Genotype x environment interaction and yield stability of bread wheat(Triticum aestivum L.) Genotypes in southeastern Ethiopia

Abstract

The significant G x E interaction has been a challenge to bread wheat breeders as this interaction limits accuracy of yield estimate, identification of stable genotypes and further complicate selection of genotypes. The objective of the study was to quantify the magnitude of genotype by environment interaction and stability in yield and yield related traits and identify appropriate genotypes for the test environments. Twenty bread wheat genotypes and two checks were evaluated at six test locations of South Eastern Ethiopia 2013/1014 during main growing season in a randomized complete block design with four replications.The combined analysis of variance showed significant differences (P< 0.01) for the genotypes, locations and genotype by location interaction for traits studied. Non-significant differences (P< 0.05) among genotypes were observed for the response variables, 1000 kernel weight and hectoliter weight.AMMI is used to partition the G x E SS in the combined anova table in to its PCAs. Accordingly, the first and second IPCAs share 60.77% and 15.70% of the G x E SS captures 20.68 %.The AMMI model clearly indicate the genotype by environment interaction by partitioning into three significant component taking 89.7% of genotype by environment variation 20.68% of the variation in the genotype by environment interaction. According to the Stability analysis of the additive main effect and multiplicative interaction, biplotanalysis ranking the genotype Digelu and ETBW6738 were the most stable coupled with higher grain yield where as the genotypes Danda’aandETBW6732were unstable with lower mean yield.Based on the AMMI, environments were highly variable both for main and interaction effects. Bokoji, Asassa,Sinana,Kulumsa and Holeta were a favorable environments; whereas Areka as low yielding (unfavorable) environments for majority of the traits. In general, the results of the analysis showed that bread wheat is highly sensitive to environmental changes and this necessitates screening of cultivars for wide and specific adaptation. Based on the one year data the varietyDigelu were stable accompanied with higher yield, but in order to recommended appropriate genotypes to the south Eastern Ethiopia repeating the experiment is vital..