BIOLOGICAL CHARACTERISTICS AND ECONOMIC VALUE TRAITS OF THE SIDERAL OILY FLAX VARIETY IN THE STEPPE CONDITIONS OF UKRAINE

Oil flax (Linum humile) is one of the valuable agricultural crops, the seeds and oil of which are used in the food, chemical, and pharmaceutical industries. Due to its unique chemical composition, linseed oil is used for the production of high-quality varnishes, paints and oils. In recent years, flax seeds and oil have been increasingly used in the food and confectionery industry. Oil flax is a highly profitable crop due to its high oil content (45-50 %) and potential yield (2-2.5 t/ha). The total cultivated area of linseed oil in Ukraine is about 70,000 hectares.The steppe zone of Ukraine is characterized by an insufficient amount of precipitation in the summer period, which makes it a risky territory for flax cultivation. Summer drought, characterized by excessive levels of solar radiation, lack of precipitation, dryness and high air temperature, contributes to excessive loss of water by plants and drying of soils. The consequences of the summer drought are a decrease in the quantity and quality of the harvest.Preservation of crop yields in dry summer conditions is possible due to sowing in the "February-March window". The use of varieties resistant to low temperatures will prevent crop losses due to earlier periods of flowering and fruiting. Therefore, the creation of cold- and winter-resistant varieties of this culture is an urgent and promising task of modern breeding. Sowing oil flax as a winter crop would allow the plants to develop a significant vegetative mass of the habitus and increase the number of stems on the plant, which would increase the yield.One of the potential highly effective genetic sources of winter hardiness of flax is the Italian variety Sideral. In the Italian regions of Tuscany and Bologna, as well as in the south of France, this variety is successfully grown as a winter variety. However, the winter period in these regions is milder: the average temperature in winter ranges from 2°С to 8°С, and at lower temperatures, snow cover appears in the north of Italy and the south of France.The purpose of our work was to study the biological features of plants and economically valuable traits of flax of the oil variety Sideral in comparison with the standard variety Southern Night for cultivation in arid climatic conditions of the southeast of Ukraine in order to involve it in breeding programs for the creation of wintering varieties of flax.In the course of the conducted research, it was established that the foreign selection variety Sideral is characterized by increased cold resistance in comparison with the Ukrainian standard variety Pivdenna Nich. It was found that the studied varieties had similar morphological features in terms of flower and seed color.It was established that the Sideral variety had a significantly higher leafiness, a lower height, a shorter root length and a larger number of lateral roots.The researched variety of Italian selection in the conditions of the Steppe of Ukraine had a growing season of 95 days, an oil content of 44.4 %, but produced a yield of 1.48 t/ha, which is lower than that of the standard variety.As a donor of cold resistance, the Sideral variety is included in the system of complex crossings to obtain valuable breeding material and create wintering flax varieties in the future.