Genetic divergence studies and heterotic grouping in maize inbred lines using microsatellite markers

Information on genetic diversity and relationship among different maize genotypes is very important in hybrid maize breeding program. The purpose of present study was to elucidate the nature and extent of differentiation and divergence among 18 inbred lines of maize based on the analysis of targeted microsatellite sites. Using 28 primer pairs, altogether 296 allelic variants including 145 shared and 151 unique alleles were detected amongst amplified products and a total of 49 loci were assigned with an average of 6.04 alleles per locus. Polymorphic information content of microsatellite primer pairs ranged from 0.34 (umc1304) to 0.93 (umc1179) with mean of 0.77 per primer. A remarkably higher level of genetic differentiation and divergence was revealed by the use of 28 microsatellite markers, which allowed unique genotyping and unambiguous classification of the maize inbred lines under evaluation. Among the inbred lines under molecular characterization, CML163 and CML467 appeared as the most diverse genotypes. Using the matrix of genetic similarity, the cluster analysis grouped the eighteen inbred lines into four heterotic groups. The markers utilized in the present study were sufficient for discrimination and unambiguous classification of inbred lines.