不同温度下铜绿微囊藻和斜生栅藻的最佳生长率及竞争作用

摘要

Growths of Microcystis aeruginosa and Senedesmus obliquus as affected by temperature were observed in monoculture and mixed-culture varying in inoculation density under controlled laboratory conditions.It was found that with the temperature varying within the range of 7 - 35 ℃, the specific growth rate of M.aeruginosa increased with the temperature, while that of S.obliquus rose first and then fell with 25 ℃ as its turning point.In the mixed culture, competition between the two algal species affected their growth rates, making them lower in the mono-culture, and in all the three mixedculture experiments, the specific growth rate of M.aeruginosa was higher than that of S.obliquus.M.aeraginosa grew the slowest in the mixed culture 10∶1 ( Microcystis aeruginosa: Scenedesmus obliquus) in inoculation ratio, whereas S.obliquus did in the mixed culture 1∶10 in ratio.In all the mixed-culture experiments, regardless of inoculation ratio and temperature, M.aeruginosa displayed stronger competitive inhibition than Scenedesmus obliquus did.The interspecific competitive inhibition, varied with the temperature, either intensified or weakened, but M.aeruginosa was always more competitive.%以温度为主要控制因子,研究了单独培养和按不同接种密度比混合培养下铜绿微囊藻(Microcystis aeruginosa)和斜生栅藻(Scenedesmus obliquus)的生长状况.结果表明,在温度为7～35℃条件下,微囊藻比增长率随着温度的升高而增大,而栅藻增长率随着温度的升高先增大后减小.竞争体系对2种藻的比增长率均有影响,微囊藻在微囊藻与栅藻接种比例为10:1的混合培养体系中增长最慢,栅藻则在微囊藻与栅藻接种密度比为1:10的混合培养体系中增长最慢.不同温度条件下在2种藻不同接种密度比的混合培养体系中,微囊藻对栅藻的竞争抑制能力均大于栅藻对微囊藻的竞争抑制能力.藻种间的竞争抑制能力因温度的变化而得到不同程度的强化或减弱,铜绿微囊藻具有更强的竞争能力.