在农业生产中，增加粒重是实现水稻高产育种的有效途径之一。然而，水稻粒重相关性状（例如粒长、粒宽、粒厚等）是受多基因和环境共同调控的复杂数量性状，目前人们对其形成的遗传基础及其调控网络的认识还非常有限。如何高效挖掘水稻粒重关键基因，解析粒重基因之间的互作调控规律，明确优异等位基因聚合的增产效应，是目前水稻分子设计育种面临瓶颈问题。本项目利用野生稻、农家种、主栽品种以及突变体库等水稻材料，综合运用多种组学、生物信息学、计算生物学等多学科交叉手段，通过GWAS分析、QTL定位、图位克隆、MutMap等方法系统鉴定水稻籽粒性状形成的基因数目；重点研究粒重关键基因功能及其分子调控机制，解析不同粒重基因之间互作规律，揭示控制水稻粒重的遗传调控网络；发掘优异等位基因，在主栽品种中评价优异等位基因的聚合增产效应，为水稻高产分子设计育种奠定理论基础和提供新基因资源。

Grain yield is determined by three important components including the number of tillers per plant, number of grains per panicle and 1,000-grain weight. In fact, the grain weight traits consist of grain length, gran wide and grain thickness, all of which is controlled by quantitative trait loci (QTL) derived from natural variations in rice. Recently, several genes have been shown to control grain size and grain shape and its relevance to grain weight. However, many of its genetic determinants are as yet explained only as QTLs, without any understanding of the nature of their gene product. In this proposal, we will focus on identification of the key genes and its natural variants using QTL, GWAS and MutMap approaches, and analyze the molecular mechanisms and integrative network of these genes responsible for grain weight in rice.