AMMI AND GGE BIPLOT ANALYSIS OF BREAD WHEAT GENOTYPES IN THE NORTHERN PART OF ETHIOPIA

The genotype environment interaction manipulates the selection criteria in a multipurpose crop like wheat. Ten bread wheat genotypes were evaluated at five wheat growing locations of Tigray region in the year 2011. Yield data was analyzed using the additive main effect and multiplication interaction model (AMMI) and GGE biplot. The AMMI analysis of variance for grain yield detected significant effects for genotype, location and genotype by location interaction. Location effect was responsible for the greatest part of the variation, followed by genotype and genotype by location interaction effects. Based on AMMI stability value, G4, G10, G8 and G9 were the most stable genotypes, while G1, G2, and G3 were the most responsive genotypes. The GGE biplot also showed G1, G2, G3, and G4 have long vectors and located far away from the biplot origin and hence are considered to have larger contribution to GEI (specifically adapted genotypes). G10 however is widely adapted genotype. The ‘which won where’ feature of the GGE biplot identified G4 as the winning genotype at Samre, Hagereselam, and Atsbi, while G1 winning at Quiha and Wukro. The GGE biplot also identified two bread wheat mega-environments. This indicates that analysis of multi-location trail data using GGE and AMMI model is important for determining visual comparisons, adaptability/stability focusing on overall performance to identify superior genotypes.