The paper presents the results of evaluation of varieties and elite forms of black currant with dessert flavor of berries for resistance to anthracnose. Selection in hybrid and inbred progeny of anthracnose-resistant forms with fruits of dessert flavor was carried out. The research was carried out at the collection and selection breeding plots of the Kokino base station, Federal Horticultural Center for Breeding, Agrotechnology and Nursery (Bryansk region). The object of the research involved 20 varieties from the genetic collection of black currants and 5 elite forms, with high-flavored fruits (>4.5 points). Hybrid and inbred stock was obtained from hybridization, open and self-pollination in 2015-2016. Evaluation of black currant resistance to anthracnose was carried out in 2018 and subsequent seasons by visual estimation in field conditions on a five-point scale, according to the generally accepted methodology for variety investigation. It has been established that years with a high value of the hydrothermal coefficient (HTC>1.4) сcontribute to the greatest spread of anthracnose on blackcurrant plants. The research has identified the varieties with high flavor of fruits as well as field resistance to anthracnose (‘Dar Smolyaninovoy’, ‘Zelenaya Dymka’, ‘Malenkiy Prinz’, ‘Mriya-5’, ‘Podarok Veteranam’). The best combinations of crosses were identified to further select dessert forms with high resistance to the pathogen (Chelyabinskaya×-Dar Smolyaninovoy, 10-141-2 ×Partizanka Bryanskaya, 5-4-2/08×Mriya-3, etc.). The highest flavor scores were given to anthracnose resistant selected forms #9-101-01 (Tiben×Selechenskaya 2), 4-57-01, 4-197-05 (Myth×Litvinovskaya), 5-57-03 (Strelets×Mriya), 5-37-03 (Debryansk×Dar Smolyaninovoy), 4-18-01, 4-18-02 (10-141-2×Partizanka Bryanskaya), 1-3-02 (Mriya-5 open pollination) and others.

Viral damage produces a significant detrimental effect on raspberry plantations. Raspberry bushy dwarf virus (RBDV) appears particularly harmful, capable to significantly reduce raspberry yields. The high prevalence of RBDV is due to its ability to be transmitted by pollen and the absence of visible symptoms on plants during the first stages of infection. Breeding of RBDV-resistant varieties can significantly reduce the damage caused by RBDV infection. Therefore, a search for genetic markers of RBDV resistance is considered particularly relevant. At present, the Bu gene is identified with the dominant mode of inheritance associated with the trait of resistance to RBDV. A number of markers, successfully tested on a large sample of foreign raspberry varieties, enable resistant phenotypes to be predicted with high accuracy. However, their testing on Russian varieties is still to be carried out. The paper presents the results of PCR-mediated searching for a diagnostic fragment of the marker rasp_N_gene_1202, associated with the trait of raspberry resistance to RBDV, involving 14 raspberry varieties from the collection of the Federal Horticultural Center. The research was conducted to test the efficacy of the rasp_N_gene_1202 marker in order to identify RBDV-resistant genotypes. The experiment involved 12 Russian varieties and two foreign varieties used as positive control. The work was carried out in the Laboratory of Reproductive Biotechnology of Federal Horticultural Center for Breeding, Agrotechnology and Nursery in 2023. Based on the analysis, a potentially RBDV-resistant variety ‘Arisha’ was identified. In addition, the diagnostic fragment was detected in moderately resistant and resistant varieties: ‘Gussar’, ‘Orangevoye Chudo’ and ‘Poklon Kazakovu’. However, no diagnostic fragment was detected in the resistant varieties ‘Lavina’ and ‘Medvezhonok’. For this reason, the investigated marker is recommended to be used in combination with other known markers of resistance to RBDV in order to increase the reliability of screening results. No diagnostic DNA fragment was detected on varieties with susceptible phenotype using the tested marker. The obtained data can be used in the selection process to develop new RBDV-resistant varieties.

