, cytological observation of internodes, genetic analysis and gene mapping were investigated. Under field conditions, leaf senescence was noticed as early as the 3-4-leaf seedling stage, featuring yellowing and browning at the edge of tip and the upper middle parts of old leaves and finally wilting. Due to shorter length of the parenchyma cells, panicle length and all internodes length of ospls7 were significantly shorter compared with wild type plants at the mature stage, resulting in dwarf phenotype in ospls7. Physiological analysis of leaf senescence indicated that compared to the wild type plants, the total chlorophyll contents, net photosynthetic rate, soluble protein content, and catalase (CAT) activity of the second and third leaves from top in ospls7 were significantly declined at the booting stage, which in turn resulting in the accumulation of H2O2 and a steady increase of malondialdehyde (MDA) contents in the mutant leaves. Moreover, due to significant up-regulation of ABA biosynthetic genes (OsNCED3 and OsAAO3) and significant down-regulation of the ABA catabolism genes (OsABA8ox2 and OsABA8ox3), the endogenous ABA levels in the leaves of ospls7 were significantly higher compared with the wild type at the booting stage. Genetic analysis and gene mapping showed that ospls7 was controlled by a single recessive nuclear gene, located in a region of 207 kb between SSR marker RM25040 and the InDel marker ID74-33/34 of chromosome 10. These results would further facilitate the cloning and functional analysis of OsPLS7 gene.

      Molecular characterization of transgenic maize GM11061 based on high-throughput sequencing technology
      YANG Ying-Xia, ZHANG Guan, WANG Meng-Meng, LU Guo-Qing, WANG Qian, CHEN Rui
      Acta Agronomica Sinica. 2022, 48(7):  1843-1850.  doi:10.3724/SP.J.1006.2022.13043
      Abstract ( 111 )   HTML ( 9 )   PDF (5654KB) ( 71 )   Save
      Figures and Tables | References | Related Articles | Metrics

      Insertion site, integrated sequences, and copy number information of exogenous DNA integrations in host genome are key steps in the safety evaluation of genetically modified plants. Traditional identification techniques for molecular characteristics of transgenic plants are complicated, laborious, inefficient and limited. Here, we reported the molecular characterization of one new transgenic maize event GM11061 via a whole genome (paired-end) sequencing approach and laboratory-developed bioinformatics methods. The results showed there was only one copy of the exogenous DNA inserted, which was located within the region of 198,621,571-198,621,620 bp on chromosome 5 in GM11061 genome, without the vector skeleton sequence. Its upstream and downstream binding sites were validated using conventional PCR and sanger sequencing. Gradient analysis of sequencing data revealed that the lowest 5× resequencing raw data could be used to identify the integration site. The study confirmed that the whole genome resequencing approach combined with bioinformatics methods could achieve simple, rapid, and accurate identification of plant molecular characteristics. These results are helpful to the basic research of functional genomics and provide technical support for the safety evaluation of transgenic plants.

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
  • Covered by SCIE
  • Open access in ScienceDirect

Editor in chief: Wan Jian-min
CN 10-1112/S
ISSN 2095-5421, 2214-5141(online)
Online published:
Submission: https://www.editorialmanager.com/cj/
E-mail: cropjournal@caas.cn
Tel: 8610-82108548