Ecological Plasticity of New Winter Wheat Varieties Under Environments of Ukrainian Forest-Steppe and Polissia

Abstract

The research was conducted to evaluate winter wheat varieties in terms of yield, stability and plasticity in different agro-ecological zones. Ten varieties of winter wheat were sown during 2015-16-2017-18 in two agro-ecological research zones: Forest-Steppe (the V. M. Remeslo Myronivka Institute of Wheat) and Polissia (Nosivka Plant Breeding and Experimental Station). Methods of descriptive statistics and analysis of variance were used for data statistical processing. For all three years during active plant vegetation the hydrothermal coefficient was 0.9-1.2 in the Forest-Steppe zone and in the Polissia zone it was 1.0-1.3. Winter wheat yield formation was negatively affected by the conditions of 2016-17 in the Forest-Steppe zone and 2017-18 in Polissia zone according to the relative environmental index (REI = 66 and 73, respectively). The analysis of hydrothermal conditions of different agro-climatic zones of winter wheat cultivation indicates on significant variation of the influence of these conditions on individual stages of plant development. This made it possible to identify varieties with high ecological plasticity which are able to respond less to fluctuations in environmental conditions. Using analysis of variance, it was found that winter wheat yielding capacity was significantly influenced by the factors "Zone" and "Year" (28.8, 22.9%, respectively), but theу most (36.4%) it was influenced by the interaction "Year × Zone", this indicates a significant difference in the impact of hydrothermal conditions on this trait depending on the agro-ecological zone of cultivation. It was established that the conditions of the Forest-Steppe zone were favorable for the maximum realization of yield potential of the variety Horlytsia myronivs'ka (8.35 t/ha), while the conditions of Polissia zone were favorable for the varieties MIP Dniprianka, MIP Valensiia, Hospodynia myronivs'ka, Estafeta myronivs'ka, Hratsiia myronivs'ka (9.42; 9.65; 9.62; 9.69; 9.66 t/ha, respectively). According to the regression coefficient, the varieties Trudivnytsia myronivs'ka, Horlytsia myronivs'ka, MIP Valensiia, MIP Kniazhna, Estafeta myronivs'ka (bi = 0.89; 0.89; 0.93; 0.95; 0.99, respectively) with the best adaptive ability to unvavourable growing conditions were identified. According to the stability variance of the trait, there were identified the most stable varieties, namely MIP Kniazhna, Trudivnytsia myronivs'ka, MIP Dniprianka, Vezha myronivs'ka, Hratsiia myronivs'ka (S 2 d i = 0.07; 0.09; 0.12; 0.17; 0.20, respectively) and the most unstable ones -Horlytsia myronivs'ka, Estafeta myronivs'ka, MIP Valensiia (S 2 d i = 1.33; 0.83; 0.68, respectively).