Ptitsa V. Biological grounds of rarity plant species of conservation ex situ in the south-east of Ukraine

The thesis is devoted to investigation of the rarity plant species conservation ex situ on the base of study their biological peculiarities and present-day state of populatoins as well as on the base of using of the introduction experience of the given species. On the base of researtch results it has been revealed that the most effective method of forming reintroductional populations of the studied species is planting. The plants can be grown either under introduction condition or they can be taken from the full-valued natural population of the given species without preliminary propagation of plant material under culture condition. Forming of reintroduction populations of the rarity plant species by the seed method may be only under condition of turfgrass removal or the upper ground layer digging over. It is necessary to take into account considerable per cent of seed elimination and the low seed germination under natural conditions. Combined method is more efective. Plants are used and seeds are sowedin the vacant plots. Imitation of sed propagation being achieved. The maximum eliminatoin index is revealed among the immature individuals, because they are most susceptible to the adverse factors. General scheme of the species plant reintroduction was worked out by us on the base of the Donetsk Botanical Garden, Nat. Acad. Sci of Ukraine. It includes basic principles and approaches to reintroduction work conducting and methods of reintroductional populations forming. Consecutive stages of the plant species reintroduction have been singled out.