普通小麦穗部性状QTL分析

QTL Mapping of Spike-Related Traits in Common Wheat

为给小麦穗部性状标记辅助选择提供可供选择的分子标记,并进一步对小麦穗部相关性状QTL进行精细定位及相关基因克隆,利用普通小麦Heyne×Lakin杂交F2代单粒传获得的145个F6代重组自交系(recombinant inbred line,RIL)群体,构建了含有2 210个标记(2 068个SNP标记和142个SSR标记)的总长度为2 139.35cM的遗传连锁图谱,并利用该图谱对小麦穗部性状(穗长、小穗数、穗密度)进行了QTL分析。结果表明,共检测出16个加性QTL,其中,与穗长相关的QTL有6个,分布在2A、2D、3B、4D、5A和7D染色体上,可解释表型变异7.58%~15.94%;与小穗数相关的QTL有4个,分布在1A、4A和7D染色体上,可解释表型变异7.28%~14.78%;与穗密度相关的QTL有6个,位于4D、5A和6B染色体上,可解释表型变异5.60%~20.06%。

Wheat is one of the most important crops in the world, and the spike-related traits of wheat are closely related to the yield of wheat. Thus, it is of great significance to study the spike related traits of wheat. This study characterized quantitative trait loci （QTL） underlying wheat spike-related traits using a high-density genetic linkage map developed from a recombinant inbred line （RIL） popu- lation derived from a cross between ＂Heyne＂ and ＂Lakin＇. The map consists of 2 068 single nucleotide polymorphism （SNP） and 142 simple sequence repeat （SSR） markers covering a genetic distance of 2 139.35 cM. The RIL population was evaluated for spike length （SL）, spikelet number per spike （SPN）, and spike compactness （SC） at Yangling and Sanyuan. Using QTL mapping, sixteen additive QTLs for spike-related traits were detected, including six of them for SL were mapped on chromo somes 2A, 2D, 3B, 4D, 5A and 7D, explaining 7.58% to 15.94% of the phenotypic variances; four QTLs for SPN were located on chromosomes 1A, 4A and 7D, accounting for 7.28% to 14.78% of the phenotypic variances;six QTLs for spike compactness （SC） were mapped on chromosomes 4D, 5A and 6B, explaining the phenotypic variation of 5.6% to 20. 06%. The findings shed light on the inher- itance of spike-related traits and provide DNA markers for marker-assisted selection in wheat breeding.