Identification of candidate gene–based SSR markers for lysine and tryptophan metabolic pathways in maize (Zea mays)

Abstract

With 3 figures and 5 tablesAbstractIdentification of candidate gene–based SSR markers is extremely useful in genetic enhancement of crop plants. A total of twenty‐four SSR loci were developed for the candidate genes of lysine and tryptophan metabolic pathways and for opaque2 (o2) modifiers. Of the 24 SSR loci, 23 yielded amplicons of expected size; however, fifteen were found polymorphic among the 22 maize genotypes including normal and quality protein maize inbreds from India and exotic inbreds from CIMMYT, Mexico. The polymorphism information content of primers was in the range of 0.16–0.72, with a mean of 0.49. The gene diversity ranged from 0.17 to 0.75, and the inbreeding coefficient was in the range of 0.48–1.0. The candidate genes of lysine metabolism showed higher polymorphism levels and genetic diversity than other candidate genes. The SSR loci developed from the candidate genes of aspartate kinase 2 and homoserine dehydrogenase were found to have high potential. Thus, the SSR loci identified in this study added useful markers for fine mapping and high‐density mapping of opaque2 modifiers.