Cryopreservation of cryosensitive basidiomycete cultures by application and modification of perlite protocol

Homolka's perlite protocol (HPP) for cryopreservation of fungal cultures was evaluated in 12 strains (7 species) of cryosensitive basidiomycete cultures maintained in NBRC culture collection by investigating viability, time to recover, and basic morphological study after freezing and storing at -80 degree C for 6 months. The viability of the fungal strains was 60 percent in Phallus hadriani and 100 percent in remaining 11 strains, indicating the efficacy of HPP method for cryopreservation of some cryosensitive basidiomycetes. The HPP method was modified by changing the addition of cryoprotectant (glycerol) from prior precultivation to post precultivation, limiting the cryoprotectant exposure time to 48 hours, and increasing the glycerol concentration from 5 percent to 12 percent. The viability of P. hadriani strain increased from 60 percent to 100 percent with the modified perlite protocol after storage at -80 degree C for 6 months.