Genetic diversity and structure of landrace accessions, elite lineages and cultivars of common bean estimated with SSR and SNP markers.

Abstract

Common bean (Phaseolus vulgaris L.) is an important source of proteins, fibers and minerals for humans, being grown mainly in developing countries and representing a source of income for small farmers. In this work, a set of 206 Brazilian landraces and 59 elite lineages and cultivars were genotyped with 23 SSR (Simple Sequence Repeats) and 251 SNPs (Single-Nucleotide Polymorphism) markers. The ideal number of groups, according to STRUCTURE, was K = 2 for both SNPs and SSRs. This could be expected considering the two original gene pools-Andean (AND) and Mesoamerican (MES). The matrices of genetic simple matching dissimilarity for SSRs and SNPs were highly correlated; therefore, the allelic data of the markers was combined and analyzed to understand the genetic relationships of the studied collection. The neighbor-joining analysis considering the genetic distance of simple matching grouped the 265 genotypes into 17 subgroups. The markers SSR and SNP presented high power to discriminate among the genotypes. The ample genetic diversity observed in the work collection makes it a valuable source for the conservation, sustainable management and exploration in breeding programs of the crop.