Development features and practical value of introduced species of the genus Sorbus L. in the North

In the Botanical Garden of the Institute of Biology, Komi Scientific Center, Ural Branch of the Russian Academy of Sciences, a collection of plants of the genus Sorbus complex is studied. Currently it includes 23 species and more than 40 samples of different geographical origin, as well as nine varieties. The studied plants are in the pregenerative and generative periods of ontogenesis. The morphobiological features of individuals of different species of mountain ash at these stages of development were determined. Introducers of East Asian origin in the conditions of the North have time to fully complete the cycle of seasonal development and are highly winter-resistant. Plants that have entered the generative period of development form full seeds. Experiments on vegetative reproduction with the use of stimulants of root formation and without them showed a different ability of half-woody cuttings of the species and varieties of mountain ash to rooting. The most promising for further cultivation in cold climates and the selection of decorative and productive forms can be considered species of East Asian and American origin, as the most winter-hardy. Other specimens of S. mougeottii and S. austriaca (species no less interesting as ornamental and fruit plants) should be brought to the test as well as plants of these species should be grown from the seeds of local reproduction.