Table of Content

12 June 2025, Volume 51 Issue 6

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CROP GENETICS & BREEDING · GERMPLASM RESOURCES · MOLECULAR GENETICS

Identification of fertility levels and quantification of the temperature-fertility relationship in rapeseed pol TCMS lines using an improved U-Net++ model

LI Shi-Peng, CHEN Cai-Wu, ZHANG Jing, LYU Tian, FU Ting-Dong, YI Bin

Acta Agronomica Sinica. 2025, 51(6):  1423-1434.  doi:10.3724/SP.J.1006.2025.44198

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Rapeseed (Brassica napus L.) is a globally important oil crop, and the exploitation of its hybrid vigor has played a crucial role in enhancing yield and environmental adaptability. The thermosensitive Polima cytoplasmic male sterile (pol TCMS) line has a unique dual-purpose advantage, as its fertility is temperature-dependent, making it highly valuable for two-line breeding systems. In agricultural practice, the classification of fertility status is primarily based on the relative lengths of stamens and pistils. However, traditional fertility grading methods rely on subjective assessment, which is prone to human error, ultimately affecting phenotypic investigations and precise trait mapping. To address this issue, we propose a novel approach for fertility classification based on image semantic segmentation using an improved U-Net++ deep learning model. An F₂ segregating population was developed using the pol TCMS thermosensitive line and the pol CMS stable sterile line. First, floral organ images representing different fertility levels within the segregating population were collected and annotated to construct a dataset. Next, we optimized the U-Net++ model by refining its encoder-decoder architecture and integrating a channel attention module to enhance segmentation accuracy. Finally, the model was trained and tested on images corresponding to different fertility levels. Experimental results demonstrated that the improved model achieved a mean intersection-over-union (mIoU) of 92.02%, precision of 98.94%, recall of 98.84%, and an F₁ score of 98.87%, outperforming other segmentation models. The model effectively distinguished floral organs across different fertility grades and enabled in situ measurements of organ length based on segmentation results. Compared with manual measurements, the predicted values exhibited a coefficient of determination (R²) of 0.989, a root mean square error (RMSE) of 0.142 mm, and a Spearman correlation coefficient of 0.983, demonstrating high accuracy in phenotypic parameter estimation across different fertility levels. Furthermore, we quantitatively analyzed the relationship between temperature and fertility (stamen/pistil ratio), revealing that fertility fluctuates in response to temperature variations during the nine days preceding anthesis in individual flowers. This study confirms the key role of temperature in regulating fertility and provides a novel methodological framework and technical support for in-depth analyses of temperature-sensitive traits and gene mapping in rapeseed.

A mini core collection of foxtail millet

LIANG Hong-Kai, ZHAO Su-Meng, LU Qiong, ZHOU Peng, ZHI Hui, DIAO Xian-Min, HE Qiang

Acta Agronomica Sinica. 2025, 51(6):  1435-1444.  doi:10.3724/SP.J.1006.2025.44204

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Germplasm resources form the foundation of crop genetic research, germplasm innovation, and variety improvement. However, as the number of available germplasm resources continues to grow, efficiently studying and utilizing them has become an increasingly urgent challenge. In this study, we analyzed genome data from 967 globally sourced foxtail millet germplasm accessions to construct a representative mini-core collection of 200 accessions, based on genetic diversity, genetic distance, and geographical distribution. This mini-core collection preserves the genetic diversity and population structure of the original germplasm while maintaining broad geographical representation and extensive phenotypic variation. Furthermore, genome-wide association analysis identified 10 QTLs associated with key agronomic traits, including PPLS1, a gene regulating leaf sheath color, and Ghd7.1, a gene linked to heading date. These findings highlight the practical value of the mini-core germplasm collection and provide a valuable genetic resource for the efficient utilization and further improvement of foxtail millet germplasm.

Meta-analysis of QTL and identification of candidate genes for fiber quality in cotton

GUO Dong-Cai, LYU Tao, CAI Yong-Sheng, MAI WU-LU-DA·AI He-Mai-Ti, CHEN Quan-Jia, QU Yan-Ying, ZHENG Kai

Acta Agronomica Sinica. 2025, 51(6):  1445-1466.  doi:10.3724/SP.J.1006.2025.44108

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Cotton fiber quality is a complex quantitative trait controlled by multiple genes. Identifying true quantitative trait loci (QTLs) and candidate genes associated with fiber quality is critical for the genetic improvement of cotton. In this study, QTL meta-analysis was performed using BioMercator 4.2 software, with a high-density molecular marker genetic linkage map published by Blenda A et al. as the reference. A total of 379 original QTLs related to cotton fiber quality, derived from 21 independent QTL mapping studies, were integrated, mapped, and analyzed. This analysis identified 74 meta-QTLs (MQTLs) associated with cotton fiber quality traits, distributed across 26 chromosomes, with the minimum confidence interval of 0.5 cM. These MQTLs collectively encompassed 13,833 genes. Through RNA-seq analysis combined with GO and KEGG enrichment analysis, 32 candidate genes related to cotton fiber quality were identified. qRT-PCR validation revealed that these genes exhibited differential expression during various stages of fiber development, suggesting their potential roles in regulating fiber growth and quality. This study provides a theoretical basis for molecular marker-assisted breeding and gene cloning for cotton fiber quality.

Identification of an adaxially-curled-leaf mutant acl3 and function analysis of the regulated gene in rice (Oryza sativa L.)

