Genetic Diversity of Maize (<i>Zea mays</i>L.) Inbreds Developed for Highlands and Mid-Altitudes as Revealed by AFLP Markers

Abstract

Fifty six maize inbred lines developed for highlands and mid-altitudes of Ethiopia and Zimbabwe were fingerprinted using amplified fragment length polymorphism (AFLP) markers. The objectives were to investigate the genetic relationships among the inbred lines and to cluster them into heterotic groups with a view to generate broad-based breeding populations. Seven prescreened pairs of AFLP primers identified 499 scorable fragments, of which 408 (81.7%) were polymorphic. The genetic diversity (Euclidean distance) varied from 0.35 to 0.71 with an average of 0.58. The UPGMA clustering using average linkage methods distinguished four major groups. The highland inbred lines generally separated from the mid-altitude germplasm. Each of these groupings possessed a number of subclusters mostly related to the pedigree records of the inbred lines. Principal coordinate analysis, also demonstrated considerable genetic divergence between and within the genotypes of the different origins. This groupings based on AFLP markers can be utilized to generate heterotic populations that can serve as source material to develop superior inbred lines revealing good combining ability. Moreover, inbred lines of different heterotic groups can be used to launch crossing activities leading to the development of high yielding maize hybrid and synthetic varieties.