Impact of high cadmium and nickel soil concentration on selected physiological parameters of Arundo donax L.

The purpose of this study was to investigate the effects of high cadmium and nickel soil concentrations on selected physiological parameters of Arundo donax L. A 2-year pot experiment was held in the field and the pots were irrigated with aqueous solutions of Cd and Ni in concentrations of 5, 50 and 100 ppm, against the control (tap water). At the end of the cultivation periods the pots soil was divided into three equal zones and total and NH4OAc extractable Cd and Ni concentrations were determined. The top zone exhibited the highest metal content. Cadmium and nickel total concentrations at the end of the experiment were up to 973.8 mg kg−1 and 2543.3 mg kg−1 respectively, while NH4OAc extractable Cd was up to 291.7 mg kg−1 and Ni up to 510.3 mg kg−1. Stomatal conductance ranged between 0.3 and 0.8 mol CO2 m−2 s−1, intercellular CO2 concentration ranged between 212.9 and 243.0 ppm CO2, stomatal resistance between 0.6 and 1.3 s cm−1, chlorophyll content (SPAD values) between 46.3 and 57.0 and chlorophyll fluorescence (Fv/Fm) ranged between 0.8 and 0.9. All studied physiological parameters did not show statistically significant differences among control and heavy metal treated plants for both years; therefore, high soil cadmium and nickel concentration did not inhibit stomatal opening and did not affect the function of the photosynthetic machine of A. donax plants.