GENETICS OF DOMESTICATION IN COMMON BEAN (PHASEOLUS VULGARIS L.): AN APPROACH FOR THE ANALYSIS OF CANDIDATE GENES VIA TILLING-BY-SEQUENCING

According to Charles Darwin, domestication can be thought as a great model to study convergent evolution. Among crops, common bean (Phaseolus vulgaris L.) represents a unique example of multiple parallel independent domestications: wild common bean is organized in two geographically isolated and genetically differentiated wild gene pools (Mesoamerican and Andean) that diverged from a common ancestral wild population, then independently domesticated in Mexico and in South America nearly 8,000 years ago. These processes resulted in morphological changes (e.g. seed and leaf sizes, seed coat color, growth habit, photoperiodic responses) that distinguish culturally adapted classes of beans. In addition to the interest emerging from its domestication history, common bean also carries a pivotal agronomic value: it is one of the most important grain legumes for human consumption and, as a legume, it also has a role in sustainable agriculture owing to its ability to fix atmospheric nitrogen. To gain deeper insights into the genetic basis of common bean domestication we used an available TILLING population, obtained by chemical EMS-mutagenesis of the Mesoamerican genotype BAT 93 (1), and developed a TILLING-by-sequencing pipeline starting as a method for the identification of mutants of candidate domestication genes.