Genomics of origin, domestication and evolution of Phaseolus vulgaris

The role of genetic diversity is crucial for future improvements to meet societal demand for food security under a climate change scenario. From this perspective, it is thus crucial to understand the structure and evolution of crop species and their wild relatives. The common bean (Phaseolus vulgaris L.) is the world’s most important food legume for direct use, and the demand for this crop can be expected to increase based on the current trends in population growth and bean consumption. The wild P. vulgaris has a Mesoamerican origin, and since its expansion, it has become distributed from northern Mexico to north-western Argentina, which has led to the formation of two major gene pools in these geographical regions. Domestication took place after the formation of these gene pools, and their structure is still clearly evident in both the wild and the domesticated forms. This evolutionary scenario renders P. vulgaris almost unique among crops, and therefore particularly useful to investigate crop domestication, as this process can be studied in the same species as a replicated experiment (i.e., in Mesoamerica and in the Andes). The present review offers an overview of the current knowledge on the evolutionary history of P. vulgaris L. including speciation, domestication, diversification, and crop expansion outside its centers of domestication in Mesoamerica and in the Andes. Within this context, we also present a description of the available genomic tools and the germplasm collections that are at present available for genetic studies on the common bean, while showing their potential for improvements to the productivity and quality of this crop.