Employment of encapsulation-dehydration method for liquid nitrogen cryopreservation of ornamental plant explants propagated in vitro

In the present studies, an attempt has been made to develop a method of liquid nitrogen preservation of plant explants propagated in vitro in the laboratory of the Department of Ornamental Plants, of Agricultural University in Kraków: shoot apical and axillary meristems of Rosa ‘New Dawn’, somatic embryos of snowdrops Galanthus nivalis L. and G. elwesii Hook, and gametophyte of Phlebodium aureum (L.) J. Sm. (golden polypody). After encapsulation of plant material, it was dehydrated by quick method (capsules were placed in liquid media containing 0.75 M sucrose for 18 h) or by gradual method (capsules were transferred to liquid solutions of media with increasing sucrose concentrations from 0.3 M to 1 M for consecutive 7 days). Moreover, some explants for cryopreservation were treated with the medium containing elevated sucrose level (0.25 M) for 8 weeks