CRYOPRESERVATION OF ALGINATE-COATED STRAWBERRY AXILLARY BUDS

Axillary buds are excised from in vitro strawberry plants, grown on multiplication medium and hardened for 2 months in cold storage.
They are then encapsulated in sodium alginate balls, precultured for 18 hrs in 0.75 M sucrose solution as a cryoprotector, dried on silicagel in a drying cabinet (23–24°C) for 6 to 7 hrs, and put directly into liquid nitrogen.

After rewarming, encapsulated buds are placed for a week on a Driver Kunyuki walnut medium (DKW) supplemented with 0.1 mg/L of BAP and 0.01 mg/L of IBA, to rehydrate the alginate balls and to promote the regrowth of buds.
They are then extracted from the balls.

The regeneration rates of the plants fluctuate from 68 to 79% with ‘Chandler’ and from 48 to 86% with ‘Elsanta’.