纳米二氧化钛缓解镉胁迫下小麦幼苗生长及生理变化

研究了水培环境中不同浓度纳米二氧化钛（TiO₂-NPs）（0，25，50，100，200 mg/L）缓解Cd对小麦幼苗造成的生理毒害的作用。结果显示:在水培环境下TiO₂-NPs的施用，缓解了Cd对小麦带来的氧化胁迫，减轻了Cd对小麦的毒害作用，显著提高了小麦生物量、根长及株高，改善了小麦光合作用。中浓度（50，100 mg/L）TiO₂-NPs的使用显著提高了小麦幼苗净光合速率。对于所有浓度TiO₂-NPs的施用，小麦幼苗POD酶活均显著低于Cd处理组；SOD酶活在较低浓度（<200 mg/L）时显著低于Cd处理组。TiO₂-NPs通过减轻Cd氧化胁迫作用，有效缓解了Cd对小麦幼苗的毒害，提高了小麦幼苗的光合作用。

GROWTH AND PHYSIOLOGICAL INDEXES OF WHEAT SEEDLINGS UNER CADMIUM STRESS ALLEVIATED BY NANO TITANIUM DIOXIDE

The research mainly studied whether the use of different concentrations of nano-titanium dioxide (TiO₂-NPs) (0, 25, 50, 100 and 200 mg/L) in hydroponic environment could alleviate the physiological toxicity of Cd to wheat seedlings. The oxidative stress on wheat caused by Cd was alleviated by TiO₂-NPs application in the hydroponic environment. The toxicity of Cd to wheat seedlings was alleviated, the biomass, root length and plant height of wheat were significantly increased, and the photosynthesis of wheat was improved. The net photosynthetic rate of wheat seedlings was increased significantly at medium concentrations (50, 100 mg/L) of TiO₂-NPs. For all concentrations of TiO₂-NPs, the POD enzyme activity was significantly lower than the Cd treatment group; the SOD enzyme activity was significantly lower than Cd treatment group at lower concentrations (<200 mg/L). Results showed that the use of TiO₂-NPs effectively alleviated the toxicity of Cd to wheat seedlings and improved the photosynthesis of wheat seedlings by reducing the oxidative stress caused by Cd.