Desiccation and cryopreservation of actively-growing cultured plant cells and protoplasts

Actively-growing cultured cells of Pogonatum and Polytrichum were desiccated and cryopreserved. Although Pogonatum was slightly more tolerant to desiccation, both species were cryopreserved with > 90% survival rate. An examination of isolated protoplasts revealed that differences in desiccation tolerance were likely dependent on levels of injury of plasma membranes. Trehalose and sucrose provided some protective effects during protoplast desiccation, but mannitol and glucose were less effective when Pogonatum protoplasts were directly desiccated and preserved at various temperatures. The effectiveness of glucose was enhanced when combined with culture medium components.