Growth changes and tissues anatomical characteristics of giant reed (Arundo donax L.) in soil contaminated with arsenic, cadmium and lead

A greenhouse experiment was conducted to elucidate the growth changes and tissues anatomical characteristics of giant reed (Arundo donax L.), a perennial rhizomatous grass, which was cultivated for 70 d in soils contaminated with As, Cd and Pb. The results show that giant reed rapidly grows with big biomass of shoots in contaminated soil, possessing strong metal-tolerance with limited metal translocation from roots to shoots. When As, Cd and Pb concentrations in the soil are less than 254, 76.1 and 1 552 mg/kg, respectively, plant height and dried biomass are slightly reduced, the accumulation of As, Cd and Pb in shoots of giant reed is low while metal concentration in roots is high, and the anatomical characteristics of stem tissues are thick and homogeneous according to SEM images. However, plant height and dried biomass are significantly reduced and metal concentration in plant shoots and roots are significantly increased (P < 0.05), the stems images become heterogeneous and the secretion in vascular bundles increases significantly when As, Cd and Pb concentrations in the soil exceed 334, 101 and 2 052 mg/kg, respectively. The giant reed is a promising, naturally occurring plant with strong metal-tolerance, which can be cultivated in soils contaminated with multiple metals for ecoremediation purposes.