Evaluation of Genotype × Environment Interaction and Grain Yield Stability of Advanced Bread Wheat Cross-bred lines by GGE Biplot Method

Investigation of the interaction of genotype × environment and identification of stable and high yielding cultivars in different environmental conditions is of great importance in plant breeding. The objectives of this study are to investigate the interaction of genotype × environment using GGE bilpot graphic method in advanced cross-breeding lines of bread wheat, to identify and introduce lines with high and stable economic performance.

In this study, the advanced stable yield of seven-line grain obtained from the reciprocal cross of bread wheat (BC2F6) in the form of a randomized complete block design with repetition in Tehran, Kermanshah and Gorgan and crop years (2017-18) and (2018-19) Was investigated. Each line was planted in plots with an eight-meter line at a distance of 25 centimeter. At the end of the season, the spikes were harvested and threshed manually from each plot, and the seeds obtained were measured by a digital scale and reported per square meter.

The results of combined analysis of variance showed a significant difference in the level of one percent probability for the effect of environment and the interaction of genotype × environment. No significant difference was observed for grain yield between the studied lines. According to the results of GGE Biplot, lines L4, L6 and L3 were the closest lines to the ideal line. Simultaneous evaluation of stability and grain yield of L4 and L6 lines identified stable high-yield lines. Examination of the polygonal diagram led to the identification of three large environments. The first large environment included E1 (Gorgan, 2017-18), E2 (Gorgan, 2018-19) and E4 (Tehran, 2018-19) environments, of which L2 was the top line of these environments and the second large environment included E6 environment (Kermanshah, 2018-19) It was that L4 and L6 lines were introduced as the top lines in these environments. The third large environment consisted of E3 (Tehran, 2017-18) and E5 (Kermanshah, 2017-18), where the L3 line showed private compatibility with the mentioned environments.

In general, based on the obtained results, L4 line is introduced as a stable line with high yield and is recommended to obtain the maximum cultivation yield of this line in the studied environments. L2 and L1 lines are introduced as the most unstable lines with the lowest performance and their cultivation is not recommended in any of the studied environments.