Low temperature is оne оf the mоst significаnt limiting factоrs determining the distribution of tree species. Evaluation of the degree of freezing of tree and shrub species is of great importance for decorative gardening. Plants freeze a lot not only in harsh winters, but also during prolonged thaws with a subsequent drop in temperature, which negatively affects their ornamentation. In this regard, one of the main ways to preserve the ornamental and plant biodiversity of city parks in a temperate continental climate is to replenish existing plantings with frost-resistant tree species. It is the first study of the frost resistance of introduced trees and shrubs, which was made to isolate species adapted to the winter conditions of the temperate continental climate to form stable landscape compositions in urban parks. Based on the results of artificial freezing, species of woody plants with high frost resistance were selected: Betula kelleriana, Betula raddeana, Staphylea pinnata, Cotinus Coggygria and Pinus pallasiana. The above species of wood are recommended for sustainable landscape design in the city.

Five Sorbus L. species of different ecological and geographical origin growing in the VNIISPK arboretum were studied. The Institute is located 368 km southwest of Moscow, on the Central Russian upland in the European part of Russia. The studies were carried out in 2014–2016. The reaction of different Sorbus L. species to a three-day thaw +2°C with a subsequent decrease in temperature to –25°C in February and –30°C in March was studied in order to identify adapted species to the climatic conditions of the Orel region for use in ornamental horticulture. As a result of the experiment, we recommend Sorbus aria (L.) Crantz, Sorbus aucuparia L. and Sorbus alnifolia (Siebold. et Zucc.) K. Koch. as adapted species for the Orel region to create sustainable landscape compositions.

Sweet mock orange f. golden dwarf (Philadelphus coronarius L. f. aureus nanus) is a promising ornamental shrub in green building within Central Russia. In the Orel Region, this species has a limited occurrence due to the lack of quality planting material, which warrants research into rhizogenesis of P. coronarius f. aureus nanus stem cuttings during soſtwood graſting. Trials were conducted during 2017-2019 in triplicate, 20 cuttings each, adhering to the common woody plant soſtwood graſting propagation technique. Two yearling types were used, side shoots and innovations. Experimental setups: 1 — control (water); 2 — aqueous indolebutyric acid (IBA) 50 mg/L at 18-h exposure; 3 — bottom cutting powdering with 0.5 g/kg active coal-IBA mixture; 4 — bottom cutting treatment with 50 mg/L IBA at 18-h exposure followed by powdering with 0.5 g/kg active coal-IBA mixture. Setup 2 (IBA 50 mg/L) rendered the highest positive effect on the rooting and reproduction of side shoot and innovation-derived stem cuttings. Te best cutting root system biometry (number and length of 1st order roots) was obtained in setup 2 with the innovation cuttings (10.50 roots of 4.53 cm) compared to the side-shoot ones (9.81 roots of 3.68 cm).

The qualitative composition and quantitative content of amino acids were studied by PC and HPLC methods. 15 free amino acids were identified in the endosperm and skin of A. hippocastanum. 16 bound amino acids were identified in the endosperm; 17 bound amino acids were identified in the skin. The GC/MS method shows that A. hippocastanum skin and endosperm contain 2 free sugars and 5 after hydrolysis. We can also distinguish specific sugars for seed endosperm which are not present in the skin of the seed: Rha, Fuc, and Sucrose. Specific sugars in the skin of the seed are Xyl and Man. The endosperm of seeds of Aesculus hippocastanum accumulates starch, WSPS, and lipophilic compounds. PS and HC are concentrated in the skin. The qualitative composition and quantitative content of 19 macro and microelements in skin and endosperm of seeds of A. hippocastanum was studied by atomic emission spectrophotometry. The skin of seeds of A. hippocastanum accumulates macro and microelements. The seeds do not accumulate toxic metals, and this enables their use as medicinal plant material. The results show big differences between endosperm and skin in their contents of primary metabolites and elements. Those differences depend on functions that the skin and endosperm are playing in plants, and they influence how medicines and food supplements might be created.

Relevance. A study of the seasonal (phenological) phenomena and natural connections between them on the background of the relevant environmental conditions is of great scientific and practical interest. Knowledge of the dynamics of the seasonal development of woody plants helps in the selection of species and their assessment from an aesthetic and sanitary points of view, as well as in the development and implementation of measures to increase the sustainability of urban green spaces. Materials and methods. The purpose of these studies is to create a database of the dynamics of seasonal development of North American woody plants based on the results of many years of phenological monitoring (2003-2017). The 20 species and forms of North American woody introducers e of the VNIISPK arboretum genetic collection were the objects. Results. It was revealed that the growing season of woody North American plants corresponds to the climatic conditions of the forest-steppe zone of central Russia. The species with the earliest beginning of the growing season (the third decade of March) were distinguished. There were Mahonia pinnata, M. aquifolia, Betula lenta and B. lutea. On the basis of phenological calendars, phenological spectrums have been constructed. These consist of three lines (the development of leaves, shoots, flowers and fruits) with the corresponding color symbols. It has been revealed that phenospectrums vary depending on the conditions of the year. As a result, the database of 20 species and forms of North American woody plants was formed in the form of phenological spectrums against the background of registration of weather conditions in the forest-steppe zone of Russia. The database includes three options for the possible dynamics of the seasonal development of introduced North American plants. The created database allows observing, comparing, evaluating and forecasting changes in the seasonal rhythm of the studied species of introduced North American plants.