The study was aimed to compare the ecological plasticity and stability of spring oat lines using the thousand-grain weight (TGW) index in order to identify genotypes adapted to the conditions of the Volga–Vyatka region. Experiments were carried out in 2022–2024 in Kirov oblast using eight lines of hulled spring oat; they were organized as a competitive variety trial with four replications. The experimental site was characterized by cultivated sod–podzolic medium loamy soil. An excessive moisture was observed in 2022 (hydrothermal coefficient (HTC) = 2.00); in 2023, the plant growth conditions were optimal (HTC = 1.64); in 2024, a moisture deficit was observed (HTC = 1.10). Ecological adaptability parameters were calculated using the methods proposed by S.A. Eberhart and B.A. Russell (bi, σd2), R.A. Udachin (I, R), A.A. Gryaznov (environmental plasticity index, EPI), and E.D. Nettevich (cultivar stability level, CSL; linearity coefficient, L). According to the results of a two-factor analysis of variance, TGW was significantly affected by weather conditions (58.9%), genotype–environment interactions (28.1%), and the genotype of the studied lines (13.0%). Favorable conditions for the formation of high TGW index were observed in 2024 (environmental index = 1.77); the maximum value of this index (47.1 g) was recorded for line 41h18. Based on the TGW coefficient of variation, the studied oat lines were classified as weakly variable (CV < 10%), with the exception of the lines 40h20 (CV = 12.74%) and 41h18 (CV = 10.46%). The line 40h20 ranked first for three ecological adaptability parameters (bi = 2.06; I = 26.4%; EPI = 1.04); however, it did not demonstrate high performance in relation to parameters characterizing genotype stability (R = 48.5; L = 3.35; CSL = 143.3). The promising line 91h18 exhibited the highest total level of adaptability to the conditions of Kirov oblast (sum of ranks = 22).
Emeleva et al. (Sun,) studied this question.