In this research, we investigate the genetic polymorphism of raspberry varieties and a promising raspberry hybrid bred at the Federal Horticultural Center for Breeding, Agrotechnology, and Nursery. The research objects were the following varieties: Penguin, Skromnitsa, Arisha, Komsomolskaya Pravda, Ivan Kupala, Salut, Lavina, Yubileynaya Kulikova, and No. 10-165-11. To differentiate the studied genotypes by the degree of genetic similarity, an SSR marker analysis was performed using the following 15 loci: RhM011, RiM019, RhM003, RiG001, Rubus123a, Rubus285a, Rubus270a, Rubus275a, RhM043, RhM021, RiM017, RiM015, RcFH01, RiAS01, and RiMY01. Across all 15 loci, unique sets of polymorphic alleles were identifi ed, and genetic profi les for each specimen were compiled. The average number of polymorphic DNA fragments per locus was equal to 3.6. The highest number of polymorphic amplicons per locus reached 6. The results of genotyping were used to calculate the coeffi cients of genetic similarity of the studied varieties. The complied coeffi cient matrix was subsequently used for cluster analysis. As a result of clustering, groups of genetically similar varieties were identifi ed. The largest group included Arisha, Komsomolskaya Pravda, Salut, Yubileynaya Kulikova, Penguin, and No. 10-165-11. Lavina, Skromnitsa, and Ivan Kupala specimens showed the largest genetic variations. The data obtained elucidates the current understanding of the phenotypic features of raspberry varieties and can be used when developing eff ective crossing schemes in raspberry breeding.

The paper presents a comparative description of hybrid apple seedlings in terms of winter hardiness and resistance to scab. The study focused on 9 families from the 2008 hybrid apple tree fund. The fi eld study revealed diff erences in the levels of winter hardiness and scab resistance among apple seedlings of various origins. The conditions during the autumn-winter-spring period of 20232024 and the growing season of 2024 were found to be optimal for assessing the studied traits. The highest proportion of winter-hardy genotypes was observed in the hybrid families Valyuta × Vasyugan (20.6 %), Lukomor × Valyuta (18.9 %), and Vasyugan × Triumph (18.2 %). The most scab-resistant hybrids (with a tissue, leaf, and fruit damage score of no more than 1.0) were identifi ed in the families Lukomor × Valyuta (56.6 %) and Senator × Podarok Grafskomu (51.6 %). Each of the 9 studied hybrid families contained samples exhibiting a high level of expression of two valuable selectable traits. The highest proportion of seedlings with a combination of high winter hardiness and scab resistance was found in the Lukomor×Valyuta family (16.9 %).

In order to facilitate the development of rational norms of food consumption, meeting the modern requirements of healthy nutrition, the databases containing information on the chemical composition of fruit and berry crops should be regularly updated. In the presented research, we studied the nutrient composition of fruits of promising strawberry and zemklunika (hybrid of wild strawberry and strawberry) varieties grown in the Central Black Earth Region of Russia (Michurinsk). The research was conducted in 2019–2023 using the facilities of the Laboratory for Biochemistry and Food Technology and the Laboratory for Genetics and Breeding, I. V. Michurin Federal Research Center. The research objects were the fruits of strawberry varieties from the FSSI of I. V. Michurin Federal Research Center, introduced varieties of domestic and foreign selection (47 specimens in total). In the varieties under study, the following chemical parameters were determined: soluble solids content – 10.3±0.2% Brix, total sugars – 7.4±0.2%, organic acids – 0.85±0.02%, pH of fruit juice – 3.48±0.03, ascorbic acid – 62.1±2.0 mg/100 g, and anthocyanins – 44.1±2.9 mg/100 g. In terms of sugar content (above 8.5%), the genotypes of Bylinnaya, Lastochka, Pamyati Zubova, Rubinovyy Kulon, Allegro, Chamora Turusi, Flamenco, and Limalexia were distinguished. In terms of ascorbic acid (above 70.0 mg/100 g), the highest parameters were shown by Kokinskaya Zarya, Kupchikha (zemklunika), Olimpiyskaya Nadezhda, Rusich, Slavutich, Torpeda, Festivalnaya, Florence, and Limalexia. The varieties Zenit, Kokinskaya Zarya, Privlekatel’naya, Rubinovyy Kulon, Torpeda, and Feyyerverk were most optimal in terms of anthocyanin content (above 70.0 mg/100 g). Considering the daily requirement in vitamin C of 100 mg, 100 g of strawberry fruits can satisfy it by 62.1 %, or by 31.2–107.1% taking varietal diff erences into account. Consumption of only 100 g of anthocyanin-rich varieties satisfi es the daily requirement for these compounds (50 mg) by 144.6–192.2%. In terms of the integral parameters of chemical composition, the following varieties were selected: Rubinovyy Kulon, Pamyati Zubova, and Flora (selection by Federal Research Center); Kokinskaya Zarya and Rusich (selection by FSBSO ARHCBAN); Allegro, Limalexia, and Vima Zanta (Netherlands), as well as Flamenco (Great Britain). High-vitamin strawberry varieties are recommended for inclusion in dietary nutrition, as the basis in the development of functional food products, and in breeding for obtaining varieties with improved chemical composition.

