Conservation of microsatellite regions across legume genera enhances marker repertoire and genetic diversity study in Phaseolus genotypes

To study the conservation of microsatellite regions, a set of 137 microsatellite markers developed from Phaseolus, Cajanus, Lens and Cicer genera of Leguminosae family were tested for their transferability across 16 genotypes of Phaseolus belonging to diverse collections from South America and Asia. Considerable transferability was observed with markers derived from Cajanus (60%), Lens (46%) and Cicer (28%). Of the total 122 loci were amplified, 82 cross-species polymorphic amplicons were obtained. Maximum number of alleles per marker was six (Cicer markers). Polymorphism information content values ranged from 0.12 to 0.96 with Cajanus, 0.13 to 0.74 with Lens and 0.30 to 0.93 with Cicer markers. Unweighted pair group method employing arithmetic averages cluster analysis of Phaseolus genotypes showed clear demarcation between the commercial cultivars falling in separate cluster with respect to their seed size and maturity. Transferability of genomic SSRs was different from that of expressed sequence tag-derived genic microsatellite markers.