粒重是影响谷粒产量三大基本要素之一，同时也是由多基因控制的复杂数量性状(QTL)。大量的粒重QTL通过发展各种遗传群体被评估出来，然而这些QTL调节粒重的分子功能在很大程度上还不清楚。油菜是一种异源四倍体作物，是世界上第二大植物油来源。前期工作我们利用SG-DH群体在10个种植环境进行油菜粒重的QTL分析，发现在A7染色体上存在一个共同的粒重主效QTL，qA7SW。经过精细定位和转基因功能验证，发现qA7SW编码的是Large Grain蛋白,一个新的转录因子。本项目拟利用近等基因系大、小粒材料以及相关的转基因材料，通过种子组织学分析、基因功能鉴定、转录组学分析以及蛋白互作研究等来阐释Large Grain调控粒重的分子机理及基因网络，为油菜高产育种实践提供理论和分子基础。

Grain weight is one of the three major factors influencing grain yield, and is controlled by quantitative trait loci (QTLs). A number of QTLs for grain weight were evaluated from various genetic populations. However, the molecular roles of these QTLs in the regulation of grain weight remained unclear to great extent. Brassica napus is an allotetraploid crops and is the second leading crop source for vegetable oil around the world. A major QTL for seed weight on A7 (qA7SW) were evaluated from SG-DH population in 10 environments. The results of fine mapping and transgenic functional verification show that qA7SW encodes Large Grain protein, a novel transcription factor. In this project, we will use NIL (Sollux), NIL (Gaoyou) and related transgenic lines as materials, and conduct seed histological analyses, gene functional characterization, transcriptome analysis and protein interaction study to elucidate the molecular mechanism and gene network of grain weight regulated by Large Grain. The main goal is to provide a theoretical and molecular foundation for the breeding of high yield rapeseed.