CRYOPRESERVATION OF POLLEN OF CAROB TREE

In this work, anthers isolated from male flowers of carob tree (Ceratonia siliqua L.) at developmental phase II were cryopreserved by vitrification, using a fast freezing method. Different types of carbohydrates at different concentrations, namely sorbitol (0.5 M, 1 M, and 2 M), mannitol (0.5 M and 1 M), sucrose (0.5 M, 1 M, and 2 M), and glucose (0.5 M, 1 M, and 2 M), namely sorbitol, mannitol, sucrose and glucose, were compared with respect to their capacity of inducing freeze tolerance in pollen of carob tree. Carbohydrates were applied as a pre-treatment to anthers before cryostorage. It was also assessed if the presence of the cryoprotectant during the storage period was beneficial for pollen viability. The viability of cryopreserved pollen was evaluated after 5 and 8 months of storage. The application of the cryoprotectants generally increased pollen viability as compared with the control. The best results were obtained after 5 months storage, in the presence of the cryoprotector, with pollen pre-treated with sucrose 0.5 M. The viability of pollen decreased with increasing the duration of storage period.