Kukharska M. Biological and ecological peculiarities of the Catalpa Scop. species and prospects of their use in the green plantations of Kyiv

The results of the complex studies of biological and ecological peculiarities of introducted Catalpa Scop. species in Kyiv are presented. The author has specified the species belonging of catalpas specimen in street plantations and collections of Kyiv's botanical gardens and assessed their state and ornamentality. The regularities in the rhythm of C. speciosa Ward., C. bignonioides Walt., C. hybrida Spaeth. and C. ovata G. Don are determined. The potential of catalpas frost- resistance was determined with using the methods of differential thermal analysis and direct freezing of shoots. The degree of resistance to air and soil drought was estimated as well as preparedness for the winter studied by measuring the electrical conductivity in catalpas' leaves and shoots. The functional state of catalpas leaves was specified with the use of the chlorophyll fluorescence induction. Feasibility of using catalpas in green plantations of Kyiv has been substantiated. The optimal cultivation plans of adapted catalpa planting stock for urban landscaping needs have been developed. The author has determined the methods of catalpas soft cuttings root stimulating, which provide maximum yield of viable seedlings. The optimum composition of nutrient media has been selected for culturing the studied representatives of the Catalpa Scop. genus in tissue culture and rooted planting material obtained by direct morphogenesis. Practical recommendations on the use of catalpas in green common use plantations in Kyiv have been proposed as well as variants of decorative compositions with studied species.