[Show abstract][Hide abstract] ABSTRACT: In this paper, submersed plant Hydrilla verticillata was cultivated in a 1/10 Hoagland culture medium added with different concentration NH4 + -N (0, 0. 5, 2. 0, 4. 0 mg x L(-1)) and 10 mg x L(-1) cadmium to study the effects of NH4 + -N on H. verticillata growth and its antioxidant enzyme system under Cd stress, and approach the degradation mechanism of submersed macrophyte in eutrophic and polluted water bodies. The results showed that under 10 mg x L(-1) Cd stress, the chlorophyll content of H. verticillata decreased obviously, and SOD and POD activities increased first but declined then. NH4 + -N accelerated the stress effect of Cd. Under 0. 5 h joint stress of Cd and NH4 + -N, SOD activity increased significantly, while such an increase needed 3 hours under single Cd stress. Relative to chlorophyll and protein, antioxidant enzyme system was an early sensitive index, and SOD was more sensitive than POD. After two days exposure to Cd plus NH4 -N, H. verticillata was mainly stressed by Cd, and NH4+ -N stress could be neglected.
No preview · Article · Mar 2007 · Ying yong sheng tai xue bao = The journal of applied ecology / Zhongguo sheng tai xue xue hui, Zhongguo ke xue yuan Shenyang ying yong sheng tai yan jiu suo zhu ban
[Show abstract][Hide abstract] ABSTRACT: Combined pollution is more ubiquitous than the single pollution in water and soil environment. Iodine method was used to study the effects of both single and combined pollution of Cd and NH4+ on Hydrilla verticillata and Myriophyllurn spicatum. Results came out that H. verticillata was distinctly stressed at 4.0 mg x L(-1) concentration of NHI4+, oxygen production of photosynthesis and oxygen depletion of respiration all declined, but for M. spicatum ,it was not be stressed. If treated with 0.2 mg x L(-1) Cd, H. verticillata and M. spicatum all were stressed, and H. verticillata was stressed more seriously. Combined pollution of Cd and NH4+ produced cooperative adverse effects on H. verticillata. But for M. spicatum, the stress was less severe comparatively. The main reason was that M. spicatum made of less crude cellulose. So it had less combined pathway with heavy mental than H. wvrticillata. It demonstrated that M. spicatum is suit for pioneer plant comparatively during the process of lake restoration.
No preview · Article · Nov 2006 · Huan jing ke xue= Huanjing kexue / [bian ji, Zhongguo ke xue yuan huan jing ke xue wei yuan hui "Huan jing ke xue" bian ji wei yuan hui.]