Korotchenko V. Biological peculiarities of species of genus Helleborus L. (Ranunculaceae) in connection with introduction to lowland part of the Forest zone of Ukraine.

The thesis is devoted to complex research of biological peculiarities of re-lict species of flora of western regions of Ukraine of Helleborus purpurascens Waldst. et Kit., introduced in plain part of the Forest area of Ukraine and H. hybridus during cultivation. As a result of the work the peculiarities of geo-graphical distribution and ecologo-coenotical differentiation of H. purpuras-cens in Ukraine are determined. The features of the actual state of populations, age-old structure and motion of ontogenesis are investigated. The tendencies of change of parameters of H. purpurascens and H. hybridus: seasonal development, terms of motion of phenophasis, seminal and using material productivity, ontogenetic and population changeability during the cultivation are exposed. Content of mineral elements and boufadienolids is explored. The measures on the future of protection of H. purpurascens in a natural flora are proposed. Possibility of introduction of the investigated species for the pers-pective use in medical practice is led. Practical recommendations for the agrotechnic of culture are developed.