   The article presents the results of studying the dynamics of photosynthetic pigment contents and the number of cultivated endophytic bacteria (EB) forms in leaves of cultivars of different genetic origin bred by FSBSO ARHCBAN. The research was conducted in 2021-2024 on the blackcurrant (Ribes nigrum L.) collection plantings of the Kokinsky experimental station (Bryansk Oblast) and the research department of the gene pool and bioresources (Stupinsky District, Moscow Oblast) of the FSBSO ARHCBAN. The cultivars included Barmaley, Bryansky Agat, Gamayun, Debryansk, Mif. Weather conditions during the growing season were found to have a signifi cant effect on the content of cultivated EB forms in leaves. On average, over the four-year research period, Bryansky Agat was determined to have the largest number of EB, i. e., up to 107,823 CFU/g. The cultivar was characterized by the most stable abundance indicators of cultivated EB forms in leaves. The blackcurrant cultivars Barmaley and Bryansky Agat were the most responsive to this indicator. The number of cultivated EB forms in their leaves predictably positively correlated with the number of sunny days, as well as with average values of daytime and nighttime temperatures in spring and fall. Except for Mif, all cultivars responded negatively or weakly to the amount of precipitation and daily mean temperature. The Debryansk cultivar was found to be the most unresponsive to weather factors, which may be associated with the lowest annual average number of cultivated EB forms in its leaves (70,713 CFU/g). The high content of cultivated EB forms and chlorophyll a in Bryansky Agat leaves may indicate a possible role of endophytic bacteria in stimulating the synthesis of photosynthetic pigments in blackcurrant leaves.

In this study, 22 medium- and late maturing potato varieties from the collection of the N. I. Vavilov All-Russian Institute of Plant Genetic Resources (VIR) were subjected to a three-year experiment with a view to identifying high-productivity sources for further breeding and cultivation in Central Russia. The study was carried out in the Moscow Oblast in 2020-2022. The Golubizna variety was used as a standard. The total and average weight of tubers per bush (total and marketable), number of tubers in the bush (total and marketable), and the marketability (share of marketable tubers in the total weight) of the varieties under study were evaluated. The total and marketable productivity was evaluated by the parameters of adaptability (K_ad), varietal stability (PUSS), ecological plasticity (bi), and stability (s²_d). On average, over the period of three years, seven varieties exceeded the standard in terms of total and marketable productivity. These included Pamyati Ligaj, Gui Valley, Vympel N, Kazsip, Grand N, Gusar N, and Arlekin. The selected varieties were characterized by high values of the adaptability coeffi  cient (K_ad ranged from 1.4 to 2.0) and marketable productivity (PUSS ranged from 150 to 480 %). Among these varieties, Pamyati Ligaj, Gui Valley, Kazsip, Arlekin, and Vympel N demonstrated high plasticity (bi ranging from 1.2 to 2.7). Grand N showed the highest stability (s²_d=0.00) of marketable productivity. The Gusar N and Arlekin varieties were selected for use in agricultural production. They demonstrated the maximum values of tuber weight per bush on average over the period of three years (total 1.01-1.06; marketable 0.73-0.75 kg), adaptability coeffi  cient (K_ad ranging from 1.7 to 2.0), and PUSS (239-480 %). On average, both varieties exceeded the standard in tuber size, number of tubers in the bush, and marketability. Gusar N was characterized by a relatively high stability of marketability parameters (s²_d=0.05); Arlekin showed high ecological plasticity (bi=2.2). The sources of valuable traits for breeding were selected, which annually exceeded the standard variety Golubizna in the size of marketable tubers (Pamyati Ligaj) and the number of marketable tubers in the bush (Bora Velley and Arlekin). 

   Mineral nutrition and water regime of soils affect significantly the yield and fruit quality of apple trees.

   In this connection, the present study was aimed at determining the effectiveness of different fertilization methods under drip irrigation on the productivity of columnar apple trees grown on sod-podzolic soils.

   Field experiments conducted in 2021–2023 involved the following variants: (1) without fertilizers and drip irrigation control (control); (2) drip irrigation; (3) drip irrigation + N₉₀K₉₀ (solid); (4) drip irrigation + N9₀K₉₀ fertigation. It was found that both drip irrigation alone and fertilization methods have a different effect on the productivity of columnar apple trees, largely depending on the genetic features of the variety and weather conditions. The highest tree productivity was achieved in the variant of drip irrigation in combination with N₉₀K₉₀ in the form of solid fertilizers. The President and Ostankino varieties showed an increase in productivity by 11.2 % and 18.5 %, respectively, compared to the control. The vegetation productivity dynamics depended on the genetic features of the variety to a greater extent. Thus, in similar experimental variants, the total growth length of the President variety exceeded that of the Ostankino variety by 45.4 %. The application of drip irrigation and fertilization methods contributed to an increase in the vegetation productivity of the President variety by an average of 18.3 % compared to the control. Conversely, the Ostankino variety showed a minor decrease in the activity of growth processes in the experimental variants. The content of chlorophyll (a + b) in leaves varied by years, experimental variants, and the interaction of factors. Chlorophyll fluorescence in leaves (F_m/F₀) was significantly influenced by the years of research. To a lesser extent, the efficiency of phytosystem II was infl uenced by irrigation and fertilization methods.

