Number of experiments that should be considered in the cluster analysis of common bean genotypes for plant architecture and grain yield traits

Abstract

The number of experiments that allows the choice of parents to be used in controlled crossings in a more assertive way in cluster analysis is unknown for plant architecture and grain yield traits in common bean. Therefore, the objective of this work was to determine the number of experiments that should be considered in Tocher's and the unweighted pair group method with arithmetic mean (UPGMA) cluster analyses to identify promising common bean parents for several plant architecture and grain yield traits. Four experiments were carried out in different years and growing seasons, in the same site. The randomized block design was used and 17 common bean genotypes with carioca (beige seed coat with brown streaks) and black grains were evaluated in relation to 12 traits related to plant architecture and five traits related to grain yield. Statistical analyses were performed with data obtained from individual and combined experiments. Significant genotype × experiment interaction was observed for most of the evaluated traits. When Tocher's and UPGMA cluster analyses was performed from data obtained in individual experiments different groups were formed. The use from data obtained in two, three or four experiments allowed greather reliability in the formation of groups. Three and two experiments are sufficient in the Tocher's and the UPGMA cluster analyses, respectively, to identify promising carioca and black common bean parents for several plant architecture and grain yield traits in a more assertive way.