Genetic dissimilarity of common bean lines for agronomic and biofortification traits

Abstract

The evaluation of the genetic dissimilarity of common bean lines obtained by the breeding program is significant to identify duplicate accessions, to select superior lines, and to plan new hybrid combinations. The objectives of this study were to evaluate the genetic dissimilarity of common bean genotypes for agronomic and mineral biofortification traits, select superior lines, and identify promising hybrid combinations for biofortification programs. For this purpose, 169 common bean genotypes (F6:8 inbred lines and parental cultivars) were evaluated in two experiments conducted in a simple lattice design in Santa Maria-RS, Brazil. The following agronomic traits were evaluated: insertion of the first pod, insertion of the last pod, cycle, mass of 100 grains, grain yield, and concentrations of potassium, phosphorus, zinc, and copper in grains. The genotypes assessed presented genetic variability for all traits, except for copper concentration in grains. The traits that showed the highest contribution to the genetic dissimilarity were the concentrations of phosphorus, potassium, and zinc in grains. In cluster analyses, six groups by principal components and 33 groups by the Tocher optimization method were identified. These methods partially agreed in the formation of different groups of common bean genotypes. Controlled crossings between the lines 17 and 162 with lines of groups XX, XXI, XXIV, and XXXIII are recommended to obtain recombinants with high grain yield and biofortified for phosphorus, potassium, and zinc.