The aim of this work was to study the mechanism of climatic adaptation of red currant genotypes (Ribes rubrum L.) on the basis of physiological, biochemical and agrometeorological measurements and to determine the different phenophases of plant development identify adaptive genotypes for introduction. The studies were carried out in 2014–2017. The indicators of the water status of annual shoots (water content, water retention capacity), the biochemical composition of berries (vitamin C) and phenological observations were evaluated, taking into account meteorological data. The genotypes of R. petraeum Wulf. and R. multiflorum Kit. had the longest production period. Ambiguous data on the influence of temperature on the content of ascorbic acid in berries were revealed. High temperatures (>+26 °C) contributed to a greater accumulation of ascorbic acid in the cultivars of R. vulgare Lam. High accumulations of vitamin C in the range of +25–27 °C were found in R. petraeum Wulf. and R. multiflorum Kit.. High water content and water loss contributed to early recovery from the dormant state and reduced resistance to spring temperature changes in R. vulgare Lam. Genotypes of R. vulgare Lam., and R. multiflorum Kit. are promising for growing in a zone with a temperate continental climate. The genotypes of the species R. petraeum Wulf are suitable for introduction to the areas with a continental climate. The obtained results are important for adaptive gardening.

Foliar calcium (Ca) treatment exhibits strong potential for enhancing yield and quality in some fruit crops. This study aimed to assess the impact of foliar application of Ca-organomineral (Ca-OM) suspension on total soluble solids (TSS) and Ca dynamics in leaves and berries across five red currant cultivars during the vegetation and storage. A randomized block design with two treatments: (1) Control (without Ca-OM treatment) and (2) foliar Ca-OM treatment, with three repetitions, was applied on five different red currant cultivars. Although foliar Ca-OM treatments did not impact Ca or TSS in leaves, they positively influenced Ca and TSS in fruits, displaying significant variability among cultivars. In addition, Ca-OM treatment increased berry density, reduced abscission, and inhibited the development of diseases, extending storage periods for “Lvovyanka,” “Vika,” and “Gazel” cultivars by three to seven days compared to the Ca-OM untreated control. Ca-OM treatment in the early stages of the ontogenesis of currants provided a high percentage of Ca intake in berries. At the stage of complete maturation, the Ca content in berries decreased and depended on the ripening period of the cultivars. Before harvesting, Ca-OM increased the strength of berries (Fc) and reduced the shedding of berries in the clusters (Fs). At the vegetation stage, Ca-OM increased TSS in berries, and the content of TSS depended on the genotype and weather conditions. The Ca-OM treatment and low temperatures contributed to preserving berry density, reducing the shedding of berries and PLW, and restraining the development of diseases during storage. In addition, the high content of TSS and Ca in berries against the background of a slow rate of decrease in berry density in the Ca-OM variants ensured an extension of the shelf life of “Lvovyanka,” “Vika,” and “Gazel” by three to seven days compared to the control untreated with Ca-OM. Clustering analyses identified these cultivars as similar in terms of TSS and calcium content in fruits, emphasizing their common traits. The study underscores the potential of foliar Ca treatment to enhance berry quality during growth and storage, significantly improve storage duration, and fortify resistance against adverse factors, presenting promising opportunities for elevating yield and quality in specific red currant cultivars.

The results of resistance studies of apple varieties (Malus domestica L.) generative sphere to low temperatures during flowering are presented. The research was carried out on the basis of areas of primary and industrial study of apple varieties and laboratory of physiology of stability of fruit crops of Russian Research Institute of Fruit Crop Breeding in the period 2009-2020. The resistance of the generative organs of the apple tree to spring frost was determined by the method of frost modeling from -1.0°C to -6.0°C. The purpose of the research is to establish a critical temperature to identify the stability of the generative sphere to frosts during flowering, to identify the reaction of different ploidiness varieties to low temperatures in flowering time and identify resistant ones. As a result of frost modes modeling, the critical temperature for flower elements (-3.5°C) was established, and apple varieties resistant to critical temperature were allocated. When using the non-parametric Mann — Whitney criterion, in different phases of flowering reliable (at the value level p = 0.05) differences in the genotypes resistance of different ploidy to the simulated spring frosts were identified. Weak stability of the generative sphere in studied triploid (3n) varietal specimens in comparison with diploid (2n) has been established. Critical temperature was taken by diploid varietal specimens with less damage to flowers and buds (11.3% in Antonovka obyknovennaya to 55.3% in Imant) than triploid (from 61.0% in ELS 30-30-114 to 100% Rozhdestvenskoye). Varieties Bolotovskoe, Imrus, Veteran, Kulikovskoe, Orlik with resistance of the generative sphere to frost are recommended for intensive plantings.

