水稻芽期耐冷性QTL的分子定位

Molecular Mapping of QTLs for Cold Tolerance at the Bud Bursting Period in Rice

以籼粳交密阳23号/吉冷1号的F2:3代200个家系作为作图群体,构建了一张含有97个微卫星(SSR)标记的分子连锁图谱。在5℃低温条件下,对F3家系进行芽期耐冷性鉴定,并利用SSR标记进行了芽期耐冷性数量性状位点(QTL)分析。研究结果表明,芽期耐冷性在F3家系群中呈单峰连续分布,表现为由多基因控制的数量性状;共检测到与芽期耐冷性有关的QTL3个,分别位于第2、4和7染色体上,对表型变异的贡献率范围为11.5%～20.5%。其中,位于第4染色体RM273～RM303的qCTBP4对表型变异的贡献率最大。

The quantitative trait loci (QTLs) for cold tolerance at the bud bursting period (CTBP) were identified by using a F2:3 population including 200 lines derived from a cross of indica and japonica Milyang 23/Jileng 1. A molecular linkage map of 97 SSR markers was constructed by using interval mapping and covered a total length of 1357.3 cM with an average distance of 13.99 cM, between adjacent markers in rice genome. The CTBP of F3 lines was evaluated at 5℃, and the percentage of seedling stand after treated under low temperature at the bud bursting period was used as cold tolerance index for CTBP. A continuous distribution near to normal for CTBP was observed in F3 lines, CTBP is a quantitative trait which was controlled by some genes. Three QTLs on chromosome 2, 4 and 7 which are associated with CTBP were detected on location of RM6-RM240, RM273-RM303, RM214-RM11, respectively, which explained the range of the observed phenotypic variance from 11.5% to 20.5%. qCTBP4, which is detected on RM273-RM303 of chromosome 4, is explained 20.5% of the observed phenotypic variance. The effect of qCTBP4’s allelic gene comes from Jileng1.