Yukhimenko Y. Bioecological features of species of the genus Crataegus L. with the introduction in conditions of Right-bank steppe Pridneprov'ya

This thesis is devoted to investigation of biologic and ecologic determinants of introduction success for 51 species, varieties, and cultivars of Crataegus L. in conditions of Right-Bank steppe Pridneprov'ya. We studied the biomorphologic characteristics of the plants of this genus in the conditions of secondary habitat. We ascertained that for the majority of representatives of genus Crataegus, seasonal rhythm of their development is consistent with natural and climatic conditions of introduction area, where they reveal high rates of pollen viability, fruiting, seed germination. According to anatomic peculiarities of structure of vegetative organs, the species of the section Oxyacanthae are the most resilient to drought; they show the best rates of the structures of the primary bark of one-year shots and the leaf epidermis.