Abstract:
Wheat is one of the major cereal crops produced in Amhara Regional State. However, productivity of wheat in the region, particularly in Wollo is low due to various production constraints. Several improved bread wheat varieties were developed and released from federal and regional research centers. Information on genotype by environment (GE) interaction and yield stability of recently released bread wheat varieties under the conditions of Wollo were scanty. Hence, this experiment was carried-out with the objective of estimating the magnitude of GE interactions for grain yield and yield related traits and to determine the stability and adaptability of bread wheat genotypes. Twenty two bread wheat varieties were tested at six locations of eastern Amhara region. The experiment was laid-out using Randomized Complete Block (RCB) design with three replications. A mixed model (genotypes fixed while environments random) was used. Individual environment and combined analysis of variance were carried out using Genstat software 18th edition and Duncan’s Multiple Range Test (DMRT) were employed to separate means. Combined ANOVA for grain yield and yield related traits showed the presence of significant difference among genotypes, environments, and GxE interactions. Genotypes Mada-walabu, Danda’a, and Hidase out-smarted in grain yield, providing mean grain yield of 3.60, 3.56, and 3.55 t ha-1, respectively. Stability measures; coefficient of variability (Cvi), cultivar superiority measure (Pi), Shukla’s stability variance (2 i), Wricke’s ecovalence (Wi), regression coefficient (bi), deviation from regression (S2 di), mean absolute rank difference (S1 i), variance of ranks (S2 i), coeffecient of determination (ri 2), Addititive Main effect and Multiplicative Interaction (AMMI)model, AMMI stability value (ASV), and Genotype effect plus Genotype by Environment interaction (GGE) biplot were used. Mada-walabu considered as stable by Pi, S2 di, ri 2, S1 i and S2 i; Danda’a, and Hidase stable by Cvi, Pi, S2 di. Gasay and Tsehay were the most stable genotypes by 2 i, S2 di, S1 i, S2 i, Wi, ASV. Grain yield has strong positive correlation at p 0.01 with Pi (r = 0.88) and significant negative correlation with Wi, S2 di, 2 i, S1 i and S2 i. Perfect positive correlation was found between 2 i and Wi. AMMI-1select most adapted genotypes such as Danda’a, and Hidaes for Jamma and Mekelle-3 for Borena. Genotypes Tsehay, Gasay, Tay, Mekelle-4, Menze, and Shorima were suitable for all environments. AMMI-2 biplot showed Borena, Mekdela and Woreilu contributed large interaction effects while Kon, Geregera, and Jamma contributed small interaction effects.GGE biplot select Danda’a, Hidase, and Mekelle-4 for Geregera, Jamma, Woreilu, and Mekdela and Mekelle-3, kingbird, Huluuka, and Ogolcho for Kon and Borena. Gasay, Tsehay and Mada-wulabu genotypes were good for all environments. Genotypes Mekelle-4, Huluuka, Ogolcho, and Honkollo were affected by yellow rust disease at Kon and Digalu, Menze, Bolo, Gasay, and Sorra affected by stem rust at Borena,Mekdella, Jamma, and woreilu. Thus, due attention should be given while selecting bread wheat genotypes for the target environments.