CTF1调控水稻抽穗开花期耐冷的分子机制及其聚合效应评价

在水稻的不同生长发育时期都会遇到低温冷害的发生。发掘耐冷基因并解析其耐冷性分子机制、开展分子育种是克服水稻低温冷害的根本途径。虽然已定位了大量水稻耐冷QTL，但是还没有抽穗开花期耐冷QTL克隆的报道，更缺乏对其分子机制的认知。本研究室以抽穗开花期耐冷品种IR58025B和优良品种华粳籼74构建的单片段代换系为材料，定位到一个主效QTLqCth-6，并通过图位克隆获得了耐冷新基因CTF1。本项目拟在此基础上，研究CTF1调控抽穗开花期耐冷的分子机制；分析CTF1的等位基因变异；聚合芽期、苗期和抽穗开花期耐冷的QTLs，评价聚合效应，创制多个生长发育时期耐冷性强的籼稻品系。本项目的成功实施将揭示CTF1的功能及耐冷调控机制，并探索出不同生长发育时期耐冷基因聚合育种的可行途径，获得综合耐冷性显著强的籼稻品系。这不仅为深入理解水稻耐冷性分子调控机制奠定基础，而且为水稻耐冷性分子设计育种提供依据。

Low temperature chilling occurred at the different growth stages of rice. Discovering cold tolerance genes and analyzing their molecular mechanisms of cold tolerance, and developing molecular breeding of cold tolerance in rice are the fundamental ways to reduce the cold damage of rice. Although a large number of cold-tolerant QTLs for rice have been mapped, there have been no report of cold-tolerant QTL clone at the heading and flowering stage, and there is a lack of knowledge about their molecular mechanisms. In our lab, the cold-tolerant QTL was identified by using a SSSL population constructed with cold-tolerant IR58025B as the donor and the promising variety HJX74 as the acceptor at the flowering stage. A QTL with high cold tolerance and stable expression was located on chromosome 6. Furthermore, a new cold tolerance gene CTF1 was obtained by map-based cloning at the flowering stage. On this basis, the project will study the molecular mechanism of CTF1 regulating cold tolerance in rice at the flowering stage; carry out allele mining of CTF1 and develop functional markers; pyramiding the QTLs of cold tolerance at the bud bursting, the seedling and the flowering stages that have been identified, evaluate the pyramiding effect, and develop many promising strains with strong cold tolerance at different growth and development stages. The successful implementation of this project will reveal the function of CTF1 and the regulation mechanism of cold tolerance; and obtain pyramiding lines with strong cold tolerance at multiple growth and development stages. This will not only lay a foundation for further understanding the molecular regulation mechanism of cold tolerance in rice, but also provide a basis for the breeding by design of cold tolerance in rice.