Genetic fidelity of cryopreserved embryogenic cultures of open-pollinated Abies cephalonica

The aim of the present study was to apply cryopreservation for the embryoge nic cultures of open-pollinated Abies cephalonica, as well as to test the g enetic fidelity of the cryopreserved cell lines using random amplified poly morphic DNAs, i.e. RAPD markers. Dimethylsulfoxide (DMSO) and two mixtures of polyethylene glycol, glucose and DMSO (PGD I and PGD II), were used as c ryoprotectants and the cryoprotectant treatments were performed with and wi thout storage in liquid nitrogen. All the tested cryopreservation methods, i.e. DMSO, PGD I or PDG II used as cryoprotectant combined with slow coolin g and fast thawing, proved to be applicable for A. cephalonica SE cultures. The best results, measured as survival percentage and mean growth ratio, w ere achieved using the PGD I treatment. The RAPD assays performed revealed considerable genetic variation in the DMSO treated but non-frozen samples, i.e. 16.8% of the produced RAPD profiles showed intraclonal variation while background variation was seen in 1.7% of the control amplifications. The p resent results show that cryoprotectants may cause a risk for genetic fidel ity of plant material and thus, monitoring it, is important. This is partic ularly true in the breeding of the long-living conifers, since the effects of occasional mutations or genetic rearrangements may not be readily observ ed in young plants but expressed substantially later on in mature trees. (C ) 1999 Elsevier Science Ireland Ltd. All rights reserved.