Cryopreservation of Cherry Rootstock Gisela 5 using Vitrification Procedure

In vitro -grown shoot tips of Gisela 5 ( Prunus cerasus × Prunus canescens ) cherry rootstock were tested for regrowth after cryopreservation using vitrification technique. Explants were precultured in the dark at 23°C, in a liquid MS medium with a progressively increasing sucrose concentration (0.3 M for 15 h, then 0.7 M for 5 h), and subsequently loaded in a solution containing 2 M glycerol and 0.4 M sucrose for 20 minutes. Shoot tips were dehydrated at 0°C using either the original PVS2 or modified PVS2 solution (PVS A3 - 22.5% sucrose, 37.5% glycerol, 15% ethylene glycol and 15% DMSO) for 30, 40 and 50 minutes. The survival and regrowth of the cryopreserved shoot tips dehydrated with the original PVS2 solution ranged between 36-54% and 8-17%, respectively. However, the dehydration with the PVS A3 solution resulted in considerably higher survival rates (81-92%), as well as higher regrowth rates (39-56%) after cryopreservation. These results prove the feasibility of the PVS A3-based vitrification technique for a long-term storage of this genotype.