graphical analysis of multi-environment trials for barley yield using ammi and gge-biplot under rain-fed conditions

the ammi and sreg gge   are among the models that effectively capture the additive and multiplicative components of genotype × environment interaction (gei) and provide meaningful interpretation of multi-environment trials’ data set in the breeding programs. the objective of this study was to assess the effect of gei on grain yield of barely advanced lines and exploit the positive gei effect using ammi and sreg gge biplot analysis. therefore, 18 lines were evaluated at four research stations (gorgan, mogan, lorestan and gachsaran) of dryland agricultural research institute (dari), located in the semi-warm regions in iran, in 2004, 2005 and 2006 cropping seasons under rain-fed conditions. analysis of variance showed that grain yield variation due to environments, genotypes and gei were highly significant (p