QTL Mapping on a Multiparent Advanced Generation Inter Cross (MAGIC) Population for Dry Bean Using Genotype By Sequencing (GBS)

Dry bean (Phaseolus vulgaris) is the most important legume for human consumption, being a common source of ions, vitamins, fiber and proteins. Its high energetic values and fast grow cycle makes bean an important crop for food security in developing countries. Recent availability of a reference genome for P. vulgaris will serve as a building block to boost basic and applied research in bean genomics. Here we present a dry bean Multiparent Advanced Generation Inter Cross (MAGIC) population of 648 individuals derived from intercrosses among eight elite founders. The large number of recombination events in a MAGIC population increases the phenotypic and allelic diversity, thus reducing the number of QTLs and the mapping accuracy for segregating traits. Four of the eight parents were derived from interspecific crosses of P. vulgaris with other Phaseolus relatives showing tolerance to different biotic and abiotic stresses. We performed Genotype by Sequencing (GBS) on this population. Using the NGSEP pipeline the reads were mapped to the Phytozome reference genome P. vulgaris G19833, and then the population was genotyped to discover SNPs and small indels. A curated dataset of 21.640 SNPs was used to perform QTL analysis of drought tolerance which allowed us to find three genomic sites related to greater yield components under drought conditions, two QTLs for 100 seed weight and one QTL for chlorophyll content. We believe that this MAGIC population will be a great resource for further discovery of genes related to a variety of agronomic traits.