Identifying Genomic Regions Controlling Plant Architectural Characteristics in Dry Bean (Phaseolus vulgaris L.)

Dry bean (Phaseolus vulgaris L.) is the most important food legume worldwide and provides crucial nutrition for millions of people. This crop possesses one of the most diverse sources of growth habit among major food crops. Three main classes of growth habits exist in current common bean cultivars in the U.S., including type I (determinate bush), type II (indeterminate upright), and type III (indeterminate prostrate). Upright (type II) is considered as the desirable growth habit because it facilitates mechanical harvest and other management practices. Furthermore, upright growth habit improves the canopy structure which helps for disease avoidance.  Genetic dissection of components underlying plant architecture can accelerate the breeding process towards ideotype bean cultivars with both desirable plant architecture and stable yield. To identify the causative genomic regions controlling growth habit, we used a genome-wide association study (GWAS) approach for 18 phenological/agronomic traits related to plant architecture. Phenotypic data of 150 genotypes belonging to the Durango race was collected from two locations in North Dakota, USA.  These lines were genotyped using a combination of two 6K Illumina Infinium chips and GBS data which provides a total number of 35K potential SNP markers. In this study, we identified several genomic regions which control plant architecture in dry bean. These regions can be utilized for marker assisted selection in breeding programs to engineer novel cultivars with desirable architectural characteristics.