Copper Effects on Growth Parameters of Hollyhock (Althaea rosea L.)

Copper is an essential micronutrient for plant growth which is involved in many metabolic processes. However excessive amounts of copper may cause environmental pollution. With an increase in the contamination of urban areas with heavy metals, more attention should be paid to the role of ornamental plants in removing pollutants from the soils. The effects of heavy metals on the growth parameters of plants also should be determined. In this research the effects of four levels of Cu (CuSO4.5 H2O) including 0, 20, 40 and 80 mg Cu kg soil on growth parameters of hollyhock plants were investigated. Results showed that in treated plants root and shoot elongation, root dry weight and shoot fresh weight were not significantly differentiate from control. However, a significant decrease in Chl.a, Chl.b and total chlorophyll content was observed by increasing the cu level in the soil. Proline content in the leaf tissues reached to the highest values when plants were treated with 80 mg Cu kg soil. Electrolyte leakage of treated plant with 20 mg Cu kg soil was not significant differentiate from control. The concentration of Cu in the shoots and roots significantly increased with increasing the Cu level in the soil. Translocation factor at all Cu concentrations significantly decreased in compared to the control. Generally, results showed that A.rosea is a suitable alternative for phytoremediation of copper contaminated area.