© 2000 Heron Publishing—Victoria, Canada
Genetic transformation of silver birch (Betula pendula) by particle bombardment
Maarit Valjakka (1, 2), Tuija Aronen (1), Jaakko Kangasjärvi (2), Elina Vapaavuori (3) and Hely Häggman (1, 4)
1. Finnish Forest Research Institute, Punkaharju Research Station, FIN-58450 Punkaharju, Finland / 2. Institute of Biotechnology, The Viikki Biocenter, University of Helsinki, P.O.Box 56, FIN-00014 Helsinki, Finland / 3. Finnish Forest Research Institute, Punkaharju Research Station, FIN-58450 Punkaharju, Finland / 4. Author to whom correspondence should be addressed (hely.haggman@metla.fi) / Received July 28, 1999
Summary
We used in vitro callus and shoot cultures as target material for genetic transformation of silver birch (Betula pendula Roth) by particle bombardment. Cultivation of in vitro shoot cultures before particle bombardment and a long selection period, combined with a high concentration of selective agent
after bombardment, led to the production of transformed plantlets that were stable, and no escapes were found among the tree
lines produced. Clonal variation in transformation efficiency was found in transient expression of the beta-glucuronidase
gene in callus cultures and in plantlets transformed by stable integration of the ribulose-1,5-bisphosphate carboxylase/oxygenase
small subunit (RbcS) and neomycin phosphotransferase (npt2) genes.
Keywords:
biolistic transformation, transgenic plantlets.
