Genetic parameters and association of common bean yield traits in Mozambique

Common bean (Phaseolus vulgaris. L) is an annual legume with a short cycle and is easy to produce. It provides fresh and dry beans of great commercial value, serving as income for smallholders. It is a rich source of proteins and minerals for human consumption in Mozambique. Despite the notorious socioeconomic importance, the grain yield achieved by farmers is low, which can be attributed to the polygenic nature of the trait, which is highly influenced by unpredictable biotic and abiotic stresses. Genetic improvement by direct selection in yield is generally not efficient, with the need to practice indirect selection in its components that are easy to measure and that have high variability, means, correlation, direct effect and heritability. Knowing these components of variance and mean between traits is one of the most important initial steps in a genetic improvement program aimed at the development of productive varieties. Thus, the objective was to evaluate the genetic parameters and associations between yield traits, aiming to select traits that can be used as selection criteria in the common bean breeding program in Mozambique. Plant height (Plh), primary branches (Pb), pod length (PdL), seeds per pod (SPd), pods per plant (PdPl), days to anthesis (Da), days to flowering (DF), seed mass (100SM), days to maturity (DM) and yield (Yd) were evaluated in the northern region of Mozambique, in Nampula, using an augmented design, 24 accessions and three checks in four blocks. Data were subjected to analysis of variance, genetic parameters, correlation network and path analysis based on the genetic correlation matrix. The results indicated genetic variability among genotypes and high heritability for all traits. High correlations were showed by Plh, Pb, Da, SPd, DM and PdPl. The traits PdPl, SPd and Pb, in addition to being highly heritable, showed high means, correlations and direct effects on yield. These traits can be used as selection criteria in the studied accessions for the genetic improvement of common bean productivity in Mozambique.