SEASONAL VARIABLITY AND GENETIC RESPONSE OF ELLITE BREAD WHEAT LINES IN DROUGHT PRONE ENVIRONMENTS OF ETHIOPIA

Abstract

Development and deployment of wheat varieties having desirable traits for drought prone wheat growing environments of Ethiopia, where unpredictable climate variability across seasons and locations is the predominant challenge, is the priority tasks of breeders. Hence, this study was aimed to evaluate the performance of 12 bread wheat genotypes across 14 environments and; assess the nature and magnitude of genotype by environment interaction (GEI) in moisture-limited environments. The field trial was conducted in a Randomized Complete Block Design with 4 replications in 2011 and 2012. Stability and GEI analysis were done using Additive Main effect and Multiplicative Interactive (AMMI) model. AMMI analysis of grain yield data revealed highly significant (p < 0.001) variation among tested genotypes, environments and GEI; and accounted for 2.9%, 80.8%, and 16.3 % of the observed significant variation in grain yield, respectively. Besides, 64% of the interaction pattern was explained by the first two principal component axes. The AMMI biplots revealed genotype ETBW6095 (G6) is the most stable and well adapted for commercial cultivation across moisture limited environments. This genotype out yielded the average of the checks by 9 %. In summary, the existence of inconsistent performance of genotypes due to temporal and spatial variability clearly confirmed the necessity of multi-environmental trials. Use of AMMI potentially enabled identification of sub-regions and selection of best genotypes for wide and specific adaptation while conducting METs.