Microsatellite marker-based genetic diversity among quality protein maize (QPM) inbreds differing for kernel iron and zinc

Quality Protein Maize by virtue of opaque2 mutation is known to possess high lysine and tryptophan which help in improving biological value of maize protein. Improvement of these genotypes for kernel Fe and Zn holds immense promise. We report here wide variation for kernel -Fe and -Zn among 46 diverse Quality Protein Maize inbreds. Promising inbreds with high kernel -Fe (>40 mg/kg) and -Zn (>35.0 mg/kg) were identified. Profiling of inbreds using 75 microsatellite markers distributed throughout the genome produced a total of 256 alleles with a mean of 3.41 alleles per locus. Seven unique- and 26 rare- alleles were identified. The average polymorphism information content was 0.50, with a range of 0.11-0.79. Genetic dissimilarity coefficient varied from 0.38-0.86 with a mean of 0.72. Cluster analysis grouped the inbreds into three major clusters; and principal coordinate analysis depicted diverse genetic nature of inbred lines. Genetically diverse inbred lines with high kernel -Fe and -Zn can be used for development of Quality Protein Maize hybrids enriched with micronutrients. Phenotypically contrasting inbreds with high genetic divergence can serve as ideal parents in developing mapping population(s) for identifying loci underlying accumulation of Fe and Zn in maize kernel.