Physiological changes to Tillandsia usneoideswere tested after fumigation with different concentrations of radon in a standard radon chamber. The results showed that the leaf relative electrical conductivity increased at concentration of 2000 Bq/m3, though not significantly different from that of the control group, which increased remarkably at concentration of 4000 Bq/m3. Moreover, soluble proteins and malondialdehyde contents didn't change much with increasing radon concentrations, i.e., no significant physiological damage induced, indicating that Tillandsia usneoides was relatively strongly resistant to radon, which was probably related to the existence of foliar trichomes on the leaf surface. In addition, superoxide dismutase content increased greatly with increasing radon concentrations, suggesting scavenging system of reactive oxygen species played a role in reducing the damage of plants exposed to radon.%通过标准氡室对松萝进行不同氡浓度熏蒸处理之后,检测其植物体的各种生理指标变化.结果表明,在2000 Bq/m3浓度的氡胁迫下,松萝相对电导率变化与对照组相比并不显著,在4000 Bq/m3的高浓度氡胁迫下,电导率才显著升高.而不管氡浓度如何,松萝可溶性蛋白含量和丙二醛(Malondialdehyde,MDA)含量均与对照组差异不显著.说明松萝在氡胁迫下没有表现出明显的生理损伤特征,暗示其对氡具有较强的抗性,这可能是与其叶表存在鳞片有关.另外,松萝的过氧化氢酶(Catalase,CAT)性随着氡浓度的上升有所降低,但超氧化物歧化酶(Superoxide dismutase,SOD)活性却随着氡浓度的上升而显著升高,说明在氡胁迫下,松萝体内活性氧清除体系开始发挥作用,能够进一步减轻氡对植物的伤害.
展开▼
