Evaluation of Grain Yield Stability of Bread Wheat (Triticum aestivum L.) Promising Lines in Temperate Regions of Iran

In this study, adaptability and grain yield stability of 18 bread wheat promising lines and two commercial cultivars (Parsi and Baharan) were evaluated using randomized complete blocks design with three replications in 2015-17 cropping seasons in eight experimental stations; Karaj, Kermanshah, Zarghan, Broujerd and Mashhad (under normal irrigation), Neishabour, Isfahan and Varamin (cessation of irrigation at the 50% heading stage), Iran. Combined analysis of variance showed significant genotype × year × location and year × location interaction effects on grain yield. Due to the significant effects of these interactions, the grain yield stability of genotypes as well as genotypes × environments interaction effects were evaluated using non-parametric ranking statistic and AMMI multivariate stability analysis. Mean comparison of grain yield showed that promising lines 16, 12, 10 and 15 had the highest grain yield, respectively. Non-parametric ranking analysis showed that promising lines; 4, 12, 14, 15 and 16 with the lowest ranks and standard deviation of ranks had the highest grain yield stability, respectively. By using biplot graphic of the first two components of AMMI, genotypes 2, 4, 13 and 14 were identified as genotypes with high yield stability, respectively, which also had the least AMMI stability values. Considering grain yield and other agronomic characteristics, promising lines; 14, 15 and 16 that had high grain yield and yield stability and were selected for being released as new commercial cultivars in temperate regions of Iran.