以两份普通野生稻核心种质资源DP15和DP30为供体、9311为受体构建染色体片段代换系鉴定苗期耐冷性QTL;利用苗期耐冷性最强的1个代换系构建QTL作图群体,用SSR标记对其主效QTL进行定位。研究结果表明,两个抗源DP15和DP30所含的苗期耐冷性QTL的数量、位点及耐冷性效应均存在明显的差异。在基本上覆盖两个亲本全基因组的230份BC4F2代换系中共发现19个苗期耐冷性QTL,分布在水稻12条染色体上,第3和第8染色体上有比较密集的苗期耐冷性QTL分布。这19个分布于全基因组的苗期耐冷性QTL被分别分离到不同的野生稻染色体片段代换系里,效应最小的微效QTL位点所在的代换系在苗期耐冷性鉴定中的活苗率仅为8%,而效应最大的主效QTL位点所在代换系的活苗率达到74%。这个主效QTLqSCT-3-1被定位在第3染色体着丝点附近长臂上的RM15031-RM3400区间,距离最近的标记RM15040、RM1164的遗传距离为1.8 c M。
Two core accessions of common wild rice(DP15 and DP30) as donor parents and the cultivar 9311 as recipient parent were used to construct chromosome segment substitution lines for identification of QTLs for cold tolerance at the seedling stage and QTL effect analysis.A QTL mapping population from the most cold-tolerant substitution line was constructed to map major-effect QTLs with SSR markers.The two donor lines,DP15 and DP30,showed obvious difference in the number,location and effect of QTLs for cold tolerance.In the 230 BC4F2 substitution lines in which substituted chromosome segments covered the whole genome of the two donors,a total of 19 cold tolerance QTLs were detected,which distributed throughout all the 12 chromosomes,and clustered on chromosome 3 and chromosome 8.These QTLs were separated each other in different chromosome substitution lines.The substitution line with the smallest effect QTL for cold tolerance and the line with the largest effect QTL showed 8% and 74% of survival rate after cold treatment,respectively.A main-effect QTL,qSCT-3-1,was mapped between SSR markers RM15031 and RM3400,near the centromere on the long arm of chromosome 3 with a distance of 1.8 cM to the closest linkage markers,RM15040 and RM1164.