Low genetic diversity of symbiotic dinoflagellates （Symbiodinium） in scleractinian corals from tropical reefs in southern Hainan Island, China

• Published in: 植物分类学报：英文版 2011, Vol.49 (6), p.598-605
• Main Author: Guo-Wei ZHOU Hui HUANG
• Format: Article
• Language: English
• Subjects: 中国; 共生组合; 海南岛; 热带; 珊瑚礁生态系统; 腰鞭毛虫; 造礁石珊瑚; 遗传多样性
• ISSN: 1674-4918; 1759-6831

Endosymbiotic dinoflagellates in the genus Symbiodinium are among the most abundant and important group of photosynthetic protists fotmd in coral reef ecosystems. In order to further characterize this diversity and compare with other regions of the Pacific, samples from 44 species ofscleractinian corals representing 20 genera and 9 families, were collected from tropical reefs in southern Hainan Island, China. Denaturing gradient gel electrophoresis fingerprinting of the ribosomal internal transcribed spacer 2 identified 11 genetically distinct Symbiodinium types that have been reported previously. The majority of reef-building coral species （88.6%） harbored only one subcladal type of symbiont, dominated by host-generalist C1 and C3, and was influenced little by the host＇s apparent mode of symbiont acquisition. Some species harbored more than one clade of Symbiodinium （clades C, D） concurrently. Although geographically isolated from the rest of the Pacific, the symbiont diversity in southern Hainan Island was relatively low and similar to both the Great Barrier Reef and Hawaii symbiont assemblages （dominated by clade C Symbiodinium）. These results indicate that a specialist symbiont is not a prerequisite for existence in remote and isolated areas, but additional work in other geographic regions is necessary to test this idea.