Investigation of Optimal Storage Temperature for Spore Preservation of Seven Rare Ferns in Japan

抄録

To determine the optimal spore storage conditions, germination after four different storage temperatures (4, -20, -80°C, and liquid nitrogen [-150°C or lower]) was investigated using seven rare fern species distributed across Japanese temperate to subtropical regions. After three years of storage, germination rates were highest after being stored in liquid nitrogen, followed by storage at -80°C. Although germination was observed for all species within the first year of storage at 4 and -20°C, rates decreased to nearly zero after three years for most species. These results suggest that liquid nitrogen and -80°C are the optimal conditions for long-term spore storage of Japanese ferns.