   The study presents data on the species composition of Syringa viruses in the ecosystems of the Tsitsin Main Botanical Garden of Academy of Sciences and describes their phenotypes. The tested Syringa populations revealed symptoms typical of viral pathogens (chlorosis, ring spot, banded chlorosis, mosaic, vein clearing, mottle, necrosis and various types of distortions). The virological examination identified specialized pathogens of Lilac ring mottle virus, as well as previously unreported viruses such as Carnation mottle virus, Cucumber mosaic virus, Alfalfa mosaic virus, and Potato virus Y. Monitoring results showed that the prevalence of polyhostal viruses with a wide range of host plants, which are not typical of lilac culture but specific for other crops, is considered as a characteristic feature of Syringa plantations. The frequency of occurrence was determined for 7 viruses. Analyzing individual genotypes for the presence of viruses typically reveals different levels of their prevalence. Cucumber mosaic virus demonstrates the highest frequency of occurrence (55-70 % of samples), followed by Arabis mosaic virus, Tobacco mosaic virus, Elm mottle virus, Potato virus Y, Carnation mottle virus (45 %, 43 %, 37 %, 28 %, 13 %, respectively). Lilac ring mottle virus was detected in only 7 % of the samples. The study focuses on the predominant prevalence of mixed infections, where two or more viruses were noted. Infection with single viruses was detected in only 40 % of the tested samples. The study discusses the adaptability of pathogens and emphasizes the risk of synergistic diseases and increase in infection rates in Syringa crops.

   The study was conducted in 2023-2024 in stone fruit plantations at the laboratory site of the Federal Horticultural Center for Breeding, Agrotechnology, and Nursery, located in Izmailovo, Leninsky District, Moscow Region.

   The study focused on trees of six cherry varieties (Molodezhnaya, Volochaevka, Assol, Rusinka, Vladimirskaya, Belye Zhuravli), three sweet cherry varieties (Fatezh, Tyutchevka, Iput), three cherry plum varieties (Kubanskaya Kometa, Shatyor, Zlato Skifov), and four plum varieties (Utro, Pamyat Timiryazeva, Tulskaya Chernaya, Yaichnaya Sinyaya).

   Meteorological conditions are presented according to the data of the automatic meteorological station of the Central Office for Hydrometeorology and Monitoring of the Environment.

   The study is aimed at determining the impact of recurrent spring frosts on the productivity and phytosanitary condition of stone fruit plantations.

   The degree of frost damage to stone fruit crops varied during the study years and depended on temperature, duration of frost, and stage of plant development during the period of negative temperatures. The frost dates coincided with the fi rst third of May: May 6, 2023 and May 4, 2024. The minimum temperature during the frost period in 2024 (-1.9 °C was slightly different from that in 2023 (-1.75 °C). The duration of frost accounted for only 4 days in 2023, while in 2024, the unusually cold period with negative temperatures lasted for 10 days. In 2024 the degree of damage to fl wers and ovaries in cherry plums, cherries, and sweet cherries was higher due to the longer exposure to low temperatures and precipitation in the form of rain and snow. A significant decrease in productivity compared to the previous year was noted in the early and mid-ripening cherry varieties Assol, Vladimirskaya, and Molodezhnaya, in the Zlato Skifov cherry plum variety, and in the Tyutchevka cherry variety. The Belye Zhuravli cherry varietiy, Fatezh sweet cherry variety, as well as Tulskaya Chernaya, Yaichnaya Sinyaya, and Utro cherry plum varieties demonstrated high productivity and the greatest resistance to frost. Monitoring of the phytosanitary condition revealed that spring frosts caused a stronger spread and development of several fungal diseases (plum leaf rust and shot-hole disease). In the spring period, a decrease in the number of the main phytophages was revealed in stone fruit orchards, which is associated with the lack of optimal temperature conditions for their development and distribution.

   Garden strawberry (Fragaria x ananassa Duch.) is an important commercial berry crop. Its productivity depends on the adaptive potential of the cultivar and is limited by the degree of exposure to unfavorable abiotic and biotic factors characteristic of a particular climatic zone. The present work studies the resistance of garden strawberry cultivars with diff erent ripening periods to damage by the two-spotted spider mite (Tetranychus urticae Koch.) when grown under simulated conditions of a climatic chamber. Cultivars were observed to respond differently to simulated extreme growing conditions such as simulate d ground frost, waterlogged soil, or soil moisture defi cit combined with damage from mite spread and exposure. The cultivars Festivalnaya, Solovushka, Solnechnaya Polyanka were the least resistant to the impact of a complex of abiotic and biotic factors. For them, the extent of mite damage was up to 100 %. Moreover, a signifi cant number of dead plants were observed. The Bereginya, Nashe Podmoskovye, and Alpha cultivars are able to adapt to adverse environmental conditions. Also, they are more resistant to damage by the two-spotted spider mite.