This article analyzes the fundamental transformation of the mission of botanical gardens in the 21^st century, tracing their evolution from centers of introduction of ornamental or economically valuable plants to key institutions responsible for the biosafety of natural phytocenoses and the sustainable development of urban ecosystems. The study highlights the growing environmental threat posed by invasive plant species in urbanized areas, exacerbated by the processes of globalization and the development of commercial horticulture. Various ways of introduction, both intentional and accidental, are considered in detail, and the special vulnerability of the urban environment is highlighted due to the disturbance of ecosystems and the multitude of vectors of introduction. A significant part of the analysis is devoted to the diverse role that modern botanical gardens play today. These functions go beyond their traditional tasks and include comprehensive monitoring and early detection of invasive species, scientific studies of their biology and ecology, as well as a thorough assessment of the risks of new plants before their introduction. In addition, botanical gardens are at the forefront of developing and testing control methods and play a key role in educating the public by raising awareness of the risks associated with alien species and promoting the use of native plants. Using the example of the Russian Federation and its network of botanical gardens as the main object of research, the article examines the practical implementation of the national Code of Conduct for Invasive Alien Species. It includes the creation of regional "blacklists" and the development of the "IRIS" database, which is a complete inventory of invasive plants throughout the country. Applied research was conducted in Moscow in response to a fundamentally new task set by the city authorities for botanical gardens: to ensure the environmental safety of urban green spaces by analyzing and optimizing their qualitative composition. The study concludes with a practical application: a detailed, categorized list of 32 dangerous invasive species for the city of Moscow, provided with specific management recommendations for urban landscaping purposes. The article concludes that there is a need for a paradigm shift towards a biosafety system coordinated by botanical gardens and integrating science, regulatory control and public engagement, which is the key to ensuring the environmental sustainability of the urban environment. This new model positions botanical gardens as indispensable leaders in curbing phytoinvasions on a global scale.

   A long-term study of the growth and development characteristics of Cassia angustifolia Vahl, a valuable medicinal tropical crop introduced to the Southern Coast of Crimea in a dry subtropical climate, has shown that the region's thermal resources in recent years (2023-2024), with sufficient effective air temperatures, contribute to the creation of favorable conditions for maintaining the long-term cycle of plant development, fruiting, and seed maturation. During this period, from mid-July to the second ten days of October, with a wide range of effective air temperature sums from 1062-2379 °C, optimal thermal conditions were observed, ensuring synchronous mass flowering and fruiting of plants. For plants to enter the phenophase of mass fruiting, a sum of effective air temperatures above 1701 °C is required. This thermal threshold was reached in early September in 2023 and in mid-August in 2024. The seeds of Cassia angustifolia are well-formed, obovate, elongated at the end, flat, cream or brown in color, with transverse grooves on the surface. The seed yield is 8,7 ± 0,94 g/m², 1000 pcs. weight is 17,33 ± 0,69 g, seed length is 3,37 ± 0,16 mm, width is 2,90 ± 0,24 mm. Freshly collected seeds, taking into account the onset, duration and maximum of germination, belong to the type of seeds with an accelerated germination type: 48 hours after laying the experiment, germination of 28,2 ± 1,11% of seeds was noted. The maximum indicators of laboratory germination (81,1±2,65%) and germination energy (63,2 ± 1,29%) were recorded for seeds of the year of collection. Seed germination after one year of storage decreases to 66,25 ± 2,63 %.

   The differences and diagnostic features of the higher classification categories of light-coniferous, small-leaved herbal forests and subalpine birch krummholz of the North Caucasus – the classes Erico–Pinetea Horvat 1956 (thermophilous xeric forests of the sub-Mediterranean type) and Brachypodio pinnati–Betuletea pendulae (European-Siberian mesophilous hemiboreal forests) were demonstrated after the results of quantitative and comparative syntaxonomic analyses of nine syntaxa (7 associations and 4 variants). The results showed that the hemiboreal forests of Brachypodio pinnati–Betuletea pendulae are subdivided into two orders according to their altitudinal differentiation and ecological factors of heat and humidity - Alchemillo sericatae–Pinetalia sylvestris (xero–mesophilous birch-pine forests) and Acero trautvetteri–Betuletalia litwinowii (mesophilous pine-birch and birch forests). Birch krummholz and birch forests cannot be considered in the class of subalpine shrub vegetation – Betulo carpaticae–Alnetea viridis in accordance with ecological, floristic and structural-phytocenotic criteria, as proposed in the vegetation classification of Europe. These vegetation types were included in European-Siberian forests of the class Brachypodio–Betuletea. The floristic composition of East Caucasian thermophilous pine forests of the sub-Mediterranean class Erico–Pinetea are characterized by a high level of endemism and specific plant life forms, which allows them to be considered in the rank of the special order Onobrychido cornutae–Pinetalia sylvestris ord. nov.

