Winter rye diploid varieties adaptive responses variability in ecological study

The purpose of the study is to determine the level of plasticity, stability and identify promising varieties of winter rye that are able to consistently obtain a high grain yield. The study was conducted in 2018-2021 on the experimental fields of the NPB Pushkin and Pavlovsk Laboratories of VIR. The material for the study was 16 varieties of winter diploid rye (Secale cereale L. var. vulgare Koern), including the standard variety Ilmen. The samples were sown with a selection seeder, at the rate of 400 germinating grains per 1 m2, in two repetitions at the optimal time for winter rye. Harvesting was carried out in the phase of full ripeness. Phenological observations, assessments and records were carried out in accordance with the VIR guidelines. Mathematical processing in order to identify significant differences was carried out by the method of analysis of variance. Adaptive response indicators were calculated: regression coefficient (bi), ecological plasticity index (O), multiplicativity coefficient (ai), intensity index (I), ecological plasticity index (I.E.P.), adaptability coefficient (K.A.), ecovalent (Wi), stability index (SI), stability index (Ϭd2), stability level index (Puss), relative ability index (St2), stability criterion (A), genotypic effect (Ԑi), coefficient of variation (V) for 16 varieties of winter rye (Secalecereale L. var. Vulgare Koern). Reliably high average yield was found in varieties: Talisman (k-11773) - 6.79 t/ha; Ophelia (k-11868) - 6.48; Lot (k-11865) - 5.91; Zilant (k-11875) - 5.86; Yaselda (k-11569) - 5.8; Zubrovka (k-11570) - 5.78 t/ha. The maximum yield was noted in the Ophelia variety - 10.3 t/ha in 2020. The most favorable cultivation conditions developed in 2020 and 2021 (ӯi = 7.63 and 7.29 t/ha, respectively). Using the distribution of varieties by ranking for all the above indicators, it was found that the most suitable for the use of highly productive varieties in the contrasting conditions of the North-West Region are rye varieties: Talisman (Ʃp.= 66); Ophelia (Ʃp. = 76); Era (Ʃp.= 89); Zilant (Ʃp.= 90); Lot (Ʃp. = 97); Irtysh (Ʃp. = 98).