纳米二氧化钛对生菜的生长效应分析

Analysis on the Growth Effect of Nano Titanium Dioxide on Lactuca sativa

摘要:

为了阐明纳米二氧化钛颗粒(TiO₂NPs)对生菜(Lactuca sativa)生长的影响，采用自行设计的水培装置探究不同浓度TiO₂NPs (300~1 200 mg/L)下，生菜生长和生理生化指标的变化。结果表明，300 mg/L TiO₂NPs能促进生菜幼苗的根长、茎长、叶表面积、鲜重和干重；随着TiO₂ NPs浓度增大，生菜的生长指标呈现下降趋势，但仍优于对照组。生菜体内的抗氧化酶(SOD、POD)在低TiO₂ NPs浓度(300 mg/L)时，活性明显下降；随着TiO₂ NPs浓度增大，这两种抗氧化酶活性逐渐增强。因此，生菜对TiO₂NPs胁迫具有浓度依赖性，表现为“低促高抑”，且能够通过抗氧化酶系统来减轻TiO₂NPs伤害。

Abstract:

In order to clarify the effect of nano titanium dioxide particles (TiO₂ NPs) on growth of Lactuca sativa, the growth, physiological and biochemical indexes of L. sativa were studied treated with TiO₂ NPs (300-1 200 mg/L) by using a self-designed hydroponic device. The results showed that the root length, stem length, leaf surface area, fresh weight and dry weight of seedlings increased treated with 300 mg/L TiO₂ NPs. With the increasing of TiO₂ NPs concentration, the growth indexes showed a downward trend, but still higher than those of the control group. The activities of antioxidant enzymes (SOD, POD) in L. sativa decreased significantly at low TiO₂ NPs concen-tration (300 mg/L). With the increament of TiO₂ NPs concentration, the activities of SOD, POD gradually increased. Therefore, it was suggested that L. sativa has a concentration-dependent effect on TiO₂ stress, showing "promotion at low concentration and inhibition at high concentration". The damage of nanomaterials of L. sativa could be reduced by its antioxidant enzyme system.