Bayura A. European ash (Fraxinus exselsior L.) and its forms: bioecology, reproduction and use in the Right-Bank Forest-Steppe of Ukraine

The dissertation is devoted to the study of biological and ecological peculiarities means of reproduction F. excelsior and its ornamental forms: F. excelsior 'Albo-variegata' Hayne, F. excelsior 'Aurea' Persoon, F. excelsior 'Crispa' Willdenow, F. excelsior 'Monophylla Pendula' Aiton, F. excelsior 'Pendula' Boom and their use in the Right-Bank Forest-Steppe of Ukraine. Systematics and phylogeny of the genus Fraxinus L. are analyzed; natural area of F. excelsior distribution and its form diversity are generalized. In the course of studying it was defined the beginning and the end of major phases of growth and development of F. excelsior and its ornamental forms. It was determined the duration and dynamics of growth of annual shoots, growing season length. It was found that the rhythmic of ornamental forms vegetation corresponds to climatic rhythm of Forest-Steppes of Ukraine and is an indicator of high adaptability to the conditions in the region.The features of the seasonal rhythms of growth and development of F. excelsior and its ornamental forms, their winter resistance and drought resistance, related to soil acidity and light sensitivity, peculiarities of flowering and fruiting in the Right-Bank Forest-Steppe of Ukraine are synthesized. It is found that F. excelsior and its ornamental forms are winter-hardy and drought tolerant. According to its intelligibility to light F. excelsior belongs to heliophyte. The study processes means of seed, microclonal in vitro propagation of F. excelsior and vegetative propagation and its ornamental forms. Ornamentality of F. excelsior and its forms are estimated. It proposes peculiarities of the studied plants usage and provides options for using them in the creation of landscape compositions in Right-Bank Forest-Steppe of Ukraine.