Long-term maintenance of Pinus nigra embryogenic cultures through cryopreservation

Abstract

Embryogenic tissues of Pinus nigra have been cryopreserved using a two step slow-freezing method. In the first experiment, 20 cell lines were included and the effect of the duration of cryostorage (1 h vs. 1 year) on regrowth was compared. After a short-term storage (1 h in liquid nitrogen, LN) out of 20 cell lines tested 15 showed regrowth (75%) with individual frequencies 10–100%. Long term storage (1 year in LN) resulted in regrowth of 14 cell lines (70%) while the individual frequencies reached 10–100%. One year storage had no negative influence on the fresh mass accumulation evaluated 2–3 months after thawing. Another 20 cell lines were included in the second experiment with the aim to study the correlation between cryotolerance and maturation capacity of cell lines. Between maturation capacity and cryotolerance expressed as regrowth frequencies of individual cell lines, no correlation has been found.