PROGRAM FOR INVESTIGATING GENOTYPE-ENVIRONMENT INTERACTION

This program was written to investigate genotype-environment (GE) interaction in two-way classification data. The analysis consists of three parts: (i) stability analysis of genotypes based on a regression or an ANOVA model, (ii) estimation and plotting of residuals, and (iii) cluster analysis for dissecting the data set into homogeneous subsets. These analyses provide diagnostic information to assess genotypic response characteristics and enable a scientist to group the genotypes in such a way that the genotypes within each subset display no GE interactions. It is hoped that by dissecting the data into homogeneous subsets the interaction structure of the data can be revealed. The program can handle five methods depending on whether a regression (linear or quadratic) or an ANOVA model is used, and whether grouping is done with respect to the similarity of GE interaction alone or the genetic effect and GE interaction combined.