水稻穗粒数调控基因RGN1的功能验证与分子遗传解析

穗粒数的增加是提高新品种产量潜力的重要因素，虽然已有一些穗粒数基因克隆，但其分子机制和调控网络还不明确。因此，进一步挖掘穗粒数基因并解析其调控途径具有重要意义。本项目利用穗粒数稀少的自然变异材料BS208与特青杂交构建定位群体，通过正向遗传学方法克隆一个新的穗粒数调控基因RGN1，其编码一个R2R3-MYB 转录因子。通过互补、敲除等遗传转化初步验证了RGN1的功能。将通过互作蛋白筛选、RNA-Seq和ChIP-Seq等分析RGN1作用机制；同时将rgn1分别与水稻穗粒数稀少突变体lax1、gnp4/lax2和moc1等杂交，进行基因间遗传互作和调控网络分析；最后利用稻种资源通过基因多样性分析和群体遗传学分析等，明确RGN1基因的起源演化规律，挖掘优势单倍型、开发分子标记并创制优良遗传材料。本项目将为水稻穗粒数形成的遗传基础和分子机制解析提供重要线索，为水稻分子育种提供重要基因资源。

The improvement of grain number per-panicle is the one of the important factors to increase the yield of new varieties. Although several rice grain number genes have been cloned, their molecular mechinasm and regulatory networks are still unclear. Therefore, it is of great significance to further explore the novel grain number genes and analyze their regulatory pathways. In this study, Regulator of Grain Number 1 (RGN1) was isolated by map-based cloning using a segregating population constructed from sparse panicle germplasm BS208 and a normal parent Teqing (TQ), which encodes an R2R3 MYB transcription factor. The function of RGN1 in regulating grain number per-panicle was verified through complementation and knock-out transgenic analysis. The molecular mechanism of RGN1 and its regulation network will be analyzed by screening the interacting proteins, RNA-seq, ChIP-seq, and so on. Meanwhile, rgn1 will be crossed with lax1, gnp4/lax2 and moc1 to explore the genetic interaction and regulation network among them. Moreover, haplotype and evolution analysis will be carried out using the rice core-collections to develop molecular markers for elite haplotype used for genetic materials creation. This study will not only provide theoretical clues for the molecular mechanism of rice panicle branch formation, but also provide important genetic resources for rice molecular breeding.