作物秸秆对铜绿微囊藻的抑制作用

Inhibition effects of different straws on Microcystis aeruginosa

通过室内模拟实验研究了大麦、水稻和小麦3种作物秸秆对铜绿微囊藻(Microcystis aeruginosa)的抑制作用,并计算了不同秸秆的抑制率和抑制中浓度(EC50)。研究结果表明,大麦秸秆、水稻秸秆和小麦秸秆对铜绿微囊藻的生长有显著的抑制作用,而且随着培养时间和秸秆投加量的增加,抑制作用提高。处理96 h后大麦和水稻秸秆处理下的铜绿微囊藻几乎全部死亡,表明本研究所用不同作物秸秆对铜绿微囊藻的生长有显著的抑制效果。研究结果还表明,大麦、水稻和小麦秸秆对铜绿微囊藻的72 h-EC50由大到小依次是大麦>水稻>小麦,分别为248、334和1 943 mg/L,表明不同植物的秸秆对藻类的影响作用不同。分析3种秸秆抑制铜绿微囊藻生长的原因可能是3种植物秸秆在好氧的条件下可以分解产生多种具有抑藻作用化学物质,如有机酸、含甲基的酚类物质、醇类和酮类物质等,这些物质通过化感作用抑制铜绿微囊藻的生长,尤以大麦秸秆作用最为明显。

The phytoxicity and grow inhibition of different straws on the growth of M.aeruginosa were evaluated.In the research the inhibition rate of M.aeruginosa growth and the EC50 were calculated using the dose-response curves.It was shown that the M.aeruginosa growth was significantly inhibited by the addition of barley,rice and wheat straws.The inhibition was increased with the treatment time and addition dose increasing and almost all of the M.aeruginosa died by 96 h treatment of barley and rice straws.To evaluate the phytoxicity to the M.aeruginosa growth,the 72 h-EC50 values was calculated.It was shown that the 72 h-EC50 values of barley,rice and wheat straws were 248,334 and 1 943 mg/L separately,indicating the inhibition capability of different straws following the sequence barley〉rice〉wheat.The mechanisms of the inhibition of M.aeruginosa growth maybe lie in the fact that in the decomposing process of different straws some organic compounds were produced,which were allelopathic to the M.aeruginosa,especially in the decomposed barley strew.