The results of many years of research in evaluation of the adaptive potential of the gene pool collection of pears growing in the Nikitsky Botanical Gardens are represented in this article. The cultivars included in various groups of cultivar types with late flowering, flower resistance to spring frosts, drought tolerance, resistance to major diseases and productivity have been identified. The highest indicators of adaptability, productivity and quality of fruits are distinguished by the cultivars of the Crimean selection - the Nikitsky Botanical Gardens and the Crimean Experimental Station of Gardening. Among them, the following cultivars deserve the greatest attention for widespread introduction into industrial intensive horticulture of the Crimea and other southern zones of fruit growing: Mariya, Mriya, Tavricheskaya, Yakimovskaya, Desertnaya, Izyuminka Kryma, Izumrudnaya, Nadezhda Stepi, Novosadovskaya, Rada, Diva. For use in breeding programs, as sources of valuable traits, the listed domestic and foreign cultivars can be used - Bere Klerzho, Zharzhonel', Triumf Zhoduan', Dekanka Bushe, Viktoriya, Vystavochnaya, Noyabr'skaya Moldavii, Bukovinka, Zhanna d ,Ark, Mervey Ribe and others.

This review article provides information on the main directions in assessing the economic and biological characteristics of sweet cherry cultivars and forms at the present stage. The problem of the need for the study of sweet cherry cultivars for winter hardiness, frost resistance, drought tolerance, resistance to fungal diseases (especially coccomycosis and moniliosis) is considered in detail. The rationale for the need for a continuous search for cherry genotypes, distinguished by self-fertility and high biochemical properties, is given. The article argues that it is necessary to continue research in the field of productivity of sweet cherry cultivars, since the order of fruit formation, fruiting features, and placement of sweet cherry productivity elements are not fully understood and often contradict each other. Information on achievements in breeding, cultivar research and economic and biological assessment of sweet cherry in domestic and foreign research institutions is provided.

The article presents the results of a study of economically valuable traits of apple cultivars of foreign selection in the Crimea. The study of yield, resistance to fungal diseases, commercial qualities, chemical composition and taste of fruits was carried out. It has been established that 16 cultivars have large fruits, 10 cultivars are distinguished by high tasting grade, and 14 cultivars have an attractive appearance. These samples are of interest as a starting material for breeding work. Cultivars Champion and Prima are promising for inclusion in the breeding process to improve the chemical composition of fruits. Cultivars Askold and Prima are distinguished by increased productivity. Askold cultivar is distinguished by productivity, taste of fruits, and resistance to pathogens and is recommended for production testing in the Crimea and various regions of southern Russia.

Boxwood moth Cydalima perspectalis (Walker, 1859) is a serious threat to plants of the genus Buxus in all agroclimatic regions of the Crimea. The use of bioinsecticides is one of the environmentally safe and effective methods of reducing the number of phytophages. The use of preparations of Lepidocidae Bitoxibacillin in three standards of application provided high biological effectiveness against boxwood moths caterpillars of all ages. For older caterpillars on the fifth day, the biological effectiveness of Lepidocidae Bitoxibacillin in all standards of use was 100%. Fitoverm proved to be more effective against young and middle-aged caterpillars. On the fifth day after treatment with Fitoverm, biological efficiency for young caterpillars was 98,8%, and for middle-aged caterpillars - from 94,4 to 96,8%.

Nine species of aphids have been identified in fruit plantations in the Crimea. The species composition and percentage varies depending on the zoning of the plantings. The correlation coefficient between the hydrothermal conditions of April-June and the number of green apple aphids r=0,55, and gray apple (rosy leaf-curling) aphids - r=0,46. Mass reproduction of apple aphids was recorded in May, which was facilitated by dry and warm weather. Low temperatures in April during the beginning of hatching of larvae restrained the growth of the number of phytophages and provoked the almost complete death of the woolly aphid population.

The results of surveys of strawberry plantations in the Krasnodar Territory and the Republic of Adygea during the period from 2017 to 2020 are presented. From the generative and vegetative parts of garden strawberry 12 species of micromycetes, belonging to 6 orders of 5 classes, were singled out: Hyphomycetes, Coelomecetes, Pyrenomycetes, Zygomycetes, Disomicetes. The infection of berries by the fungi Alternaria tenuissima (Kuntze: Fr.) Wiltshire and Discohainesia oenotherae (Cookeet Ellev.) Nanf., which previously were not found in the southern region, was noted for the very first time in 2020. The species, representing the greatest danger for strawberry cultivation, have been identified and the frequency of their occurrence has been determined.

