利用SSR标记研究玉米自交系的遗传变异

 利用 SSR标记研究了 2 1个玉米 ( Zea mays L.)自交系的遗传变异 ,初步进行了杂种优势群划分。从 69对 SSR引物中筛选出 43对扩增产物具有稳定多态性的引物。43对引物在供试材料中共检测出 1 2 7个等位基因变异 ,每对引物检测等位基因 2～ 7个 ,平均为 2 .95个 ;平均多态性信息量为 0 .51 1。 2 1个自交系之间的遗传相似系数变化范围为 0 .480～ 0 .768,平均为0 .62 7。 UPGMA聚类分析结果表明 ,供试自交系可分为两个类群。黄早四自成一群 ;其余 2 0个自交系又分为 5个亚群。生产上利用的高产杂交组合的亲本均属于不同的类群 (亚群 ) ,而在类群 (亚群 )内未发现高产组合。研究发现 8对具有较高多态性信息量的引物 ,利用这些引物可以对供试材料进行初步鉴定。研究表明 ,利用 SSR标记可以进行玉米自交系遗传变异分析 ,并用于杂种优势群划分

Genetic Variation of Inbred Lines of Maize Detected by SSR Markers

Simple sequence repeats (SSRs) were used to detect genetic variation among 21 maize inbred lines. Forty three SSR primers selected from all 69 primers gave stable profiles amplified in the sample of 21 inbred lines, which could clearly resolve on 3% Metaphor agarose gel.Forty three primers produced 127 polymorphic amplified fragments. The average number of alleles per SSR locus was 2.98 with a range from 2 to 7. The polymorphism information content (PIC) for the SSR loci varied from 0.172 to 0.753 with an average of 0.511. Genetic similarities among the 21 lines ranged from 0.480 between the combination of CA156 vs. Ye478 to 0.768 between Zhongzi451 vs. K12. The cluster analysis showed that the inbred lines could be classified into two distinct clusters with several subclusters, which corresponded to the heterotic groups determined by their pedigree analysis. Eight SSR primers, which had high level of polymorphism, could allow a rapid and efficient identification of 21 inbreds. Consequently, SSR markers could be used for measuring genetic variation and assigning maize inbred lines to heterotic groups.