Somaclonal variation in cryopreserved embryogenic clones of white spruce [Picea glauca (Moench) Voss.]

Trees were regenerated from six white spruce embryogenic clones after cryop reservation for 3 and 4 years, respectively. Genetic stability was evaluate d using randomly amplified polymorphic DNA (RAPD) fingerprints. Somaclonal variation was detected in some in vitro embryogenic cultures 2 and 12 month s after they were re-established following cryopreservation but not in the corresponding regenerated trees. These results suggest that trees regenerat ed from cryopreserved cultures in subsequent years are primarily geneticall y stable in the genomic regions tested and that variation observed due to t he in vitro culture process infrequently affects trees regenerated from nor mally maturing and germinating somatic embryos. However, trees regenerated from somatic embryos that matured or germinated abnormally in in vitro cult ure exhibited altered RAPD fragment patterns.