Invasions of aggressive alien plant species that have a high rate of expansion and pose a threat to ecosystems and their biodiversity have become more active in the 21st century due to anthropogenic disturbances of vegetation cover, the lack of systematic control of their numbers, the expansion of transport corridors, etc. Research for the search of new locations of adventitious plant species is carried out in the Republic of Bashkortostan especially intensively during the last 10 years. The result of this work was the publication of the "blacklist" flora of Bashkortostan [1] including 100 invasive and potentially invasive plants and "Synopsis of adventive species of the Republic of Bashkortostan" [13], who presented data on 457 localities of alien plant species, is not peculiar to the nature of Bashkortostan. This article is an addition to the previously published data obtained during the route expedition research in 2019-2020, conducted in the Western regions of the Republic. More than 150 new localities of 22 invasive and potentially invasive plant species were identified. 11 species are included in the “Black book of flora of Central Russia” [9]. The data obtained clarify and expand the understanding of the modern secondary range of invasive plants on the territory of the Republic.

In the waters of the Kazan Bay of the Kuibyshev reservoir, located within the city of Kazan, excessive concentrations of phenols are periodically present in the summer period, the number of Cyanophyta (Cyanoprokaryota) exceeds 100 million с./l, reaching a potentially dangerous level for public health. As a result of statistical analysis (p<0,05), it was revealed that in the spring-autumn period of 2017 - 2018, to a certain extent, the content of phenols correlates with structural characteristic of Cyanophyta (linear correlation coefficient was 0.66), Ochrophyta (-0,36 - -0,62) and Cryptophyta (-0,31). Hydrometeorological factors (air temperature, precipitation) can influence the number and biomass of phytoplankton and its individual taxonomic groups. In the Kazan Bay, which is characterized as a low-flow, in the rainy spring-autumn season, the risk of increasing phytoplankton biomass and phenol content in the water increases.

As a result of the expedition, herbarium and literature review, the article presents a new conspectus of the genus Lathyrus L. s. l. of the South Caucasus (Azerbaijan Republic). The study revealed a new area of two species (L. hirsutus L., L. inconspicuus L.) and clarified the status of one species (L. leptophyllus Bieb.). For the first time, micromorphology structure of seeds in some species (L. annuus, L. cicera, L. hirsutus, L. tuberosus, L. miniatus, L. pratensis, L. laxiflorus, L. aphaca, L. nissolia, L. sphaericus) were included by scanning electron microscope. Morphological characters of the sections were analysed according to Kupicha with some additions. Our work showed that Lathyrus seeds are circular, pressed-angular, elliptical, coloured in brown tones, with tuberculate, smooth, reticulate-rugulose surface. In the article, in contrast to the classification according to "Flora of Azerbaijan", species belonging to the genus Orobus are included in the genus Lathyrus.

Complete lists of biota are the scientific foundation on which studies of the regional biological diversity are based. Considering the emergence of a new classification scheme of cyanoprokaryotes, there is a need to revise the species composition of Cyanobacteria of various biotopes. The article describes the flora of Cyanobacteria of the Meganom Peninsula (eastern Crimea). Taking into account the latest nomenclature-taxonomic changes, 44 species of Cyanobacteria were listed for the supralittoral zone of the protected area of the peninsula. Species are representatives of 23 genera, 15 families, 5 orders and 2 subclasses. A fifth part of the species list consists of rare and endangered species that need protection. A complex of the leading species of the marine supralittoral zone of the Meganom Peninsula was identified; species, which are indicators of saprobity, were determined, and the algal community saprobity index was calculated (S = 0,9). The supralittoral microalgoflora is characterized by the predominance of attached benthic species and complex of marine and brackish-water forms. The prevalence of cosmopolitans and wide-range boreal-tropical species highlight the azonality of the biotope of the marine rocky supralittoral zone.

Cotoneaster melanocarpus Fischer ex Blytt is rare species and included in Red Books of Russia (8 Regions) and Belarus, it is included in the list of wild rare and endangered plants of the Kostanay Region in Kazakhstan. C. melanocarpus is used as an ornamental, medicinal, honey-bearing plant, but it is difficult to propagate both seed and vegetative methods. Microclonal propagation of plants is a promising method of propagation and conservation of this species, but there are no researches in this direction in the world scientific literature for C. melanocarpus . The article presents the conditions of in vitro propagation for other species of the genus Cotoneaster , studied at different times by scientists from France, Korea, China, Russia and Iraq. It is shown how the application of various types of explants, sterilization modes, nutrient media, plant growth regulators affect on features of the morpho- and rhizogenesis of Cotoneaster in culture in vitro . This review was conducted for the first time and can serve as a basis for the development of a method for microclonal propagation of C. melanocarpus , which will conserve its gene pool and obtain plant material for practical use.

