大豆百粒重主效QTL的克隆与功能研究

Seed weight is an important factor influencing yield in soybean. Therefore, discovery genes involved in regulating seed weight is very important not only for basic research of seed development, but also for applied research of high-yield breeding program in soybean. Previous research of this project has focused on genetic analysis of recombined inbreed lines (RILs) developed by crossing ZH28 and Xiaoling. A major QTL was identified by QTL-seq analysis and the mapping region was reduced to about 187kb by further mapping using SNP markers. The aim of this project was fine-mapping of the major QTL using residual heterozygous lines and secondary mapping population. The major QTL will be cloned by combining sequence and expression analysis of candidate genes located in the fine mapping region. Its function will also be studied by genetic transformation, expression analysis, and other methods. The results of these studies will play a basis for molecular mechanisms of seed development in soybean. Meanwhile, different alleles will also be identified and the applied value of these alleles will be evaluated by molecular marker development and selection efficiency identification. The results of these studies will provide guidance for high-yield breeding by molecular marker assistant selection.

大豆百粒重是构成产量的重要因子，发掘调控大豆百粒重的基因对于大豆籽粒发育调控的基础研究和高产品种培育的应用研究都具有重要意义。前期利用百粒重差异显著的大豆创制的重组自交系群体进行遗传分析，在物理距离为187kb的区间鉴定出一个主效QTL位点。本项目将在前期工作的基础上，利用次级群体和近等基因系在初定位区间内加密标记并精细定位；结合候选基因的序列和表达分析克隆调控大豆粒重的主效基因并研究基因的功能，为解析大豆籽粒发育的分子调控机制奠定理论基础；同时，通过鉴定不同大豆种质资源中的等位基因，开发功能标记并明确标记的鉴定效率及育种价值，为大豆分子标记辅助高产育种提供指导。

百粒重是大豆产量的重要组成因子，发掘调控大豆百粒重的基因对于大豆籽粒发育调控的基础研究和高产品种培育的应用研究都具有重要意义。本项目旨在前期工作的基础上，对控制大豆百粒重主效QTL进行精细定位和克隆，并研究基因的功能，同时鉴定大豆种质资源中的分子标记，为解析大豆百粒重的遗传机制和分子标记辅助选择奠定基础。通过项目实施，利用遗传定位群体精细定位了百粒重主效QTL并确定了候选基因GmSW，通过基因编辑和大豆遗传转化GmSW基因在调控籽粒大小和百粒重中的功能。同时，筛选鉴定出4个与百粒重密切相关的SNP并在野生和栽培大豆群体中进行了验证，发掘的分子标记为大豆籽粒大小和百粒重的选择提供指导。