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On-line version ISSN 1678-4596
CARGNELUTTI FILHO, Alberto et al. Comparison of cluster methods for the study of genetic diversity in common bean cultivars. Cienc. Rural [online]. 2008, vol.38, n.8, pp.2138-2145. ISSN 1678-4596. http://dx.doi.org/10.1590/S0103-84782008000800008.
The aim of this research was to compare cluster methods, on the basis of the dissimilarity (standardized average euclidian and Mahalanobis generalized) and obtain information on genetic diversity in common bean cultivars (Phaseolus vulgaris). Fourteen common beans cultivars were evaluated in nine experiments conducted in Santa Maria, Rio Grande do Sul State, Brazil (latitude 29°42 S, longitude 53°49 W, altitude 95m), in agricultural years from 2000/2001 to 2004/2005. Randomized blocks design with three repetitions was installed to evaluated the following characters: grain yield, number of pods per plant, number of seeds per pod, weight of 100 grains, final population of plants, number of days of the emergency to flowering, number of days of the emergency to harvest, height of first pod insertion and height of the final pod insertion. Clusters based on the standardized average euclidian distance are distinct from those formed on the basis of Mahalanobis generalized distance. The Tocher's method and hierarchical methods of the single linkage, Ward, complete linkage, median, the average linkage within the group and average linkage between groups, based on the Mahalanobis generalized distance form agreement cluster. The cultivar 'Iraí' presents distinct behavior from other cultivars.
Keywords : Phaseolus vulgaris L.; dissimilarity measures; cluster algorithms; cofenetic correlation coefficient.