SSR分子标记在玉米杂种优势群划分中的应用

利用SSR标记研究了20个玉米自交系的遗传变异,初步进行了杂种优势群划分,从85对SSR引物中筛选出70对扩增产物具有稳定多态性的引物.70对引物在供试材料中共检测出270个等位基因变异,每对引物检测到等位基因2～6个,平均3.86个,多态性信息含量变化范围为0.26～0.80,平均多态性信息量为0.59.20个自交系之间的遗传相似系数变化范围为0.5946～0.7711,平均为0.6601.UPGMA聚类分析结果表明,供试自交系可分为5群,分类结果与系谱基本一致,划群后群间平均距离大于群内平均距离,群间平均产量大于群内平均产量.SSR标记可以进行玉米自交系遗传变异分析,并用于杂种优势群的划分。

Application of SSR Markers to Heterotic Grouping of Maize Inbred Lines

Simple sequence repeats(SSRs) were used to detect genetic variation among 20 maize inbred lines. Seventy SSR primers selected from 85 primers gave stable profiles amplified in sample of 20 inbred lines. Seventy primers produced 270 polymorphic amplified fragments. The average number of alleles per SSR locus was 3.86 with a range from 2 to 6. The polymorphism information content(PIC) for the SSR loci varied from 0.26 to 0.80 with an average of 0.59. Genetic similarities among the 20 inbred lines ranged from 0.594 6 to 0.771 1 with an average of 0.660 1. The cluster analysis showed that the inbred lines could be classified into five distinct clusters which correspond to the heterotic groups determined by their pedigree analysis, average genetic distance among groups was greater than that within group, and average yield among groups was greater than that within group. Consequently, SSR markers could be used for measuring genetic variation and assigning maize inbred lines to heterotic groups.