Yield is an important indicator when creating new varieties of crops. Seeking high and stable yields is considered essential in barley breeding. The stability of the studied genotypes was analyzed using various statistical indicators, namely, bᵢ, S²dᵢ, Wi2, σ2i, CV. The experiment was conducted to evaluate yield and stability of barley mutants of M5-M7 generations by parametric statistics. The experiment involved 40 mutants of spring barley belonging to the two-row subsp. distichon L. and six-row subsp. vulgare obtained after mutagenic treatment with phosphemide in two concentrations. The research was carried out in 2020‒2022 on the experimental plot of Federal Horticultural Center for Breeding, Agrotechnology and Nursery (Moscow region, Russia). Phenotypic manifestation of the considered traits and yield varied depending on the year of the experiment. Mutants G3, G5, G7, G16, G19, G20, G22, G23, G24, G27, G29, G33, G34, G40 were characterized by a statistically significant excess of control samples on the weight of 1000 grains. The yield of the studied mutants obtained from the Zernogradsky 813 sample was noted in the range of 282.0– 317.9 g/m2, Dz02-129 had 137.2–201.5 g/m2, C.I.10995 had 90.9–282.7 g/m2, a high variability of this trait was observed with the coefficient of variation equal to 71.02 – 152.42%. The highest value of pair correlation of yield was registered with grain weight per plant (r=0.370) and weight of 1000 grains (r=0.371). Strong conjugation was found between bi and CV (r=0.659); S²di and Wi 2 (r=0.885), σ2i (r=0.885); σ2i and Wi 2 (r=1.000). In addition, a close correlation of yield was noted with bᵢ (r=0.459), S²di (r=0.462), Wi2 (r=0.470), σ2 (r=0.470). Mutants G4, G28, G29 were characterized by relatively stable yields. The complex of economic traits combined with high yield potential was possessed by two-row G1, G2, G40 and multi-row G16, G23 to be recommended for use in the breeding process for high productivity.

The paper presents the results of research for 2022–2023, as well as the analysis of the effect of prolonged negative late spring temperatures on garden strawberry on May 8-12, 2023. The research was aimed at evaluating garden strawberry varieties for a complex of economically valuable characteristics after exposure to prolonged late spring frosts on May 8–12, 2023. Objects of study included 14 garden strawberry varieties of foreign selection: NF 421, ‘Festivalnaya romashka’, ‘Florida Festival’, ‘Verona’, ‘Dely’, ‘Joli’, ‘Senga Sengana’ (k), ‘Sweetheart’, ‘Syria’, ‘Cabot’, ‘Elianni’, ‘Malvina’ and 2 varieties selected by the Institute: ‘Zvezdochka’ (k), ‘Zhanna’. The plants were planted on May 6, 2022, the survival rate accounted for 100%. The research was conducted in the Research Institute of Horticulture and Medicinal Plants “Zhigulyovskie sady” (Samara, Russia) on the collection variety plot in accordance with the generally accepted program and methodology of varietal study of fruit, berry and nut crops. The analysis of weather conditions for 2022–2023 was performed using the data of the Volga Department for Hydrometeorology and Environmental Monitoring (UGMS), with additional data obtained from the temperature and humidity control system located on the test plot in Malaya Tsarevshchina, Krasnoyarsky District, Samara Oblast. The varieties ‘Verona’, ‘Zvezdochka’ (k), ‘Cabot’, ‘Sweetheart’, ‘Festivalnaya Romashka’, and ‘Malvina’ demonstrated the highest resistance to late spring frosts according to the complex of characteristics. The main part of the varieties had 28-33% damage to flowers and buds. The highest damage figure was revealed in the variety of the average maturity period NF 421 and the early variety ‘Zvezdochka’ (k). The late variety ‘Malvina’ did not suffer from frost.

