水稻永久F_2群体抽穗期QTL的上位性及其与环境互作效应的分析

Use of Permanent F_2 Population to Analyze Epistasis and Their Interaction Effects with Environments for QTLs Controlling Heading Date in Rice

利用源于杂交水稻汕优 6 3的重组近交系 (RI) ,进行系间随机交配构建了水稻永久F2 (IF2 )群体。采用QTL作图软件QTLMapper2 0对IF2 群体的抽穗期性状进行了分析 ,共发现了 2 1个QTLs ,分布于 10条染色体上。对抽穗期QTL的加性效应 ,显性效应 ,加×加、加×显、和显×显上位性效应进行了估计 ,对遗传主效应与环境的互作效应作了预测。结果表明 ,鉴别出的QTL中 ,加×加上位性显著程度最高 ,其次是加性效应。加×加上位性与环境的互作效应以及加性与环境的互作效应预测值 ,显著性程度相对较高 ;加×显上位性与环境的互作效应预测值均不显著 ;显性、显×显上位性与环境的互作效应预测值只有很少达到显著。本文讨论了构建IF2 群体的困难及其对QTL作图可能产生的影响。

Immortalized F 2 population in rice was constructed by random mating among recombinant inbred (RI) lines derived from a famous elite hybrid rice, Shanyou 63. Analysis on heading date of permanent F 2 population was conducted through QTL Mapper 2.0, a software for QTL mapping. A total of 21 QTLs which distributed on 10 chromosomes were identified. Additive effects, dominance effects, epistatic effects of additive × additive, additive × dominance, and dominance × dominance of QTLs for heading date were estimated, the interaction effects between main genetic effects and environments were predicted. The results showed that a few of single effects for identified QTLs were up to the significance of 0.05, among which epistatic effects of additive × additive were most significant, next were additive effects. The interaction effects of additive and epistasis of additive × additive with environments presented higher significance; no significant interaction effect of additive × dominance with environments was found; only few of interaction effects of dominance and dominance × dominance with environments were observed. The difficulty for constructing IF 2 population and the possible influence on QTL mapping were discussed also.