LEI Song-Han, FAN Jun-Yang, CHE Yan-Yi, DAI Yong-Dong, ZHENG Yu-Meng, TIAN Wei-Jiang, SANG Xian-Chun, WANG Xiao-Wen

Acta Agronomica Sinica. 2025, 51(6):  1467-1479.  doi:10.3724/SP.J.1006.2025.42052

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Moderate leaf curling is beneficial for cross-pollination, fruit set, and enhancing the photosynthetic efficiency of crop canopies, making it highly valuable for hybrid rice seed production and cultivation. To elucidate the molecular mechanisms underlying leaf rolling in rice, we identified a stably inherited adaxial leaf-rolling mutant, acl3 (adaxially curled leaf 3), from an ethyl methanesulfonate (EMS)-mutagenized population. In addition to leaf curling, acl3 exhibits reduced plant height and seed-setting rate, along with a significant increase in thousand-grain weight. Histological analysis using paraffin sections revealed that the extreme curling in acl3 primarily results from a reduction in both the number and area of bulliform cells between vascular bundles in the adaxial epidermis. Genetic analysis indicated that the acl3 mutant phenotype is controlled by a single recessive nuclear gene, which was preliminarily mapped to a 409 kb physical region between Indel markers 07g89 and 07g498 on chromosome 7. Whole-genome sequencing of acl3 and the wild-type Xida 1B was performed, and sequence variations within the acl3 mapping interval were identified using IGV software. A G-to-A base substitution was detected in the sixth exon of the annotated gene LOC_Os07g01240/SRL1/CLD1, leading to a structural change in the encoded protein. This gene was preliminarily identified as the candidate gene for ACL3. Complementary vector construction and transformation of the acl3 mutant restored the mutant traits—leaf curling, plant height, and grain size—to wild-type levels, confirming that ACL3 is a new allele of SRL1 with pleiotropic effects. Quantitative real-time PCR (qRT-PCR) analysis revealed significant upregulation of leaf-rolling-related genes REL2 and NAL7. Further investigation of auxin IAA pathway-related genes showed that auxin synthesis gene YUCCA2, auxin response genes ARF1 and ARF7, and primary auxin response genes IAA10, IAA21, and IAA22 were all upregulated to varying degrees, suggesting that ACL3 may regulate rice plant architecture development through the auxin signaling pathway.

Rapid transcriptome and AlphaFold-based identification of classical effector proteins of Magnaporthe oryzae and receptors in rice

FENG Wu-Jian, XIAN Xiao-Qing, ZHANG Xin-Bo, CAO Dan, QIANG Cheng-Kui

Acta Agronomica Sinica. 2025, 51(6):  1480-1488.  doi:10.3724/SP.J.1006.2025.42049

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Effector proteins play a crucial role as weapons for plant pathogens to evade host immunity. During the early stages of infection, pathogens secrete various effectors to facilitate invasion. To identify key classical effectors in pathogens and their corresponding plant target genes, we propose establishing a pipeline for the identification of classical effector and target proteins using bioinformatics and structural biology approaches. In this study, 535 effector proteins of Magnaporthe oryzae were identified and classified into five clusters using SignalP, TMHMM, PredGPI, WoLF PSORT, and EffectorP, focusing on M. oryzae-rice interactions. A total of 282 key effector proteins were identified, and a co-expression network was constructed to examine early effector protein–plant interactions using transcriptomic data. AlphaFold3 predictions further suggested that the rice proteins Os06t0633800 and Os03t0114400 may serve as potential targets for the M. oryzae effectors MGG_08817 and MGG_03865, respectively. Complementary validation using luciferase assays confirmed the interaction between MGG_08817 and Os06t0633800, as well as MGG_03865 and Os03t0114400, in Nicotiana benthamiana. The rapid screening and identification of effector proteins and their target proteins are of great significance for the prevention and control of plant diseases. The findings of this study contribute to the identification of key effector proteins and plant target genes, providing a theoretical foundation for further research on plant–pathogen interactions and laying the foundation for the green prevention and control of plant diseases.

Cloning and expression analysis of the phosphatidylinositol transfer protein AhSFH gene in peanuts responsive to Aspergillus flavus infection

GUO Teng-Da, CUI Meng-Jie, CHEN Lin-Jie, HAN Suo-Yi, GUO Jing-Kun, WU Chen-Di, FU Liu-Yang, HUANG Bing-Yan, DONG Wen-Zhao, ZHANG Xin-You

Acta Agronomica Sinica. 2025, 51(6):  1489-1500.  doi:10.3724/SP.J.1006.2025.44191

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Phosphatidylinositol transfer proteins (PITPs) are a class of proteins responsible for transporting phosphatidylinositol and phosphatidylcholine monomers across the inner membrane systems of eukaryotic cells. They play essential roles in plant growth and development, signal transduction, stress responses, and other vital biological processes. To date, the involvement of PITP genes in peanut (Arachis hypogaea) responses to Aspergillus flavus infection has not been reported. In this study, the PITP gene was cloned from the highly resistant peanut variety “J11” using RT-PCR, and its molecular characterization and functional prediction were analyzed through bioinformatics, RT-qPCR, and subcellular localization studies. The results showed that the gene’s coding region is 1836 bp in length, encoding an unstable hydrophilic protein with the molecular formula C₃₁₁₄H₄₉₃₈N₈₈₀O₉₄₃S₃₅. The protein consists of 611 amino acids, with a molecular weight of 70.91 kD and an isoelectric point of 7.84. It lacks signal peptide and transmembrane domains but contains typical Sec14 and nodulin domains. It belongs to the SFH subfamily of the plant PITP family and is closely related to soybean and ricinus SFH proteins. Subcellular localization analysis indicated that the AhSFH protein is primarily localized in the cytoplasm. Promoter cis-acting element analysis revealed that the AhSFH promoter contains large number of light-, hormone-, and stress-responsive elements. Transcriptome and RT-qPCR analyses showed that AhSFH expression increased sharply in resistant materials during the early stages of A. flavus infection (T2–T3), surpassing the expression levels observed in highly susceptible materials. Additionally, protein interaction prediction suggested that AhSFH is associated with several transferase-related family proteins. These findings indicate that the AhSFH gene in peanuts plays a crucial role in responding to A. flavus infection and may function as a positive regulator in enhancing peanut resistance to this pathogen.

