Novel SSR Markers for Polymorphism Detection in Pigeonpea (Cajanusspp.)

With an objective to expand the repertoire of molecular markers in pigeonpea (Cajanus cajan), 36 microsatellite or simple sequence repeat (SSR) loci were isolated from a SSR-enriched genomic library. Primer pairs were designed for 23 SSR loci, of which 16 yielded amplicons of expected size. Thirteen SSR markers were polymorphic amongst 32 cultivated and eight wild pigeonpea genotypes representing six Cajanus species. These markers amplified a total of 72 alleles ranging from two to eight alleles with an average of 5.5 alleles per locus. The polymorphic information content for these markers ranged from 0.05 to 0.55 with an average of 0.32 per marker. Phenetic analysis clearly distinguished all wild species genotypes from each other and from the cultivated pigeonpea genotypes. These markers should be useful for genome mapping, trait mapping, diversity studies and assessment of gene flow between populations in pigeonpea.