The article presents the results of long-term (2021–2023) studies of pollen production in Clematis armandii Franch. under the introduction on the Southern Coast of the Crimea, in order to find out the prospects for its use in the breeding process. Morphological characteristics and quality of the pollen grains have been studied. It has been determined that the pollen grains are ellipsoidal in shape, oblong-rounded in the equatorial projection, tricolpate with three apertures, of medium size. It has been revealed that in most cases the species produces high quality pollen, 59.43% and 73.1%, which indicates its promise as a paternal parent in breeding process. The effect of the particular year weather conditions on changes in the male gametophyte parameters towards sterility has been shown. It has been also found that during long-term storage, more than 140 days, pollen quality decreases by 1.1 - 1.4 times. Thus, for successful hybridization, it is advisable to check the quality of long-stored C. armandii pollen just before use.

The article presents data about the ability for seed propagation, timing of fruit and seed formation, parameters of seeds ornamental winter-hardy geraniums in open ground conditions in the Central Non-Black Earth Region. In the field collections of the Russian State Agrarian University - Moscow Timiryazev Agricultural Academy and the All-Russian Research Institute of Medicinal and Aromatic Plants, about half of the Geranium L. samples are capable of forming seeds in the period from the end of May to September. It has been established that the fruiting phase after the end of flowering of individual flowers is about 1 month; in agrocenopopulations of various geraniums the duration of fruiting ranges from 18 to 99 days. Calendar terms this phenological phase depends on the ecological and geographical origin of geranium species. The differences in the degree of elongation of the seeds are determined. The weight of 1000 seeds of geranium samples during the years of research varied from 1.36 to 9.0-9.5 g. High and medium connections between certain seed parameters has been established.

In the last three years, rust has been spreading more and more on roses. The article presents the most resistant and susceptible groups, as well as cultivars of roses included in the collection of the Botanical Institute of V.L. Komarov and presented in the park part of the garden. The causative agents of the disease were identified and described: Phragmidium rosaepimpinellifolia Dietel and Phragmidium tuberculatum Jul. Mull. (Phragmidium, Phragmidiaceae). The degree of damage to various groups of rusty roses in the Botanical Garden of Peter the Great is shown. A comparison of the effectiveness of the combined action of the drug Strobitek multi, the growth regulator Ecogel and the universal fertilizer Siliplant on the Angelique and Crimson Glory cultivar is presented. The spread and development of rose rust on the leaves of the most affected cultivars of roses has been established. Effective growth regulators, biological products and fertilizers that increase plant resistance to pathogens have been identified. An effective system for using biological products and growth regulators has been developed to increase the resistance of roses.

The article presents the results of a survey of the phytosanitary condition of the collection of trees and shrubs from the collection of the Botanical Garden of the State Scientific Institution "BIN ANA" in the period 2021-2024. The dominant species of pests and affected plant species are indicated, information is provided on diseases caused by pathogenic fungi: various types of spotting, black spot, powdery mildew. Successful experience in controlling the number of boxwood moth and combating palm weevil is presented. The group of the most dangerous pests includes Sudalima perspectalis Walker (boxwood moth), Paysandisia archon Burmeister (palm moth), Rhynchophorus ferrgineus A.G. Olivier (red palm moth), Ophelimus vaskelli Ashmead (Ophelimus), Leptocybe invasa Fisher & La Salle (eucalyptus chalcid), Cacopsyla pulchella Löw (pretty cacopsyla).

The collection of the park-arboretum of the Botanical Garden of Peter the Great (St. Petersburg) contains various species of the genus Rosa (rose hips). Repeated attempts to germinate seeds have shown that their field germination is very low. Using the X-ray method, it was revealed that representatives of the genus Rosa cultivated in the Botanical Garden of the BIN RAS produce seeds of low quality, they are damaged by pests, and in all fractions a large percentage consists of unfulfilled seeds, which reaches the highest values among small seeds. The fruits of R. myriacantha and R. rugosa contain the largest number of valuable seeds.

