粉绿狐尾藻（Myriophyllum aquaticum）对铜绿微囊藻（Microcystis aeruginosa）的化感抑制效应及其生理机制

由于生物法,尤其是水生植物化感控藻方法在治理水体富营养化及水华现象中具有多方面的优势,近年来该领域的理论和技术研究备受世界各国关注.采用初始添加种植水和连续添加种植水的方法,研究挺水型粉绿狐尾藻对铜绿微囊藻的化感抑藻效应,并从光合作用的角度探讨其对铜绿微囊藻化感抑制的生理生态机制及作用靶点.研究结果表明:粉绿狐尾藻能够分泌某些化感物质有效抑制铜绿微囊藻的正常生长,其抑藻效应是通过连续释放某些化感物质作用于铜绿微囊藻而实现的,且具有累积性;粉绿狐尾藻分泌化感物质对铜绿微囊藻的Chl a、PC及APC的损伤程度存在差异(如处理5 d后,Chl a、PC、APC的相对含量分别降至52.7%、15.3%、7.6%),其中藻胆蛋白(尤其是APC)比Chl a 更为敏感,说明藻胆蛋白是粉绿狐尾藻化感物质抑制铜绿微囊藻的关键靶点.研究为水生植物化感控藻技术的发展提供了新的材料,并有助于深入了解水体生态系统的化学生态作用及其机制.

Allelopathic inhibitory effect of Myriophyllum aquaticum (Vell.) Verdc. on Microcystis aeruginosa and its physiological mechanism

Eutrophication and algal blooms are the most serious environmental problems in the world, and biological tools, especially the allelopathic inhibitory effects of aquatic macrophytes on phytoplankton growth have been receiving world-wide attention. In our experiments, the allelopathic inhibitory effect of Myriophyllum aquaticum culture water on Microcystis aeruginosa and its eco-physiological mechanism were investigated by initial addition assays and continuous addition assays. The results showed that the growth of M. aeruginosa was markedly inhibited by M. aquaticum culture water. Compared with initial addition assays, M. aquaticum exhibited stronger inhibitory potential on M. aeruginosa by continuous addition assays, indicating that allelopathic compounds might be excreted continuously by M. aquaticum, and the inhibitory effects would be cumulative. We also found that the relative content of chlorophyll a (Chl a), phycocyanin (PC) and allophycocyanin (APC) of M. aeruginosa decreased to 52.7%, 15.3% and 7.6% respectively after being treated by M. aquaticum culture water for 5 days, and phycobiliprotein (especially APC) decreased more than Chl a. These results suggest that the phycobiliprotein would be the target of allelopathic inhibition of M. aquaticum on M. aeruginosa, and a new macrophyte to control cyanobacterial blooms would be found.