Population Structure and Genetic Diversity of Common Bean Accessions from Brazil

Brazil can be considered a secondary center of common bean diversification (Phaseolus vulgaris L.), and the landraces grown throughout Brazil are valuable sources of genes for breeding programs and evolutionary studies. The objective of this study was to evaluate the population structure of 109 accessions of common bean, including cultivars and landraces from southern and central-western regions of Brazil. The population structure analysis based on simple sequence repeat markers demonstrates that the accessions can be separated into two distinct subpopulations—the Andean and the Mesoamerican—with some admixtures observed according to Delta K = 2 groups. The optimal number of groups was found at K = 4, a level at which the Andean accessions were divided into two subpopulations and the Mesoamerican accessions into two subpopulations. Accordingly, the accessions preserved in the current collection maintained by the Universidade Estadual de Maringá are an important source of genes for germplasm conservation programs and the development of common bean cultivars.