The Effects Of Dodecane On The Vegetative Growth,Photosynthetic Pigments And Antioxidative Enzymes Of Spirodela Polyrrhiza

Environmental pollution has become a restricted factor of social and economic development with economic globalization. Anilines are an important raw materials for some industries, and some wastes containing aniline are potential environmental pollutants. Aquatic ecosystems are one of ecosystems which are easy damaged by aniline. In this paper, the ecotoxicological effects of aniline on Spirodela polyrrhiza have been studied from both morphological and physiological aspects. The main results were shown as follows:1. Aniline could significantly affect the frond number of S. polyrrhiza. During the experiment, the frond number in control was significantly bigger than that of other experiment groups, but there was no significant correlation between the effect and aniline concentration. When the concentration was≥0.4ml/L. aniline could accelerate the etiolation of frond of S. polyrrhiza. The effect was positively correlated with aniline concentration. When the concentration was≥0.8ml/L， aniline could cause the death of S. polyrrhiza and the effect was also related with the exposure time.2. Aniline could result in the separation of the fronds from the mother plants. The individuals of S. polyrrhiza with1-5fronds increased significantly, especially under the higher concentrations of aniline.3. When the concentration was≤0.1ml/L. aniline had no significant effect on the biomass of S. polyrrhiza. However, when the concentration was over0.1ml/L. the biomass of S. polyrrhiza decreased significantly. The main reason for this phenomenon was the decrease of water content, leaf area and photosynthetic pigments in the plants.4. Aniline could significant decreased the activities of CAT and SOD. and increased that of POD. These results suggested that S. polyrrhiza could resist the negative influences of aniline through its antioxidase systems, but higher aniline concentration would decrease this ability significantly.5. After exposure to aniline24hours, the content of MDA of S. polyrrhiza increased significantly, and the effect was positively correlated to the concentration of aniline. With the additions of aniline concentration, there was significant increase between control and treatment group. The results suggested that aniline could damage the cellular membrane systems. The higher concentration, the more severely cell damage.6. During the experiment, the pH value and electric conductivity of cultivation medium of treatment groups did not change compared with control. This suggested that aniline did not change some of physical and chemical properties to influence the growth of S. polyrrhiza.Based on the results above, we could conclude that aniline had significant effects on the vegetative growth of S. polyrrhiza by damaging the photosynthetic pigments, leaf area, and water content in plant. It also impacted the plant by damaging its cellular membrane systems. Some of morphological and physical parameters of S. polyrrhiza were sensitive to aniline, so the species could be used as an indicator for monitoring the aniline pollution in water.