Evaluation of Seed Yield Stability of Faba Bean (Vicia faba L.) Genotypes Using GGE Biplot Analysis

To investigate adoptability and pattern of G × E interaction, 15 faba bean lines as well as four check cultivars (including Barekat, Saraziri, Baloochi and Zereshki) were evaluated using a randomized complete block design with three replications in four agricultural research field stations of Gorgan, Dezful, Brojerd and , Iranshahr, Iran during two cropping seasons (2015-2016 and 2016-2017). Combined analysis of variance showed significant effects of location, year, year × location interaction, genotype × location interaction, genotype × year interaction and year × location × genotype interaction on grain yield. Stability in performance of the 19 genotypes was tested using GGE-Biplot approach across eight environments. GGE- Biplot analysis using a genotype × environment interaction (GEI) model explained 91.5% of total interaction effect variance. View of polygon graph revealed three superior mega-environments and the compatible genotypes were determined for each mega-environment; Gorgan (Line G15), Brojerd-Iranshahr (Line G3) and Iranshahr (Line G19). Lines G15, G7 and G13 with average seed yield of 3439, 3128 and 3094 kg ha-1, respectively, had higher seed yield and yield stability. Based on GEI and GGE- Biplot analysis, Gorgan and Brojerd experimental environments had good differentiation ability. Finally, genotypes G12, G14 and G15 were the most stable genotypes with wider adaptation to all the tested environments and can be recommended as the superior genotypes for being released as new commercial faba bean cultivars.