Effect evaluation and investigation on molecular mechanism of the ZmKL1 favorable allele in regulating maize kernel size

YANG Xiao-Hui, YAN Xuan-Jun, YANG Wen-Yan, FU Jun-Jie, YANG Qin, XIE Yu-Xin

Acta Agronomica Sinica. 2025, 51(6):  1501-1513.  doi:10.3724/SP.J.1006.2025.43052

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To evaluate the effects of different alleles of the kernel size-related gene ZmKL1 on agronomic traits and to elucidate the molecular mechanisms by which ZmKL1 regulates kernel size in maize, this study constructed near-isogenic lines (NILs) and analyzed their field performance, ear morphology, and kernel traits at two locations. Transcriptome and proteome analyses were conducted to explore the regulatory effects of different alleles on kernel size. The results revealed significant differences in kernel length, kernel width, hundred-kernel weight, plant height, and ear height among the NILs, while no significant differences were observed in flowering time or ear traits. A total of 744 differentially expressed genes (DEGs) and 152 differentially expressed proteins (DEPs) were identified between the two NIL groups. Gene Ontology (GO) analysis indicated that DEGs were enriched in pathways related to protein binding and oxidoreductase activity, while DEPs were primarily associated with transcriptional regulation, gene expression, RNA biosynthesis, and metabolic processes. The expression differences of eight key genes were further validated by quantitative real-time PCR (qRT-PCR). This study not only provides a comprehensive phenotypic assessment of ZmKL1 alleles, demonstrating the potential of the favorable allele for maize yield improvement, but also offers preliminary insights into the molecular mechanisms underlying ZmKL1-mediated kernel size regulation through integrative transcriptomic and proteomic analyses. These findings contribute to the identification of key genes and pathways involved in maize kernel development, laying the foundation for future genetic improvement strategies.

Functional dissection of sucrose synthase gene TaSUS2 regulating grain starch synthesis and quality in wheat

WU Mei-Juan, ZHANG Yin-Hui, LI Yuan-Hao, LIU Hai-Xia, HUANG Yi-Lin, LI Tian, LIU Hong-Xia, ZHANG Xue-Yong, HAO Chen-Yang, GUO Jie, HOU Jian

Acta Agronomica Sinica. 2025, 51(6):  1514-1525.  doi:10.3724/SP.J.1006.2025.41076

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Wheat is one of the world’s most important cereal crops, and improving yield remains a key goal in wheat breeding. Grain weight is a major determinant of yield, and starch is the primary component of wheat grains. To investigate the function of TaSUS2, a key enzyme gene in the starch synthesis pathway, we amplified its full-length cDNA sequence from the wheat genome and performed gene editing in the cultivar Kenong 199 (KN199). This resulted in the generation of two homozygous diploid mutants (KO-1 and KO-2) and one homozygous triploid mutant (KO-3). Phenotypic analysis of the transgenic lines revealed that TaSUS2 mutant grains exhibited pronounced wrinkling and a significant reduction in grain weight compared to the wild type. Additionally, the total starch content, amylose content, absolute starch content, and the diameter of A-type starch granules in the endosperm were significantly reduced in TaSUS2 mutant grains. These findings confirm that TaSUS2 plays a crucial role in starch synthesis and grain weight determination. Transcriptome analysis indicated that multiple enzyme-encoding genes involved in starch biosynthesis were upregulated in TaSUS2-KO-3 grains at 21 days post-anthesis. Furthermore, genotyping of a natural population of 145 wheat accessions using the TaSUS2-2A-CAPS marker revealed that TaSUS2 was significantly associated with starch content, wet gluten content, protein content, and sedimentation value. Notably, the TaSUS2-2A-Hap-G haplotype was identified as a favorable allele for these quality traits. Overall, this study provides valuable insights into the biological function of TaSUS2 and offers novel genetic resources for molecular breeding aimed at improving wheat yield and quality.

Genetic diversity analysis and comprehensive evaluation of Qingke germplasm based on six phenotypic traits

WANG Mu, ZHUO Ga, ZHA Sang, XIRUO Qu-Zong, DAWA Dondup, GUO Gang-Gang, ZHANG Jing, ZHUO Ga, LHUNDRUP Namgyal

Acta Agronomica Sinica. 2025, 51(6):  1526-1537.  doi:10.3724/SP.J.1006.2025.41085

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Evaluating the genetic diversity of Qingke germplasm enhances our understanding of beneficial variations within these resources, facilitating the selection of complementary parental lines for breeding and improving the efficiency of elite gene exchange, aggregation, and new variety development. In this study, 1,112 local Qingke varieties from different ecological regions were analyzed to assess genetic diversity based on six phenotypic traits and identify superior germplasm resources. The results revealed rich phenotypic genetic diversity, with significant variation observed in tiller number, plant height, spike length, stem diameter, grains per main spike, and grain weight per main spike. Compared to landraces, cultivated varieties derived from artificial hybridization exhibited noticeable changes, particularly in yield-related traits, with genetic gains primarily reflected in increased grain number and grain weight per spike. The genetic diversity of regionally bred hybrid cultivars was lower than that of non-local cultivars; however, regionally bred varieties demonstrated superior overall trait performance. Cluster analysis grouped the Qingke germplasm into four categories: Category I exhibited the highest average phenotypic values across all traits; Category II had the largest tiller number with moderate levels for other traits; Category III had the fewest tillers, with other traits at moderate levels; and Category IV had the lowest phenotypic values for all traits. Principal component analysis and stepwise regression indicated that, except for spike length, the remaining five traits served as the primary indicators for Qingke phenotypic evaluation, with an explanatory power of R² = 0.999. This study highlights the substantial genetic diversity within Qingke germplasm and provides valuable insights for the selection and breeding of improved varieties.