Relevance.A study of the seasonal (phenological) phenomena and natural connections betweenthem on the background of the relevant environmental conditions is of great scientific and practical interest. Knowledge of the dynamics of the seasonal development of woody plants helps in theselection of species and their assessment from an aesthetic and sanitary points of view, as well asin the development and implementation of measures to increase the sustainability of urban greenspaces.Materials and methods.The purpose of these studies is to create a database of the dynamics ofseasonal development of North American woody plants based on the results of many years of phenological monitoring (2003-2017). The 20 species and forms of North American woody introducers e of the VNIISPK arboretum genetic collection were the objects.Results.It was revealed that the growing season of woody North American plants corresponds tothe climatic conditions of the forest-steppe zone of central Russia. The species with the earliestbeginning of the growing season (the third decade of March) were distinguished. There wereMahonia pinnata, M. aquifolia, Betula lenta and B. lutea. On the basis of phenological calendars,phenological spectrums have been constructed. These consist of three lines (the development ofleaves, shoots, flowers and fruits) with the corresponding color symbols. It has been revealed thatphenospectrums vary depending on the conditions of the year. As a result, the database of 20species and forms of North American woody plants was formed in the form of phenological spectrums against the background of registration of weather conditions in the forest-steppe zone ofRussia. The database includes three options for the possible dynamics of the seasonal development of introduced North American plants. The created database allows observing, comparing,evaluating and forecasting changes in the seasonal rhythm of the studied species of introducedNorth American plants.

Global climate change with the cyclicity of natural and climatic processes in the growing season of berry plants, causes weakening at the defense system to (a)biotic stressors, which actualize the need for accelerated cultivar-improving breeding. A new hybrid red currant material was obtained and studied by the method of interspecific hybridization. Correlation analysis was used to assess the relationship between adaptively significant and economical and biological traits. To assess intergenotypic variability, hierarchical clustering was used according to the studied features, which allowed combining three standard methods of multidimensional data analysis. Genotypes adapted to different stressors were identified. The genotypes 271-58-24, 44-5-2, 261-65-19, and ‘Jonkheer van Tets’ were found to have a higher ratio of bound water to free water as compared with the others. Moreover, the genotypes of 271-58-24, 261-65-19, 77-1-47, and ‘Jonkheer van Tets’ were found to have less cold damage during the cold periods. The two most productive genotypes were found to be the genotypes 44-5-2, 143-23-35, and 1426-21-80. A dependence of yield on the beginning of differentiation of flower buds, which led to the abundance of flower inflorescences, was revealed. Rapid restoration of leaf hydration ensured successful adaptation of genotypes to the “temperature shock” of the growing season. The genotypes 271-58-24 and ‘Jonkheer van Tets’ were then observed to be far from the test traits and none of these traits were observed to characterize these two genotypes. The genotypes of 261-65-19 and 77-1-47 were then observed to be characterized by their high stability to Cecidophyopsis ribis scores. Genotypes 261-65-19 and 271-58-24, obtained with the participation of ‘Jonkheer van Tets’ as the maternal form, showed sufficient resistance to Pseudopeziza ribis and Cecidophyopsis ribis. Overall results suggested that the hydration recovery of red currant plants is significantly important for a yield improvement. A new cultivar ’Podarok Pobediteliam (genotype 44-5-2) was obtained that meets the requirements of intensive gardening and is characterized by high adaptability, productivity, and technological effectiveness.

This study focuses on refining in vitro propagation protocols for red currant cultivars of the Ribes genus and evaluating the role of LED lighting in the adaptation of microplants. The cultivars ‘Red Lake’, ‘Englische Grosse Weisse’, ‘Marmeladnitsa’, and ‘Podarok Leta’ were successfully introduced into in vitro culture during their dormancy phase using 0.1% HgCl₂ as a sterilizing agent. The period of spring introduction is not very efficient in connection with the intensive development of saprophytic microflora and weak morphogenesis microplants. Using 0.01% C₉H₉HgNaO₂S sterilizer resulted in a decrease in the necrosis percentage, but an increase in mold proportion. The preparation of the plants with 12% H₂O₂ was considered environmentally not effective enough to obtain a large number of healthy microplants. The use of 12% H₂O₂ resulted in increased necrosis rates by 24.76% compared to 0.01% C₉H₉HgNaO₂S and 0.1% HgCl₂ sterilizers. The variety specificity of Ribesia plants in terms of the content of MS and LF nutrient media components was determined by the survival rate of explants, the formation of additional micro-shoots, and the morphological development. The MS medium with the addition of 1 mg∙L⁻¹ BAP decreased the percentage of mold and necrosis infection and provided a high percentage of viable plants with optimal growth and reproduction rate. In contrast, the LF medium with the same concentration of 6-BAP resulted in poor explant quality and leaf chlorosis at later stages. The study also investigated the effects of different LED light spectra on morphological and physiological traits. For ‘Red Lake’ and ‘Englische Grosse Weisse’, RWUV-A (625–740 nm) lighting enhanced biomass and chlorophyll (Chl a and Chl a + b) accumulation, while the White (W) spectrum benefited ‘Podarok Leta’. Conversely, the RW spectrum with minimal green and no ultraviolet light restricted growth and photosynthetic pigment accumulation across all cultivars, promoting compact plant structures. The RWUV-A lighting condition resulted in the highest NDVI values across all cultivars, indicating an improved physiological status and biomass accumulation. These findings underscore the importance of refining the microclonal reproduction protocols for Ribesia subgenus representatives, emphasizing the genotype-specific light modulation during the proliferation stage. The study highlights the utility of the MS medium and tailored light conditions in enhancing the effectiveness of propagation techniques for producing high-quality planting material.