不同浓度镉胁迫对稗草生理特性的影响

通过室外盆栽法研究不同浓度镉(Cd)对稗草Echinochloa crusgalli生理特性的影响。结果表明，0.3 mg·kg-1 Cd2+胁迫增强稗草分蘖期的光合作用及抗氧化酶活性；但0.6、0.9 mg·kg-1 Cd2+胁迫抑制分蘖期稗草的光合作用，增强抗氧化酶活性以及提高MDA含量；3.0 mg·kg-1 Cd2+胁迫提高稗草分蘖期的抗氧化酶活性；6.0 mg·kg-1 Cd2+胁迫增加稗草分蘖期MDA含量。Cd2+浓度为0.6、6.0 mg·kg-1将抑制稗草抽穗期的光合作用，高浓度镉胁迫抑制稗草抽穗期的抗氧化酶活性。不同浓度镉胁迫下，稗草的脯氨酸含量较高，表现出较高的抗逆能力。

Effects of Cadmium Stress on the Physiological Characteristics of Echinochloa crusgalli

The physiological properties under different Cd2+ concentrations (0, 0.3, 0.6, 0.9, 1.5, 3.0 and 6.0 mg·kg-1) were investigated for the potential use of Echinochloa crusgalli as a candidate for phytoremediation of Cd-contaminated soils. In tillering stage, the photosynthesis and antioxidant enzyme activities were increased under 0.3 mg·kg-1 Cd2+ stress, and 0.6, 0.9 mg·kg-1 of Cd2+ stress inhibited photosynthesis, but promoted the antioxidant enzyme activities and MDA content. In tillering stage, antioxidant enzyme activities was improved under 3.0 mg·kg-1 Cd2+ stress, and MDA content increased under 6.0 mg·kg-1 Cd2+ stress. In heading stage, the photosynthesis was inhibited under 0.6 mg·kg-1 and 6.0 mg·kg-1 Cd2+ stress, and the antioxidant enzyme activities were also inhibited under high Cd stress. The proline content was increased under Cd stress, showing the higher resistance of Cd stress.