Object: Determination of variability of quantitative and qualitative characteristics in M1 and M2, manifestation of mutational variability of valuable traits in M2 and its inheritance in mutant families and selection, on this basis, of new forms as starting material for sunflower breeding. Objective: Study of variability of a set of useful quantitative and qualitative economic features in mutant sunflower generations under the influence of dimethyl sulfate (DMS) and gamma-rays and of the effectiveness of induced mutagenesis to create starting material, generation of valuable new forms on this basis. Methods: general scientific, field, biochemical, cytogenetic, statistical. Novelty: For the first time, on the basis of new homozygous self-pollen lines of sunflower peculiarities of variability of quantitative and qualitative characteristics under the influence of dimethyl sulfate and gamma-rays were established in mutant generations. It was found that gamma-rays, in comparison with DMS treatment, resulted in a greater number of cells with meiosis distortions and a greater number of changes in M1 and M2 at early stages of sunflower plant development. Negative mutagenic effect of gamma-rays on the field germinability of M1 seeds in comparison with DMS action was shown. Specific features of generating mutants with marker traits - increased contents of unsaturated fatty acids were established. Individual genotypic responses of new homozygous self-pollinated sunflower lines to the frequency and range of mutations in M2 were determined. Results: New forms with altered quantitative and qualitative characteristics were identified as valuable starting material for breeding: with increased content of oil in seeds, increased 1000-seed weight, increased contents of behenic, linoleic and palmitoleic acids, absolute resistance to downy mildew, marker traits of "lemon ray flowers, "Virescent", "Xantha" ("golden top"), crimson shade of leaves, and with altered morphological features of "polyphylly" and "dwarfism". It was demonstrated that 0.01% DNS was effective for the induction of sunflower mutants with absolute resistance to downy mildew. The expediency of using homozygous self-pollinated lines for the effective production of mutants with altered parameters of useful economic features, which are necessary for expanding the diversity of starting material in heterosis sunflower breeding, was justified. Degree of Implementation: Mutant lines derived from of new self-pollinated sunflower lines were transferred to the Center of Genetic Resources of Ukraine; they are used in research programs of breeding institutions of Ukraine. The dissertation results became a basis for the manual "Induced Mutagenesis in Sunflower Breeding." Scope of Implementation: research institutions of NAAS and the Ministry of Agrarian Policy and Food of Ukraine, higher educational establishments, agrarian enterprises of Ukraine.
