利用SSR标记研究爆裂玉米自交系的遗传变异及其与普通玉米的遗传关系

 利用113对多态性SSR引物研究了来源于8个基础材料的26个爆裂玉米自交系的遗传多样性及其与分属6个杂种优势类群的20个普通玉米骨干自交系的种质关系。在26个爆裂玉米自交系间共检测出301条带，平均每个位点的等位基因数为2.66个，多态性信息量为0.068～0.217，平均遗传距离为0.357。利用SSR数据进行聚类分析，将46个供试自交系分为爆裂和普通玉米自交系两大类；26个爆裂玉米自交系分为8个类群，高杂种优势组合的双亲自交系均属于不同类群，而在同一类群自交系间尚未组配出具有高杂种优势的组合；普通玉米自交系的分类结果与以往研究和育种实践相一致，表明SSR标记技术可以用于爆裂玉米自交系间的遗传多样性研究。不同类群爆裂玉米自交系与各类群普通玉米自交系的平均遗传距离为0.549～0.672，应根据两类自交系间的遗传关系对爆裂玉米自交系实施有针对性的分群改良。

Genetic Variation of Popcorn Inbreds and Their Genetic Relationship with Normal Corn Inbreds Revealed by SSR Markers

One hundred and thirteen SSR markers with polymorphism were used to study the genetic diversity of 26 popcorn inbred lines derived from 8 sources, and their genetic relationship with 20 normal maize inbred lines representing 6 different heterotic groups. Among the 26 popcorn inbred lines, the average number of alleles per SSR locus was 2.66 with a range of 1 to 3, the polymorphism information content (PIC) for the SSR loci varied from 0.068-0.217, and the genetic distance ranged from 0.148-0.524 with an average of 0.357. The cluster analysis showed that all the inbred lines could be classified into two distinct clusters, popcorn and normal maize. The 26 popcorn inbred lines were divided into 8 clusters, with all the parents of elite popcorn crosses being classified into different clusters. The cluster analysis of 20 normal maize inbred lines was accordant with previous studies. Consequently,SSR makers could be used to study the genetic diversity of popcorn inbred lines. The average genetic distance among different clusters of popcorn and normal maize inbred lines were 0.55 to 0.67. To improve popcorn inbreds using normal maize lines in the long run, the genetic relationships should be taken into serious consideration.