Studies on Responses of Carex dispalatato Cd Stress and Its Accumulation Ability

The effects of Cd2+ on growth characteristics,physiological indices and Cd accumulation ability of Carex dispalata were studied with water culture method.The results showed that:(1) The plant height,length of longest root,number of new root and new tillers,fresh weight and the ratio of shoot to root dry weight were significantly reduced with increasing Cd2+ level.(2) The activities of antioxidant enzymes increased at beginning,and then decreased with increase of Cd2+ concentrations.(3) MDA content,proline content and cell membrane permeability increased with increase of Cd level and time.(4) Chlorophyll content increased under lower Cd2+ concentration,but decreased gradually under higher Cd2+ concentration and longer stress time.(5)The Cd content in Carex dispalata increased with the increase of Cd2+ concentration,and the Cd accumulation ability of root was distinctly higher than that of the above-ground part.The Cd average retention rate in root of Carex dispalata was 93.21% and the biological transfer coefficient to Cd was less than one,which indicated that the root of Carex dispalata has stronger retention action and accumulation ability on Cd.