Liquid nitrogen - A medium to store germplasm

Collections of plant genetic resources require secure storage systems and s imple conservation techniques. A simple freezing method has been developed for the cryopreservation of old potato varieties kept as an in vitro collec tion. During the initial project 219 varieties and genotypes have been froz en and stored. Currently cryopreservation of potato cultivars is carried ou t at two locations in Germany. In Braunschweig cryopreservation of the in v itro collection is continued and in addition virus free material of partner institutes stored in the frame of an EU project. In Gatersleben potato cul tivars of the in vitro collection of Gross Lusewitz is frozen and stored in liquid nitrogen using the same freezing protocol.