COPPER AND NICKEL UPTAKE, ACCUMULATION AND TOLERANCE IN TYPHA-LATIFOLIA WITH AND WITHOUT IRON PLAQUE ON THE ROOT SURFACE

The effects of iron plaque on the growth of Typha latifolia L. and acc umulation of copper and nickel in T. latifolia were investigated under laboratory conditions in nutrient solution cultures. Seedlings with a nd without iron plaque on their roots were exposed to 0.05 mu g ml(-1) Cu and 0.10 mu g ml(-1) Ni solutions for 72 d. The results showed no differences in root and shoot d. wt and leaf elongation when Cu or Ni were added to the solution and in the presence or absence of plaque. H owever, root length was reduced by Cu and Ni, and the reduction in roo t length was greater in the presence of plaque. Some Cu and Ni was ads orbed on root surfaces; roots with plaque took up more Cu, but less Ni than those without. The presence of plaque did not alter Cu uptake an d translocation but increased Ni uptake and translocation. Most of the Cu and Ni taken up was retained in the roots, suggesting that the roo t tissue rather than the root surface or plaque is the main barrier fo r Cu and Ni transport. The results differ from those reported for othe r species.