Number of experiments necessary to more accurately differentiate common bean genotypes for grain physical traits and minerals in cluster analysis

Abstract

The number of experiments that provides greater detail in the differentiation of common bean genotypes for grain physical traits and minerals in cluster analysis is not known. This study was undertaken to determine the number of experiments necessary to more accurately differentiate common bean genotypes for grain physical traits and minerals in cluster analyses. Seven traits of grain physical quality and the concentration of six minerals were evaluated in 17 common bean genotypes with carioca (9) and black (8) grains. Statistical analyses were performed in data obtained from one, two, three and four experiments. A significant genotype × experiment interaction occurred for all traits, except for the potassium concentration. Tocher’s and the unweighted pair group method with arithmetic mean (UPGMA) cluster analyses were efficient in differentiating common bean genotypes by grain type when the data obtained from one experiment were considered. However, the use of data obtained from four experiments made it possible to recognize differences regarding grain lightness and brightness as well as the other traits. Four experiments are need for the Tocher’s and the UPGMA cluster analyses to more accurately differentiate carioca and black bean genotypes for grain physical traits and minerals.