Evaluation of genotype × environment interaction using WAASB and WAASBY indices in multi-environment yield trials of rainfed lentil (Lens culinaris L.) genotypes

Combinining features of the best linear unbiased predictions (BLUP) and additive main effects and multiplicative interaction (AMMI) through “Weighted average of absolutescores of best linear unbiased predictions” (WAASB) index in multi-environment experiments may lead to more percise evaluation of genotypes and assessment of genotype × environment interaction. In the present study, the seed yield stability of 14 advanced lentil lines was evaluated in a multi-environment trials in four locations including; Gachsaran, Khorramabad, Moghan and Ilam, Iran in 2018-2019 and 2019-2020 cropping seasons. The experimental design was s randomized complete block design with three replications. Statistical analyzes were performed using multi-environment trials analysis. Considering the significant G×E interaction based on the results of the relative likelihood test (LRT), it was possible to perform BLUP analysis on the data. The highest predicted seed yield by BLUP method belonged to genotype no. 9 followed by genotypes no. 11, 10, 5, which had higher than average predicted seed yield. To enable simultaneous selection based on both seed yield and yield stability, by combining seed yield (Y) and WAASB, a new index “WAASBY” was created. Considering 50% contribution of each of the two components of seed yield and yield stability, eight genotypes showed above average WAASBY. Genoype no. 9 had considerably higher WAASBY when compared with other genotypes and was identified as the best genotype followed by genotypes no. 10, 1, 2, 12, 14, 7 and 13 were ranked respectively. Both control cultivars (genotypes 15 and 16) had lower than average WAASBY. In conclusion, considering WAASBY index, genotypes 9, 10, 1 were identified as genotypes with highe seed yield and yield stability, and can be considered for being released as new lentil cultivars.