Winter hardiness and drought resistance of wild rose species in the Lower Volga Region.
Species of the Rosa L. genus belong to the extensive Rosaceae family, with a very wide area, which makes this genus promising for the use in plantations of various species. The aim of the research was to assess the introduced representatives of the Rosa genus and the selection of promising species for forest reclamation and landscaping in arid conditions. The objectives of the research were to determine the ratio of different Rosa species to limiting environmental factors-drought and frost by field and laboratory studies with subsequent statistical processing of data. Of the species introduced and naturally distributed in the Lower Volga region, the following can be distinguished:R. rugosa Thunb., R. canina L., R. beggeriana Schrenk, R. spinosissima L., R. ecae Aitch, R. pomifera Herrm., R. cinnamomea L., R. acilularis Lindl. The climate of the Lower Volga region is continental, arid, moisture regime - unstable, which greatly limits the development and growth of plants, as well as the success of their adaptation. When transferring Rosa species from their natural habitat to a new one, an important issue is the degree of their adaptation to new environmental conditions. In materials research comparative evaluation of winter hardiness of species of wild roses, and also presents data on the study of water deficit and relative yield of electrolytes, the ranking of species according to the degree of distinction of parameters of leaf plates. In the process of studying the species of rosehip, it was found, that with prolonged exposure to cold and drought, the studied samples undergo adaptive changes aimed at improving the water balance and adaptive capabilities. According to laboratory and field studies identified the most promising species for the use in protective afforestation and landscaping settlements of the Lower Volga region, drought-resistant species as: R. ecae, R. beggeriana, R. spinosissima, R. canina, and winter hardy species as:R. acicularis, R. pomifera, R. spinosissima and R. canina.