Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao, 266100, China.
Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao, 266100, China.
Mar Environ Res. 2019 Jun;148:19-25. doi: 10.1016/j.marenvres.2019.05.005. Epub 2019 May 3.
Allelopathy between algae is an ecological strategy that can facilitate or inhibit the occurrence of algal blooms. The role of allelopathic effects of marine microalgae Cylindrotheca closterium in other phytoplankton population dynamics are still limited. In the current study, the effects of cell-free filtrates of diatom Cylindrotheca closterium on two common dinoflagellates (Prorocentrum donghaiense and Prorocentrum cordatum), a chrysophyceae (Isochrysis galbana) and a diatom (Chaetoceros curvisetus) were investigated within controlled laboratory experiments. It was observed that the growth of P. donghaiense was significantly suppressed and approximately 80% cells disappeared after 8-d exposure, while the other three algae was less sensitive. P. donghaiense was very sensitive to the exudates of C. closterium from the stationary phase by comparing various percentage (10, 30, 50, 70 and 100%) of filtrates. In addition, the allelopathic effects of extracellular compounds of C. closterium extracted by three different organic solvents (ethyl acetate, chloroform and petroleum ether) on P. donghaiense were explored by determining cell density, chlorophyll content and maximum photosystem II (PSII) quantum yield (F/F). It was found that the compounds extracted by ethyl acetate and chloroform appeared to exhibit less toxicity on P. donghaiense than that of petroleum ether. The present results indicated that the allelochemicals released by C. closterium might be concentrated effectively in the petroleum ether extraction phase, which provided a new perspective for controlling the red tides of P. donghaiense in the East China Sea by means of the ecological inhibitors extracted.
藻间化感作用是一种生态策略，可以促进或抑制藻类大量繁殖的发生。海洋微藻 Cylindrotheca closterium 的化感作用对其他浮游植物种群动态的影响仍然有限。在本研究中，在受控实验室实验中研究了硅藻 Cylindrotheca closterium 的无细胞滤液对两种常见的甲藻（东海原甲藻和中肋骨条藻）、金藻（球等鞭金藻）和硅藻（优美卡塔藻）的影响。结果表明，东海原甲藻的生长受到显著抑制，暴露 8 天后约 80%的细胞消失，而其他三种藻类则不太敏感。通过比较不同滤出液比例（10%、30%、50%、70%和 100%），发现静止期 C. closterium 的分泌物对 P. donghaiense 非常敏感。此外，还通过测定细胞密度、叶绿素含量和最大光系统 II（PSII）量子产量（F/F），研究了 C. closterium 三种不同有机溶剂（乙酸乙酯、氯仿和石油醚）提取的细胞外化合物对 P. donghaiense 的化感作用。结果表明，乙酸乙酯和氯仿提取的化合物对 P. donghaiense 的毒性似乎低于石油醚。本研究结果表明，C. closterium 释放的化感物质可能在石油醚提取相中得到有效富集，为利用生态抑制剂控制东海赤潮提供了新的思路。
