Clone stability and in vitro phytoextraction capacity of
vegetative clones of R x canescens (2n = 4x = 38) including two
transgenic clones (ggs11 and lgl6) were studied as in vitro leaf
disc cultures. Presence of the gshI-transgene in the transformed
clones was detected in PCR reactions using gshI-specific
primers. Clone stability was determined by fAFLP (fluorescent
amplified DNA fragment length polymorphism) analysis. In total,
682 AFLP fragments were identified generated by twelve selective
primer pairs after EcoRI-MseI digestion. Four fragments
generated by EcoAGT-MseCCC were different (99.4% genetic
similarity) which proves an unexpectedly low bud mutation
frequency in R x canescens. For the study of phytoextraction
capacity leaf discs (8 mm) were exposed to a concentration
series of ZnSO4 (10(-1) to 10(-5) m) incubated for 21 days on
aseptic tissue culture media WPM containing 1 mu m Cu. Zn2+
caused phytotoxicity only at high concentrations (10(-1) to 10(-
2) m). The transgenic poplar cyt-ECS (ggs11) clone, as
stimulated by the presence of Zn, showed elevated heavy metal
(Cu) uptake as compared to the non-transformed clone. These
results suggest that gshI-transgenic poplars may be suitable for
phytoremediation of soils contaminated with zinc and copper
