以关联分析发掘小麦整穗发芽抗性基因分子标记

Exploring Molecular Markers of Preharvest Sprouting Resistance Gene Using Wheat Intact Spikes by Association Analysis

利用分布于小麦全基因组的181对分子标记,分析264份自然群体的基因型,采用TASSLE软件的GLM和MLM模型检测与整穗发芽抗性紧密关联的标记位点,发掘相关位点内的优异等位变异。在2012年和2013年室内整穗发芽率、2013年田间自然降雨整穗发芽率3个环境中,共关联到20个显著位点(P<0.05),分布于小麦染色体1AS、2DS、3AS、3BL、4AL、5AS、5BL、6BS、6DS、7AL和7BL上。分别位于2DS和7BL上的分子标记gwm102和barc340同时在3个环境下关联到,属于稳定的抗性位点;另有6个标记位点同时在2个环境下关联到;其余12个标记位点仅在1个环境下关联到。位于7BL上的barc340标记位点为一新报道位点。从重复关联的8个标记位点内共检测出10种优异等位变异。barc28-229bp和barc28-217bp对提高整穗发芽抗性效应最显著,主要分布在地方品种中(如遂宁坨坨麦等),而gwm102-142bp和barc186-199bp效应虽然相对较小,但多分布在推广品种中(如扬麦158等),有利于穗发芽抗性分子育种的直接应用。

To improve pre-harvest sprouting （PHS） resistance in wheat breeding, it is important to explore marker loci and elite alleles associated with PHS resistance using intact spikes. In this study, a total of 181 markers were used to 264 genotype materi-als. General and mixed linear models （GLM and MLM） were used to analyze PHS phenotypic data in three environments （2012-in house, 2013-in house and 2013-in field）. The results showed that twenty markers were identified by association analysis, and lo-cated on chromosomes 1AS, 2DS, 3AS, 3BL, 4AL, 5AS, 5BL, 6BS, 6DS, 7AL, and 7BL. The markers gwm102 on 2DS and barc340 on 7BL were detected stably in three environments, among which barc340 was likely to be novel and needs to be further studied through biparental linkage mapping analysis. Six markers were detected in two environments, and the other loci linked with 12 markers were detected only in one environment. A total of ten elite alleles were further explored among the eight loci with repeated associations. The alleles barc28-229bp and barc28-217bp for high PHS resistance were all distributed in local cultivars （e.g. Suiningtuotuomai）. However, the alleles gwm102-142bp and barc186-199bp with intermediate PHS resistance were mainly detected in released cultivars （e.g. Yangmai 158）, which could be beneficial to wheat molecular breeding.