Interação genótipos por ambientes e divergência genética em genótipos de feijoeiro (Phaseolus vulgaris L.)

Abstract

In this work were studied two main aspects of the common bean breeding: a) - Genotype by environment interaction (Chapter 1) and; b) – Genetic divergence (Chapter 2). The trials were carried out at the experimental Campus at the Universidade Estadual de Mato Grosso do Sul, in Aquidauana and at the Universidade Federal da Grande Dourados, in Dourados-MS, in the period from 2000/2001 to 2005/2006, in the “dry” and “rain” harvest, composing a total of 12 environments, where each environment was characterized by the combination of local x year x crop season. There were thirteen genotypes of common bean assessed in randonized blocks, with three replications per treatment, where each genotype became a treatment. In the study of the genotype by environment interaction the parameters of adaptability and stability of the genotypes were estimated by traditional and multivariate analysis methods, in each trial experimental environment, searching to compare results and efficiency of these methodologies in discrimination of genotypes face to variation of the environment. The pattern analysis was used to identify and group genotypes with similar responses in all environments as well as environments that discriminate similarly the genotypes. The study allowed discriminate genotypes whit high performance, broad adaptation and good predictability of response that may be recommended to favorable and unfavorable environment, in general, and genotypes of less predictability behaviour, whith specific adaptation to certain environments. Multivariate analysis techniques were also used in the study of genetic divergence aiming the formation of genotypes groups based on the genetic distance among them. The study of genetic divergence identified dissimilar groups of genotypes that based on agronomic characters of interest, may be employed in hybridizations, in breeding programs, that are designated to acquisition of hybrids with heterosis, which in combination, can generate populations of broad genetic base.