氮磷浓度对惠氏微囊藻和斜生栅藻生长的影响

以惠氏微囊藻(Microcystis wesenbergii)和斜生栅藻(Scenedesmus obliquus)为研究对象,对比研究了氮(N)或磷(P)营养盐的相对限制对种群增长的影响。结果表明,培养11 d后,氮限制对惠氏微囊藻比生长速率、生物量、叶绿素浓度的最大抑制效应分别为2.25%、2.75%和40.01%;而对斜生栅藻的抑制效应分别为38.56%、58.64%和72.51%。磷限制对惠氏微囊藻比生长速率、生物量、叶绿素浓度的最大抑制效应分别为11.79%、10.94%和51.94%;对斜生栅藻的抑制效应分别为22.69%、49.62%和26.87%。氮磷营养盐起始浓度与2种微藻比生长速率、生物量之间多呈线性或指数型正相关关系。氮或磷单一营养盐处于富营养状态时,磷或氮营养盐浓度降低,惠氏微囊藻的生长仍能够维持在较高的水平,而斜生栅藻的生长则表现出显著的抑制效应。惠氏微囊藻对氮、磷限制的低敏感性是其获得种间竞争优势的生理学基础。

Effect of nitrate and phosphate concentration on growth of Microcystis wesenbergii and Scenedesmus obliquus

Taking Microcystis aeruginosa and Scenedesmus obliquus as samples,we investigated the effect of concentration of nitrate and phosphate on algal growth.The results show that the maximum inhibitory rates of nitrate limitation on algal growth rate,biomass and chlorophyll content of M.wesenbergii were 2.25%,2.75% and 40.01%,respectively,while those of S.obliquus were 38.56%,58.64% and 72.51%,respectively.The maximum inhibitory rates of phosphate limitation on algal growth rate,biomass and chlorophyll content of M.wesenbergii were 11.79%,10.94% and 51.94%,respectively,while those of S.obliquus were 22.69%,49.62% and 26.87%,respectively.The positive correlation was observed among nitrate,phosphorus concentrations and algal growth rate,biomass both in linear or exponential types.Growth of S.obliquus was inhibited seriously compared with that of M.wesenbergii at nitrate or phosphate limitation.Lower sensitivity to nitrate or phosphate limitation of M.wesenbergii might support the priority of algal growth and competition.