菖蒲干体提取液对两种水华藻类生长的影响

通过不同浓度的提取液添加试验,研究了水生植物菖蒲的干体提取液对铜绿微囊藻和蛋白核小球藻生长的影响.结果表明:菖蒲干体提取液中含有抑藻活性的化感物质.高浓度的提取液（>40 ml·L^-1）对两种低接种密度藻的生长有显著的抑制作用（P＜0.01），最高抑制率分别为9866%和9238%；而低浓度的提取液（<30 ml·L^-1）能促进蛋白核小球藻的生长，第7天最低抑制率为-4952%.但两种浓度的提取液对高密度藻的生长并无显著影响（P＞0.05）.对比提取液的半连续添加和一次性添加试验发现，提取液中的抑藻组分较易分解，表明自然水体中化感物质的持续分泌可能是菖蒲对浮游藻类产生抑制作用的重要因素.

Inhibitory effects of dry Acorus calamus extracts on the growth of two water bloom-forming algal species

A trial with different concentrations of aqueous extracts from dry Acorus calamus plants was conducted to study the effects of the extracts on Microcystis aeruginosa and Chlorella pyrenoidosa growth.Allelopathic effects were observed.High concentration(>40 ml·L~(-1))extracts inhibited the growth of the two algal species at low inoculation cell density significandy(P<0.01),with the maximal inhibition rate being 98.66%for M.aeruginosa and 92.38%for C.pyrenoidosa,while low concentration(<30 ml·L~(-1))extracts promoted the growth of C.pyrenoidosa.Neither high nor low concentration extracts had significant effects on the growth of the two algal species at high inoculation cell density(P>0.05).The comparison of adding the aqueous extracts once and semiconsecutively showed that the allelochemicals in the extracts were easy to be degraded,suggesting that the continuous secretion of allelochemicals in natural water bodies could play an important role in inhibiting algal growth.