Population structure and genetic diversity in common bean accessions from Northeast Brazil

Abstract

Common bean is of great relevance for several countries, especially those located in tropical regions. Common bean in Brazil has a wide genetic diversity, which is used by breeders to improve this crop. In this study, we used GBS methodology to genotype common bean accessions from Northeast Brazil, and to study its population structure and genetic diversity. After a filtering process, we identified 30,529 high-quality SNPs distributed in 11 linkage groups. The number of SNPs per chromosome ranged from 1,731 to 3,853. The population structure analysis separated the accessions into two subpopulations, according to K=2, one subpopulation with 26 Andean and the other with 60 Middle American accessions. Considering K=3, Middle American accessions were divided into two subpopulations with presence of allele mixture between these two groups. Based on the PCA, we were able to verify a narrow genetic base of accessions belonging to the Andean gene pool, as well as a vast genetic diversity among the accessions from the Middle American gene pool. The knowledge on the genetic diversity among the accessions is of extreme importance to subsidize the common bean breeding programs in Northeast Brazil, and to explore the variability existing in cultivars adapted to the specific bioclimatic conditions.