为更好地理解水稻大剑叶角的分子遗传机制,对已初定位的控制剑叶角度的 qFla-8进行精细定位和候选基因预测.利用以863B 为受体亲本、A7444为供体亲本衍生的 BC3 F3群体中仅在目标基因区段杂合的172个单株自交构建的次级分离群体,对 qFla-8所在的 RM6215－RM8265区间9个 SSR 标记的基因型进行鉴定,结合表型数据进一步缩短 qFla-8所在染色体区段.结果发现 qFla-8位点所在染色体区段存在两个紧密连锁的位点 qFla-8-1和 qFla-8-2.其中,qFla-8-1位于RM6215和 RM3153之间,可解释22．33％的表型变异；qFla-8-2位于 RM1309和 RM3491之间,可解释23．81％的表型变异.进一步对加性效应较大的 qFla-8-2精细定位,通过开发插入缺失(InDel)分子标记,将 qFla-8-2位点限定于 InDel 标记 Z7和SSR 标记 RM23071之间,该区间的物理距离为67 kb.该区段包含3个预测基因 Os08g0408200,Os08g0408300和Os08g0408500,分别编码功能类似 GAMYB 的 WD40结构域蛋白、假定蛋白以及类 APETALA2蛋白.%To better understand the genetic mechanism regulating large rice flag leaf angle,qFla-8 detected previously was further fine-mapped and the candidate genes were predicted.Using a secondary segregating population,composed of 1 72 selfing individual plants with heterozygous region of target gene merely in BC3 F3 population derived from the backcross between 863B (recipient parent)and A7444 (donor parent),genotypes of nine SSR markers in the interval of RM621 5 - RM8265 containing qFla-8 were identified.Combining the phenotypic data, chromosome segment containing qFla-8 was further narrowed and there are two closely linked loci,qFla-8-1 and qFla-8-2 .qFla-8-1 was localized between RM621 5 and RM3 1 53,explaining 22.33% of phenotypic variation,and qFla-8-2 was localized between RM1 309 and RM349 1 ,explaining 23.81 % of phenotypic variation.By developing insertion-deletion (InDel) markers,qFla-8-2 with higher additive effect was finally limited to 67 kb region between InDel marker Z7 and SSR marker RM23071 ,which contains three predicted genes,Os08g0408200 encoding WD40 domain containing protein similar to GAMYB-binding protein, Os08g0408300 encoding hypothetical protein and Os08g0408500 encoding APETALA2-like protein.
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