Abstract:

To determine the copy number of the transgene, the single- restriction enzyme Pst I was used to digest the genomic DNA. Southern blot analys is of transgenic birch plants indicated that the GUS gene had been integrated into the birch genome. Among the 11 transgenic birch lines, the copy number of GUS varied from1 to 4. The expression of the GUS gene w as studied by his tochemic al staining and spectrophotometry . His tochemical staining with X-gluc showed the GUS gene silenced in TP30 and TP96 plants , and that significant dif ferences of GUS activity was observed in other transgenic plants, with GUS activity remarkably high in TP23, TP36 and TP71 plants. However, the copy number and expression of the GUS gene were not significantly related.

Key words: Transgenic Birch, Integration Pattern, Expressive diversity, GUS