| Low temperature tolerance was determined for gametophytes of food alga Undaria pinnatifida according to various cryopreservation methods. Survival durations after storage in a medium containing 28% glycerol at −80 °C or in a 5-10% glycerol solution at −196 °C were only 9 and 4 days respectively. On the other hand, cooling at 5 °C/min. and storage at −15 °C for 15 minutes, without cryoprotective medium, did not reduce viability but this was highly decreased by storage for 15 minutes at −30 or −196 °C, with or without DMSO. The morphological cooling injuries were depigmentation and/or a contraction of the cells. |