The objective of the study is to identify, genetically consolidate and preserve for use in breeding programs for creating more adaptive sweet cherry cultivars the sources of adaptability and genotypic resistance of introduced, geographically distant wild representatives of Cerasus avium L., which most optimally combine the winter hardiness of vegetative and generative tree tissues, disease resistance and consumer qualities. Methods. To introduce wild representatives of the sweet cherry Cerasus avium L. and study their resistance to sharp and gradual changes from thaws to frosts during years of experience, in years with the most critical temperature regimes for sweet cherries, and to evaluate their resistance to fungal diseases Monilia cinerea Bonord and Coccomyces hiemalis Higg in epiphytotic years. Conduct phenological observations. When performing the above tasks, generally accepted methods were used. Results. The introduction and study of the biological and economic traits of the ancestral wild representatives of the sweet cherry Cerasus avium L. (bird cherry), growing in its natural state in vast territories with different climatic conditions - the genetic centers of origin of the species. Samples with a high level of complex winter hardiness of vegetative buds and tree tissues were isolated and genetically fixed in hybrid offspring with cultivated cultivars of the northern group of sweet cherries. The generative buds of these samples were studied for winter hardiness depending on the dynamics of morphogenesis in various winter and spring periods. Plants, ancestral representatives, with slow dynamics (rate) of development of flower buds and later flowering, and hybrids derived from them are recommended for use in breeding. Conclusion. The identified ancestral wild species and their hybrids with sweet cherry cultivars are of interest for the creation of winter-hardy sweet cherry cultivars with improved biological traits.

Scientific knowledge on grapevine genetics and breeding is developed on the basis of general laws of plant genetics, which are implemented in culture breeding. In relation to a certain grapevine culture, specific genetics and corresponding breeding patterns are generated. This article presents study results of the forms of wild-growing forest grapes in Crimea to be analyzed as ecological-genetic population of a certain habitat. Generation of conceptual development of grapevine genetics and breeding is carried out taking into account the research analysis at the molecular-genetic level from populations of wild-growing grapes to specific selectable traits, which is reflected in this publication as a result of grapevine culture research at the Institute Magarach.

The article presents the results of the introduction assessment of 19 apricot forms mobilized from natural habitats, private gardens and various settlements of Dagestan (720–1735 meters above sea level). The genetic diversity of apricot in the conditions of Mountain Dagestan is assessed, some administrative districts are identified as separate natural zones with a rich set of valuable and biologically stable forms. A conveyor of fresh fruits to the consumer is created, which will extend the apricot season in Dagestan from 25 to 120 days or more. Three promising forms for cultivation in the mountainous and highland regions of Dagestan are identified – 'Seyanets Bukhara', 'Makhachevsky' and 'TsEB 1'.

In the article, on the basis of previous research, promising ways of using X-ray methods in the scientific process and industrial production in the viticulture industry are identified. Radiography, as a non-destructive complex of studies, allows for a number of calculations: the degree of maturation of the vine, the length and diameters of rootstocks and grafts, as well as the viability of buds. Fluoroscopy in industrial viticulture can be used to determine the potential fruitfulness of the buds on the vine, as well as their survival in winter. Promising ways of using X-ray fluorescence analysis to determine the content of basic macro- and microelements, as well as concentrations of basic plastic substances (starch, proteins, polysaccharides, etc.) are shown.

The article presents the results of studying the pomological qualities and productivity of peach cultivars bred by the Nikitsky Botanical Gardens. The cultivars were distributed by ripening time with the allocation of the corresponding control. Among the early ripening cultivars, eight were distinguished by a high overall fruit score (4.7–4.9 points), and five peach cultivars had a high productivity (218.5–281.3 c/ha). Among the early-mid ripening samples, five were noted by the best overall fruit score (4.6–5.0 points), and three cultivars had a high productivity (232.4–261.5 c/ha). The early and mid-early ripening cultivars did not differ significantly in fruit quality and productivity. ‘Temisovsky’ cultivar stood out by the content of dry matter, total sugars and ascorbic acid in fruits, and ‘Granatovy’ cultivar stood out by the amount of P-active substances. The distinguished cultivars are sources of economically valuable traits, promising for use in hybridization.

The data on the structure of the reforestation fund of 11 subjects of the European part of Russia, the dynamics of annual carbon deposition by modal plantations of the main forest-forming species are presented. The analysis of the dynamics of productivity of modal stands showed that the wood stock per 1 ha of plantations in the steppe region is 41.7% less than in the forest-steppe region. Based on the dynamic series of the current increase, the carbon-depositing capacity of modal stands of pine, oak, birch and aspen was calculated, which amounted to 1.0-1.1 t C*ha-1*year-1 for pine forests, 1.2-1.3 t C*ha-1*year-1 for high-stemmed oak forests, 1.0-1.3 t C*ha for birch forests1*year-1. The lowest volumes of current carbon accumulation are typical for modal aspen plantations, which are 20-40% less than similar indicators for other forest-forming species. Calculations have shown that for the fund of artificial reforestation of pine, the volume of average annual carbon deposition is 1,453 t C*ha-1*year-1, and oak – 1,679 t C*ha-1*th.

