不同浓度和形态磷模拟调控浮游植物群落演替实验

Experiments on simulation regulation of phytoplankton community succession with different concentrations and forms of phosphorus

为研究水体浮游植物对不同浓度和不同形态磷的利用能力差异,采集福建九龙江江东库区冬季的水样,设置培养温度为20℃,分别进行原位水(TP=0.11 mg·L^(-1))、低浓度有机磷(单磷酸胞苷(5’-CMP)和无机磷(0.01 mg·L^(-1))、高浓度的有机磷(单磷酸胞苷5’-CMP)和无机磷(1.00 mg·L^(-1))调控模拟实验.比较了不同藻群落结构起点,经磷调控培养后群落演替的情况,并对培养过程的藻细胞进行碱性磷酸酶荧光标记,观察碱性磷酸酶的分布情况.经过15 d的实验室培养,结果显示:原水组由隐藻(54.7%)、甲藻(28.0%)、绿藻(11.9%)演替为绿藻(67.7%)和硅藻(25.2%)为主,绿藻的增殖优势明显;低有机磷浓度模拟培养组演替为绿藻(63.7%)和硅藻(22.4%)为主,低浓度无机磷模拟培养组也是演替为绿藻(60.6%)和硅藻(28.3%)为主;高浓度有机磷模拟培养组浮游植物的结构从甲藻(52.8%)、隐藻(26.5%)、硅藻(7.4%)演替为甲藻(40.9%)和硅藻(32.9%)为主,高浓度无机磷组的结构演替为硅藻(52.1%)和绿藻(21.1%)为主;高浓度有机磷组培养过程中,绿藻门的栅藻(Scenedesmus)和楯形多甲藻不等变种(Peridinium umbonatum var.inaequale)细胞上观察到明显的碱性磷酸酶分布,表明两种藻都能利用单磷酸胞苷(5’-CMP),其中楯形多甲藻不等变种利用有机磷单磷酸胞苷能力更强.初春温度适宜且磷充足时,起点的藻群落结构和磷形态共同决定浮游植物群落的演替;当磷的浓度较低时,九龙江江东库区群落中绿藻门容易占据优势.本研究结果对九龙江藻类水华的防控具有现实意义.

In order to investigate phytoplankton's ability to use different concentrations and forms of phosphorus,water samples were collected from the Jiangdong Reservoir on the Jiulong River,Fujian,China,in winter.Simulation experiments were set up at the culture temperature of 20℃and different phosphorus environments:original water(TP=0.11 mg·L^(-1)),low concentration of organic phosphorus(Cytidine monophosphate 5'-CMP)and inorganic phosphorus(0.01 mg·L^(-1)),high concentration of organic phosphorus(Cytidine monophosphate 5'-CMP)and inorganic phosphorus(1.00 mg·L^(-1)).Phytoplankton community structures were compared before and after culture experiments.During the culture process,the algal cells were labelled with alkaline phosphatase to observe the distribution of alkaline phosphatase.After 15 days of laboratory culture,in the original water group,Cryptophyta(54.7%),dinoflagellate(28.0%)and green algae(11.9%)were succeeded mainly by green algae(67.7%)and diatom(25.2%),and the proliferation of green algae was obvious.In the culture group with low concentrations of organic phosphorus concentration,phytoplankton was succeeded mostly by green algae(63.7%)and diatom(22.4%).In the culture group with low concentrations of inorganic phosphorus concentration,phytoplankton was also succeeded largely by green algae(60.6%)and bacillariophyta(28.3%).In the culture group with high concentrations of organic phosphorus,phytoplankton has been succeeded mainly by dinoflagellate(52.8%),cryptophytes(26.5%),and diatom(7.4%).In the culture group with high concentrations of inorganic phosphorus,phytoplankton was succeeded dominantly by dinoflagellate(40.9%)and diatom(32.9%).In the culture group with high concentrations of inorganic phosphorus,phytoplankton was succeeded mainly by bacillariophyta(52.1%)and green algae(21.1%).In the culture group with high concentrations of organic phosphorus concentration,Scenedesmus and Peridinium umbonatum var.inaequale were identified,and alkaline phosphatase was observed in the cells,indicating that both species can utilize 5'-CMP effectively.In addition,varieties of Peridinium umbonatum var.inaequale have stronger abilities to use cytidine monophosphate.With suitable temperature and sufficient phosphorus in early spring,the succession of phytoplankton community was determined by algae community structure and phosphorus form.When phosphorus concentrations were low,the phytoplankton community in Jiangdong Reservoir,Jiulong River,was dominated by Chlorophyta.This study provides some practical significance for the prevention and control of algae blooms in the Jiulong River.