DNA sequence polymorphism discriminated mesoamerican and andean genepools in common bean (Phaseolus Vulgaris L.

Common bean (Phaseolus vulgaris L.) is the most important edible food legume in the world. It is an important source of calories, proteins, dietary fibres, minerals and vitamins for millions of people in both developing and developed countries. Common bean was originated and domesticated in the New World and has two major gene pools, the Andean and the Mesoamerican, based on their centers of origin in South and Central America, respectively. The existence of Andean and Mesoamerican gene pools is supported by molecular marker analyses (seed storage protein, isozymes, RFLPs, RAPDs, AFLPs, and SSRs). These can be complemented by DNA sequence data that provide a complete and unambiguous genotype of all specific genomic regions. In this study we assessed the frequency of SNPs in a fragment of P. vulgaris DNA localized on the B8 linkage group. This fragment was obtained from genomic DNA. We conducted a sequence analysis of 80 European domesticated landraces, belonging to a European core collection, 147 American wild and domesticated common bean genotypes, that had been previously assigned to the Andean or Mesoamerican gene pools using phaseolin patterns and as a control, 10 genotypes of P. coccineus, P. lunatus, P. acutifolius and P. polyanthus. Including indels, sequence lengths was 393 bp. In P. vulgaris one 46 bp indel and 4 SNPs distinguished unequivocally the Mesoamerican and the Andean gene pools. The population structure identified in this study is generally consistent with the current hierarchical scheme of gene pools. This DNA sequence displays 5 polymorphic markers that discriminate very clearly the two gene pools of P. vulgaris.