Genotype x environment interaction implication: A case study of durum wheat breeding in Iran

Abstract

The genotype x environment (GE) interaction is a major challenge to plant breeders as it complicates testing and selection of superior genotypes and consequently reduces gains from selection. This chapter introduces and compares different statistical models to handle GE interaction by applying them to the durum wheat breeding program in Iran as an example. The results indicate significant crossover GE interaction suggesting the need for applying appropriate analysis for the exploitation and/or the minimization of GE interaction in multi-environment trials (MET) data. The test locations differed in their discriminative ability and representativeness. Highly significant correlations were found between univariate and multivariate statistical models in ranking genotypes for stability and for integrating yield with stability performances, indicating that they can be used interchangeably. Evaluation of genotypes based on multiple traits data identified parental germplasm for earliness, short stature, high grain weight and high grain yield. The proposed statistical analysis can assist in increasing the efficiency of breeding program through (a) selection of the most discriminate locations, (b) identifying superior genotypes based on both strategies dealing with exploitation and minimization of GE interaction and (c) exploring significant genetic gains in yield and yield stability.