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.

Purpose. The systematization of information on the micro clonal reproduction of representatives of the Ribes spp. genus, including the rooting of micro shoots and their adaptation in ex vitro conditions. Methods. A comparative analysis was used to review foreign and domestic literature on the cultivation of berry crops using the method of microclonal propagation. Results. It is possible to increase the reproduction coefficient of healthy pure-cultivar Ribes spp. planting material in conditions of micro clone reproduction, taking into account genotypic features. Obtaining viable explants when introduced into in vitro culture is achieved, first of all, by choosing a high-quality source material, the phase of plant development during the isolation of explants and the selection of nutrient media. In addition, the positive introduction is influenced by the effectiveness and toxicity of the sterilizing agent, the fight against phenolic oxidation of explants and the medium, the range of growth regulators during the periods of the introduction, micropropagation and rhizogenesis. The greatest production losses occur at the stage of acclimatization of micro-shoots in non-sterile conditions, which is associated with the weak work of enzymes for carbon fixation in the required volumes and the unformed water regime due to the difference in the microclimate in the test tube and open ground conditions. Various technologies of adaptation of the representatives of this genus to external conditions are presented, ranging from the selection of a substrate in greenhouses to the development of special climate chambers with optimal conditions. Despite the contradictory results, the idea of the success of the use of certain preparations for Ribes spp. is expanding, the quality of the planting material is improving, however, the methodology for obtaining pure-variety planting material taking into account the varietal characteristics, has not been fully developed, and the issues of adaptation at the ex vitro stage have not been fully resolved. Scientific novelty: The review of the reports is presented taking into account new domestic and foreign scientific developments of the stages of microclonal reproduction of berry crops, depending on the species and genotypes, as well as the issue of acclimatization in ex vitro conditions is discussed.

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.

The cultivation of berry crops by the type of "intensive plantings" is an economic and scientific approach in modern horticulture. The principles of forming a red currant assortment adapted to mechanized harvesting are considered. The bush should be compact for mechanized harvesting and have a straight-growing or slightly spreading shape. The morphological structure of the bush is a feature determined by the genotype. The ripening period of berries and the mechanical parameters of berries assess the effectiveness of the berry harvesting process. With the help of agrotechnical techniques, the mechanical parameters of berries cannot be improved and are de-termined by weather, soil, water, and climatic factors. The present study was conducted in the 2021-2022 season using 14 red currant genotypes of different geographical and genetic origins to assess cultivars' suitability for machine harvesting. In most of the studied cultivars, berry quality indicators, the parameters of separation force (Fs) and crushing force (Fc) decreased by the time of biological maturity of the genotype. Several cultivars have shown a non-simultaneous decrease in Fs and Fc. A minor limiting feature determines the duration of harvesting. The high correlation of Fs and Fc (R=0.75-0.85) allows us to predict the most significant period for the high-quality operation of a mechanized harvester. There was no dependence of the strength of the attachment of berries to the peduncle on the thickness of the skin of the berries. Jonkheer Van Tets, Red Lake, Rovada, Rolan, Vika, Asya, and Niva can be attributed to technological cultivars as sources of compact and erect bush habit, Jonkheer Van Tets, Rovada, Rolan, Vika, and Asya are recommended for mechanized harvesting.