Abstract: Drying time and pretreatment temperature were explored to find out the optimum conditions of spores of  Haplocladium microphyllum storaged in Liquid nitrogen. Different time (1 d, 15 d, 30 d, 90 d, 180 d) of cryopreservation were studied using the optimum storage conditions and without any treatment. The spore average germination rate and protonema growth were compared before and after cryopreservation. The results showed that (1) After drying 5 h, --20^oC low temperature pretreatment and thawing at room temperature conditions, the spore average germination rate was highest (88.26%), there were no significant difference between the average germination of spores of drying 5 h, 15--18^oCand 20 h, --20^oC low temperature pretreatment; (2) The average germination rate (88.26%) of spores stored in liquid nitrogen for 1 d was comparatively higher than that of the control (77.90%), the average germination rate of spores stored in liquid nitrogen for 30 d dropped to 6.03%, the spore average germination rate stored for 90 d appeared to rise and reaching 88.47%, the
spore average germination rate stored for 180 d remained at 49.46% and the relative retention rate reached 63.49%. The results demonstrated the feasibility of cryopreservation for the long-term storage of spores of  Haplocladium microphyllum.

Key words: bryophyte, Haplocladium microphyllum, spore, cryopreservation