铅·镉单一及复合胁迫对玉米幼苗生理生化特性的影响

Effect of Pb^(2+),Cd^(2+) and Combined Stress on the Physiological and Biochemical Parameter of Maize Seedling

通过水培试验,研究重金属铅、镉单一及复合胁迫对玉米幼苗生理生化特性的影响。结果表明,随着胁迫浓度升高,玉米幼苗叶绿素含量和叶绿素a/b比值均明显下降,丙二醛(MDA)含量均升高,细胞膜透性均明显增大,根系活力受到抑制;Pb、Cd复合胁迫对玉米幼苗的毒害作用高于单一胁迫;Cd胁迫的毒害作用强于Pb胁迫。

The effects of heavy metal Pb^2＋, Cd^2＋ and single or combined stress on physiological and biochemical parameter of maize seedling were studied. The results showed that the content of chlorophyll and the ratio of chlorophyll a/b of maize seedling were decreased apparently with the increasing of concentrations of Pb^2＋, Cd^2＋ single or combined stress, but the membrane permeability was increased, the content of malondialdehyde （ MDA ） was increased and the activities of root subsystems were inhibited. The low concentration Pb^2＋ improved the activity of root subsystems slightly. Pb^2＋ and Cd^2＋ combined stress had stronger toxic harm than single press and the toxic harm of Cd^2＋ press was stronger than Pb^2＋ press.