Genome Wide Association Study of Agronomic Traits in Common Bean (Phaseolus vulgaris L.)

Genome wide association study (GWAS) is one of the most common methods used to find the differences in DNA that explain the natural phenotypic variation. Finding markers that are associated with important agronomic traits will not only provide valuable information for genetics and genomics studies but also facilitate breeding through marker assisted selection (MAS). Indeed, in the breeding programs of economically important crops such as common bean (Phaseolus vulgaris L.) the selection is based on the best combination of agronomic and seed characteristics in the first steps. However, there is little known about the genetic and genomic control of many traits in this species and GWAS can lead to the discovery of affecting loci. GWAS was conducted on two Middle American trials using the same set of 10,287 SNPs. The large national trial consisted of 271 genotypes which were planted in four locations. The small trial consisted of 87 genotypes under drought and irrigated condition.  Drought is the most important abiotic stress that affects the yield of dry bean in the Great Plains where common bean is mostly planted in United States. The 87 genotypes were grown in five locations. Both trials were phenotyped for days to flower, days to maturity, plant height, growth habit, lodging, seed weight and seed yield. These studies let us compare the effect of large and small trials as well as stress and non-stress conditions on GWAS in search for genomic regions that are associated with agronomic traits.