Genetic diversity analysis of elite maize inbred lines of diverse sources using SSR markers


Genetically diverse and complementary elite inbred lines are fundamental for hybrid maize breeding or for stra- tegic conservation. The objectives of this study were to determine the genetic diversity present among 79 elite maize inbred lines collected from five different sources using 30 SSR markers and to identify unique genotypes for breeding. The mean numbers of observed and effective alleles were 4.7 and 2.4 per marker, respectively. The polymorphic information content (PIC) of the 30 SSR markers ranged from 0.01 to 0.92, with a mean of 0.51. Six markers: phi 031, phi 308707, phi 96100, phi 114, phi 299852 and phi 063 revealed the highest PIC values greater than 0.70 suggesting the potential of these loci for genetic diversity analysis. The mean value of total gene diversity was 0.51 which partitioned 72% among inbred lines, 26% within inbred lines and 7% was attributed to variation between the five sources. Cluster analysis allocated the inbred lines into three main genetic groups. The principal coordinate analysis explained 67% of the total genetic variation detected among inbred lines and separated them into two main clusters. The study identified elite maize inbred lines such as TL2012-2, TL2012-14, TL2012-20, TL2012-31, TL2012-54 and TL2012-55 from Cluster I; TL2012-6, TL2012-35, TL2012-53 and TL2012-75 from cluster II; TL2012-12, TL2012-27, TL2012-29 and TL2012-58 from cluster III with marked genetic differences for hybrid breeding to exploit heterosis.


cluster analysis, genetic diversity, inbred line, principal coordinate analysis, Zea mays, SSR markers

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