Physiological effects of copper treatment and its uptake pattern in Festuca rubra cv. Merlin

A study is reported on the physiological effects of copper on two cultivars of Festuca rubra, the zinc/lead-tolerant cv. Merlin and a sensitive cultivar S59. The former was shown to withstand copper with a high tolerance index (80.33%) at 50 mg L^-1 Cu²⁺ concentration in the culture medium. Copper treatment up to 50 mg L^-1 appeared to cause little change (less than 5%) in root and shoot elongation. Fresh weights of roots were however significantly reduced when the copper concentration was above 10 mg L^-1, although the metal appeared to have no effect on shoot fresh weights. Similarly, Cu seemed to affect the water content of the root but not the shoot. The accumulation of Cu in the root tissues increased rapidly with an increase in metal concentration in the medium until levelling off at about 20 mg L^-1, suggesting that there might be limited binding sites for the metal. Metal transport to the shoot was minimal (about 3% of root) indicating that the root may play a major role in preventing the toxic metal from being transported to the more sensitive upper portion of the plants.