Object: Restoring ability of fertility restorers, influence of abiotic factors on pollen-forming ability, winter rye pollen viability and parameters of quantity and technological properties of winter rye hybrid grain, heredity patterns of economically valuable traits in winter rye hybrids. Objective: To determine the breeding value of lines - winter rye fertility restorers and varieties-populations, to establish heredity patterns of economically valuable traits, to create starting material - lines - fertility restorers with a set of valuable traits for heterosis winter rye breeding - based on P-type CMS and to compare the restoring ability of lines - fertility restorers and varieties - populations. Methods: field, measuring and weighing, technological, cytological, statistical and general scientific. Novelty: For the first time in the conditions of Ukraine, peculiarities of new accessions - fertility restorers for P-type sterility sources were established in terms of restoring, combining, pollen-forming abilities, pollen viability and fertility; the breeding value was estimated, and fertility restorers were characterized by valuable traits; evaluation criteria of fertility restorers were regularized for use in breeding for heterosis; sources with a set of valuable traits were identified; the possibility of usage of simple highly heterotic hybrids in production, provided proper selection of parents on the basis of preliminary assessments of combining, pollen-forming and restoring abilities was proven. Results: Accessions with 100% restoring ability were distinguished. Three lines with a set of valuable traits, which are recommended for the creation of novel starting material in the breeding of highly heterotic hybrids were identified. A source of increased winter hardiness of 9 points was found and recommended for use in breeding for winter hardiness. Two lines with high GCA, regardless of weather conditions, which are recommended for use in the breeding of highly heterotic hybrids, were revealed. Three lines with high GCA in dry weather conditions, which are recommended to be used in breeding programs to create drought-tolerant hybrids, were identified. F1 hybrid 'Neptun', which was submitted to the state variety trial in 2015, was evolved from line l. 063491 V. Degree of Implementation: The research results are used in breeding programs and winter rye seed production, in particular in the Plant Production Institute nd. a VYa Yuryev NAAS, Verkhniachka Research-Breeding Station of the Institute of Bioenergy Crops and Sugar Beet NAAS. Two registration certificates for the winter rye gene pool accessions in Ukraine were received on the basis of these results. Scope of Implementation: Scientific institutions of NAAS and the Ministry of Agrarian Policy and Food of Ukraine, higher educational establishments, agrarian enterprises of Ukraine.
