Selection value of winter rapeseed varieties by yield structure elements

Rapeseed has a significant potential for intraspecific genotypic variation in valuable economic traits. In recent years, significant changes and fluctuations in hydrothermal parameters over the years have significantly affected the manifestation of individual traits, and as a result, macro-traits, including yield. One of the tasks of breeding research in rapeseed is to select for productivity by combining simple quantitative traits - weight of 1000 seeds, number of seeds per pod, number of pods per plant, etc. Quantitative traits that determine the productivity and adaptability of rapeseed plants have not yet been sufficiently studied genetically, as the genetics of quantitative traits is currently practically disconnected from ontogenetics, environmental genetics and plant physiology. The negative critical factors include extreme environmental factors that affect plant development and growth, such as winter-frost periods, dry conditions during different critical growth periods, waterlogging during the period of crop formation and ripening. Evaluation of adaptability in plants of different rapeseed varieties allows to identify forms that show a wide range of responses to the components of macro-trait. An urgent task now is to study the breeding and genetic value and adaptability of the working collection of rapeseed varieties and to create new source material. In recent years, weather conditions in the Kyiv region have differed dramatically in several respects, which has had a sharp negative impact on plant productivity and generally reduced rapeseed yields. To study the response of genotypes to environmental conditions, they were evaluated for adaptability parameters. The study of the adaptive value of winter rape varietal populations was conducted in the experimental field of the Research Center of Bila Tserkva National Agrarian University. Key words: rape, variety, plant height, stability parameters, breeding value, correlation coefficient.