籼渗粳对提高籼型杂交稻恢复系产量性状一般配合力的分子遗传研究

To explore the genetic basis of improvement of general combining ability (GCA) for yield-related agronomic traits by using indica-type restorer lines which infiltrated japonica genome segments with strong heterosis, one of the research will be conducted using 60 indica-type restorer lines which infiltrated japonica genome segments with strong heterosis as male parent and 4 typical indica cytoplasmic male sterile (CMS) lines as female parent making crosses with incomplete diallel design to calculate the general combining ability for yield-related agronomic traits. In the meanwhile, more than 500 pairs of primers for differentiating rice subspecies will be used for identifing the genotypes of all the parents and progenies. Those loci with positive effect for improving GCA would be detected through association analysis between phenotypes and genotypes. in the other research, a set of chromosome segment substitution lines (65 lines) will be used as male parent and the same 4 CMS lines as female parent to make crosses with incomplete diallel design for calculating GCA. The same primers mentioned above will be also used for identifing the genotypes of all the parents and progenies for detecting positive effect loci of GCA through association analysis. Moreover, on the basis of genetic linkage map, QTL of GCA would be detected by statistical software QTL IciMapping using new different SSR map (Genotypes of 65 CSS lines derived from indica restore line c.v. IR24 chromosome segment substitution lines with Japonica c.v. Asominori were rescreened by 132 good polymorphism SSR markers, replacing 82 original RFLP markers). At last, through the comparison of these two methods mentioned above (association analysis based on linkage disequilibrium and QTL mapping based on linkage map), we hope (1) to understand the genetic basis of GCA, and (2) to identify japonica genomic regions of interest responsible for the improvement of GCA in indica hybrid rice.

为探析籼渗粳对提高籼型杂交稻恢复系产量性状一般配合力的分子遗传基础，本研究一方面拟用60份籼渗粳强优势恢复系为父本，4份三系不育系为母本，按不完全双列杂交配组计算产量相关性状的一般配合力。同时利用500多对籼粳特异标记以及前人开发的其它多态性标记进行亲本和F1代的籼粳基因型分析，通过表型与基因型的关联分析，发掘关联显著提高一般配合力的位点；另一方面，拟用一套以籼稻恢复系IR24为背景渗入粳稻Asominori血缘的染色体片段置换系65个株系为父本，按相同设计与上述相同的4个不育系测交配置四套F1群体，利用同上的分子标记进行基因型分析和关联分析发掘有利位点；并结合已有置换系分子图谱，进行一般配合力性状的QTL定位，对比四套F1群体检测到的QTL并作稳定性分析；最后结合自然群体与遗传群体的关联分析和图谱定位的结果，以期为进一步揭示籼渗粳对提高杂交水稻一般配合力的分子遗传基础提供理论依据。

为探析籼渗粳对提高籼型杂交水稻产量相关性状一般配合力的分子遗传基础，本研究一方面拟用60份籼渗粳强优势恢复系为父本，4份三系不育系为母本，按不完全双列杂交配组计算产量相关性状的一般配合力。同时利用500多对籼粳特异标记以及前人开发的其它多态性标记进行亲本和F1代的籼粳基因型分析，通过表型与基因型的关联分析，发掘关联显著提高一般配合力的位点；另一方面，拟用一套以籼稻恢复系IR24为背景渗入粳稻Asominori血缘的染色体片段置换系65个株系为父本，按相同设计与上述相同的4个不育系测交配置四套F1群体，利用同上的基因型分析和关联分析发掘有利位点；并结合已有置换系分子图谱，进行一般配合力性状的QTL定位，对比四套F1群体检测到的QTL并作稳定性分析；最后结合自然群体与遗传群体的关联分析和图谱定位的结果，解析筛选到的提高一般配合力的关联位点与稳定表达QTL之间的关系。结果表明，共检测到32个和37个分别影响产量相关性状一般配合力和杂种优势的QTL，其中有些QTL如来自第1染色体上的RM5496能够被重复检测到，有些QTL能够在多个群体中检测到，但年份之间没有重复，如第8染色体上的RM506和RM6356；有些杂种优势QTL表现出一因多效的现象，可能是杂种优势形成的重要原因之一。