   Identifying rare and endangered plant species is a fundamental requirement for any level of biodiversity conservation program. According to the IUCN, 12.5 % of higher vascular plants worldwide are threatened with extinction. The Socialist Republic of Vietnam (SRV) is a country with enormous biodiversity, where noted approximately 12000-15000 vascular plant species, including 1132 fern species. SRV has developed various regulations regarding the conservation status of threatened plant species and published Red Data Book. Two decrees have been issued by the Ministry of Agriculture and Rural Development (MARD) and the Ministry of Natural Resources and Environment (MONRE). The most recent of these is Decree 84/2021 (2021), which lists two species groups, IA and IIA, of plants and animals growing and recorded in SRV, prohibited for collection/catching and commercial use. Ferns can be found only in List IIA: Huperzia serrata (Thunb.) Trevis., all species of Cyathea ssp. (after taxonomic changes these are the genera Alsophila R. Br, Gymnosphaera Blume, Sphaeropteris Bernh.), Cibotium barometz (L.) J. Sm., Drynaria bonii Christ, D. roosii Nakaike. Considering the categories of rarity, as well as the occurrence/distribution of ferns in the territory of the SRV, it should be noted that some species are noted only from herbarium specimens. Due to the practical lack of study of the pteridoflora, many species are presented by us for the first time within the region, such as Adiantum membranifolium S. Linds. & Suksathan, Anisocampium cuspidatum (Mett. ex Bedd.) Yea C. Liu, W.L. Chiou & M. Kato. While working in the field in northern Vietnam, we found endemic species from Philippine: the extremely rare Diplazium pseudocyatheifolium Rosenst., and, as it turned out, Microsorum sarawakense (Baker) Holttum, which is well represented outside the locus classicus. Some species were described only from herbarium specimens: Leptochilus heterophyllus (S. K. Wu & P. K. Lôc) Kalyuzny (syn. Kontumia heterophylla S. K. Wu & P. K. Lôc), which was cited as a local endemic for Kontum Province. We also found many species previously reported for the People's Republic of China (PRC): Athyrium erythropodum Hayata, Cyrtomium serratum Ching & K. H. Shing, Coniogramme emeiensis Ching & K. H. Shing, and others. As can be seen from the above review, there are numerous documents regulating various activities, including laws on protected areas and the Red Book. However, many laws are ignored by local populations; the Red Book is published very irregularly (the first was published in 1996, the second in 2007), and there is currently no more recent edition. Unfortunately, it should be noted that there is absolutely no interaction between the PRC and the IUCN, and lists of rare species for international protection (Red List) are not maintained or compiled. However, forestry legislation is evolving, and new laws are emerging that restrict economic activities.

   Monitoring studies of changes in the alien fraction of the spontaneous flora of Donbass over a 40-year period showed an increase in the degree of its adventitization from 14% (256 species) in 1985 to 23.5% (548 species) in 2025. This process has intensified in recent decades. This is likely due to the aridization of the climate, as well as the active and poorly controlled import of ornamental plants and other cargo into the country. The families Asteraceae, Poaceae, Brassicaceae, Chenopodiaceae, Fabaceae, Rosaceae, Lamiaceae, Solanaceae, Apiaceae, Amaranthaceae are leading in the systematic structure of the alien fraction of the Donbass flora, which occupy the same positions in the flora of other arid territories of Eurasia. In the range of life forms, more than half of the species are annuals (54.8 %). By origin, the species of the Mediterranean-Iranian-Turanian primary range geoelement predominate – 39.9 %, and by the method of import dominating are xenophytes (60%) and
ergasiophygophytes (20 %). 16 transformer species from agriophyte group pose the greatest invasive threat.

   A hydrobotanical study was conducted at a stationary monitoring site in the area where the emergency collector of the Gurzuf treatment plant discharges into the sea (Southern Coast of Crimea – SCC). It was established that the flora of the rocky supralittoral zone within its boundaries is formed by Cyanobacteriophyta; no macrophytes were recorded. A total of 17 species belonging to 12 genera, 7 families and 5 orders were recorded during the year. The minimum species diversity was observed in spring (5 species), while in the other seasons of the year the values of this indicator were higher and fairly stable (8-9 species). In general, marine benthic cosmopolitans are most widely represented in the flora, with an increase in the proportion of warm-water species in certain seasons of the year. The supralittoral biotope is located in the critical part of the ‘land-sea’ contact zone, which is inhabited by organisms that are most tolerant to extreme environmental conditions. This explains the similarity in the composition and structure of the flora at high taxonomic ranks, its generalised bioecological characteristics, and the dynamics of key indicators within the boundaries of the surveyed area with corresponding data obtained for the flora of other areas of the SCC. At the same time, the sparse set of taxa in the ranks from species to family inclusive and the low value of the generic coefficient (1.42) are obviously determined by chronic local eutrophication of anthropogenic origin, the level of which is extreme even for many Cyanobacteriophyta. This poses a threat to biodiversity and the sustainable development of the recreational and tourist sector in the South Coast. It is unlikely that the volume of wastewater entering the sea will be reduced, so the only way to solve the problem in the region is to improve the quality of wastewater treatment.

