弯囊苔草对Cd胁迫的响应及其Cd富集能力的研究

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

通过水培实验,研究了不同Cd2+浓度(0、50μmol/L、100μmol/L、200μmol/L、400μmol/L)下和不同时间内(1d、4d、7d、10d)Cd2+对弯囊苔草生长、生理指标及富集能力的影响。结果表明:(1)株高、最长根长、新增根数、新分蘖数、鲜重和地上与地下部分的干重比均随着Cd2+浓度的提高而逐渐下降。(2)3种抗氧化酶活性均随着Cd2+浓度的增加呈现先上升后下降的趋势。(3)MDA含量、Pro含量和质膜透性均随着Cd2+胁迫浓度的增加和胁迫时间的延长而增加。(4)叶绿素含量在低浓度Cd2+胁迫时增加,高浓度和胁迫时间长时下降。(5)弯囊苔草体内Cd含量随Cd2+浓度的增大而增加,根系对Cd的富集能力明显高于地上部分。根系对Cd的平均滞留率为93.21%,弯囊苔草对Cd的转移系数小于1,表明弯囊苔草根系对Cd有较强的滞留作用和富集能力。

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.