Genetic analysis of key target traits in the early-maturing wheat cultivar Yangmai 37

LYU Guo-Feng, FAN Jin-Ping, WU Su-Lan, ZHANG Xiao, ZHAO Ren-Hui, LI Man, WANG Ling, GAO De-Rong, BIE Tong-De, LIU Jian

Acta Agronomica Sinica. 2025, 51(6):  1538-1547.  doi:10.3724/SP.J.1006.2025.41063

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Hybridization between winter and spring wheat varieties is an important approach to broaden the genetic base of wheat cultivars. Yangmai 37, an early-maturing spring wheat cultivar, was developed from a cross between the spring wheat Zhenmai 9 and the semi-winter wheat Han 6172. To investigate the genetic composition of Yangmai 37 and the selection of functional genes during its breeding process, we compared key breeding traits—including growth period, yield components, disease resistance, and quality-related traits—as well as the haplotypes of 64 functional genes associated with these traits between Yangmai 37 and its two parents. The results showed that Yangmai 37 matured four days earlier than Zhenmai 9. Its plant height was similar to Zhenmai 9, while its spike density (spikes m^-2) and thousand-grain weight (TGW) were intermediate between its parents. However, its grain number per spike (grains/spike) was higher than both parents. In terms of disease resistance, Yangmai 37 exhibited moderate resistance to Fusarium head blight (FHB), similar to Zhenmai 9, but was susceptible to powdery mildew (PM) and wheat yellow mosaic virus (WYMV), like Han 6172. The protein content of Yangmai 37 was comparable to Zhenmai 9, but its dough stability time was significantly lower. Genetic contribution analysis revealed that 62.5% of Yangmai 37’s genetic makeup originated from Zhenmai 9, while 37.5% came from Han 6172. Yangmai 37 inherited the same haplotypes for vernalization, photoperiod, and flowering genes as its female parent. It also carried the dwarf gene Rht-B1b from Zhenmai 9 and inherited high grain weight haplotypes at TaGS-D1 and TaSus2-2B from its female parent, as well as TaSus1-7A from its male parent. Additionally, Yangmai 37 retained the QTL QFhs.crc.2D, associated with FHB resistance, from Zhenmai 9 but lost the Pm21 gene for PM resistance and QYm.nau-2D, a QTL for WYMV resistance, from its female parent. For pre-harvest sprouting (PHS) resistance, Yangmai 37 harbored the same Sdr-B1a and Vp-1Bc haplotypes as Zhenmai 9. However, Yangmai 37 lacked the high-molecular-weight glutenin subunit (HMW-GS) combination 1Dx5+1Dy10, which is associated with superior gluten strength in Zhenmai 9. Instead, it inherited the 1RS.1BL translocation, known to negatively impact gluten quality, from its male parent. The selection of flowering-related genes and PHS resistance haplotypes contributed to the unequal distribution of parental alleles in Yangmai 37. Meanwhile, the loss of Pm21, QYm.nau-2D, and 1Dx5+1Dy10, along with the introduction of the 1RS^.1BL translocation, were key factors influencing the differences in disease resistance and quality traits between Yangmai 37 and its female parent, Zhenmai 9.

Genetic mapping of mutant genes on flag leaf length and width in wheat

YANG Si-Jie, DU Qi-Di, CHAI Shou-Xi, XIONG Hong-Chun, XIE Yong-Dun, ZHAO Lin-Shu, GU Jia-Yu, GUO Hui-Jun, LIU Lu-Xiang

Acta Agronomica Sinica. 2025, 51(6):  1548-1557.  doi:10.3724/SP.J.1006.2025.41095

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Leaf morphology is a key determinant of plant architecture, influencing photosynthetic efficiency, yield, and stress responses. In wheat, the flag leaf serves as a critical photosynthetic organ, directly impacting grain yield and quality. Identifying novel genes and alleles associated with flag leaf traits can facilitate high-yield wheat breeding. In this study, we used the wheat variety Jing 411 as the wild type and developed a stable mutant, je0261, which exhibited a significantly reduced flag leaf area. Compared to Jing 411, the mutant had a 38.9% shorter, 29.3% narrower, and 56.7% smaller flag leaf. Analysis of segregation ratios for flag leaf length and width in the F₂ and F₃ populations derived from Jing 411 × je0261 indicated that these traits were each controlled by a single recessive gene. Using bulked segregant analysis (BSA) combined with exome capture sequencing, we mapped the target genes to chromosome 7A. Seven KASP markers were developed within the target region, and the genes controlling flag leaf length and width were mapped to a 1.17 cM genetic interval, corresponding to an 8.08 Mb physical region in the Chinese Spring reference genome. The genetic distance between these two genes was 1.00 cM, suggesting that they are two distinct, novel genes regulating flag leaf length and width. The identification of this candidate interval enhances our understanding of the genetic basis of flag leaf area in wheat and provides valuable mutant gene resources for future wheat architecture improvement.

Genome-wide association analysis and candidate genes prediction of flowering time and maturity date traits in soybean (Glycine max L.)

WANG Qiong, ZOU Dan-Xia, CHEN Xing-Yun, ZHANG Wei, ZHANG Hong-Mei, LIU Xiao-Qing, JIA Qian-Ru, WEI Li-Bin, CUI Xiao-Yan, CEHN Xin, WANG Xue-Jun, CEHN Hua-Tao

Acta Agronomica Sinica. 2025, 51(6):  1558-1568.  doi:10.3724/SP.J.1006.2025.44166

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Soybean is a typical short-day crop that is highly sensitive to photoperiod, with its cultivation and yield constrained by field photoperiodic conditions. In this study, we analyzed the flowering time and pod maturity date in 264 diverse soybean accessions. We examined the relationships between flowering-related traits and key agronomic traits, including protein content (PC), oil content (OC), 100-seed weight (HSW), and plant height (PH). A genome-wide association study (GWAS) identified 235 loci associated with flowering time and pod maturity date. Additionally, we predicted 14 candidate genes involved in the regulation of these traits, including 10 genes related to flowering time and 5 genes associated with pod maturity date. Notably, one gene exhibited pleiotropic effects on both traits. These findings provide valuable genomic insights into the regulatory pathways of flowering in soybean and offer a foundation for genetic improvement aimed at enhancing soybean adaptation across broader latitudinal regions.