   The article presents the results of studying the adaptation of Hydrangea L. regenerant plants to ex vitro conditions. There is comparison of morphometric parameters of adaptable cultivars of H. arborescens L., H. paniculata Siebold, H. macrophylla (Thunb.) Ser. in the conditions of a hydroponic using the ionite substrate Zion The proportion of viable plants was 87 %. Their height and root length were variety-specific. The greatest raising in the morphometric parameters of the aboveground part was noted in H. paniculata, 1.4 times compared with the control. A positive effect on the development of the root system was found for the large part of the researched objects. For the varieties H. macrophylla and H. paniculata, an increase in roots was noted by 1.4 and 1.6 times, сorrespondingly. The use of agroperlite with Zion substrate for a hydroponic plant, while adapting micro plants to ex vitro conditions, makes it possible to obtain planting material for representatives of Hydrangea with a developed aboveground part and root system.

   The identification of stress-resistant ornamental crops is an urgent task in the context of climate aridization.

   The main objective of this work was to evaluate the response of the photosynthetic apparatus in garden roses to hydrothermal stress in order to identify informative diagnostic parameters.

   Using the OJIP-test method, changes in six genotypes were studied under water deficit (22-25 %) induced by combinations of air temperature (40°C) and humidity (25 % and 70 %). It was shown that the response to stress is specific for different species and cultivars and is also related to the conditions of stress exposure. Based on the analysis of fluorescence kinetics and calculated JIP-test parameters, the most sensitive (Rosa roxburhii Tratt.) and resistant (Rosa × odorata (Andrews) Sweet., Rosa lucieae Franch. & Rochebr. ex Crép., ‘Solnechnaya Dolina’) genotypes were identified. It was found that low air humidity causes more significant damage to the oxygen-evolving complex, while high humidity primarily disrupts electron transport. The ABS/RC index was established to be a highly informative indicator for assessing stress resistance.

   The article presents the results of long-term work on artificial freezing of flower buds of 15 zoned apricot cultivars bred by the Nikitsky Botanical Gardens (NBG) for the period from 1997 to 2025. The studies were conducted in the Greenland (from 1997 to 2009) and TTS 256 Memmert with PO (from 2015 to 2021) climatic chambers. Freezing was carried out at different temperatures, the choice of which depended on the stage of morphogenesis of the generative buds and the calendar timing of the experiment. The zoned Burevestnik cultivar bred by the Nikitsky Botanical Gardens, characterized by increased frost resistance, was used as a control.

   The aim of this study was to summarize the results of artificial freezing of generative buds of 15 zoned apricot cultivars bred by the NBG and to develop recommendations for their placement in the agroclimatic regions of Crimea.

   Cultivars with very high, high, above-average, and average frost resistance were identified. No genotypes with high frost resistance were identified among cultivars with early and early-mid-season ripening fruit. Three genotypes were selected from apricot cultivars with mid- and late-season ripening fruit: one cultivar with very high frost resistance, and two with high frost resistance. Twelve genotypes with average and above-average frost resistance were identified. Determining the frost resistance of flower buds allowed us to substantiate the placement of cultivars in the agroclimatic regions of Crimea. Twelve apricot cultivars with average and above-average frost resistance are recommended for planting in favorable agroclimatic regions. Three cultivars with very high and high frost resistance of flower buds are recommended for unfavorable regions. These varieties can also be grown in favorable agroclimatic regions of Crimea.

   The article discusses the problems of assessing the compatibility of cultivar-rootstock combinations of walnuts using modern analysis methods such as radiography, water resistance and electrical conductivity. The research is aimed at developing non-destructive methods of quality control of grafted seedlings to improve the accuracy of the selection of planting material.

   Special attention is paid to the analysis of the parameters of the water resistance of tissues and the interpretation of X-ray data.

