Identification of transgenes from wood of genetically transformed poplar trees

We have extracted total DNA from different fractions of fresh wood as well as from cold-stored and air-dried wood harvested from transgenic aspen grown in the field. The highest amounts of DNA were obtained from bark/cambium tissue; the DNA quality, however, was poor. Best results in PCR and Southern blot analyses were obtained from DNA extracted from early wood. Using appropriate primer pairs, amplification products were obtained from both the foreign gene (transgene) and aspen genomic sequences. In Southern blot analyses transgene-specific hybridisation signals were obtained. This is the first report on the detection of foreign genes in wood sampled from genetically modified trees.