La micropropagazione per la salvaguardia della biodiversità vegetale: esperienze condotte presso il CNR-IVALSA

Numerous studies have been carried out in the last 10 years at the CNR-IVALSA of Florence, Italy, with the aim to apply the micropropagation technique to the medium- (slow growth storage) an longterm (cryopreservation) conservation of plant germplasm. Taking into consideration the necessities of commercial micropropagation laboratories, trials on slow growth storage investigated some factors affecting the storage at 4°C in the dark of rootstock and fruit shoot cultures, such as light conditions, sugar content in the conservation medium, gas exchanges in the containers. The cryopreservation (in liquid nitrogen, at -196°C) of a wide range of explants (naked and encapsulated shoot tips, embryogenic callus, seeds, embryonic axes, dormant buds) is considered of great interest in terms of plant biodiversity conservation. In time, various cryogenic techniques have been applied, such as the "treatment with vitrification solution", the "encapsulation-dehydration/vitrification", the "droplet freezing", the "dehydration" of seeds and dormant buds. All these techniques take great advantage of the availability of efficient micropropagation protocols, during the preparation and/or the recover of explants from the storage in liquid nitrogen.