Proposal of methodologies for environment stratification and analysis of genotype adaptability

Abstract

A cultivar which performs well in a given environment will not necessarily perform as well in others. Thus studies on environmental stratification must be carried out to provide indications for cultivars. A procedure commonly used is the stratification of environments through the analysis of genotype-environment interactions, which must be minimal or statistically not significant. We propose an alternative procedure based on factor analysis. Moreover, we propose a methodolo gy for the analysis of genotype adaptability through graphic analysis, generated by plotting scores from factor analysis. These new methodologies were used to assess grain yield of maize hybrids evaluated in diferent environments. Results provided the establishment of environmental subgroups with high correlations within the subgroups, and low or no correlations among them. The scores provided plot that helped understand the adaptability of the hybrids. The methodologies proposed for environment stratification and adaptability analysis were effective and of easy interpretation.