Cryopreservation of Ribes nigrum and Ribes rubrum cuttings for long-term storage

The development of fruit growing in Kazakhstan, especially for berry crops, requires planting material for storage and propagation using vegetative methods. There are no industrial areas for blackcurrants and redcurrants in the republic, although the demand for berries and products based on them remains high. The purpose of the study is to investigate the features of cryopreservation of Ribes nigrum and Ribes rubrum cuttings to create a genetic bank for species and varieties and increase the possibilities for their long-term storage for subsequent propagation. Experiments to optimize cryopreservation conditions were carried out at the laboratory “Research Park of Biotechnology and Eco-Monitoring” of Karaganda Buketov University in 2023-2024. The cuttings were frozen in liquid nitrogen in Dewar vessels at a temperature of -196°C. Cuttings of Ribes nigrum and Ribes rubrum of different thicknesses harvested in autumn were used. Freezing was carried out without the use of cryoprotectants and with the use of cryoprotectants (glucose, sucrose, and glucose at concentrations of 20 and 40%). The influence of container type, freezing conditions, thickness of plant materials, and cryoprotectants on the viability of blackcurrant and redcurrant cuttings after storage in liquid nitrogen was investigated. It was found that plastic cryotubes are the best containers for both types of currants. It is better to choose thicker cuttings with a diameter of 6-8 mm, which showed the best survival results after freezing in liquid nitrogen. The highest survival rates for black currant cuttings were obtained with two-stage freezing; no reliable data were obtained for red currants. The use of cryoprotectants significantly increased the survival rate of currant cuttings. The highest survival rate was obtained when using glycerin at a concentration of 40%. Thus, the results of the study show that the optimal conditions for cryopreservation of black and red currant cuttings are plastic containers, thick cuttings 6-8 mm in diameter, the use of two-stage freezing, and a cryoprotectant glycerol at a concentration of 40%. The results obtained were used for long-term storage of currant cuttings and the creation of a genetic bank at Karaganda Buketov University.