Approaches for the cryopreservation of Plantago algarbiensis, a rare endemic species of the Algarve.

Background: Plantago algarbiensis is an endangered endemic species from the Algarve, Portugal.

Objective: The main goal of this study was to investigate the viability of cryopreservation procedures in the conservation of seeds and nodal explants from this species.

Materials And Methods: Seeds were directly immersed in liquid nitrogen (LN) for 30 days. Two methods were tested for the cryopreservation of nodal explants, namely droplet-vitrification and encapsulation-dehydration. For both methods, nodal segments were precultured on Murashige and Skoog (MS) medium and recovered on MS supplemented with 0.2 mg l(-1) 6-benzyladenine (BA), after freezing.

Results: After 30 days in LN, the germination capacity of seeds was not affected. The regrowth percentages of cryopreserved nodal segments were approximately 60%. With the droplet-vitrification method, a regrowth percentage of 60.0+/-15.2% was obtained after 120 min exposure to PVS2 (plant vitrification solution 2) and with encapsulation-dehydration method the highest percentage, 63.3+/-9.6%, was achieved after 3 h desiccation.

Conclusion: Seed cryopreservation and cryopreservation of nodal segments by droplet-vitrification and encapsulation-dehydration are therefore effective approaches for the conservation of P. algarbiensis.