The lowest degree of fruit deformation was observed in the varieties ‘Sweetheart’, ‘Zvezdochka’ (k), and ‘Malvina’. The greatest degree of freezing after exposure to low temperatures on May 8-12 was observed in the varieties ‘Dely’, ‘Joli’, ‘Florida Festival’ and ‘Elianni’. The best adaptive capacity according to the results of overall plant condition for the period 2022-2023 was shown by the varieties ‘Verona’, ‘Zvezdochka’ (k), ‘Senga Sengana’ (k), ‘Cabot’, ‘Sweetheart’, ‘Syria’. The highest average berry weight was recorded in NF 421 (19.5 g/bush). The highest productivity was observed in later ripening varieties – ‘Malvina’ (261.4 g/bush) and ‘Cabot’ (241.0 g/ bush), as well as in the control variety ‘Seng Sengana’ (k) (197.1 g/bush). The lowest indicators were reported in ‘Dely’ (50.1 g/bush) and ‘Florida Festival’ (29.0 g/bush). The genotype was revealed to influence the resistance to low late spring temperatures and recovery ability of plants after late spring frosts.

Shrubs of the genus Spiraea L. are distinguished by a great variety of ornamental features, but are still underused in ornamental horticulture in the northern territories. The issues of passing the seasonal cycle of plants under new harsh climatic conditions remain fragmentarily studied. The research was aimed at examining the features and identifying patterns of the seasonal rhythm of introduced species of the genus Spiraea L. The research was carried out on the basis of the collection of the Botanical Garden of the Institute of Biology, located in the middle taiga subzone of Komi Republic. Plants to be observed included nine species of three taxonomic sections of the genus Spiraea L. The long-term averages of phenological phases and periods of seasonal rhythm of species, as well as variability of features based on the results of phenological observations for six years in the period 2013-2018 were determined. The vegetation period of plants under new conditions lasts up to 145 days and corresponds to the vegetation period of the introduction station. Shoot growth lasts from 65 to 80 days in different species. The sequence of flowering, differences in the dates of onset and duration of flowering in different Spiraea species of three sections were noted. The duration of the prefloral period ranges from 18 to 41 %, the flowering period – from 8 to 31 % of the total vegetation period of plants. The total duration of flowering of the studied species accounts for almost 100 days. The least variability is specific for the period of vegetation of species (variability index up to 5.9 %), the greatest variability – for the period of flowering of plants (variability – up to 26.7 %). The taxonomic factor (85-91 %) was revealed to influence the passage of the generative phases of the seasonal cycle. The correlation interaction was determined between the main phenophases and the early leaf fall phase. The seasonal type of growth and phenological development of Spiraea plants is characterized by an early beginning and end of vegetation, a relatively short period of growth of shoots, and the consistency of average phenological dates. This phenorhythm of the studied species of the genus Spiraea demonstrates their potential for ornamental gardening in the northern region.

