Molecular Diversity and Gene Pool Structure in Common Bean (Phaseolus vulgaris L.): A Review

Increase in food production and quality of food is important to feed the growing human population to attain food as well as nutritional security. The availability of diverse germplasm of any crop is an important genetic resource to mine the genes that may assist in attaining food as well as nutritional security globally. The common bean (Phaseolus vulgaris L.) is the most important source of dietary protein, calories and minerals especially iron and zinc for a very large population of the world. In many regions/countries, it provides about 15% of total daily calories and greater than 30% of daily protein intake. Being such an important part of the diet around the world, common bean as a crop is subjected to various improvement programs. Edible parts and growing habits of the common bean show a high degree of genetic variation. Different molecular markers have been used to study genetic diversity among common bean. The high density linkage map of common bean was developed using SSR’s or microsatellite. SSR markers have also been used to evaluate intra-specific diversity within the genus of Phaseolus. Among all the markers, SSR’s have been deployed for population structure studies from time to time in various cereals, as well as legume crops. Race structure analysis was done in cultivated Andean and Mesoamerican beans. Microsatellite markers have been efficiently used to study genetic variations among cultivars and landraces in almost all the bean growing regions of the world. The review is written with the aim to provide bean breeders useful information regarding, the global status of common bean diversity.