利用连锁和关联分析剖析花生种子大小的遗传基础

Peanut (Arachis hypogaea L.) is one of the most important oilseed, economic and edible crops in China. With the increasing consumption of vegetable oil in China, it becomes the urgent issue to further improve the seed production of peanut. In the study, we plan to construct a high-density genetic map with more than 1,000 SSR markers. Combined with phenotypic data collected in multiple locations and years, we will conduct the genome-wide QTL scans for seed size related traits in peanut. Based on the results of linkage mapping, we will perform the QTL based association analysis in a panel of peanut micro-core germplasm that had been comprehensively characterized previously. Through this procedure, we not only validate the linkage QTLs and fine map the QTLs, but also assess the effect series of QTL alleles and mine the varieties with favorable alleles. The results will provide the important foundation for molecular marker assistant breeding and germplasm innovation in the breeding program of high yield peanut varieties.

花生（Arachis hypogaea L.）是我国重要的油料作物、经济作物和食用作物。针对我国食用植物油供应现状，保障我国人民生活对食用油日益增长的需要，进一步提高花生单位产量是重中之重。本课题拟构建一张花生高密度的遗传连锁图谱（>1,000个标记），并结合多年多点的表型数据，对种子大小性状进行QTL定位。根据连锁分析定位结果，利用一个花生微核心种质群体，进行候选QTL区间关联分析，对QTL进行验证并精细定位，同时在种质资源中评估不同等位变异的效应，发掘携带优良变异的品种。本研究的开展将为花生高产聚合育种、分子标记辅助育种、优良种质的创制和鉴定提供理论依据，进一步加快高产育种的进程。

花生是我国重要的油料作物、经济作物和食用作物。针对我国食用植物油供应现状，保障我国人民生活对食用油日益增长的需要，进一步提高花生单位产量是重中之重。本项目对一个RIL群体进行了SSR分子标记扩增，构建了一张含有1219个SSR位点、覆盖基因组遗传距离2038.75cM的高密度遗传连锁图。该RIL群体的种子长、种子宽和百仁重性状在多环境下表型变异丰富。利用连锁分析，获得了24个、19个和17个与种子长、种子宽、百仁重相关的QTL，贡献率分别为6.1-17.6%、3.7-27.5%和5.1-18.8%。同时，对104份种质资源的种子大小性状进行多环境调查，并利用实验室已有的SSR标记基因型数据，进行关联分析，检测到6个、2个和6个SSR标记分别与种子长、种子宽、百仁重显著关联，贡献率为11.22-32.3%。基于关联分析的结果，将重复检测到的种子长关联标记AGGS1312和AHGA44686进行标记等位变异聚合分析，发现同时含有AGGS1312-266等位变异和AHGA44686-259等位变异的材料种子长平均值最大，为1.94cm，显著高于其他等位变异组合。