水稻籽粒大小调控的分子遗传网络解析

水稻籽粒大小是重要的产量性状，但水稻籽粒大小调控的分子机制和遗传互作网络目前仍不清楚。为了解析水稻籽粒大小调控的分子遗传网络，集成项目成员已饱诱变和筛选得到了水稻籽粒大小改变的突变体，克隆了系列水稻籽粒大小调控基因，发现了几个水稻籽粒大小调控的新途径。本项目将在已有的研究基础上，以水稻籽粒大小突变体等为材料，系统克隆水稻籽粒大小调控的关键基因；建立GSK2-GS2和LG1-LG2-LG3为中心的水稻籽粒大小调控的分子遗传网络；进一步建立上述网络间以及与已知籽粒大小调控基因间的遗传网络；发掘籽粒大小调控基因的优良等位变异，探讨其增产潜力和育种价值。该研究将建立水稻籽粒大小调控的分子遗传网络，有望在水稻籽粒大小调控领域取得重要突破，也将为水稻高产育种的分子设计提供理论基础和基因资源。

Grain size is one of the most important yield traits, but the molecular mechanisms and genetic interactions of grain size genes are almost unknown in rice despite their central importance. To build up molecular and genetic networks of grain size control, we have isolated a series of mutants with altered grain size using saturation mutagenesis and cloned a set of genes of grain size control and discovered several novel pathways of grain size control in rice. In this proposal, we plan to clone grain size genes on large scale, build up molecular and genetic frameworks for GSK2-GS2 and LG1-LG2-LG3-mediated control of grain size, dissect genetic networks of grain size genes identified in this study and known grain size genes, and explore beneficial alleles of these grain size genes for improving grain yield in rice. This study will build up molecular and genetic networks of grain size control, make a breakthrough in grain size control, and discover important genes for engineering high crop yield.