中国17个优良玉米自交系的分子标记杂合性及其与杂交种性状的关系研究

在玉米单交种育种中 ,鉴定高产杂交种和具有优良特性的自交系是一个重要的问题。研究以 1 7个优良玉米自交系为亲本 ,按照双列杂交配组合 ,利用 RAPD技术分析了 1 7个自交系的多态性以及 RAPD标记与 9个重要农艺性状 (包括产量 )的关系。基于 RAPD标记计算的相似系数聚类将 1 7个自交系分为 5个类群 ,经分析与系谱亲缘关系基本一致。杂交种性状及其特殊配合力与亲本间的遗传距离是高度相关的 ,与聚类前比较 ,聚类后平均遗传距离与平均产量、平均特殊配合力的相关系数显著提高 ,类间平均产量高于类内平均产量。RAPD技术可揭示优良玉米自交系的系谱亲缘关系 ,将自交系划分成不同的类群 ,从而为选择类间自交系杂交 ,进行亲本选配和分子标记辅助育种提供一种方法。

Molecular marker heterozygosity and its relationship to hybrid performance in seventeen elite maize inbreds

In maize ( Zea mays L.) single cross breeding programs,identifying high yielding hybrids and inbred lines with superior performance is an important problem.The seventeen inbred lines were analyzed by random amplified polymorphic DNA (RAPDs),and the relationship between performance data from a diallel cross among seventeen elite maize inbreds and RAPD marker were evaluated for nine traits of agronomic importance,including grain yield.Cluster analysis based on similarity coefficient calculated from the 229 non redundant RAPDs variants divided the 17 inbreds into five major groups,which is consistent with the pedigree information.Correlations between genetic distance and hybrid performance,and between genetic distance and specific combining ability (SCA) were generally positive and significant.Correlations of average GD,SCA and F 1 yield after clustering were much higher than values before clustering.Average yield and average GD among groups were greater than that within group.Our results suggest that RAPDs can be used to reveal relationships among maize inbred,and divided inbred lines into different group and thus provides a method for parent mating and molecular marker assisted breeding.