Object: patterns of productivity, oil content and morphotype trait expression in lines, their combining ability, level of heterosis upon hybridization between unrelated lines. Objective: Determination of morpho-biological and breeding-genetic characteristics of accessions and identification of valuable for breeding lines - fertility restorer, development, on their basis, of high-yielding sunflower hybrids adapted to the conditions of the Forest-Steppe of Ukraine. Methods: field, laboratory, molecular-biological, mathematico-statistical and general scientific. Novelty: For the first time in the conditions of the Eastern Forest-Steppe of Ukraine, breeding-genetic peculiarities of a wide range of new sunflower lines were determined by a set of valuable economic and morphological traits. Genetic distances were determined, and new starting material, lines - sunflower pollen fertility restorers, was identified, which contributed to enrichment of breeding programs with valuable material for hybrid creation. The breeding of sunflower highly-heterosis hybrids was improved by utilizing identified male lines with new genetic basis in hybridization and determining their expression patterns of valuable economic characteristics with regard to the combining ability specificity and heterosis level. Results: To systematize selection of the best lines, molecular-biological methods based on PCR with determination of genetic distances were proposed along with traditional assessments of morphological traits, which increases the efficiency of use of lines in heterosis sunflower breeding. Five lines - pollen fertility restorers (Kh720V, Kh04112V, Kh06135V, Kh785V, Kh06134V) having advantages in breeding in terms of valuable economic features were selected and used in crosses. Five hybrids, 'Intehral', 'Klad', 'Bunchuk', 'Forsazh', and 'Atlet' were developed and submitted to the state variety trial. Hybrids Intehral', 'Klad' and 'Bunchuk' were entered in the State Register of Plant Varieties Suitable for Cultivation in Ukraine, the other two hybrids are being tested in the state variety trials. Degree of Implementation: Two lines - sunflower pollen fertility restorers, Kh06134V and Kh06135V, received certificates of the state registration of plant varieties in Ukraine. "Catalogue of lines - sunflower (Helianthus annuus L) pollen fertility restorers", which is used in research programs of the Plant Production Institute nd. a V.Ya. Yuryev NAAS and the Institute of Oil Crops NAAS as well as in training programs of VV Dokuchaev KhNAU, was created. Scope of Implementation: Scientific institutions of NAAS and the Ministry of Agrarian Policy and Food of Ukraine, higher educational establishments, agrarian enterprises of Ukraine.
