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.