Smykov A. Theoretical bases of selection and improvement of assortment of peach in South of Ukraine

The dissertation is devoted to theoretical bases of selection and improving methods for evaluation of the genefund, selection of sources and donors of economically important characteristics, experimental mutagenesis using physical and chemical mutagenes, modifying the mutagenic effect, breeding of new varieties of peach for industrial horticulture in Ukraine. Systematization of peach varieties in ecological and geographical groups and ecotypes allowed to compare them according to economically important characteristics and identify the frequency of occurrence in groups and ecotypes. The most effective combinations of varieties crosses belonged to different eco-geographical groups and ecotypes, the output of seeds and perspective seedlings has been shown. The features of inheritance of qualitative and quantitative sings in hybrid progeny of peach varieties and donor agronomic properties have been determined. The effective doses and periods of treatment by chemical mutagens for the forming vegetative buds of peach on the survival, morphological variability and affecting of plant by fungal diseases in nursery have been established. The influence of combined treatment of vegetative peach buds by gamma radiation, chemical mutagens, growth substances have been determined, and the optimal doses of their combination on the survival, morphological variability and affecting of plant by fungal diseases in nursery have been marked. Radiosensitivity of gamma-irradiated pollen and seeds of peach have been determined. Physiological, biochemical, anatomical and cytogenetic features of peach radiomutants, which give an opportunity to select promising forms on complex of valuable industrial characteristics for breeding and production have been revealed. 28 new peach varieties have been selected. Nine varieties among them have been registrated in State Service on Right Protection for Plant Varieties, nineteen varieties have been included in the Register of Plant Varieties of Ukraine and pat-ented. The majority of them concerns to the Iranian eco-geographical group (75%).