The paper presents the results of long-term research into winter hardiness, yield, and resistance to scab of introduced pear varieties. The research was carried out in 2021-2023 on collection plots (established in 2002, 2003) of the Orenburg branch of the Federal Horticultural Center for Breeding, Agrotechnology and Nursery in accordance with generally accepted methods. Objects of research included pear varieties ‘Krasnobokaya’ (K), ‘Krasulya’, ‘Vekovaya’, ‘Myth’, ‘Kuibyshevskaya Zolotistaya’, ‘Nezhnost’, ‘Isetskaya Sochnaya’, ‘Lel’, ‘Bolshaya’. The analysis of the obtained data showed that the damaging factors for the pear in the Orenburg region included low negative temperatures and thaws in winter, followed by frosts (2021 and 2023). The maximum degree of freezing (3.0 points) was observed in ‘Kuibyshevskaya Zolotistaya’ and ‘Nezhnost’ varieties in the winter of 2023, affecting their productivity (4.6 t/ha and 5.0 t/ha, respectively). Most of the studied varieties were found to be winter-hardy (slight freezing up to 2.0 points): ‘Krasnobokaya’ (K), ‘Krasulya’, ‘Vekovaya’, ‘Myth’, ‘Isetskaya Sochnaya’, ‘Lel’, ‘Bolshaya’. It was revealed that the maximum average yield for three years of research was obtained in varieties ‘Krasnobokaya’ (K) (8.3 t/ha), ‘Krasulya’ (9.1 t/ha), ‘Vekovaya’ (8.1 t/ha), ‘Myth’ (8.2 t/ha),’ Isetskaya Sochnaya’ (9.7 t/ha), ‘Lel’ (7.9 t/ha), ‘Bolshaya’ (8.5 t/ha). The highest average fruit weight was obtained in varieties ‘Vekovaya’ (120.6 g) and ‘Bolshaya’ (101.2 g). Meanwhile, ‘Bolshaya’ and ‘Lel’ varieties revealed no significant deviations in fruit sizes from the pomological description, unlike the other varieties. It was found that the degree of leaf scab damage varied from 0 (‘Krasulya’, ‘Vekovaya’, ‘Myth’, ‘Bolshaya’) to 2.0 points (‘Kuibyshevskaya Zolotistaya’, ‘Nezhnost’), fruit damage occurred in varieties ‘Nezhnost’ (1.0 point) and ‘Kuibyshevskaya Zolotistaya’ (1.5-2.0 points). Long-term research afforded ground for comprehensive economic and biological evaluation of the introduced pear varieties and identifying valuable samples to be involved in the selection process in the steppe zone of the Southern Urals: ‘Krasnobokaya’ (K), ‘Krasulya’, ‘Vekovaya’, ‘Myth’, ‘Isetskaya Sochnaya’, ‘Lel’, ‘Bolshaya’.

Intensive biological technologies of apple-tree cultivation with application of organic and mineral fertilizers form high nitrogen nutrition, thus leading to prolonged growth of fruit plants and reducing their winter hardiness. Columnar apple tree fail to demonstrate high potential for winter hardiness. Therefore, research into regularities and mechanisms behind the influence of nutritional status of columnar apple tree on indicators of plant winter hardiness is considered relevant. The research was aimed at establishing the influence of mineral, organic, organomineral fertilization on the components of winter hardiness of columnar apple trees grown on podzolic soil. Materials and methods. The research involved the ‘Triumph’, ‘President’, ‘Ostankino’ columnar apple varieties, as well as organic and mineral fertilizers. The experiment was conducted in 2016–2021 in the agrochemical experiment station of the Federal Horticultural Center for Breeding, Agrotechnology and Nursery (Moscow region) on podzolic soil of medium-loam particle size distribution. The experimental design included 4 variants: 1) control without fertilizers; 2) N₉₀K₉₀; 3) organic fertilizers 100 t/ha; 4) N₉₀K₉₀ organic fertilizers 100 t/ha. Naa (ammonium saltpeter), KCl mineral fertilizers were applied annually, organic fertilizer (horse manure with sawdust) was applied in 2014. Winter hardiness components and plant samples were analyzed according to generally accepted methods. According to the research into the influence of mineral, organic, organomineral fertilization on the components of winter hardiness of columnar apple tree (Malus domestica Borkh.) grown on podzolic soil in the conditions of the Moscow region, the fertilizer is found inefficient in terms of providing the optimal level of nitrogen nutrition of columnar apple tree plants, except for ‘Triumph’ variety when getting organic fertilizers at a dose of 100 t/ha. In January, fructose prevailed in the sugars of annual shoots of columnar apple tree plants. The ‘Triumph’ and ‘President’ varieties showed a tendency to increase in the content of fructose and glucose as compared with the control when getting organic fertilizers and their combination with mineral fertilizers. The same tendency was observed in the ‘Ostankino’ variety for the content of ascorbic acid in annual shoots, whereas this indicator of the ‘Triumph’ and ‘President’ varieties demonstrated the opposite trend. The ascorbic acid content in annual shoots in winter appeared consistent with its content in August shoots and remained independent on the content in leaves in August. With a decrease in temperature to -40 °C (component II of winter hardiness), the ‘Triumph ‘and ‘Ostankino’ varieties suffered reversible damage to the vegetative buds from 0 to 2.0 points, the ‘President’ variety introduced with 100 tons/ha organic fertilizers demonstrated an increase in damage to the vegetative buds to 3.17 points. The greatest damage to reproductive buds in the ‘President’ and ‘Ostankino’ varieties (3.85-3.91 on the control) was observed in component II of winter hardiness. The application of mineral and organic fertilizers increased these damages to complete death of reproductive buds. Injuries to bark, cambium in all variants of the studied varieties did not exceed 2.0 points. Wood appeared more damaged in the ‘Ostankino’ variety (up to 4.03 points in the combined application of N₉₀K₉₀ and 100 t/ha of organic fertilizers) as well as in the Triumph variety (up to 3.80 points in the N₉₀K₉₀ variant). As for component III of winter hardiness, an irreversible damage was noted for reproductive buds of the studied varieties in all variants of the experiment. In terms of component IV of winter hardiness, irreversible changes occurred in reproductive buds to the greatest extent (complete death in the ‘Triumph’ and ‘President’ varieties); in the tissue under reproductive buds, to the greatest extent in the ‘President’ variety (3.07 points in the variant of 100 tons/ha of organic fertilizers) and in the ‘Ostankino’ variety (2.76 points in N₉₀K₉₀), at the core, the maximum damage was noted in the N₉₀K₉₀ variant in the ‘Triumph’ (3.22 points) and ‘Ostankino’ (2.76 points) varieties.

