Evaluation of collective samples of winter rapes for ecological plasticity and stability

Creation of high-yielding «00» varieties of winter rape, adapted to the conditions of the Forest-Steppe is one of the important problems in rape breeding. The aim of the study is to assess the ecological adaptability of collection samples of winter rapeseed by seed productivity (yield, weight of 1000 seeds), taking into account the specifics of the growing area and the instability of climatic conditions in the autumn-spring period. Collective samples of winter rape in the amount of 27 varieties of domestic and Ukrainian selection were used for research. Research methods: field and laboratory, mathematical and statistical. The results of the assessment of ecological adaptability of winter rapeseed collection samples of different ecological and geographical origin are given. The average yield of winter rape for the years of research ranged from 1.81 to 2.37 t/ha. The range of fluctuations of the coefficient of plasticity (bi) varied in the studied samples from 3.58 to 5.95. Of the 27 studied samples, the values of the regression coefficient (bi) had more than one variety: Bazhanyy (bi = 1.17), Amor (bi = 1.15), NPC 9800 (bi = 1.15), Atlant (bi = 1.11), Dema (bi = 1.11), Svitoch (bi = 1.08), Cheremosh (bi = 1.08), Antariya (bi = 1.06), Ranok Podillya (bi = 1.04). As a result of research it was found that the average weight of 1000 seeds of collection samples of winter rapeseed ranged from 3.73 to 4.73 g. The value of the stability variance (Si2) of the mass of 1000 seeds varied from 14.69 to 23.84), indicate that the empirical values differ from the theoretical ones. The lowest values of stability variance were obtained in the samples of Cheremosh and Dembo - (Si2) = 14.69 and 15.50 with a mass of 1000 seeds of 3.73 and 3.81 g. According to the results of four-year data, collection samples were selected, which showed stable indicators in terms of yield and are the most promising: Sveta (2,37 t/ha), Horyzont (2,36 t/ha), Elvys (2,32 t/ha), Halytskyi (2,27 t/ha). The study of the sign of the mass of 1000 seeds showed that the most stable indicator was found in varieties: Antariya, Vektra, Ranok Podillya, Votan, Demarka, Horyzont, Halytskyi. The obtained results can be used in further selection work to create competitive varieties with a high level of yield and stable manifestation of these characteristics.