Optimization of the Clonal Micropropagation Methodology Elements of Red Currant (Ribes rubrum L.) Taking into Account Genotypic Features

The purpose of the research is to study the effectiveness of microclonal reproduction of red currant depending on the period of isolation of meristems, genotypic characteristics of varieties and the organic composition of the nutrient medium at various stages of cultivation. The studies were conducted in 2022–2023 at the Biotechnology Laboratory of the Russian Research Institute of Fruit Crop Breeding. The following varieties bred by the Russian Research Institute of Fruit Crop Breeding were selected as the objects of the research. Meristems were isolated in two periods: April and June. Three media were tested based on Murashige – Skoog macro- and microsalts with the addition of 0.2 mg/l 6-BAP, 10 mg/l ascorbic acid, triple iron chelate content and different vitamin content: 1) B₁ (0.5 mg/l), B₆ (0.5 mg/l), PP (0.5 mg/l) (control, MS); 2) B₁ (0.1 mg/l), B₆ (0.5 mg/l), PP (0.5 mg/l) (MS₁); 3) B₁ (10.0 mg/l), B₆ (10.0 mg/l), PP (5.0 mg/l) (MS₂). The most significant effect on the result of introduction into in vitro culture was exerted by the terms of explant isolation and the corresponding climatic conditions, as well as the genotypic characteristics of the varieties. Explants of the Gazel and Vika varieties had a higher survival rate when introduced in April. The summer period of introduction for all the studied varieties was characterized by an increase in the proportion of necrosis and infection of explants, up to their death (Valentinovka variety). Changing the concentration of vitamins did not have a significant effect on the survival rate of explants at the initiation stage in in vitro culture. Cultivation of red currant microplants on nutrient media containing 6-BAP 0.8 mg/l (MS₃) and 6-BAP 0.5 mg/l, IMC 0.1 mg/l, GA 0.1 mg/l (MS₄) did not have a significant effect on the multiplication coefficient. Addition of low concentrations of cytokinins, auxins and gibberellic acid to the nutrient medium contributed to an increase in the height of red currant microshoots of the Gazel variety.