粳稻云引稻瘟病抗性近等基因系构建及遗传背景恢复分析

Construction and Genetic Background Recovery of Blast-resistant Near-isogenic Lines from Japonica Variety,Yunyin

通过对稻瘟病抗性近等基因系的构建和评价,为抗稻瘟病基因的抗性分析和遗传学研究提供良好载体。分别以广谱抗稻瘟病品种云引和普感稻瘟病品种丽江新团黑谷(LTH)为抗病基因的供体亲本和轮回亲本,结合分子标记辅助选择和人工接种抗性鉴定,经连续4代回交和8代自交,获得7个以LTH为遗传背景的稻瘟病抗性近等基因系。选取均匀分布于水稻12条染色体上的184对SSR标记,对所获得的近等基因系进行遗传背景分析、评价。结果表明:在亲本云引和LTH之间具多态性的SSR引物有72对,标记多态性频率为39.1%。以在亲本间具有多态性的标记对7个近等基因系与LTH间的遗传多态性进行分析,发现其中W15、W17的遗传背景恢复率为97.61%,W18的遗传背景恢复率为97.22%,其他4个株系的遗传背景恢复率均大于98%。成功构建并获得了以LTH为背景的含有云引稻瘟病抗性基因的近等基因系,且近等位基因系的遗传背景与表型值均恢复良好。

Construction of near-isogenic lines(NILs)is an effective mean for analyzing blast-resistance genes as well as genetic research in general.This study applied the broad-spectrum blast-resistant japonica variety,Yunyin,as the donor parent and the blast-susceptible variety,LTH,as the recurrent parent.Combining the molecular markers assisted selection and artificial inoculation,7 blast-resistant NILs were bred with LTH for the genetic background analysis after 4 generations of backcrossing and 8 generations of self-crossing.184 pairs of SSR markers evenly distributed on 12 chromosomes of the rice were selected to evaluate the genetic background of the NILs.The results showed that 72 pairs of SSR primers to be polymorphic with a frequency of 39.1%.The polymorphisms between 7 NILs and LTH were analyzed by markers among the parents.The background recovery rates of W15 and W17 were 97.61%,that of W18,97.22%,and those of other 4 lines,greater than 98%.It appeared that the construction of NILs carrying Yunyin blast-resistance gene with LTH as background were successful,and that all phenotypic indices of the NILs recovered well in this study.