   In the course of the work, a comparative analysis of the levels of water resistance of grafted plant tissues was carried out depending on rootstocks and grafts for the period 2018-2021. The results showed significant variability of this indicator within the cultivar-rootstock combinations. The highest values of specific water resistance were observed in the combination "Walnut × Franquette", which indicates optimal tissue fusion and a well-developed conducting system. On the contrary, the combination "Walnut black × Ideal" demonstrated minimal values of water resistance, which indicates a low compatibility of the components. The use of radiography revealed hidden defects in the vaccination sites, such as incomplete tissue fusion and the presence of necrotic areas. This method has proven to be effective for non-destructive quality control of seedlings. The results obtained confirm the relationship between water resistance, mechanical strength of accretion and the quality of the internal structure of plants. The article contains a detailed statistical analysis of the data, including a two-factor analysis of variance, as well as a description of the research methodology. The presented data can be used to develop recommendations for the selection of optimal cultivar-rootstock combinations and to improve technologies for the production of walnut planting material.

   The article presents the results of studying drought resistance of 35 American peach cultivars and a control cultivar in the collection of the Nikitsky Botanical Gardens (Yalta) by four physiological parameters: leaf water content, water deficit, water-holding capacity, and leaf turgor recovery after moisture loss. Seven cultivars were identified: Dixired, Loadel, Redcap, Summerglo, Sun Beam, Sunhaven, Topoz Peach Halford, which had a lower leaf water deficit than the control cultivar Naryadny Nikitsky. A high correlation was found between leaf water content and water deficit (correlation coefficient r = -0.57), as well as between moisture loss after 24 hours and leaf turgor recovery (r = -0.58). The multiple regression equation reflects the relationship between leaf turgor recovery and physiological parameters of drought resistance of American peach cultivars. The most significant partial regression coefficient (b) was found for the moisture loss trait after 24 hours (-2.19). The multiple regression coefficient was (R = 0.59).

   Promising plants of the Lamiaceae family include representatives of the genus Monarda L. that are perennial and annual herbaceous plants, which contain essential oil in their above-ground mass characterized by high biological effectiveness against microorganisms, particularly antifungal. However, Monarda itself is susceptible to fungal agents. Selection of the resistant plant from the seed population involves structural and genetic studies, information about which is limited.

   Therefore, the aim of our work was a comparative morphological and anatomical analysis of Monarda didyma L., M. fistulosa L., M. citriodora Cerv. ex Lag. leaf blades, and determining the genetic similarity of the plants. It was shown that the leaves differed morphologically in color, shape, and size.

   Surface structures' investigation revealed a significant predominance of papillae and peltate trichomes in M. fistulosa and M. didyma L. Leaves of M. citriodora had better developed cuticle, palisade and spongy mesophyll cells, affecting the organs' thickness. These differences are confirmed by genetic analysis. The dendrogram constructed on RAPD-PCR results showed a separate clustering of M. citriodora, while M. didyma and M. fistulosa had high values of genetic similarity. Based on the obtained results and literature sources, it is assumed that there are several mechanisms of adaptation to external factors affecting to mycopathogens' susceptibility.

   An important advantage of conducting breeding research by biotechnology methods is the preservation of genetic stability of plant material, the possibility of mass propagation and a significant reduction in the time of its obtaining. Apricot (Prunus armeniaca L., Rosaceae Juss. family) is one of the most important stone fruit crops in the world. In the Nikita Botanical
Gardens - National Scientific Center («NBG-NSC»), continue to obtain breeding forms to expand cultivars diversity and create new valuable genotypes by biotechnology methods.

   The objective of our work was to study methods for obtaining and propagating hybrid apricot material using biotechnology methods for subsequent accelerated testing of plants obtained in vitro under controlled conditions.

   Embryoculture and clonal micropropagation methods were used in our research. The influence of genotype on morphogenesis of seedlings and developed microshoots in vitro on the example of embryos of each parental pair of cultivars Kioto × Shalard 2 (form 1), Kolobok × Bergarouge (form 2), Odyssey × Shalard 2 (form 3) was shown. The use of embryos made it possible to induce 100 % development of full value seedlings on a hormonal-free Monnier culture medium. Optimal conditions inducing multiple in vitro adventitious shoot formation in studied breeding forms were determined. Different concentrations of cytokinin 6-BAP were tested for the induction of multiple shoot formation, and the morphogenetic responses of microshoots were analyzed on DKW, SMM, MS, WPM, and B5 culture media and it was found that DKW and MS media promoted leaves and shoots development in forms ‘Kolobok’ × ‘Bergarouge’, ‘Odyssey’ × ‘Shalard 2’, while for form ‘Kioto’ × ‘Shalard 2’ SMM medium was more effective. The DKW medium with 0.75 mg/l 6-BAP promoted the induction of multiple shoot formation of the studied apricot forms. Effect of the genotype also was shown in a decrease in the propagation rate of microshoots of the ‘Odyssey’ × ‘Shalard 2’ form (3,87 microshoots/explant) over the following 3 and 4 subcultivations in comparison with ‘Kioto’ × ‘Shalard 2’ (4.80 microshoots /explant) and ‘Kolobok’ × ‘Bergarouge’ (4.2 microshoots /explant).