中国农业科学 ›› 2026, Vol. 59 ›› Issue (1): 17-28.doi: 10.3864/j.issn.0578-1752.2026.01.002

• 作物遗传育种·种质资源·分子遗传学 • 上一篇    下一篇

小麦穗密度主效QTL的鉴定、验证及其遗传效应分析

叶美金1(), 陈家婷2(), 周界光2, 尹丽2, 胡欣荣2, 兰雨昕2, 陈斌2, 苏龙兴2, 刘家君3, 刘天超1, 李小雨4,*(), 马建2,*()   

  1. 1 成都师范学院化学与生命科学学院,成都 611130
    2 四川农业大学小麦研究所,成都 611130
    3 四川文理学院/大巴山农业资源开发与生态保护达州市重点实验室,四川达州 635000
    4 南充市农业科学院,四川南充 637000
  • 收稿日期:2025-07-22 接受日期:2025-09-01 出版日期:2026-01-01 发布日期:2026-01-07
  • 通信作者:
    马建,E-mail:
    李小雨,E-mail:
  • 联系方式: 叶美金,E-mail:091048@cdnu.edu.cn。陈家婷,E-mail:2806131080@qq.com。叶美金和陈家婷为同等贡献作者。
  • 基金资助:
    四川省自然科学基金项目面上项目(2024NSFSC0330); 四川省大学生创新创业训练计划(S202514389093); 成都师范学院2025年第二批次高级别科研项目托举专项(CSTJZX2550)

Identification, Validation and Genetic Effect Analysis of Major QTL for Spike Density in Wheat

YE MeiJin1(), CHEN JiaTing2(), ZHOU JieGuang2, YIN Li2, HU XinRong2, LAN YuXin2, CHEN Bin2, SU LongXing2, LIU JiaJun3, LIU TianChao1, LI XiaoYu4,*(), MA Jian2,*()   

  1. 1 College of Chemistry and Life Sciences, Chengdu Normal University, Chengdu 611130
    2 Triticeae Research Institute, Sichuan Agricultural University, Chengdu 611130
    3 Sichuan University of Arts and Science/Dazhou Key Laboratory of Agricultural Resources Development and Ecological Conservation in Daba Mountain, Dazhou 635000, Sichuan
    4 Nanchong Academy of Agricultural Sciences, Nanchong 637000, Sichuan
  • Received:2025-07-22 Accepted:2025-09-01 Published:2026-01-01 Online:2026-01-07

摘要:

【目的】穗密度(spike density,SD)是小麦重要的农艺性状之一,其遗传调控机制解析对构建理想穗型结构、实现产量突破具有重要意义。挖掘和遗传评价调控穗密度的关键遗传位点,为小麦穗型分子设计育种提供理论依据。【方法】利用自然突变体msf和川农16构建的198个F6代重组自交系(recombinant inbred lines,RIL)群体,结合基于小麦16K SNP芯片的遗传连锁图谱,通过4个环境下的表型数据系统鉴定穗密度相关数量性状位点(QTL)。进一步利用2个不同遗传背景群体对主效且稳定表达的QTL进行验证,分析稳定表达位点对产量相关性状的遗传效应,评估其对产量提升的潜力。【结果】RIL群体穗密度表型值范围为0.62—2.35,穗密度遗传力为0.71。穗密度与有效分蘖数和小穗数之间存在显著正相关,而与穗粒数、穗粒重、穗长存在极显著负相关。基于4个环境共鉴定到9个控制穗密度的QTL,主要分布在1A、1D、5A(2个)、5B、7A(3个)和7B染色体上。其中,QSd.sicau-MC-1A定位于1A染色体侧翼标记1A_12082541A_3911208之间,在2个环境及最佳线性无偏预测(best linear unbiased prediction,BLUP)值中被检测到,可解释9.05%—15.84%的表型变异率,为主效且稳定表达的QTL,其正效应位点来源于亲本川农16,并且该位点的效应在2个具有不同遗传背景的验证群体中得到进一步验证。QSd.sicau-MC-7A.1定位于7A染色体侧翼标记7A_6714137887A_672390144之间,也在2个环境及BLUP值中被检测到,为稳定表达位点,其正效应位点来源于msf,但其效应较小,可解释7.06%—10.39%的表型变异率。剩余7个QTL均为微效QTL。遗传效应分析表明,QSd.sicau-MC-1A的正效应位点对主要产量性状具有负效应,而QSd.sicau-MC-7A.1的正效应位点起正效应作用。加性效应分析表明,同时携带QSd.sicau-MC-1AQSd.sicau-MC-7A.1正效应位点的株系的穗密度显著高于仅携带单一位点或没有携带任何正效应位点的株系,穗密度增幅达到9.01%,而仅携带QSd.sicau-MC-1A或者QSd.sicau-MC-7A.1正效应位点的株系的穗密度均显著高于没有携带任何正效应位点的株系,增幅分别为5.03%和4.19%。与前人报道的穗密度位点进行比对,发现QSd.sicau-MC-1A可能为新位点【结论】在小麦1A和7A染色体各定位到一个稳定表达的穗密度位点,分别为QSd.sicau-MC-1AQSd.sicau-MC-7A.1,后者更具有育种利用潜力。