TILLAGE & CULTIVATION · PHYSIOLOGY & BIOCHEMISTRY

Genetic analysis and molecular identification of a small kernel mutant mn-like1 in maize

YUAN Xin, ZHAO Zhuo-Fan, ZHAO Rui-Qing, LIU Xiao-Wei, ZHENG Ming-Min, LIU Yu-Sheng, DONG Hao-Sheng, DENG Li-Juan, CAO Mo-Ju, HUANG Qiang

Acta Agronomica Sinica. 2025, 51(6):  1569-1581.  doi:10.3724/SP.J.1006.2025.43056

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The kernel serves as the primary storage organ in maize, and its proper development requires on an adequate carbohydrate supply and efficient nutrient transport channels. In this study, we identified a natural mutant, small kernel 18 (smk18), exhibiting defects in kernel development. After multi-year and multi-location field trials, the smk18 mutant trait remained genetically stable. Segregation analysis of the (B73 × smk18) F₂ population revealed that the mutant phenotype was controlled by a single recessive gene. The smk18 mutant was backcrossed to the inbred line RP125 for five generations to construct the near-isogenic mn-like1 (RP125^{smk18 smk18}). Phenotypic evaluation showed that mn-like1 exhibited increased plant height and ear height compared to RP125, whereas hundred-kernel weight, kernel length, and kernel width were significantly reduced. Through molecular mapping, we localized the causal gene between Indel 4 and Indel 5 on chromosome 2. Within this interval, the Miniature1 (Mn1) gene had been previously reported to encode a cell wall invertase (INCW2) essential for carbohydrate transport during early kernel development. Sequencing of the Mn1 coding sequence (CDS) in mn-like1 revealed a 9-bp deletion in exon 5, leading to the loss of three amino acids (positions 409–411) in the Mn1 protein and alterations in its structure. Expression analysis showed that Mn1 transcript levels were significantly reduced in mn-like1 kernels at 13 days after pollination (DAP). An allelism test between mn-like1 and the transposon insertion mutant mn1-mu confirmed that mn-like1 is a novel allelic variant of Mn1. Further subcellular localization studies, carbohydrate quantification, and glycogen staining indicated that Mn1 is specifically expressed in the basal transfer layer of the endosperm. Mutation of Mn1 disrupted carbohydrate transport, leading to a significant reduction in sucrose and starch content in mn-like1 kernels, ultimately resulting in kernel developmental defects. In conclusion, this study expands the repertoire of Mn1 mutants in diverse genetic backgrounds and provides valuable genetic resources for elucidating the regulatory mechanisms of Mn1 in kernel development and the catalytic function of Mn1 protein.

Morphological characteristics, types, and developmental process of potato leaf trichomes

YANG Shuang, BAI Lei, GUO Hua-Chun, MIAO Ya-Sheng, LI Jun

Acta Agronomica Sinica. 2025, 51(6):  1582-1598.  doi:10.3724/SP.J.1006.2025.44188

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The surfaces of angiosperm leaves are often covered with various types of trichomes, whose structures and functions have been extensively studied in multiple plant species. However, a systematic investigation of the morphology, structure, and classification of Solanum tuberosum trichomes remains lacking. In this study, we used optical and electron microscopy to examine the distribution, morphological characteristics, and developmental processes of trichomes in different potato (Solanum tuberosum) varieties. Our results revealed that potato trichomes can be classified into two main categories: non-glandular trichomes (types II, III, and V) and glandular trichomes (types VI and VII). Non-glandular trichomes are primarily found on the epidermis of stems and leaves, as well as along leaf margins, whereas glandular trichomes are predominantly distributed on the lower epidermis of leaves. The development of non-glandular trichomes begins with localized conical protrusions emerging from epidermal cells, followed by a single periclinal division that produces a basal cell and a terminal cell. The basal cell differentiates into the trichome base, while the terminal cell elongates and may further divide to form multiple stalk cells. The mature stalk cells exhibit warty protrusions on their surfaces, and the terminal cell does not develop a glandular head, resulting in sharp or hook-like structures. In contrast, glandular trichome development is initiated by protrusions from epidermal cells, which gradually expand into initial glandular trichome cells. These cells undergo division to form a basal cell and a terminal cell. The basal cell does not undergo further division and directly differentiates into the base of the glandular trichome, while the terminal cell expands and gives rise to the initial glandular head cell. Based on their division patterns and cell numbers, glandular trichomes are classified into types VI and VII. Mature glandular trichomes possess secretory capabilities, accumulating secretions in the subepidermal space. Once the secretions reach a certain level, they protrude from the surface of the head cell and are released either through secretory pores or by direct rupture. As the glandular trichomes age, they gradually shrink and eventually detach. These findings demonstrate that potato leaves harbor diverse types of trichomes, with glandular trichomes playing a role in synthesizing, accumulating, and releasing secretions. By integrating these results with existing research on trichome functions in other Solanum species, such as tomatoes, we hypothesize that potato leaf trichomes may contribute to physical and chemical defenses against insect herbivory and pathogen attack. Further studies are required to validate these functions and elucidate the underlying mechanisms.

