Selecting the right varieties for the environment and taking account of genotype/environment interactions

Genotype-environment interaction is the expression of differential genotypi c adaptation across environments. Statistical and agro-physiological techni ques for quantifying genotype adaptation and for characterizing environment s are presented. This will be illustrated by examples from wheat, focusing upon analyses of two-way tables of genotype-environment interaction and upo n several regression models. Adaptation is caused by "genes of adaptation" or by the genetic structure. Several key aspects of a breeding programme ar e discussed in relation with genotype-environment interaction.