【摘要】 选取水稻（Oryza sativa）为研究对象,采用营养液水培法,以营养液(0 mg·L^-1 MWCNTs、0 mg·L^-1 Cd²⁺)为参照,分析不同浓度梯度下多壁碳纳米管（MWCNTs）单一处理、MWCNTs与Cd²⁺复合处理对水稻生长的影响.结果表明,MWCNTs单一处理中,水稻幼苗的生长与MWCNTs添加浓度呈明显负相关.低浓度的MWCNTs(1.5 mg·L^-1)对水稻幼苗的生长产生抑制作用,较高浓度的MWCNTs(≥6.0 mg·L^-1)会显著（P<0.05）抑制水稻幼苗的生长.添加5 mg·L^-1 Cd²⁺会增强MWCNTs对水稻幼苗的生长抑制,当MWCNTs浓度从1.5 mg·L^-1上升到12 mg·L^-1,单一处理组与复合处理组相比,水稻幼苗的根系活力分别下降6.4%、10.4%、24.4%和13.9%;水稻幼苗的叶绿素含量显著降低;复合处理组的水稻叶片的POD活性略高于单一处理组,分别高出11.0%、46.1%、5.6%、11.6%;水稻幼苗叶片气孔导度变小、胞间CO₂浓度升高、光合速率减慢.MWCNTs与Cd²⁺对水稻幼苗的生长具有明显的协同抑制效应.更多还原

【Abstract】 Rice（Oryza sativa） seedlings were co-cultured with multi-walled carbon nanotubes（MWCNTs） and cadmium（Cd） of different concentrations to explore the effects of combined contamination on their growth. The results showed that the growth of rice seedlings was negatively related with the concentration of MWCNTs in the single treatment of MWCNTs. Low concentration of MWCNTs(1.5 mg·L^-1) inhibited the growth of rice seedlings, whereas higher concentrations(≥6.0 mg·L^-1) significantly（P<0.05） inhibited its growth. The addition of 5 mg·L^-1 Cd²⁺ enhanced the growth inhibition of MWCNTs on rice seedlings. When the concentrations of MWCNTs increased from1.5 to 12 mg·L^-1, the root vigors of rice seedlings decreased by 6.4%, 10.4%, 24.4% and 13.9% in comparison with the composite treatment groups, respectively. The chlorophyll contents were significantly reduced, and the peroxidase activity of rice leaves in the composite treatment groups were 11.0%, 46.1%, 5.6%, and 11.6%, respectively, which were slightly higher than those in the single treatment group. The leaf stomatal conductance of rice seedlings decreased. The intercellular CO₂ concentration increased, whereas the photosynthetic rate and leaf stomatal conductance of rice seedlings decreased. It was indicated that MWCNTs and Cd²⁺ had obvious synergistic effects on the growth of rice seedlings.更多还原