Genotype-Environment Interactions in Wheat in the IV and Vsouth Argentinean Subregions

Abstract

The objective of the present study was to evaluate the genotype X environment inter-action and its quantification by means of additive main effects and multiplicative interaction (AMMI) and joint linear regression analysis at the IV and Vsouth Argentinean wheat (Triticum aes-tivum L.) subregions. Grain yield data from 1992–1995 wheat regional trials network were ana-lyzed. The data were divided in early sowing date (late May - late June) and late one (during July to beginning of August). Nine genotypes and 50 environments (location by year combination) were evaluated at early sowing date and 8 genotypes and 44 environments were analyzed at late one. AMMI and Joint Linear regression analyses were employed. Regression heterogeneity was nonsignifiicant at neither of two sowing dates. This technique didn’t reveal the components of interaction. AMMI analysis, suggested the inclusion of the first three principal component analysis (PCA) for the early sowing date that accounted for 47.67, 29.41 and 12.24% of interaction sum of squares (SS), respectively, while two first PCA axes captured 44.20 and 21.33% of interaction SS, respectively, for the late one. The AMMI model retained 98.87% (early) and 96.64% (late) of the total SS. AMMI analysis proved to be a more efficient way of evaluating the GXE interactions than joint linear regression for the data set used here.