Effects of a 3–4°C increase in air temperature under natural conditions on root-shoot senescence and yield in plastic-film mulched maize

ZHANG Shi-Bo, LI Hong-Yan, LI Pei-Fu, REN Rui-Hua, LU Hai-Dong

Acta Agronomica Sinica. 2025, 51(6):  1599-1617.  doi:10.3724/SP.J.1006.2025.43053

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With the ongoing rise in global temperatures and the increasing frequency of flash droughts, premature senescence in plastic film-mulched spring maize has become more severe, significantly limiting maize yield formation. Current research on this issue primarily focuses on the relationship between moisture stress and leaf characteristics, while the mechanisms underlying film-induced warming and its effects on root-shoot senescence in spring maize remain unclear. To address this knowledge gap, we conducted a two-year field experiment (2021–2022) in Changwu (average annual temperature > 9°C) and Yangling (average annual temperature > 12°C), two semi-humid, drought-prone regions in northwestern China. The experiment included a bare land control (CK) and two mulching treatments: transparent film mulching (TM) and dual mulching with transparent film and black polyethylene net (TM+BN), designed to maintain the film’s water retention effect while modifying soil temperature. Using ‘Zhengdan 958’ as the test variety, we investigated the effects of these mulching strategies on soil conditions, root growth and senescence, leaf stay-green characteristics, and yield performance in dryland maize farming. The results showed that, compared to CK, both mulching treatments increased soil water storage at both locations, with no significant differences in average soil water storage between TM and TM+BN. Meanwhile, the average topsoil temperature of spring maize in Yangling from the three-leaf stage to maturity (V3–R6) was 2.1–2.3°C higher than in Changwu. Across both locations, the average topsoil temperature under TM was 2.0–2.2°C higher than under TM+BN, indicating that TM+BN had a moderate soil cooling effect. Compared to TM, the soil cooling effect of TM+BN extended the reproductive growth period of spring maize by 10–12 days, improved nutrient supply during the late growth stages, and enhanced root antioxidant capacity and leaf greenness. As a result, root dry weight at 0–40 cm depth increased by 8.6%, aboveground dry matter accumulation at maturity increased by 14.4%, and grain yield improved by 18.5%–24.5% compared to TM. These findings suggest that, under projected global warming of 3–4°C, maintaining an average topsoil temperature between 26.3°C and 29.0°C during the V3–R6 period in heat-rich dryland agricultural regions may delay premature senescence in film-mulched maize and enhance grain yield. This study provides a scientific basis for high-yield, efficient cultivation and sustainable production of film-mulched maize in a warming climate. 

Long-term combined application of organic and inorganic fertilizers achieving high yield and high quality of maize in northwest irrigated oasis

ZHENG Hao-Fei, YANG Nan, DU Jian, JIA Gai-Xiu, ZOU Yue, MA Wen-Hao, WANG Yan-Ting, SUO Dong-Rang, ZHAO Jian-Hua, SUN Ning-Ke, ZHANG Jian-Wen

Acta Agronomica Sinica. 2025, 51(6):  1618-1628.  doi:10.3724/SP.J.1006.2025.43040

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The long-term effects of combined organic and inorganic fertilizer application on maize yield and grain quality were evaluated based on a long-term field experiment initiated in 1982 in the irrigated desert soil region of Northwest China. The experiment was conducted at the Zhangye Academy of Agricultural Sciences Experimental Station in Gansu Province, China, using a two-factor split-plot design. The main factor was the application of organic manure (M) versus no organic manure (NM), while the sub-factor consisted of different chemical fertilizer treatments: no chemical fertilizer (CK), nitrogen fertilizer (N), nitrogen and phosphorus fertilizer (NP), and nitrogen, phosphorus, and potassium fertilizer (NPK), resulting in a total of eight treatments. Agronomic traits were assessed at harvest in 2022 and 2023, and maize grain quality parameters, including protein, starch, and fat content, were measured. Crude protein yield was also calculated. The results showed that, compared with N application alone, the addition of organic manure (M) significantly increased maize grain yield by 11.51%–18.26%, with a 17.02% increase in crude protein yield. Under M conditions, NP and NPK treatments achieved higher yields, averaging 12.85 t hm^?2 and 13.29 t hm^?2, respectively, with no significant difference between them. Regardless of organic manure application, N, NP, and NPK treatments increased yield by 17.89%, 49.86%, and 54.44%, respectively, compared with CK. Additionally, NP application significantly improved yield by 27.12% compared with N. The interaction between organic manure and inorganic fertilizer had a significant effect on maize grain protein content. Compared with CK, N application increased grain protein content by 12.83%, while NP and NPK showed no significant difference in protein content relative to CK. Organic manure application (M) increased protein yield by 21.88% and starch content by 0.56% compared with NM. Furthermore, compared with CK, N, NP, and NPK treatments increased protein yield by 29.08%, 52.31%, and 61.84%, respectively, but had no significant effect on maize grain fat content. In conclusion, organic manure application enhances maize yield, while inorganic fertilizer application, particularly NP, further improves both yield and grain quality. The combined use of organic and inorganic fertilizers promotes high-yield, high-quality maize production and contributes to sustainable agricultural development.

Effects of potassium fertilizer application rates on rapeseed yield and potassium absorption and yield reduction caused by frost damage

CUI Xin, GU He-He, SONG Yi, ZHANG Zhe, LIU Shi-Shi, LU Zhi-Feng, REN Tao, LU Jian-Wei

Acta Agronomica Sinica. 2025, 51(6):  1629-1642.  doi:10.3724/SP.J.1006.2025.44150

