不同浓度氨氮对轮叶黑藻的生理影响  

Physiological effects of ammonia-nitrogen concentrations on Hydrilla verticillata

作　　者：颜昌宙[1] 曾阿妍[2] 金相灿[1] 赵景柱[3] 许秋瑾[1] 王兴民[1] 

机构地区：[1]中国环境科学研究院湖泊生态环境创新基地/国家环境保护湖泊污染控制重点实验室,北京100012 [2]吉林大学环境与资源学院,长春130012 [3]中国科学院生态环境研究中心城市与区域生态国家重点实验室,北京100085

出　　处：《生态学报》2007年第3期1050-1055,共6页Acta Ecologica Sinica

基　　金：国家重点基础研究发展规划资助项目(2002CB412307);国家自然科学基金杰出青年基金资助项目(70325002)~~

摘　　要：在实验室条件下,比较研究了不同浓度(0.5、1、2、4、8、16mg/L)的氨氮(NH4+-N)对沉水植物黑藻(Hydrilla verticillata)的生理生化影响,测定了黑藻生物量、叶绿素、可溶性糖、蛋白质含量和过氧化物酶(POD)、超氧化物歧化酶(SOD)、谷氨酰氨合成酶(GS)的活性变化。实验结果表明低浓度的氨氮(0.5、1、2mg/L)对轮叶黑藻的生长稍有促进作用,但培养液中氨氮浓度超过4mg/L时,黑藻的相对生长率(R)明显下降,当浓度达到16mg/L时,黑藻在20多天内全部死亡。在低浓度氨氮条件下,黑藻叶绿素和可溶性糖含量随氨氮浓度增加呈上升趋势,当培养液中氨氮浓度超过4mg/L时,叶绿素和可溶性糖含量在第24、32、40天取样时较对照组明显降低。低浓度氨氮处理组(0.5、1、2mg/L)的蛋白质含量先下降后又上升,而对照组的蛋白质含量一直在上升,高浓度氨氮处理组(8、16mg/L)的蛋白质含量则呈明显下降趋势。POD、SOD和GS活性变化趋势基本一致,在高浓度氨氮条件下增加显著,并表现为先上升再下降的格局,在第16天或第24天达到最大值。研究结果提示在富营养化条件下氨氮浓度的升高将影响其生理功能,过高浓度的氨氮对轮叶黑藻是一种逆境胁迫,可抑制其生长甚至导致植物死亡。轮叶黑藻对氨氮浓度变化虽有一定耐性,但耐性会随时间延长而变弱。Physiological effects of NH4^-N concentrations （0.5, 1, media were investigated at laboratory conditions. The biomass, 2, 4, 8, 16 mg/L） on Hydrilla verticillata cultured in chlorophyll contents, soluble sugar contents, protein contents, as well as the activities of superoxide dismutase （ SOD）, peroxidase （POD） and （GS） of Hydrilla verticillata were analyzed. The results showed that low NH4^- -N concentration （0.5, 1, 2 mg/L） could simulate the growth of H. verticillata cultured in media while a NH4^--N concentration of above 4 mg/L would deter the growth of H. verticillata markedly. The plants died within three to mg/L. The chlorophyll contents and the four weeks when the concentration of NH4^--N in culture solution soluble sugar contents of H. verticillata went up with increase reached 16 of NH4^- -N concentration in low NH4^--N concentration experiments （0.5, 1,2 mg/L NH4^--N）. However, when NH4^--N concentration was above 4 mg/L the contents of chlorophyll and soluble sugar in the 24^th d, 32^nd and 40^nd sampling decreased noticeably compared to the control experiment. In low NH4^--N concentration （0.5, 1, 2 mg/L） experiments the protein contents of H. verticillata decreased initially and increased later; in control experiments the protein content went up continuously; in high NH4^--N concentration （8, 16 mg/L） experiments the protein content decreased remarkably. Overall, the activities of GS, POD and SOD showed no difference in their changing trends; these enzymatic activities increased noticeably under the condition of high concentration of NH4^--N and showed a pattern of initial increasing and subsequent decreasing with activities peaking in the sixteenth or the twenty-fourth day. The results indicate that the increased NH4^--N concentrations were a stress to H. verticillata under eutrophic condition. The increased NH4^--N concentrations could affect the physiological function of H. verticiUata, by restraining its growth, and even resulting in its death. Although H. vertic

关 键 词：氨氮 黑藻 生理影响 胁迫 

分 类 号：X173[环境科学与工程—环境科学]