水稻幼苗活力性状的低温反应数量性状基因座检测

以籼粳交“密阳23/吉冷1号”的F2：3代200个家系作为作图群体，在12℃冷水胁迫下，进行苗高、苗鲜重和苗干重等水稻幼苗活力性状的低温反应鉴定，并利用由SSR标记构建的分子连锁图谱为基础，对冷水胁迫下苗高、苗鲜重和苗干重以及它们的低温反应指数进行了数量性状基因座（QTLs）检测。研究结果表明，低温胁迫下上述幼苗活力性状在F3家系群中均表现为接近正态的连续分布，表现为由多基因控制的数量性状；在第1、2、7、8和12染色体上，检测到与幼苗活力性状的低温反应相关的QTL共12个，对表型变异的贡献率范围为5．2％-17．9％，其中位于第2染色体RM262-RM263区间和第12染色体RM270-RM17区间的与低温下苗高相关的qCSH2和qCSH12，以及位于第12染色体RM19-RM270区间和第1染色体RM129-RM9区间的分别控制低温下苗干重及其低温反应指数的qSDW12和qCSDW1对表型变异的贡献率较大，分别为16．6％、17．9％、15．9％和16．2％。其增效等位基因均来自吉冷1号，前两者均表现为加性效应，后两者分别表现为显性和超显性。

Identification of Quantitative Trait Loci for Cold Response of Seedling Vigor Traits in Rice

The quantitative trait loci (QTLs) for the seedling vigor traits under 12 degrees C cold water irrigation, such as the seedling height, the seedling fresh weight, the seedling dry weight, and their cold response index, were identified using an F(2/3) population including 200 individuals and lines derived from a cross of indica and japonica "Milyang 23/Jileng 1" with microsatellite markers. All seedling vigor traits exhibited a continuous distribution near normal in F3 lines; these traits were quantitative traits controlled by multiple genes. Twelve QTLs conferring the seedling vigor traits under cold water irrigation were detected on chromosomes 1, 2, 7, 8, and 12, which explained the observed phenotypic variance from 5.2% to 17.9%. Among them, qCSH2 and qCSH12 were located in RM262-RM263 on chromosome 2 and RM270-RM17 on chromosome 12, respectively, which were associated with the seedling height. qSDW12 and qCSDW1 were located in RM19-RM270 on chromosome 12 and RM129-RM9 on chromosome 1, respectively, which were correlated with the seedling dry weight and its cold response index, and the explained 16.6%, 17.9%, 15.9%, and 16.2% of the observed phenotypic variation, respectively. These QTLs alleles were derived from cold-tolerant parent Jileng 1; the gene actions of the two front genes showed their additive effect, and the two genes blind showed dominant and over dominant effects, respectively.