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Low-temperature frost damage during the overwintering and budding stages of winter rapeseed significantly affects yield formation. Increasing potassium fertilizer application is an effective strategy to enhance stress resistance and mitigate yield losses caused by frost damage. This study aimed to evaluate the effects of different potassium fertilizer rates on rapeseed yield reduction following frost damage. Field experiments were conducted in Wuxue City and Wuhan City, Hubei Province, during the 2022/2023 and 2023/2024 growing seasons. The study compared the effects of varying potassium fertilizer rates (0, 60, 120, 180, and 240 kg hm^?2) on rapeseed yield, yield components, aboveground nutrient content and distribution, and potassium nutrient use efficiency under extreme low-temperature conditions in the 2023/2024 season. The results indicated that, compared to the 2022/2023 season, the 2023/2024 frost conditions led to a 13.4%–24.1% yield reduction at the Wuhan site and a more pronounced 35.7%–57.1% reduction at the Wuxue site under the same treatments. This was accompanied by a decline in total aboveground biomass, ranging from 32.3%–42.5% in Wuhan and 23.9%–38.9% in Wuxue. The primary factors contributing to yield loss were a substantial decrease in pod number per plant (35.5%–56.0%) and a reduction in 1000-seed weight (28.1%–31.6%). Potassium application alleviated yield losses, with the K180 treatment exhibiting the smallest yield reduction. After frost damage, the potassium content and its distribution within rapeseed increased, although aboveground potassium accumulation declined significantly. Additionally, potassium absorption efficiency and the partial factor productivity of potassium fertilizer decreased. Potassium application enhanced potassium accumulation in rapeseed, slowed the decline in aboveground potassium absorption, and promoted the transfer of potassium from non-seed tissues to seeds. Model fitting using a linear-plus-plateau approach suggested optimal potassium application rates of 163.1 kg hm^?2 for Wuhan and 147.9 kg hm^?2 for Wuxue, representing an average increase of 35.2 kg hm^?2 compared to the 2022/2023 season. In conclusion, appropriate potassium fertilization during low-temperature frost periods can significantly improve rapeseed growth and mitigate yield losses caused by severe climatic fluctuations.

Effects of straw mulching on soil water temperature effect and winter wheat yield in different rainfall years in Dryland Loess Plateau

ZHAO Gang, ZHANG Jian-Jun, DANG Yi, FAN Ting-Lu, WANG Lei, ZHOU Gang, WANG Shu-Ying, LI Xing-Mao, NI Sheng-Li, MI Wen-Bo, ZHOU Xu-Jiao, Cheng Wan-Li, Li Shang-Zhong

Acta Agronomica Sinica. 2025, 51(6):  1643-1653.  doi:10.3724/SP.J.1006.2025.41083

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To elucidate the mechanisms by which straw mulching influences soil moisture, temperature, and winter wheat yield under varying rainfall conditions in the Loess Plateau, we conducted a seven-year field study examining the effects of different straw mulch amounts on soil moisture dynamics, temperature variation, water consumption, and wheat yield. The results demonstrated that straw mulching significantly increased soil temperature during the overwintering period, though the warming effect diminished as mulch amounts increased. In dry and normal rainfall years, the 1500 kg hm?2 treatment exhibited a warming effect during the greening stage, whereas in wet years, it had a cooling effect. Across all rainfall conditions, higher mulch amounts intensified cooling effects. Straw mulching consistently enhanced soil water storage in the 0–2 m soil layer throughout the wheat growth period, with greater mulch amounts leading to increased water retention. In dry and normal years, water consumption decreased with increasing mulch amounts, whereas in wet years, the trend was reversed. During the greening–grain filling stage of dry years, the 1500 kg hm?2 treatment increased soil water storage by 8.1–20.0 mm compared to bare land. Across all rainfall conditions, total water consumption over the entire growth period exceeded that of bare land by 7.0–14.8 mm, with the greening–jointing and grain filling–maturity stages showing the most pronounced increases. In terms of yield and water use efficiency (WUE), the 1500 kg hm?2 treatment increased yield and WUE by 21.5% and 18.5%, respectively, compared to bare land, primarily due to an increase in ear number. In contrast, the 3000 kg hm?2 treatment resulted in yield and WUE levels comparable to bare land, while further increases in mulch amounts led to declines in both yield and WUE. Under the 1500 kg hm^-2 mulch condition, soil temperature during the greening stage in dry and normal rainfall years was effectively increased, supporting high yield and WUE. However, 3000 kg hm^-2 was identified as a critical threshold; although excessive mulching significantly enhanced soil water retention, it also caused excessive cooling, ultimately leading to reduced yield and WUE.

Effects of poly-γ-glutamate acid on lodging resistance of direct seeding rice

LI Zi-Xiang, HUANG Rong, WANG Zhi-Chao, LI Hong-Yan, TAN Jun-Xing, CHENG Yu, DU Xue-Zhu, SHENG Feng

Acta Agronomica Sinica. 2025, 51(6):  1654-1664.  doi:10.3724/SP.J.1006.2025.42054

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This study investigated the effects of poly-γ-glutamic acid (γ-PGA) on lodging resistance, yield, and grain quality in direct- seeded rice, aiming to provide a theoretical foundation and technical guidance for high-yield, high-quality rice cultivation. A field experiment was conducted in Huaqiao Town, Wuhui City, Hubei Province, in 2022 and 2023 using a two-factor split - plot design. The main plots consisted of two irrigation treatments: flooded (W) and dry (D) conditions. The subplots included two γ-PGA fermentation liquid treatments: no application (P0) and application at 25 kg hm^?2 (P1). Key indicators of lodging resistance, yield, and grain quality were measured. The results showed that γ-PGA application significantly enhanced stem structural characteristics. Specifically, the first internode stem diameter increased by 10.3%–10.6% and 7.5%–13.3%, while the second internode stem diameter increased by 10.5%–11.8% and 8.2%–17.5%. Stem wall thickness improved by 23.7%–27.9% and 12.5%–22.0%. Additionally, bending moment increased by 3.8%–7.6% and 4.1%–5.9%, and breaking bending distance increased by 37.3%–52.7% and 50.8%–54.5%. Furthermore, the lodging index decreased by 21.9%–29.1% and 30.2%–32.2%, indicating improved lodging resistance. Overall, γ-PGA application enhanced stem strength, contributing to improved lodging resistance, increased yield, and enhanced grain quality in direct-seeded rice. These findings suggest that γ-PGA has the potential to be an effective agronomic strategy for optimizing rice production.

