优良玉米自交系的杂种优势类群划分研究

Classification of Heterotic Group of Elite Maize Inbred Lines

以代表不同种质类群的国内16个常用优良玉米自交系为材料,从140多对SSR引物中筛选出91对能够较清晰反映其多态性的引物,依SSR多态性,用UPGMA法进行聚类分析。同时按GriffingⅣ交配设计,对所组配的120个杂交组合进行产量、穗长、穗粗等性状调查,并依各组合产量的特殊配合力效应对16个自交系进行种质类群划分。结果表明:分子标记分析结果将供试自交系分为6个优势类群,与配合力分析结果基本一致,其中自选系87-1、87-3与带有明显热带血缘的自交系P138、许178聚为一类,证明87-1、87-3含有部分热带种质成份;群间杂种优势明显,分属Ⅱ、Ⅲ类群的自交系87-1与综3间的遗传距离较远,二者在穗部等重要性状方面呈现明显优势互补。

SSR markers were used to study genetic diversity among 16 elite maize（ Zea mays L. ）inbreds, which from different heterotic groups. Ninety-one SSR primers selected from all 140 primers gave distinct profiles amplified in the sample of 16 inbred lines. Simultaneously, 120 diallel crosses were composed using 16 inbred lines according to Griffing IV ,and the 16 inbred lines were classified on the base of special combining ability（SCA）. The results showed that：sixteen inbreds were classified into 6 heterotie groups according to the SSR Polymorphism, which similar to the result of SCA analysis .The genetic distance between 87-1,87-3 and P138, Xu178, which have distinctly tropic germplasm, was closer than that of others and it could be concluded that inbred lines of 87-1,87-3 possess partially tropic germplasm ele- ments. The genetic distance between 87-1 and Zong3 was long in two kinds of cluster analysis chart, they have complimentary characteristic in many important characters such as ear trait.