Genotype by Environment Interaction and Grain Yield Stability Analysis for Finger Millet (Eleusine coracana (L.) Gaertn) Genotypes from Western Oromia

Abstract

Crop yield is a complex trait influenced by a number of component characters along with the environment directly or indirectly. Genotype performance  depends on its genetic potential and the environment where it is grown. Genotypes by environment (GxE) interactions are generally considered to be  among the major factors limiting response to selection and the efficiency of breeding programs. Ten advanced finger millet genotypes and one standard  check were evaluated at Bako and Gute research center for three years (2013-2015) and at Bilo Boshe for one year (2014) with objectives of identifying  high yielding and stable genotypes. Analysis using additive main effect and multiplicative interaction (AMMI) model revealed highly significant (P≤0.01)  variations among environments, genotype and GxE interaction. This implied that the tested genotypes respond differently over environments as the test  environments are highly variable. Only the first IPCA-I was significant (p ≤0.01) and contributed 41.57% of the total genotype by environment interaction.  It is found that genotypes 214995 and BKFM0063 are high yielding and IPCA value closer to zero, an indicator of stable yield performance across years  and location. Analysis using Eberhart and Russell regression model showed that genotypes 214995, BKFM0063 and BKFM0052 were the most stable  candidates with better grain yield of 2.99, 2.70 and 2.53 ton ha^-1, regression coefficients of 0.9879, 1.22 and 0.9459 and reasonably acceptable deviation  from regression 0.0321, -0.01135 and 0.0607, respectively, further confirming that these genotypes are stable and widely adaptable. Genotype and  genotype by environment interaction biplot (GGE) also portrayed the stability of Acc. 214995. Overall, the AMMI, Regression and GGE Biplot revealed  similar results and both 214995 and BKFM0063 genotypes were proposed for possible release. Finally, 214995 was released and recommended for the  test environments and similar agro-ecologies of western Ethiopia based on farmers preferences, stable yield performance and disease tolerance across    locations.