Análise multivariada e índice de seleção na identificação de genótipos superiores de feijão-caupi

Abstract

This work aimed to evaluate the genetic divergence among cowpea genotypes through multivariate techniques and identify those with the best combination for size, production and quality of grain using a selection index. The experiment was carried out at the Federal University of Ceará in the period from February to June 2008, using 47 cowpea genotypes. The experiment was carried out in a plot with eight plants, without replications. The following traits were analyzed: plant size, pod position in plant, number of pods per plant, pod length, number of seeds per pod, weight of a hundred seeds, grain yield, number of days to flowering and cycle, shape and color of grain. The main component coupled with the methods of Tocher and Euclidian distance was used to evaluate the genetic divergence. The rank sum selection index was used to identify genotypes with superior characteristics. New genetic combinations can appear in the crossings between CE-264 and CE-200, CE-274 and CE-93, CE-200 and CE-274, and CE-93 and CE-282 genotypes. Thirteen genotypes demonstrated superiority for production, earliness and grain quality traits.