Physiological And Biochemical Characteristics Of Three Aquatic Plants Under Eutrophied Waters

Lythrum salicaria, Thalia dealbata, Canna glauca as a new variety of aquatic plants has been widely used in the landscape water in recent year. However, their repaired function for pollution water should be further studied. Hence, for selecting suitable aquatic plants used to repair polluted water the change of physiological and biochemical characteristics of three aquatic plants under sewage, urban sewage and industrial wastewater treatment through pot experiments have been studied in this paper. The characteristics of photosynthesis and chlorophyll fluorescence have been further studied for comparing with traditional physiological analysis. Conclusively, it would be provide a scientific foundation for restoration of polluted aquatic ecosystem and implication of fast and no-harmful diagnostic technology. The main conclusions are as follows:(1) The three plants were injured seriously under contaminated water. It showed that the MDA content and membrane permeability of leaves increased while the chlorophyll content decreased. There were significantly differences among different treatments.(2) The defense mechanism of physiological and biochemical have been aroused after stress. The superoxide dismutase activity and proline content of three aquatic plants increased. So they can resist the damage of stress by increasing the activity of antioxidant enzymes and osmotic adjustment. The accumulation degree of stronger one was significantly higher than others.(3)The results of comprehensive evaluation for different treatment showed that the resilience capability of Thalia dealbata are stronger than Lythrum salicaria,Canna glauca at three treatments. Among the different treatments, the effect of industrial wastewater on Thalia dealbata was more serious than sewage and urban sewage; The effect of sewage on Lythrum salicaria was lower than urban sewage and industrial wastewater; The performance of Canna glauca under urban sewage was more than excellent than sewage and industrial wastewater.(4)The results of photosynthesis and chlorophyll fluorescence characteristics of Thalia dealbata indicated that the light saturation point and compensation point were decreased significantly due to the change of light response curve. The maximum transfer rate of optical quantum (ETR), FV/Fo , FV/Fm were also decreased significantly. The injured degree in sewage was lower than in urban sewage and industrial wastewater. It is indicated that the original light energy conversion efficiency and the energy conversion efficiency from LHCP to PSII were damaged. Thereby, the photosynthetic capacity was decreased.(5)The result of chlorophyll fluorescence parameter of Thalia dealbata was similar to other physiological and biochemical characteristics. So it is feasible that the sewage were remedied directly by Thalia dealbata in wetland ecosystem. The accumulation of nutrient-rich and pollutants of three aquatic plants should be further studied for implication for industrial wastewater and urban sewage.