Strategy for grouping wheat genotypes according to environmental responses in multi-location trials

Abstract

A better understanding of genotype x environment interactions (GEIs) can improve the selection and recommendation of wheat genotypes that are widely adapted and stable in different environments. The objective of this study was to evaluate a strategy to perform a joint analysis in wheat yield trials with genotypes classified according to their interactions with the environment. Measurements of the adaptability and stability estimates were used in the proposed strategy. We analyzed grain yield data from 367 wheat genotypes in 348 yield trials classified into 58 groups. In each group, 25 genotypes at different numbers of locations were evaluated using data from 2010, 2011 and 2012. Joint analysis of variance was performed for each group to determine the genotype contribution to the GEI. The genotypes were grouped into two classes: genotypes that interacted with the environment and genotypes with no interaction with the environment. An additional joint analysis of variance was performed for each class. Grouping genotypes into different classes provided valuable information concerning the dynamics of the GEI, which could enable plant breeders to maximize the efficiency of selection and offer recommendations for stable and widely adapted genotypes. The highest selective accuracy for the genotype effects was obtained for the joint analysis when the GEI was insignificant. The joint analysis of trials for wheat genotypes that interacted with the environment presented the highest selective accuracy for the GEI effect and a reduced selective accuracy for the genotype effect.