Parametric stability analyses for grain yield of durum wheat

Abstract

Grain yield of 15 durum wheat (Triticum durum Desf.) genotypes consisting of 13 cultivars and 2 advanced lines, tested in a randomized complete block design with four replications across 8 environments of Central Anatolian Region of Turkey was analyzed using nine parametric stability measures. The objectives were to assess genotype-environment interactions (GEI), determine stable genotypes, and compare mean grain yield with the parametric stability parameters. To quantify yield stability, nine stability statistics were calculated (b_i, S²_di, R_i², W _i², σ_i², S²_i, α_i and λ_i). Yilmaz-98, Cakmak-79, Kiziltan-91, Selcuklu-97 and C-1252 were more stable cultivars, which had 9, 8, 6, 6, 6 out of all 9 stability statistics used, respectively. Especially, among these cultivars, Yilmaz-98 and Cakmak-79 were the most stable cultivars. Furthermore, three-dimensional plots of mean response versus each stability statistic were shown to visually evaluate the yield potential and stability estimates of the genotypes. Genotype mean yield (–x) was significantly positively correlated to the regression coefficient (b_i), environmental variance and genotype to the environmental effects (α_i), indicating that high grain yielding genotypes had larger values b_i, S²_i, and α_i, S²_i, W _i², CV_i, α_i and b_i, were significantly correlated, indicating that they measured similar aspects of stability