联合连锁与关联分析方法精细定位玉米穗行数主效QTL

项目名称： 联合连锁与关联分析方法精细定位玉米穗行数主效QTL

项目编号： No.31201219

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 食品科学、农学基础与作物学

项目作者： 翁建峰

作者单位： 中国农业科学院作物科学研究所

项目金额： 26万元

中文摘要： 玉米产量构成因子包括穗数、穗粒数和粒重，其中穗粒数可分解为穗行数和行粒数。穗行数属于数量性状，目前尚未有相关基因被克隆。同时，联合连锁与关联定位已成为解析复杂数量性状的重要手段。通过以自交系丹340和掖478组配的F2:3定位群体，联合7个环境表型，鉴定出第7染色体上存在稳定表达的控制玉米穂行数的主效QTL qkrn7。在此研究基础上，本项目以自交系丹340和掖478组配的BC3F2连锁定位群体，284份自交系构成的关联分析自然群体为材料，通过联合连锁与关联分析，挖掘和鉴定丹340自交系中能够增加穗行数的主效位点候选基因和优异单体型。同时，基于自交系系谱，解析来自丹340的穗行数增效位点qkrn7的优异单体型在其衍生系中的传递与分布；另外，利用多个遗传背景下目标区段的单片段回交导入系，分析该候选基因在不同遗传背景中增加穗行数的效应，为开发玉米高产分子育种工具提供理论与实践基础。

中文关键词： 玉米；穗行数；关联分析；精细定位；候选基因

英文摘要： Corn yield is a complex trait and mainly composed of ear number, kernel number (KN) and kernel weight. Also, KN could be decomposed into kernel row number (KRN) and kernel number per row. However, KRN is a quantitative trait and major genes for it have not been identified yet. Meanwhile, jointed linkage and association mapping has become an important means for isolation of genes controlling such complex quantitative traits. In our previous study, one major QTL for KRN, qkrn7, had been detected on chromosome 7 with a F2:3 population derived from a cross of Dan340 and Ye478 across seven environments. In this study, the candidate gene for qkrn7 and its favorite haplotype from Dan340 inbred line will be isolated using a jointed linkage and association mapping. Meanwhile, the distribution of favorite haplotype for qkrn7 will be analyzed with Dan340 and its derivatives. In addition, effect of the candidate gene for increasing kernel row number will be detected with single fragment introgression lines under multiple genetic backgrounds. In summary, these results will play an important role in molecular breeding for high yield in maize.

英文关键词： maize；kernel row number；association mapping；fine mapping；candidate gene