Adaptive properties and ecological plasticity of promising lines of spring soft wheat in the conditions of the Central Non-Black Earth Regions of Russia

In the conditions of the Ryazan region, adaptive properties and ecological plasticity of 8 breeding lines of spring soft wheat (standard Agatha variety) were studied in 2020–2023 according to the "yield" trait using diverse statistical methods. Ecological plasticity (b i ), stability (σ 2 d ), index of environmental conditions (I j ) were determined by S. A. Eberhart, W. A. Russell, variation – by B. A. Dospekhov, stress resistance and genetic flexibility – by A. A. Rossielle, J. Hemblin, index of ecological plasticity – by A. A. Gryaznov, indicator the level of the variety yield stability – according to E. D. Nettevich, homeostaticity (H om ), breeding value (Sc) – according to V. V. Hangildin, relative stability, stability criterion – according to N. A. Sobolev, multiplicativity (KM) – according to V. A. Dragavtsev. It has been established that the yield level is mostly influenced by the factor "environment" – 51.5 %, the contribution of the factor "genotype" is 11.5 %. The average yield in the experiment was 5.19 t/ha, favorable conditions in 2022 (I j = 0.50) allowed the yield to be 17.9 % higher than in 2021 (I j = -0.52). Lines 2-17 (6.24 t/ha) and 21-17 (6.05 t/ha) had high yields, their genetic flexibility index was 5.58 and 5.41 t/ha, respectively. Lines 1-17, 465-17 and 531-17 had the highest resistance to stress (-0.63, -1.00), they are characterized by high yield stability (σ 2 d = 0.27–0.65) and the least decrease in it under adverse conditions. Strong responsiveness to changes in environmental conditions was noted for lines 290-17, 2-17 and 21-17: b i – 1.25–1.29, KM – 2.22–2.27. According to the degree of homeostaticity, line 1-17 was distinguished (Sc – 4.63, PUSS – 212, H om – 18.3), these indicators exceeded the average values by 10.2 %, 81.0 abs. %, 98.9 %, respectively. According to the results of the integrated assessment by the ranking method, breeding lines 1-17; 465-17 and 21-17 showed varying degrees of adaptability, environmental stability, homeostaticity and had a high rating. The lowest rating in terms of the sum of the ranks of adaptability and plasticity parameters was obtained by the standard Agate variety.