Graphical analysis of grain yield stability for selection of suprior barley (Hordeum vulgare L.) promising lines in temperate regions of Iran

Quantifying genotype × environment interaction effect and yield stability under different environmental conditions is very important challenge in plant breeding programs. The aim of this study was to quantify genotype × environment interaction effect on grain yield and grain yield stability of barley promising lines in temperate regions of Iran. Nineteen promising barley lines (G1-G19) along with one check cultivar (Behrokh), were evaluated at eight agricultural research stations (Karaj, Varamin, Birjand, Neishabour, Mashhad, Zarghan, Isfahan and Yazd) in 2016-17 and 2017-18 cropping cycles. The experimental design at all locations was randomized complete block with three replications. Combined analysis of variance and grain yield stability and compatibility analysis performed using GGE biplot method. The results of GGE biplot showed that the first component and second component explained 30.16% and 28.22% (overall 58.38%) of the total variation, respectively. The average grain yield of barley promising lines in all field stations varied from 5208 to 5870 kg.ha-1. In GGE biplot polygon, superior genotypes were identified in each mega environment. Among environments, Karaj could be considered as the closest environment to the ideal environment. Comparison of barley promising lines with ideal genotype identified G7 as the closest genotype to ideal genotype. Also the closest genotypes to G7 were G5, G13, G20 and G4. These barley promising lines had high grain yield, wide adaptation and grain yield stability in temperate regions of Iran. Among these genotypes, promising line(s) that maintained high grain yield and desirable agronomic characteristics compared to control cultivar can be selected as candidate line(s) for further verification in on-farm trials, and if proved superior for being released as commercial cultivars.