Aim. Evaluation of promising collection samples of linseed for economically valuable and marker traits to identify the sources of these traits and their further use in the creation of new breeding material. Methods. Field, laboratory, measuring and weighing, mathematical and statistical. The research was conducted in 2019–2021 at the research fields of the Institute of Agriculture, located in the Fastiv district of the Kyiv region. Results. According to the results of the study and evaluation of 17 promising samples of oil flax of different ecological and geographical origin, the best genotypes were selected in the collection nursery for the main economic, valuable and marker characteristics. It was established that the majority of the collection samples belong to early ripening with a duration of the vegetation period of 85 days. The highest weight of 1000 seeds was found in varieties Evrika, Debut (8.74 and 8.44 g) and Vohni Dniprohesu (7.96 g). The maximum seed productivity was characterized by varieties Evrika (237 g/m2) and Legur (231 g/m2), which also had the largest number of seed pods per plant (17.1 pcs.). According to the total length of the stem, the samples were at the level of 41.8–63.3 cm, and according to the technical length of the fiber – 26.2–44.1 cm. The varieties Svitlozir and Aisberh, which have white flower color and pink and white, were characterized by contrasting marker features color of anthers, respectively. The varieties Debut (dark brown) and Svitlozir (yellow) differ in seed color. The average content of oil in the seeds for the entire sample of varieties was 47.7%. The highest oil content was determined for the Rucheek, Nebesny, Zaporizhzhya Bohatyr, and Vodohray samples (48.5–49.1%). According to the results of the analysis of the fatty acid composition of the flax samples, the best genotypes were selected based on the content of palmitic, stearic, oleic, linoleic, and linolenic acids. Conclusions. According to the results of the study, the best collection samples of oil flax were selected, which are sources of economically useful and marker traits: high seed productivity, increased oil content in seeds, early maturity, which will be involved in the hybridization program to create a new source breeding material with a given set of traits. Basic information on the economic and valuable characteristics of oilseed flax was obtained, which can be used in further scientific research.

Aim. Comparative assessment of new promising numbers of winter rape by a complex of economic and valuable traits in nurseries of the breeding process and selection of the best of them for further testing. Methods. In 2019–2021, in the nurseries of variety testing, an evaluation of the breeding material of winter rape of the breeding of the NSC “Institute of Agriculture of the NAAS” was carried out. Field studies were conducted on research fields of breeding and seed crop rotation, located in the Fastiv district of the Kyiv region. The main methods of research: measurement-weighing, analytical, calculation-comparative, mathematical-statistical. Analyzes to determine the biochemical composition of seeds were carried out by infrared spectroscopy and gas chromatography. Results. The breeding material was primarily analyzed for seed yield and oil content, as well as the content of erucic acid in oil, glucosinolates in meal, and protein content in seeds. The numbers were assessed for winter hardiness, plant height and weight of 1000 seeds. Based on the results of a three-year study, the best numbers were selected based on individual valuable indicators and a set of economically important features. In the competitive variety test in terms of seed yield, the best numbers were KSV 2/21, KSV 9/21, KSV 10/21, KSV 11/21 (up to 5.18 t/ha), which are relatively resistant to lodging and diseases and have oil 00 − of zero quality. KVS numbers 9/21 and KVS 2/21 are selected for the combination of high yield and high oil content (47.4 and 48.2%), for high oil content − KVS numbers 6/21 and KVS 3/21 (47.1 and 47.3%), protein − KVS 4/21, KVS 5/21 and KVS 6/21 (23.0 −24.0%). In the preliminary variety test, the numbers PSP 21/21, PSP 17/21 and PSP 19/21 (5.10−5.42 t/ha) were selected according to the highest yield, according to the set of characteristics (increased seed yield, oil content and yield) - numbers PSP 17/21, PSP 18/21, PSP 19/21 and PSP 21/21. Number PSP 15/21 is allocated for the increased content of oil (50.0%), and number PSP 14/21 – for the combination of increased content of oil (50.3%) and protein (24.0%). In the control nursery, in terms of seed yield, content, and oil yield, the numbers KS 30/21, KS 26/21, KS 33/21, KS 39/21, KS 28/21 were characterized by the best indicators, which provided a yield level from 2.82 to 5 ,18 t/ha and oil content 47.3−49.4%. The numbers KS 34/21, KS 31/21 and KS 50/21 (from 48.4% to 49.5%) were selected for the increased oil content, protein – KS 50/21, KS 30/21 (22.0%). Conclusions. Selected numbers are valuable sources and are involved in hybridization schemes to create new breeding material with a given set of traits. The best rapeseed numbers of the winter competitive variety test are promising for transfer to the Ukrainian Institute of Plant Varieties Examination for qualification examination.