Genotype × environment interaction and parametric stability of grain yield in durum wheat (Triticum durum Desf.) under contrasting agroecological conditions

The aim of this study was to evaluate grain yield, ecological plasticity, and stability of ten durum wheat (Triticum durum Desf.) cultivars in multi-environment trials in terms of their suitability for dissemination under the conditions of the Western region of Ukraine. Field experiments were conducted over two growing seasons (2023-2024 and 2024-2025) at three agroecologically distinct locations, which in combination with years constituted six environments. Grain yield data were analyzed using combined analysis of variance and parametric stability approaches, including the Eberhart-Russell regression model and a set of nine stability parameters. The ANOVA results revealed a predominant contribution of the genotype effect to grain yield formation (over 90% of the total variation), while the effects of environment and genotype × environment interaction were statistically significant but comparatively smaller. Analysis of the G × E structure indicated the dominance of a linear, predictable component, suggesting that cultivar responses to changing growing conditions can be adequately described using regression coefficients. The cultivars differed markedly in their levels of plasticity and stability: high-yielding genotypes exhibited specific adaptation to favorable environments, whereas more stable cultivars produced moderate yield levels. The obtained results confirm the relevance of an integrated assessment of durum wheat cultivars that combines yield performance, stability, and plasticity as a scientifically sound basis for cultivar recommendation under conditions of increasing climatic variability