水稻籽粒粒型不仅影响稻米外观和加工品质，还影响千粒重及产量。本项目利用水稻材料D50和HB277构建的RIL群体，在第7染色体定位到一新的同时控制水稻粒长、粒宽与长宽比的主效QTL- GS7，通过高代次级分离群体，已经将GS7限定在4.8Kb染色体区域内，在此基础上，本研究拟通过序列分析与转基因等方法克隆GS7，对其时空表达模式，编码蛋白的亚细胞定位等进行研究，利用GS7功能标记与基因测序分析不同水稻品种GS7的基因型，了解GS7是否广泛调控着不同水稻品种的粒型，并初步分析其起源与驯化特征。初步阐明其影响稻米粒型的分子机理。本研究结果将对阐明稻米粒型形成机理，利用分子标记辅助选择改良水稻品质、提高水稻产量，培育满足不同市场需求的高产、优质水稻品种具有重要意义。

Grain shape is a major determinant of appearance and the processing quality and yield of rice grain. GS7, a major QTL associated with rice grain length, grain width and the ratio of length to width was identified by the D50/HB277 RILs. Now GS7 was narrowed down to a 4.8kb region on Chr7 base on a larger secondary segregating population. In this project, GS7 will be position cloned; the sequence analysis and functional complementary test will be finished. The temporal and spatial expression patterns and protein subcellular localization of GS7 will also be analyzed. In order to elucidate the characteristics of origin and domestication of GS7, genotype and haplotype analysis will be carried based on function marker and sequencing. The results of this research will be useful to elucidate the molecular mechanism of control the grain shape, and breed high yield and good quality rice cultivar for different market demand by MAS.