The work provides information on the current state of forest fund of «Cape Martyan» regional natural park and presents a comparative assessment of the change in areas of forest and non-forest lands, areas by predominant stands, classes of bonity and canopy density of the main forest-forming species over 33 years. The conclusion is made about the change of species composition in the plantations. The modern forest on the territory of «Cape Martyan» is a unique enclave of sub-Mediterranean vegetation for the Southern Coast of the Crimea (SCC). Mountainous nature of the relief largely determines climate, the typological zoning of forest plant communities, orographic distribution and the feature of the internal structure of the natural park. Recently, there have been trends in the transformation of the forest structure. The causes of these processes can be both global climate change and the influence of anthropogenic factors (changes in the purpose of land plots, frequency of fires, unregulated recreational activities, etc.). Therefore, the establishment and preservation of the legal regime of specially protected natural areas of the SCC will ensure a stable balance of local vulnerable natural ecosystems on the trend of global climatic transformations.

Based on generally accepted methods and approaches, an assessment of the current state of the Quercus ilex population in the specially protected natural area "Cape Martyan" is given, reflecting the trends in the distribution of the species in the forest communities of the Southern Coast of the Crimea. It has been established that the species occurs in different types of relatively closed tree and shrub communities, at an altitude of 45 to 255 m above sea level, on slopes from southwestern to southeastern exposure with a steepness from 5° to 65°. The largest number of identified plants (87%) grow in the altitude range from 100 to 180 m above sea level, on slopes with a steepness from 15° to 25°, southeastern exposure, as part of the sub-Mediterranean hemixerophilic pubescent-oak and eastern-hornbeam communities, with the participation of Juniperus excelsa, Juniperus deltoides, Pinus pallasiana, Arbutus andrachne, belonging to the Quercetea pubescentis class. All the studied cenopopulations belong to young, incomplete, with a left-sided ontogenetic spectrum according to the classifications of A.A. Uranov, O.V. Smirnova (1969, 1975) and "delta-omega" classification (Zhivotovsky, 2001), in most of them the absolute maximum is accounted for by pregenerative individuals (from 93% to 98%). High values of the recovery index indicate the invasive nature of the spread of the species in the studied phytocenoses, however, the further spread of the species depends primarily on the introduction of rudiments from the outside.

The article presents the results of studying the content of essential oil in the green mass of two autochthonous and three introduced species of the genus Juniperus L., growing in the conditions of the Southern Coast of the Crimea. The mass fraction of essential oil in freshly collected raw materials of the studied species ranges from 0.03% to 0.81%. The common features of the essential oil of the studied species were the presence in the composition of monoterpene hydrocarbons: α-pinene, β-myrcene, α-terpinene, p-cymene, γ-terpinene, α-terpinolene, linalool, terpinene-4-ol and sesquiterpenes: α-muurolene, δ-cadinene. The major components of J. excelsa essential oil were α-pinene (46.47%) and cedrol (19.48%), J. deltoides: α-pinene (26.52%) and D-limonene (12.54%), J. chinensis – bornyl acetate (41.35%), J. virginiana: safrole (29.32%), D-limonene (20.18%), elemol (12.7%) and pregeidgerene (10.49%), J. phoenicea: α-pinene (28%), β-fellandrene (19.63%) and α-terpinyl acetate (13.8%). The study of the chemotypic diversity of species of the genus Juniperus L. indicates that in most cases, there is a certain pattern of accumulation of individual components in essential oil, which is of crucial importance both for the practical use of juniper raw materials in order to obtain biologically active substances, and for the possibilities of using available data for the genus chemosystematics.

The degree of biological activity of aqueous and alcoholic extracts of medicinal plants on strains of Staphylococcus aureus and Escherichia coli was assessed. The raw materials of medicinal plants from the pharmacy network and growing in natural plant communities of the North Caucasus (mountainous regions of the Republic of North Ossetia-Alania, Upper Tsey gorge) were used. The degree of antibacterial activity of the tested substances was determined by the standardized Kerby-Bauer method. High antibacterial activity of extracts of common thyme, common garlic, coltsfoot and rod-shaped eucalyptus against Staphylococcus aureus was established. The Escherichia coli culture turned out to be resistant to almost all tested substances (no growth retardation, or low sensitivity). The results of the comparative analysis of the antibacterial activity of the tested medicinal plants revealed more significant biological activity of raw materials of medicinal plants from natural plant communities of the North Caucasus.