This study was conducted in 2019–2022 in Samara oblast and aimed to evaluate the adaptive potential of promising oilseed flax lines in order to identify the best genotypes under the conditions of the Middle Volga region. The objects of the research included seven promising oilseed flax lines undergoing competitive variety testing. The Kinelsky 2000 variety was selected as the standard. The soil of the experimental plot was typical medium-humus, medium-deep, medium-clayey chernozem with a humus content of 5. 8–6. 9%, mobile phosphorus content (according to Chirikov) of 133. 6–156. 5 mg/kg, exchangeable potassium content (according to Maslova) of 154. 0–180. 0 mg/kg, and pHsol value of 4. 5 units. Weather conditions during the growing season were predominantly very dry to moderately dry, with hydrothermal coefficients (HTC) of 0. 41–0. 56 for the May–August period, except for 2022 with the HTC of 0. 91. The highest seed yield was obtained from the lines Kin × Wal/2011k/s, L-4764, L-4910, and L-7309/14-9, averaging 1. 71–1. 94 t/ha and exceeding the standard by 11. 8–26. 8%. The intensive-type line L-7309/14-9 (bi = 1, 36, ₃^2 = 0. 001) (identified according to the technique by S. A. Eberhart and W. A. Russel) was characterized by high ecological plasticity and yield stability and exceeded the standard by 26. 8% over four years. The highest stress resistance (according to A. A. Rassielle and J. Hemblin) was observed in the L-619223 line (Ymin – Ymax = –0. 90). High compensatory capacity ( (Ymln – Ymax) /2 = 1. 83–1. 94) has been recorded for the Kin × Wal/2011k/s, L-4764, and L-7309/14-9 lines. KinkhLiin/2010zh/s and L-619223 have proven to be the best lines in terms of homeostaticity (according to V. V. Khangil’din) in combination with stable productivity (Hom = 5. 96–6. 90% and V = 26. 2–27. 2%, respectively). L-619223, L-4764, and L-4910 have been classified as genotypes with high selection value (Sc = 0. 92–0. 95). An integrated assessment has identified L-4764, L-619223, and L-7309/14-9 lines as the most promising genotypes, combining high productivity with environmental adaptability, ecological plasticity, and stability under the conditions of the Middle Volga region.
Kazarina et al. (Sun,) studied this question.