The research was performed in 2021-2022 in an orchard planted in 2015 and located on the laboratory plot of Federal Horticultural Center for Breeding, Agrotechnology and Nursery (Moscow region). Objects of study included Spartan and Common Antonovka apple varieties, on a semi-dwarf clone rootstock 54-118. The research was aimed at studying the impact of crown shapes, irrigation and fertilizer methods on the biochemical composition of apple fruit. The impact of the studied factors on the biochemical composition of apple fruit when grown on sod-podzolic soil was established to depend on the biological characteristics of the variety and to manifest itself in different ways. The Spartan variety, when the spindle-shaped crown was formed, revealed the decrease in the vitamin C content by 7.1-11.2 % compared to the other two forms of crowns. Drip irrigation increased this rate by 9.5 % compared to the control, and the fertilizer methods had no significant differences. The spindle-shaped crown of the Common Antonovka variety, on the contrary, increased the content of ascorbic acid, as did the combination of drip irrigation with N₁₂₀K₁₅₀ in the form of solid fertilizers. The studied factors and their interaction had no significant impact on the total amount of sugars and the content of soluble dry substances in the fruits of the Spartan apple variety. The titratable acidity largely depended on the biological characteristics of the variety. The Common Antonovka variety had much higher titratable acidity than the Spartan variety. The highest indicators were specific for the combinations of drip irrigation with N ₁₂₀K₁₅₀ in the form of solid fertilizers with a spindle-shaped crown (0.7%) and drip irrigation with N₁₂₀K₁₅₀ fertigation with a semi-flat crown and cutting of the central extension shoot in the Common Antonovka variety (1.63%). The sugar-acid ratio was influenced by both the crown shape and drip irrigation in combination with fertilizer methods. The highest values of the sugar-acid ratio in the Spartan variety were revealed during the formation of a column-type crown (20.1), and in the Common Antonovka variety – with a spindle-shaped crown (7.7). The content of nitrates in apple fruit in all variants of the experiment was significantly lower than the MAC.

The review is devoted to resistance of apple clonal rootstocks to bacterial blight of fruit trees considering current data on the biology of its pathogen Erwinia amylovora. The paper provides data on the main known loci of quantitative resistance in Malus species, their genetic markers, and resistance of the main forms of foreign selection. The study collects data on the resistance of Russian clonal rootstocks.