小麦抗旱性状的遗传分析与分子标记开发 -农学专业

摘要

随着全球气候变化加剧，干旱胁迫已成为制约小麦生产的主要非生物逆境因素。本研究以我国主要小麦品种为材料，系统开展了抗旱性状的遗传分析与分子标记开发工作。通过田间干旱胁迫试验，对200份小麦种质资源的株高、穗长、千粒重等12个农艺性状进行表型鉴定，发现不同基因型间存在显著差异。利用全基因组关联分析技术，结合90K SNP芯片数据，共检测到与抗旱性相关的显著位点38个，其中位于2B染色体上的QTL-qDSI.2B-1解释表型变异率最高。基于连锁不平衡分析，筛选出5个与抗旱性密切相关的候选基因，包括编码脱水素蛋白的TaDhn1和调控气孔开闭的TaSTOM1。进一步开发了3个功能性分子标记，经验证在育种群体中具有较高的选择效率。研究首次揭示了小麦抗旱性的多基因调控网络，明确了关键QTL位点的遗传效应，开发的分子标记为小麦抗旱育种提供了有效的辅助选择工具。这些成果不仅丰富了小麦抗旱遗传理论体系，也为培育高产稳产小麦新品种奠定了重要基础。

关键词：小麦抗旱性；全基因组关联分析；分子标记；QTL定位

GENETIC ANALYSIS AND MOLECULAR MARKER DEVELOPMENT OF DROUGHT RESISTANCE TRAITS IN WHEAT

ABSTRACT

With the intensification of global climate change, drought stress has become the main abiotic stress factor restricting wheat production. In this study, the genetic analysis and molecular marker development of drought resistance traits were systematically carried out based on the main wheat varieties in China. Through field drought stress test, 12 agronomic traits such as plant height, ear length and 1000-grain weight of 200 wheat germplasm resources were identified and significant differences were found among different genotypes. Using genome-wide association analysis and 90K SNP chip data, a total of 38 significant loci related to drought resistance were detected, among which QTL-qDSI.2B-1 on chromosome 2B had the highest interpretive phenotype variation rate. Based on linkage disequilibrium analysis, five candidate genes closely related to drought resistance were screened, including TaDhn1 encoding dehydrin protein and TaSTOM1 regulating stomatal opening and closing. Three functional molecular markers were further developed and proved to have high selection efficiency in breeding population. This study revealed for the first time the multi-gene regulatory network of wheat drought resistance, identified the genetic effects of key QTL loci, and developed molecular markers to provide an effective auxiliary selection tool for wheat drought resistance breeding. These results not only enrich the genetic theory system of wheat drought resistance, but also lay an important foundation for breeding new wheat varieties with high and stable yield.

KEY WORDS：Wheat drought resistance; Genome-wide association analysis; Molecular marker; QTL mapping

摘要 I

ABSTRACT II

第1章绪论 2

1.1 研究背景及意义 2

1.2 小麦抗旱性状遗传分析研究现状 2

第2章小麦抗旱性状的遗传基础 3

2.1 小麦抗旱相关基因的鉴定 3

2.2 抗旱性状的遗传多样性分析 3

2.3 QTL定位与基因功能验证 4

第3章小麦抗旱分子标记的开发与应用 5

3.1 SSR标记的开发与筛选 5