Evaluation of grain yield stability of recombinant inbred lines in bread wheat (Triticum aestivum L.) based on AMMI method

The development of high yielding cultivars with wide adaptability is the ultimate aim of plant breeders. However, attaining this goal is made more complicated by genotype-environment interactions. The genotype by environment interaction is a major problem in the study of quantitative traits because it complicates the interpretation of genetic experiments and makes predictions difficult, also it reduces grain yield stability in different environments. Multi-environment trials are often analyzed to assess the yield stability of genotypes. Additive main effects and multiplicative interaction (AMMI) model proved to be a powerful tool in diagnosing genotype × environment interaction patterns. The AMMI statistical model has been widely used to explain complicate G×E interaction, to enhance selection efficiency and to ensure genetic gain from selection. The objective of this study was to investigate the response of the lines in studied locations and to identify lines adapted to the test environments.

Order to investigate response of wheat lines to different environmental conditions and determination of yield stability, this study was conducted by 76 recombinant inbred lines derived the cross between Roshan× Superhead based on randomized complete block design with two replications in five environments. The trials were performed at five locations in Kerman, Jopar, Mahan, Yazd and Ardakan. In order to evaluate the interaction and determine the stable lines, the stability analysis was done using AMMI methods. The data were subjected to statistical analysis using SAS and Excel software.

The results of the combined analysis of variance revealed significant differences of grain yield among lines, environment and also line× environment interaction (P<0.01). Since interaction of line × environment was significant, stability analysis was performed using AMMI analysis in order to more accurate evaluate and status of lines stability. The results of Ammi2 bi-plot showed that the least distance from the center of bi-plot with minimum interaction were identified lines 3, 33, 22, 9, 271, 36, 309, 200, 114, 11, 264, 320, 194, 20, 280, 1, 26, 250, 19, 18, 25, 5, 322, 169, 152, 161 and 32 as stable lines. Lines 258, 218, 176, 48, 82 and 314 for Yazd and line 225 for Ardakan indicated the best response and they had private adaptation to these places.

Overall, based on results of this experiment, among evaluated lines, were introduced lines 9, 3 and 22 based on AMMI1, AMMI2 and AMMI stability value (ASV) parameter as general stable lines. Therefore, the identified promising lines can be recommended to complementary studies for introduce to farmers.