利用基础导入系分析粳稻基因的遗传效应

 【目的】为了有效地评价粳稻等位基因在籼稻遗传背景中的遗传效应，为籼粳亚种间优良基因的利用提供理论和实践依据。【方法】以粳稻品种日本晴（Nipponbare）为供体亲本、籼稻品种珍汕97B（Zhenshan 97B）为受体亲本，经过杂交、回交，结合分子标记辅助选择，构建了88个基础导入系, 每个导入系具有相同的籼稻遗传背景，且只含有一个或少数粳稻的导入片段，每个导入系的导入片段叠加起来能覆盖整个粳稻的染色体。利用基础导入系群体进行单株产量、有效分蘖数、千粒重和每穗实粒数的数量性状基因（QTLs）定位和遗传效应分析。【结果】共检测到29个具有显著遗传效应的位点（QTLs）。其中6个QTL具有正向的加性效应和超显性效应，其余23个QTL具有负向的加性效应和超显性效应。【结论】一些粳稻基因导入到籼稻中能表现出不同程度的增产效应；超显性效应对水稻籼粳杂种优势起重要作用。

Genetic Effect of Japonica Alleles Detected in Indica Candidate Introgression Lines

【Objective】To accurately assess genetic effect of alleles from japonica in a genetic background of indica and to efficiently utilize inter-subspecific heterosis between indica and japonica. 【Method】We have developed a set of novel population with 88 candidate introgression lines (ILs) through backcross program and marker-aided selection, which using japonica variety Nipponbare as donor and indica variety Zhenshan97B as recurrent parent. Each of the ILs contains single one or few japonica introgression segments within the uniform indica genetic background, and together all the introgression segments can cover the whole japonica genome. The genetic effects of each introgression segment in the 88 ILs were analyzed on yield and its component traits including number of tillers, grains per panicle and 1000-grain weight. 【Results】Twenty nine quantitative trait loci (QTLs) with significant effects were detected, of those 6 QTLs had positive additive and overdominant effects, 23 QTLs had negative additive and overdominant effects. 【Conclusion】 Some favorable alleles from japonica could increase yield or its components in the indica background. The overdominant effects play important role in heterosis of intersubspecies.