EFFECT OF Cd AND Pb ON Ailanthus altissima AND Acer negundo SEED GERMINATION AND EARLY SEEDLING GROWTH

An important activity in environmental protection is the possibility to grow woody plants in soils contaminated by toxic metals for phytoremediation, or biomass production in order to obtain energy. The aim of this paper was to find out the effects of the heavy metals cadmium (Cd) and lead (Pb) on germination and early seedlings growth of tree species Ailanthus altissima (Mill.) Swingle and Acer negundo L. Seeds were germinated in 0, 20, 50 and 90 mu M concentrations, in the form of lead nitrate and cadmium nitrate. Results show that seeds of both species can germinate in the presence of both heavy metals. Germination capacity of seeds treated with highest concentrations of Cd and Pb nitrate was higher for A. altissima (88.66 and 94.67%, respectively). Seedlings development of both species was possible in terms of stronger concentrations of both heavy metals, so these species can be considered to be tolerant to presence of Cd and Pb, and need further investigation. A. altissima seedlings had 4-7 fold higher biomass production and higher tolerance to Cd and Pb treatment. Results can be a contributing step in investigating and defining the tolerance limit of these woody species at different levels of Cd and Pb.