We studied variation of morphological characters, ontogenetic structure and vitality of 10 cenopopulations of Traunsteinera sphaerica (M. Bieb.) Schltr. within the Kabardino-Balkar Republic. The studies were conducted in the meadow plant communities under different conditions of anthropogenic load (recreation and grazing). The species presents medium phytocoenotic plasticity of morphological characters (I_p=0,51%) and high variation of morphological characters (CV_х¯ср=20,08-42,66%). The maximum increase of the cenopopulation vitality with the stable seed reproduction is observed in the composition of undisturbed meadows; the portion of generative individuals is increased in ontogenetic spectra (55,9-65,3%). Under the intensification of the anthropogenic load, vitality of cenopopulations and the density of individuals (0,64 ind./m²) are decreased; the portion of virginal individuals is increased in ontogenetic spectra. The rate of the seed reproduction of cenopopulations, in which the density of individuals accounts for 18,24-23,17 ind./m², is high on the rubbly substrata with low total projective cover (75-80%).

The preconditions for creating an exposition on the botanical and geographical site "Altai" of the Polar-Alpine Botanical Garden of the KSC RAS, represented by cenotic elements characteristic of the forests of the Altai mountains: dark-coniferous, light-coniferous and black taiga. Such expositions in botanical gardens are one of the forms of preserving the biodiversity of introduced plants ex situ. The condition, structure, species composition of the created plantings for this period - the completion of the first stage of work ("Creating a tree tier") is described. Preliminary results of plant introduction the main tree species ( Abies sibirica Ledeb., Picea obovata Ledeb., Larix sibirica Ledeb., Pinus sibirica Du Tour, Pinus sylvestris L., Tilia cordata Mill ., Populus tremula L.) forests of the Altai mountains. The condition of coniferous plants is characterized as normal: they show climate and soil resilience, have a natural rhythm of development here, go through all stages and phases of ontomorphogenesis. A comparative analysis of the rhythms of seasonal development of plants of herbaceous species characteristic of the most contrasting ecotypes of the Altai mountains (foothill and high-mountain) showed that the conditions of the Northern taiga of the Khibiny mountains of the Kola Peninsula are more consistent with plants of high-altitude habitats (high-mountain ecotype). Features of growth and development of plants of Altai species ex situ indicate successful adaptation of most of these species to the conditions of the Kola Arctic.

The article presents the research results of the genesis of biology of Crocus angustifolius and Crocus speciosus . Some aspects of formation of the male and female gametophytes, pollination and seeds formation have been presented. The wall of microsporangium develops centripetally as monocotyledonous and formed consists of the epidermis, endothecium, 2-3 middle layers and secretory tapetum. A tetrad of microspores is formed simultaneously. Mature pollen grains are 2-cell. The ovary is three-celled, the ovary is anatropic, crassinucellous, bitegmal, funiculous. Polygonum-type embryo sac. Pedestal, podium and hypostasis are formed. Both species are entomophilous plants. The fruit is a multi-seeded three-nest box. Both species propagated by seeds and vegetatively using corms.

The influence of technogenic pollution on the dynamics of the content of biologically active substances and the antioxidant activity of the previously poorly studied species Rosa lupulina Dubovik was studied for the first time. The compliance of R. lupulina fruits growing in the Donbas with the requirements of regulatory documentation was evaluated. The relationship between the content of heavy metals (lead, cadmium, mercury) in the fruits of R. lupulina and the soil on which they grow was studied. The environmental safety of raw materials was evaluated.

The results of studies of photosynthetic processes in annual leaves of two species of the genus Osmanthus - Osmanthus x fortunei and O. fragrans in the cold period on the Southern coast of the Crimea and under the controlled action of negative temperatures are presented. It is shown that the main parameters of chlorophyll fluorescence induction (CFI) in annual leaves of O. x fortunei was relatively more stable during the winter months compared to O. fragrans . The effect of temperature -8,0°C for 8 hours on the leaves of the species in O. fragrans caused a decrease in the fluorescence decay coefficient to the lower limit of the norm of vitality and a significant increase in the processes of thermal dissociation of light energy. It is established that the temperature is -10°C is critical for the leaves of O. fragrans , which indicates its lower frost resistance. Changes in the state of PSII depend on both the duration and intensity of low-temperature exposure. It was found that for the more resistant species of O. x fortunei a relatively long-term effect of -10,0°C and a short one of -8,0°C temperature have a similar effect on the state of the photosynthetic apparatus, which is probably due to the activation of protective mechanisms.

During the summer season, on the southern coast of Crimea, the parameters of the water regime of 6 varieties of Ficus carica L. of various origins were studied. As a result of a comparative assessment of the experimental indicators, potentially adaptive, resistant to stressful weather factors, genotypes were identified - 'Sabrutciya Rosovaya' of the Nikitsky Botanical Garden selection, an introduced plant from Bulgaria 'Ranniy is Sozopoliya'. These cultivars have demonstrated high water-retention forces and the possibility of the most complete repair of leaf tissues. A relatively weak ability to retain moisture and restore turgor after dehydration was shown by the cultivar Vladimirska Krupna introduced from Yugoslavia and the Bulgarian cultivar Pomoriyskiy 6.