DEVELOPMENT OF A PLANT TEST SYSTEM FOR EVALUATION OF THE TOXICITY OF METAL CONTAMINATED SOILS. I. SENSITIVITY OF PLANT SPECIES TO HEAVY METAL STRESS

Sa？etak The sensitivity of young bean, cucumber and lettuce plants to heavy metals stress was studied at control conditions in a climatic room. The plants were grown in pots with perlite and supplied daily by half-strength Hoagland nutrient solution. The plants were treated for 8 days with different heavy metal doses (full, ？ and ？) starting at appearance of the fi rst true leaf (cucumber and bean) or the full development of the second leaf (lettuce). The full dose consisted 500 μM Zn, 50 μM Cd and 20 μM Cu added to the nutrient solution. Based on the measured morphological (fresh weight, leaf area, root length) and physiological parameters (photosynthetic pigments content and activity of guaiacol peroxidase in roots), the cucumber plants presented the highest sensitivity to heavy metal stress