Grain yield and quality of maize in response to dense density and intercropped peas in oasis irrigated areas

YAN Shang-Long, WANG QI-Ming, CHAI Qiang, YIN Wen, FAN Zhi-Long, HU Fa-Long, LIU Zhi-Peng, WEI Jin-Gui

Acta Agronomica Sinica. 2025, 51(6):  1665-1675.  doi:10.3724/SP.J.1006.2025.43051

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To address the decline in maize grain quality caused by increased planting density in oasis irrigation areas, this study examines the effects of intercropping pea on maize grain quality under different planting densities, aiming to provide theoretical and practical guidance for optimizing high-yield, high-quality maize cultivation systems. A split-plot experiment was conducted from 2020 to 2021, with monocropped maize (M) and intercropped maize with pea (M||P) as the main plots, and different maize planting densities as subplots: for monocropping, 78,000 plants per hectare (M1, low density), 103,500 plants per hectare (M2, medium density), and 129,000 plants per hectare (M3, high density); for intercropping, 45,000 plants per hectare (M1||P, low density), 60,000 plants per hectare (M2||P, medium density), and 75,000 plants per hectare (M3||P, high density). The results showed that increasing planting density significantly improved maize grain yield and biological yield, while intercropping with pea further enhanced these effects. Among the intercropping treatments, medium-density maize (M2||P) achieved the highest grain and biological yields, increasing by 34.6%–36.6% and 30.0%–39.3%, respectively, compared to low-density monocropped maize. As planting density increased, starch content in maize grains significantly increased, whereas protein and fat contents significantly decreased, with the total yield of nutritional components first increasing and then declining. Intercropping with pea significantly improved maize grain nutritional content and total nutritional yield, enhanced the positive effect of higher planting density on grain starch content and total nutritional yield, mitigated the negative impact of increased density on protein content, and reduced the decline in total nutritional yield observed at high density compared to medium density. Higher planting density significantly reduced the content of phenylalanine, leucine, isoleucine, and valine in maize grains while significantly increasing tryptophan and lysine concentrations; intercropping significantly increased phenylalanine, leucine, isoleucine, and valine levels and alleviated the reduction in phenylalanine and leucine content caused by increased planting density, with the best effects observed under medium-density intercropping (M2||P). Overall, both increased planting density and intercropping significantly improved the comprehensive performance of maize, with the best overall performance achieved by intercropping pea and a maize planting density of 60,000 plants per hectare (M2||P), yielding a performance score of 0.47. This planting model maximizes grain yield while enhancing grain quality, making it a feasible and effective cultivation strategy for improving maize production in the Hexi Oasis irrigation area.

RESEARCH NOTES

Exploring the prediction of planting suitability distribution and quality zoning of Angelica publicen Maxin f. biserrata Shan et yuan based on MaxEnt model and HPLC

HU Chao-Gui, DONG Peng-Bin, WANG Chen-Yue, LI Qian

Acta Agronomica Sinica. 2025, 51(6):  1676-1689.  doi:10.3724/SP.J.1006.2025.44126

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Angelicae publicentis Radix (Duhuo), a traditional Chinese medicine (TCM) and an economically important crop, presents challenges in quality control due to its wide geographic distribution. In this study, the MaxEnt model was employed to predict the current and future potential distribution of Duhuo in China, elucidating how climate change influences its spatial distribution patterns. Furthermore, High-Performance Liquid Chromatography (HPLC) combined with ArcGIS spatial analysis was applied to investigate the key environmental factors affecting coumarin accumulation and to identify optimal cultivation zones. The results revealed that the primary environmental factors influencing the current distribution of Duhuo include the annual temperature range, minimum temperature of the coldest month, solar radiation in May, mean temperature of the coldest quarter, and precipitation in the warmest quarter. The most suitable planting regions are primarily located in monsoon-influenced areas, including central Sichuan (Aba and Ganzi), southern Gansu (Pingliang), southern Shaanxi (Qinling), southern Hubei (Yichang), and southern Yunnan. Climate change projections suggest that the centers of suitable habitats will shift northward and to higher latitudes, resulting in a reduction in suitable areas. Coumarin content appears to decline gradually from high-suitability regions to low-suitability regions, possibly influenced by precipitation patterns. The optimal areas for cultivating high-quality Duhuo are concentrated in central Sichuan, southern Gansu, Hunan, Henan, southern Hubei, and southern Anhui, aligning closely with current suitable planting regions, although these areas are also expected to shrink in the future. This study provides valuable insights for optimizing Duhuo cultivation areas, enhancing quality control, increasing economic benefits, and promoting industrial development.

Cloning, hormone-induced expression analysis, and interaction protein screening of OsPUB4 in rice

LI Fu-Yuan, YANG-Yi, MA Ji-Qiong, XU Ming-Hui, LIN Liang-Bin, SUN Yi-Ding

Acta Agronomica Sinica. 2025, 51(6):  1690-1700.  doi:10.3724/SP.J.1006.2025.42045

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To investigate the function of the E3 ubiquitin ligase OsPUB4 and elucidate its regulatory mechanism, we cloned the coding sequence of OsPUB4, a U-box-type E3 ubiquitin ligase gene, from the rice cultivar “Nipponbare”. The cis-acting elements of the promoter and the sequence characteristics of the coding region were predicted using bioinformatics tools, and a phylogenetic tree was constructed. The expression patterns of OsPUB4 under different plant hormone treatments were analyzed by quantitative real-time PCR (qRT-PCR). Additionally, interaction proteins of OsPUB4 were identified using a yeast cDNA library screening approach. Our findings revealed that: (1) The promoter region of OsPUB4 contains multiple response elements associated with hormones, light, and temperature. The coding region is 2187 bp in length, lacks a signal peptide, and contains a transmembrane domain and 62 phosphorylation sites. (2) OsPUB4 is closely related to the PUB4 protein of Triticum Urartu. (3) Exogenous jasmonic acid (JA) treatment rapidly suppressed OsPUB4 expression in rice leaves, whereas indole-3-acetic acid (IAA) had the opposite effect. (4) OsPUB4 interacts with OsTPS5, Di19, and THIC. These results suggest that OsPUB4 is induced by exogenous hormones and interacts with multiple stress response-related proteins, providing a theoretical foundation for further investigations into the role of OsPUB4 in rice stress responses.