Physiological Characteristics and Nitrogen and Phosphorus Uptake of Myriophyllum aquaticum Under High Ammonium Conditions
Ammonium nitrogen ( NH +4 -N) at high concentrations is toxic to plants. In order to explore the NH +4 -N tolerance of Myriophyllum aquaticum (M. aquaticum) and its ability of nitrogen ( N) and phosphorus ( P) uptake, this study used a nutrient solution with three NH +4 -N levels (70, 210, 420 mg·L - 1 ) to incubate M. aquaticum for 21 d. The characteristics of plant physiology and N and P uptake of M. aquaticum were measured. At NH +4 -N of 70 mg·L - 1 , M. aquaticum grew healthily, and shoot height and biomass linearly increased with the increase incubation time. Relative shoot height and biomass of M. aquaticum were 40. 56 cm and 17. 82 g·hole - 1 on day 21, respectively. Compared to the control with 70 mg·L - 1 ammonium, malondialdehyde (MDA) content of M. aquaticum was significantly increased; chlorophyll and soluble sugar contents were also high at NH +4 -N of 210 mg·L - 1 . M. aquaticum suffered from the NH +4 -N stress. However, the stress of 210 mg·L - 1 NH +4 -N did not affect its normal growth and there was no significant difference in the relative growth rate of the shoot height and biomass compared with the control. At NH +4 -N of 420 mg·L - 1 , MDA contents of M. aquaticum doubled and the shoot height and biomass growth rate were only 27. 4% and 17. 9% of those for 70 mg·L - 1 NH +4 -N, indicating that M. aquaticum was subjected to serious stress that caused unhealthy growth or even death. At three NH +4 -N levels, the ranges of N and P content of M. aquaticum were 30. 7-53. 4 mg·g - 1 and 3. 8-7. 7 mg·g - 1 , respectively, which indicated that M. aquaticum had a high uptake capacity of N and P. M. aquaticum is an ideal wetland plant that has a good application prospect for constructed wetlands in biological treatment of high-ammonia wastewater.
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NSTL
万方数据
维普
