Cadmium Tolerance and Accumulation in a Halophyte Salicornia europa ea as a New Candidate for Phytoremediation of Saline Soils

The ability of a halophyte Salicornia europaea to accumulate cadmium (Cd) in the shoots was examined in laboratory conditions. Aseptically growing seedlings were transferred at 7 days after sowing onto a sterilized nutrient medium solidified with 0.2% Gellan Gum, and cultivated for 21 days in a growth chamber. In the presence of 0.3 M NaCl in the medium, the growth of the shoots was not influenced by the addition of Cd to the medium at the concentrations up to 0.8 mM. At the addition of 0.2 and 0.8 mM CdCl2, the amount of Cd in the plant shoots was 2.2 ± 0.1 and 7.2 ± 0.8 μmol Cd g dry weight, respectively. The more NaCl in the range of 0.1 to 0.4 M was added to the culture medium, the significantly less amount of Cd per g dry weight was accumulated in the shoots, though the total amount of Cd accumulated in a plant shoot was not affected except at 0.4 M NaCl addition. If the plants were grown for 5 weeks on a sterilized saline soil instead of the nutrient medium, they accumulated Cd in the shoots at the concentration of roughly half of those in the shoots cultured on the nutrient medium when compared at the same doses. We propose here that S. europaea is a new candidate plant species for using in effective phytoremediation of Cd-contaminated saline soils.