Genotype by environment interaction for agro-morphological traits and herbage nutritive values and fodder yield stability in oat (Avena sativa L.) using AMMI analysis in Ethiopia

Abstract

This study aimed to evaluate the genotype by environment interaction for agro-morphological traits and fodder nutritive values of oat (Avena sativa L.) genotypes under diverse environmental conditions and to identify high fodder yielding and consistently performing genotypes in Ethiopia. Oat genotypes usually demonstrate inconsistent performance in different environments due to variations in growing environments and the existence of significant genotype by environment interaction complicates the selection process. Therefore, the genotype by environment interaction study was executed using the additive main effects and multiplicative interactions model to select superior and stable genotypes. The effects of genotype by environment interaction on fodder yield stability in twenty-four oat genotypes were investigated in nine environments using a randomized complete block design. The additive main effects and multiplicative interaction analysis of variance for fodder yield showed significant variation for genotype, environment, and genotype by environment interaction effects and the highest contributor for the total variation was the environment (67.45 %) main effect followed by genotype by environment interaction (22.73 %) and the genotype (9.82 %). The first (44.11 %) and the second (26.79 %) interaction principal component axes were significant and cumulatively accounted for 70.91 % of the total interaction variance. Based on the first two additive main effects and multiplicative interaction analyses, E6, E4, and E2 were located far from the biplot origin and had a high contribution to the total variation of genotype by environment interaction. The fodder yield of the genotypes G6, G10, G23, G7, G9, G18, G13, G1, G24, G15, G2, G3, G19, G4, and G11 were above the grand mean. The fodder yield stability result obtained from the second additive main effects and multiplicative interaction is usually more accurate compared to the first additive main effects and multiplicative interaction. Consequently, genotypes which had mean fodder yield above the grand mean and relatively stable performance were observed for G23, G6, G10, G7, G11, G1, G9, G15, G2, G3, G4, and G19. However, G2, G3, G4, G11, and G19 have released varieties while the remaining genotypes have not been yet released. Therefore, G6, G10, G23, G7, and G9 were selected for verification and cultivation of these selected genotypes would contribute more for oat fodder yield improvement programs in Ethiopia.