Molecular characterization and insights into the origin of common bean (Phaseolus vulgaris L.) landraces of north western Himalayas

Common bean is the principal grain legume of North-India including Jammu & Kashmir and Ladhak. Owing to its high protein content, abundance of various micronutrients and essential amino acids and low cost, it is sometimes referred to as poor man’s meat. It is a very diverse crop and presents a rich reservoir of genetic resource to be explored. In the present study, we collected 102 common bean genotypes from different north western Himalayan regions of Jammu & Kashmir and Ladakh. This germplasm was then systematically purified and then characterised using SSRs. In order to examine the genetic diversity, various parameters were considered. The PIC values for the SSR loci ranged from 0.738 to 0.966 with an average of 0.899. The gene diversity between common bean genotypes ranged from 0.751 to 0.967. The major allele frequency ranged from 0.076 to 0.469 and the expected heterozygosity ranged from 0 to 0.135. Further, model based STRUCTURE analysis generated three subpopulations that correspond to distance based groups. Furthermore, the PCR assay for phaseolin locus led to the characterization of 81 genotypes into Meso-American and Andean types. Out of 81 genotypes, 40 possessed “S” type phaseolin and 41 possess “T” type phaseolin. The results of this study revealed the origin of common bean landraces grown in the north western regions of Jammu & Kashmir and Ladakh, India. The characterised material can be planned for conservation and can further be used as a genetic resource for improvement of common bean.