Cryopreservation of shoot-tips by droplet vitrification applicable to all taro (Colocasia esculenta var. esculenta) accessions

The application of the droplet vitrification cryopreservation technique to taro accessions from a range of Asia Pacific countries is presented. The optimum protocol involves excision of about 0.8 mm shoot-tips from in vitro plants, 20-40 min PVS2 exposure at 0 degrees C followed by rapid plunge into liquid nitrogen. Thawing was done at room temperature (25 degrees C) and shoot-tips inoculated on MS medium with 0.1 M sucrose regenerated into plantlets 4-6 weeks later. This new droplet vitrification protocol improved the mean post-thaw regeneration rates to 73-100% from 21-30% obtained with the previous cryo-vial vitrification protocol.