|HOYOS-VILLEGAS, VALLEIRO - Michigan State University|
|KELLY, JAMES - Michigan State University|
Submitted to: The Plant Genome
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/27/2016
Publication Date: 12/29/2016
Citation: Hoyos-Villegas, V., Song, Q., Kelly, J.D. 2016. Genome-wide association analysis for drought tolerance and associated traits in common bean. The Plant Genome. 10(1)):1-17.
Interpretive Summary: Common bean is one of the most important food legumes grown worldwide, and its production is limited by drought stress. Drought events, both intermittent and terminal, affect more than 60% of the annual dry bean production worldwide. The bean-growing regions of the western US are also subject to drought conditions and irrigation is necessary to bring a crop to harvest, making this region one of the largest water consumers in the country. For this reason, a major goal of bean breeding programs has been to introduce drought tolerance into new varieties. Our objective was to evaluate drought tolerance traits for diverse set of beans that originate from Central America. We also identified DNA markers associated with physical traits such as shoot biomass at harvest, total shoot biomass at flowering, 100-seed weight, lodging score, leaf elongation rate and wilting. These markers can be used in breeding programs to develop varieties resistant to drought and with improved characteristics for bean productivity. This information is useful to breeders at universities, institutes, government agencies and companies who want to improve bean varieties.
Technical Abstract: A genome-wide association study (GWAS) was conducted to explore the genetic basis of variation for drought tolerance and related traits in a Middle American diversity panel comprised of 96 common bean (Phaseolus vulgaris) genotypes. The panel grown under irrigated and rainfed conditions and single nucleotide polymorphism (SNP) data was used to explore genetic diversity and ancestry of the diversity panel and discovered varying levels of admixture and purity as well as distinctly divergent individuals. Estimations of genome-wide heterozygosity revealed that, on average, greater diversity is present in individuals from race Mesoamerica (3.8%) ancestry, followed by admixed individuals (2.3%). Race Durango had the lowest level of heterozygosity (1.4%). We report 27 significant marker-trait associations based on Best Linear Unbiased Predictors (BLUPs). Associations include seven markers for shoot biomass at harvest under irrigated conditions and five markers under rainfed conditions on chromosome Pv11, two markers for shoot biomass at flowering under irrigated conditions on Pv02 and Pv08, two markers for seed size under irrigated and rainfed conditions on Pv09, seven markers for lodging score under irrigated conditions on Pv02 and Pv07, one marker for leaf elongation rate on Pv03 and one marker for wilting score on Pv11. Significant QTL identified in this study could potentially be used in marker-assisted breeding to accelerate genetic improvement of drought tolerance common bean.