理想株型培育是水稻品种高产育种的基础。株高是株型最重要的因子之一。目前籼稻矮秆基因主要是sd1，粳稻主要利用的是数量性状位点(QTL)。sd1的过度利用潜伏着由遗传单一而带来的风险，而控制株高的QTL研究尚不够深入。因此，挖掘具有重要利用价值的株高基因特别是QTL显得十分迫切。本课题组在以前的研究中从粳稻骨干亲本Balilla中鉴定出一个新的水稻株高QTLqPH6，不具育种负效应，具有重要的育种价值。本项目拟在精细定位和确定候选基因的基础上，利用互补试验进行候选基因的验证；构建过表达株系和RNAi株系，研究qPH6的生物学功能；通过转录组学和蛋白质组学，揭示qPH6调控水稻株高的分子机理和遗传调控网络；利用近等基因系明确该基因对各农艺性状的遗传效应，评价其对水稻品种改良的价值；通过测序明确qPH6在不同水稻高产品种中的遗传变异，为开展水稻株型的分子改良提供遗传和资源信息。

As one of the most important crops worldwide, rice (Oryza sativa L.) provides 35-60% of the world's dietary calories and is consumed by more than three billion people. In the 1950s, world rice production has dramatically increased due to a reduction in plant height resulting from the use of the semi-dwarf gene sd1. The reduced plant height enhances lodging resistance, and improves harvest index and biomass production. However, the frequent use of sd1 gene might cause genetic vulnerability. Now, an appropriate increase in plant height on the basis of semi-dwarf varieties has been an important strategy of rice high-yield breeding. Characterization of genes, especially QTL (Quantitative Trait Loci), associated with rice plant height is urgent to break the ceiling of yield potential. In our previous work, we identified a novel QTL, qPH6, for plant height in the backcross introgression population derived from japonica c.v. Balilla and indica c.v. Dular. qPH6 has no pleiotropic effect on other agronomic traits including panicle number, grain number, grain weight and grain yield. So qPH6 is a valuable locus for breeding and can be used in plant architecture improvement. Fine mapping was carried out with a total of 2378 recessive individuals from F2 and F3 generations of Balilla and C33084, and the gene was finally narrowed into a 41-kb region containing three annotated genes. Two of them, LOC_Os06g44010 and LOC_Os06g44030, were considered as the candidates of qPH6 according to the sequencing analysis. In this project, complementary test will be used to confirm the candidate genes. The biological function of the qPH6 related to plant height will be validated by the performance of transgenic lines of RNAi and overexpression of qPH6. The genetic regulatory network of qPH6 involved in rice plant height will be revealed by transcriptome and proteomics. We will further analyze the genetic effects of qPH6 by construction of nearly isogenic line and assess the breeding value. The allelic variation of qPH6 in various varieties will also be uncovered. After the completion of the project, the molecular mechanism and breeding value will be clearly elucidated. About 2-3 high-level papers will be published.