控制水稻柱头外露率的数量性状基因座初步分析

Mapping of QTLs for percentage of exserted stigma in rice

为研究柱头外露率的遗传机理,用柱头外露率低的粳稻品种糯5号与柱头外露率高的籼稻品种优ⅠB构建包含190株的F2群体.在长沙对各单株进行柱头外露率调查,并用均匀覆盖水稻整个基因组的92个SSR标记构建连锁遗传图谱,进行控制柱头外露率的数量性状基因座QTL分析.结果表明,控制柱头外露率的3个QTL为qPES-2、qPES-5、qSPES-8,分别位于第2染色体的RM1285～RM12595、第5染色体的RM17952～RM18114、第8染色体的RM8020～RM7080,QTL的LOD峰值分别为3.54、4.79、3.85,解释的表型变异分别为10.1%、11.1%、9.0%,增效基因皆来源于高柱头外露率的亲本优ⅠB.研究并发现控制单边柱头外露率的QTL与总外露率的完全一致,第5染色体检测到的QTL是1个新的座位.

To understand the genetic mechanism of exserted stigma, a mapping population of 190 F2 plants derived from the cross between a japonica variety-Nuo5 and an indica variety-YouⅠB with higher percentage of exserted stigma （PES） was constructed to map quantitative trait loci （QTL） for PES. Genetic linkage map was constructed using 92 SSR markers throughout the whole genome, and PES was investigated in Changsha. As a result, three QTLs controlling ratio of stigma exsertion were qPES-2, qPES-5 and qSPES-8, detected and located respectively at the region of RM1285～RM12595 on chromosome 2, RM17952～RM18114 on chromosome 5 and RM8020～RM7080 on chromosome 8. The QTL of LOD peak was 3.54, 4.79, 3.85 respectively; The phenotypic variation was 10.1%, 11.1%, 9.0%, and all their positive alleles were from YouⅠB. Two QTLs might be identified in previous studies, and the QTL on chromosome 5 might be a new one which had never been reported before.