【摘要】 以单株藻为对象的纯培养抑藻测试体系被广泛用于化感抑藻活性物质筛选和作用机理研究,但自然水体中藻类常常相伴而生并相互作用,共存藻类对化感物质抑藻效果的影尚不清楚。为探讨藻类共存状态下对化感物质的响应,选择沉水植物穗花狐尾藻（Myriophyllum spicatum）的典型化感抑藻物质焦酚,以有害蓝藻铜绿微囊藻（Microcystis aeruginosa）和经济绿藻雨生红球藻（Haematococcuspluvialis）为受试藻,同时设置混合共培养体系和纯培养体系,比较焦酚对不同培养体系中两株藻的影响。结果显示,纯培养和共培养体系中,焦酚对铜绿微囊藻细胞增长的抑制率分别为96.82%和93.18%,而对雨生红球藻细胞增长的抑制率显著降低,分别为29.39%和45.40%。焦酚处理的纯培养和共培养体系中铜绿微囊藻胞外藻毒素质量浓度分别为3.23、2.00μg·L^-1,雨生红球藻单个细胞内虾青素质量浓度分别为0.82、1.21 pg·cell-1。与纯培养相比,共培养体系中焦酚对铜绿微囊藻生长的抑制作用减弱,微囊藻毒素释放量显著降低（P<0.05）,而对雨生红球藻生长的抑制作用增强（P<0.05）,单个细胞内虾青素积累量最大（P<0.05）,表明两者共存减弱了焦酚对铜绿微囊藻的抑制效应,却增强了焦酚对雨生红球藻的影响。这些结果初步说明共存藻类会影响化感物质对目标藻株的抑制效应,在后续化感抑藻作用研究中,充分考虑藻类所处生物和非生物环境,将有助于深入揭示水生植物化感抑藻作用生态机制,明确化感作用和化感物质的生态学价值。更多还原

【Abstract】 The algal inhibition test using pure culture system with single algae or cyanobacteria species as the target has been widely used in the screening of algal inhibitory allelochemicals and revealing of allelopathic mechanism. However, algae and cyanobacteria species often coexist and interact with each other in natural water bodies. The influence of coexisting phytoplankton species on the allelopathic inhibition against target species is not clear. A typical allelochemical isolated from submerged macrophyte Myriophyllum spicatum, pyrogallol was used, harmful cyanobacteria Microcystis aeruginosa and economic green algae Haematococcus pluvialis was selected as the tested organisms, to investigate the response of each phytoplankton species to allelochemicals in the coexistence state. The mixed co-culture system and the pure culture system was set up simultaneously to compare the effects of pyrogallol on both phytoplankton species in different culture systems. The results showed that the inhibition ratio of pyrogallol on the growth of M.aeruginosa was 96.82% and 93.18%, respectively, in the pure culture system and the co-culture system, while that of H. pluvialis was significantly reduced to 29.39% and 45.40%（P<0.05）, respectively. Extracellular microcystin mass concentration of M. aeruginosa in the pure culture and co-culture systems treated with pyrogallol was 3.23, 2.00 μg·L^-1, respectively, whilst the cell quota of intracellular astaxanthin of H. pluvialis was 0.82, 1.21 pg·cell^-1, respectively. The inhibition ratio of pyrogallol on the growth of M.aeruginosa in the co-culture system was reduced comparing with that of the pure culture systems, where the increase extent of extracellular microcystin mass concentration was significantly lower than that of the pure culture（P<0.05）. However, the inhibition ratio of pyrogallol on the growth of H. pluvialis was significantly enhanced（P<0.05）, and cell quota of intracellular astaxanthin was much higher in the co-culture systems compared with that of the pure culture. These preliminary results indicate the inhibitory effects of pyrogallol on M. aeruginosa is reduced while that on H. pluvialis is enhanced when they are co-existing, and it can be deduced that the co-existence of phytoplankton species can affect the inhibitory effects of allelochemicals on target algae or cyanobacteria. We should fully consider the biotic and abiotic environment of target organisms in the further research on allelopathic inhibition on phytoplankton, which will help us to figure out the ecological mechanisms of this process and ecological value of allelopathy as well as allelochemicals.更多还原