Study on Adaptability and Grain Yield Stability of Soybean Genotypes [Glycine Max (L.) Merril] Through AMMI & GGE Biplot Analysis

Selection of desirable genotypes with high yield and stability is the main goal of most soybean breeding programs. The aim of this study was to evaluate the grain yield and stability of 19 pure soybean lines along with Williams’s control (20 genotypes) during two cropping years (2014-2015) in four regions: Karaj, Gorgan, Moghan and Shahrekord. A randomized complete block design with three replications was used in all experimental areas. The AMMI and GGE Biplot methods were used to determine the compatibility and stability of performance. Combined analysis of variance showed significant effects of environment, genotype, genotype × environment interaction, and components of IPCA1 and IPCA2 (AMMI analysis) at 1% level of significance. Genotype × environment interaction variance accounted for 42% of the total variance and the two components of IPCA1 and IPCA2 accounted for 81% of the total variance. Based on AMMI criteria (IPCA1, IPCA2 and ASV) genotype G17 (Williams x Steel / L3) with yield of  2449 kg ha-1 was determined as the most stable genotype while based on GGE biplot G18 (Williams x Steel/L4) with 2865 kg ha-1 and G20 (Williams/Check) with 2927 kg ha-1 yield  were identified as the most favorable genotypes. Also environments: E7 and E8 (first and second year Shahrekord) were selected as the most favorable environments and genotypes: G18 and G20 based on GGE biplot were also among the top four genotypes of the two environments. Two mega environments were identified in the bi-plot analysis that the first mega environment includes the E3 (Gorgan first year), E5 (Moghan first year) and E6 (moghan second year) and the second mega environment includes the E1 (Karaj first year) and E2 (karaj second year) and E4 (Gorgan second year).