INCREASE OF SELECTION EFFICIENCY OF FLAX INITIAL MATERIAL IN PRIMARY SEED PRODUCTION

The studies were carried out on the basis of the laboratory of breeding technologies of the Federal State Budgetary Scientific Institution "Federal Scientific Center of Bast Crops" (Tver region) in 2019-2021. The purpose of the research is to study selection effectiveness of fiber flax plants for a new trait - height at various seeding amounts in the selection nursery. It was established that initial testing with subsequent removal of plants that were not included in the interval of typical height (± 10% of the average value) allowed to ensure a higher uniformity of typical plants in terms of fiber content compared to the control in the stalk, when sowing 200 viable seeds per meter of row in the selection nursery, the highest yield of renewed seed material (91.8 g/m²), it also allowed to reduce labor costs. Studies showed that selection of fiber flax plants by height provided an increase of seeding energy in case of sowing of 150 and 200 viable seeds by 14-15%, seed strength by 20.8-27.3%, and 1 cm of seed germination by 7.0 - 21.4% compared with the control variant. However, the studied methods of plant selection did not affect mass formation of 1000 seeds. According to soil control data, when testing plants for a new trait, their high uniformity was achieved in terms of the main varietal trait - fiber content in the stem, which was characterized by variation coefficient at a level of 3.0-3.5% with 3.0-3.1% in control. A good evenness of plants was also revealed by another varietal trait - height. Variation coefficient for this trait was 4.3-5.5%. The effectiveness of selection method of fiber flax plants by a new trait-height is confirmed by the results of its verification. When checking the method, the cost reduction for work performance on selection and testing of plants by height amounted to 27% compared to the control.