Effect of heavy metals (Cd and Ni) on yield and agronomic traits of common purslane (Portulaca oleracea)

In order to soil remediation from pollution by heavy metals, a new technical has been recently proposed called phytoremediation. Purslane is also highly tolerant against lack of water and salinity and can be regarded as a hyper accumulator of heavy metals. To study the effect of the nickel and cadmium on growth, yield and other characters of Portulaca oleracea L. a pot experiment was carried out in a completely randomized factorial design with three replications in the field of Azad University of Shahrekord, Iran, in the spring and summer of 2012. Treatments of this experiment included different levels of nickel (0, 20, 60, 120 mg/kg) and different levels of cadmium (0, 5, 20, 40 mg/kg). The results of this research showed that different levels of nickel and cadmium have a significant effect on the morphological and physiological characters of Portulaca oleracea L. and along with increasing the concentration of the heavy metals, these characters significantly decreased in comparison with the control plants. In classifying the averages of height, shoot and root dry matter and percentage of the extract, the highest amount belonged to the control plants and the lowest amount to the plants under combined treatment of nickel (120 mg/kg) and cadmium (40 mg/kg) and the single treatment of cadmium (40 mg/kg). Furthermore, the toxic properties of cadmium are more than nickel decreased most of measured characters.