中国农业科学 ›› 2026, Vol. 59 ›› Issue (17): 3712-3729.doi: 10.3864/j.issn.0578-1752.2026.17.002

• 作物遗传育种·种质资源·分子遗传学 • 上一篇    下一篇

旱地小麦穗粒数全基因组关联分析与候选基因发掘

王浩栋1,2(), 王鹏3, 吴宇轩2, 张钦2, 王巧芸2, 郭利建1, 杨德龙1,2(), 陈涛2()   

  1. 1 省部共建干旱生境作物学国家重点实验室, 兰州 730070
    2 甘肃农业大学生命科学技术学院, 兰州 730070
    3 甘肃农业大学农学院, 兰州 730070
  • 收稿日期:2026-02-03 接受日期:2026-04-01 出版日期:2026-09-03 发布日期:2026-09-03
  • 通信作者:
    杨德龙,E-mail:
    陈涛,E-mail:
  • 联系方式: 王浩栋,E-mail:17789375583@163.com。
  • 基金资助:
    甘肃省科技重大专项(25ZDNA001); 甘肃省麦类产业技术体系(GSARS07); 甘肃省基础研究创新群体项目(24JRRA633); 甘肃省农业农村厅种业攻关项目(GYGG-2024-2)

Genome-Wide Association Study and Candidate Gene Identification for Grain Number per Spike in Dryland Wheat (Triticum aestivum L.)

WANG HaoDong1,2(), WANG Peng3, WU YuXuan2, ZHANG Qin2, WANG QiaoYun2, GUO LiJian1, YANG DeLong1,2(), CHEN Tao2()   

  1. 1 State Key Laboratory of Aridland Crop Science, Lanzhou 730070
    2 College of Life Science and Technology, Gansu Agricultural University, Lanzhou 730070
    3 College of Agronomy, Gansu Agricultural University, Lanzhou 730070
  • Received:2026-02-03 Accepted:2026-04-01 Published:2026-09-03 Online:2026-09-03

摘要:

【目的】小麦是全球最重要的粮食作物之一,提高产量对保障粮食安全具有重要意义。穗粒数是影响小麦产量的核心因素之一,深入解析小麦穗粒数遗传基础并挖掘关键候选基因,为小麦穗粒数遗传改良和分子标记辅助育种提供依据。【方法】以123份小麦品种(系)为材料,在不同干旱环境条件下进行穗粒数表型鉴定,结合35K SNP芯片基因分型信息,采用混合线性模型开展全基因组关联分析。针对与穗粒数显著相关的标记-性状关联位点(MTA),进一步开展单倍型分析,开发KASP分子标记并进行多环境表型验证。利用公共RNA-seq数据筛选穗部组织特异性高表达基因,结合qRT-PCR验证其表达模式。通过同源比对和已有功能研究信息,对候选基因进行功能注释。【结果】穗粒数在不同环境条件下的变异系数为17.18%—22.48%,表明该性状受环境影响较大。GWAS共检测到47个与穗粒数显著关联的MTA,其中,5A染色体上分布最多,达9个MTA。标记AX-94445381位于5A染色体,在2个环境中被重复检测到,表现出稳定的遗传关联。单倍型分析将该标记划分为HapⅠ和HapⅡ 2种单倍型,进一步开发的KASP标记验证结果表明,在3个环境中,携带HapⅡ单倍型的小麦品种的穗粒数均显著高于携带HapⅠ单倍型的小麦品种。利用公开的重测序数据分析优异单倍型AX-94445381-HapⅡ的分布情况,发现其在育成品种中的分布频率(30.1%)低于地方品种(40.0%),表明该单倍型在小麦育种进程中尚未得到充分利用。对AX-94445381上下游1 Mb区间进行基因检索,整合RNA-seq数据筛选出穗部组织特异性高表达基因,经qRT-PCR验证并结合水稻同源基因信息,发现3个已被报道直接参与穗部发育的候选基因,分别编码UDP-糖基转移酶、MADS-box转录因子和WD重复序列蛋白。【结论】鉴定到与小麦穗粒数稳定关联的重要位点AX-94445381,明确了优异单倍型AX-94445381-HapⅡ具有显著提高穗粒数的功能,具有进一步挖掘和应用的潜力。

关键词: 小麦, 穗粒数, 全基因组关联分析, KASP标记, 候选基因

Abstract:

【Objective】Wheat (Triticum aestivum L.) ranks among the most vital cereal crops globally, making the enhancement of its yield crucial for ensuring food security. The grain number per spike (GNS) serves as a critical determinant of wheat yield. Understanding the genetic architecture of GNS and identifying key candidate genes will promote genetic improvement and enable marker-assisted selection for this trait.【Method】A panel of 123 wheat accessions was phenotyped for GNS across multiple drought-prone environments. Genome-wide association studies (GWAS) were conducted utilizing a mixed linear model (MLM) based on genotyping data derived from a 35K SNP array. For marker-trait associations (MTAs) significantly correlated with GNS, haplotype analysis was performed, Kompetitive Allele-Specific PCR (KASP) markers were developed, and multi-environment phenotypic validation was executed. Candidate genes were identified through public RNA-seq data to screen for genes with high expression levels in spike tissues. This was followed by validation using quantitative real-time reverse transcription PCR (qRT-PCR) and functional annotation based on homology and previously reported functional information.【Result】GNS exhibited coefficients of variation between 17.18% and 22.48% across different environments, indicating a significant environmental impact. The GWAS identified 47 significant MTAs, with the highest concentration of 9 MTAs located on chromosome 5A. Notably, the marker AX-94445381 on chromosome 5A was consistently detected in two environments, demonstrating a stable genetic association. Haplotype analysis categorized this marker into two distinct haplotypes (HapⅠ and HapⅡ). Validation of the KASP marker indicated that accessions carrying HapⅡ displayed significantly higher GNS across three environments compared to those with HapⅠ. An analysis of the favorable haplotype AX-94445381-HapⅡ, utilizing publicly available resequencing data, revealed that its frequency was lower in modern cultivars (30.1%) than in landraces (40.0%), suggesting that this haplotype has not been fully exploited in wheat breeding programs. Candidate gene screening within the 1 Mb region surrounding AX-94445381, in conjunction with RNA-seq data, identified genes that are highly expressed specifically in spike tissue. Validation through qRT-PCR and homology analysis with rice orthologs identified three candidate genes directly involved in spike development, which encode a UDP-glycosyltransferase, a MADS-box transcription factor, and a WD repeat-containing protein, respectively.【Conclusion】A major stable locus, AX-94445381, associated with GNS has been identified. The advantageous haplotype AX-94445381-HapⅡ was shown to markedly enhance GNS, underscoring its potential for further exploitation and application in wheat breeding.

Key words: wheat, grain number per spike, genome-wide association study, KASP marker, candidate genes