关键词: 小麦, QTL, 穗密度, 遗传效应, 产量

Abstract:

【Objective】Spike density (SD) is an important agronomic trait in wheat, and elucidating its genetic regulatory mechanisms is crucial for constructing ideal spike architecture and achieving yield breakthroughs. This study aimed to identify and genetically characterize key genetic loci controlling SD, providing a theoretical basis for molecular design breeding of wheat spike morphology. 【Method】A recombinant inbred line (RIL) population consisting of 198 F6 lines derived from a cross between the natural mutant msf and cultivar Chuannong16 was used. Combined with a genetic linkage map based on the wheat 16K SNP array, quantitative trait loci (QTL) associated with SD were systematically identified using phenotypic data from four environments. Furthermore, two populations with different genetic backgrounds were employed to validate the major and stably expressed QTL. The genetic effects of the stable QTL on yield-related traits were analyzed, and their potential for yield improvement was evaluated. 【Result】The SD of the RIL population ranged from 0.62 to 2.35, with a heritability of 0.71. SD showed a significant positive correlation with productive tiller number and spikelet number, while exhibiting a highly significant negative correlation with grains per spike, grain weight per spike, and spike length. Nine QTLs controlling SD were identified, distributed on chromosomes 1A, 1D, 5A (2 QTLs), 5B, 7A (3 QTLs), and 7B. Among them, QSd.sicau-MC-1A was mapped between flanking markers 1A_1208254 and 1A_3911208 on chromosome 1A and detected in two environments and in the best linear unbiased prediction (BLUP) dataset, explaining 9.05%-15.84% of the phenotypic variation. This QTL, with its positive allele derived from Chuannong 16, was considered a major and stably expressed locus, and its effect was further validated in two independent genetic backgrounds. QSd.sicau-MC-7A.1 was located between markers 7A_671413788 and 7A_672390144 on chromosome 7A and also detected in two environments and BLUP. Although stably expressed, this QTL had a relatively minor effect (7.06%-10.39% phenotypic variation), with its positive allele originating from msf. The remaining seven QTLs were minor-effect loci. Genetic effect analysis revealed that the positive allele of QSd.sicau-MC-1A had negative effects on major yield-related traits, whereas QSd.sicau-MC-7A.1 exhibited positive effects. Additive effect analysis demonstrated that lines carrying both QSd.sicau-MC-1A and QSd.sicau-MC-7A.1 positive alleles had significantly higher SD (9.01% increase) compared to those carrying only one or no positive alleles. Lines with only QSd.sicau-MC-1A or QSd.sicau-MC-7A.1 showed 5.03% and 4.19% increases in SD, respectively, over lines without any positive alleles. Comparative analysis with previously reported SD QTLs suggested that QSd.sicau-MC-1A might be a novel locus. 【Conclusion】Two stably expressed QTLs for SD, QSd.sicau-MC-1A and QSd.sicau-MC-7A.1, were identified in wheat. The latter shows greater potential for breeding applications.

Key words: wheat, QTL, spike density, genetic effect, yield