鼠尾藻和鸭毛藻水提液对三角褐指藻的抑制作用

调查了鼠尾藻Sargassum thunbergii和鸭毛藻Symphyocladia latiuscula水提液对三角褐指藻Phaeodactylum tricornutum 生长的抑制作用.结果表明,海藻水提液明显抑制三角褐指藻生长,并且这种抑制作用来自藻体活性物质(化感物质);鼠尾藻和鸭毛藻的化感物质既溶于水也溶于乙醇,随时间可能被三角褐指藻消耗尽或发生降解,因而抑制作用减弱以至消失,最大抑制发生在接种4 d.鼠尾藻和鸭毛藻水提液抑制三角褐指藻生长的半效应质量浓度(EC_(50,96h))分别为4.37g·L~(-1)和3.59g·L~(-1),暗示三角褐指藻对鸭毛藻水提液抑制的反应更敏感.

Inhibitory effect of water extracts from Sargassum thunbergii and Symphyocladia latiuscula on Phaeodactylum tricornutum

The interaction between macroalgaes and microalgaes is one of current focus in environmental science. In this study, inhibitory effect of crude extracts from Sargassum thunbergii and Symphyocladia latiuscula on the growth of Phaeodactylum tricornutum was investigated. The results showed that the growth of Phaeodactylum tricornutum was obviously inhibited by water extracts from macroalgaes, and the inhibitory effect was possibly ascribed to the bioactive substance(allelopathic chemicals) existing in macroalgaes. The allelopathic chemicals from Sargassum thunbergii and Symphyocladia latiuscula could dissolve in water and etha-nol, and could be exhausted or decomposed by Phaeodactylum tricornutum with cultivation time, which resulted in the gradual weakening even vanishing of inhibitory effect. The maximum inhibitory effect occurred during 4 day of inoculation, where calculated EC_(50,96h) was 4.37g·L~(-1) for Sargassum thunbergii extract and 3.59g·L~(-1) for Symphyocladia latiuscula extract, respectively. It suggested that Phaeodactylum tricornutum was more impressionable.to the inhibition from Symphyocladia latiuscula extract.