福建东山岛附近海域造礁石珊瑚共生藻的分子系统分类和遗传多样性研究

Molecular taxonomy and diversity of symbiotic algae in reef-building corals in the sea near Dongshan Island in Fujian Province

本研究利用核糖体大亚基5′端序列PCR-RFLP以及转录单元内间隔区(Internal TranscribedSpacer,ITS)序列分析相结合的方法,首次对福建东山岛附近海域3种优势种类造礁石珊瑚共生藻进行了分子系统分类和遗传多样性研究.PCR-RFLP分析发现东山岛附近海域3种优势种类造礁石珊瑚共生藻都属于C系群共生藻,而ITS序列的序列分析结果表明东山岛附近海域3种优势种类造礁石珊瑚共生藻都属于C1亚系群.研究结果表明ITS序列进化速度快,适合于造礁石珊瑚共生藻属亚系群水平的鉴定.而东山岛附近海域造礁石珊瑚共生藻的多样性低,暗示东山岛附近海域造礁石珊瑚共生藻共生系统面对外界环境压力的适应能力较低.

The molecular taxonomy and diversity of symbiotic dinoflagellates in symbiosis with three dominant scleractinian corals in the sea near Dongshan Island in Fujian Province were investigated by restriction analysis of large subunit rRNA and sequencing of polymerase chain reaction-amplified fragments of ITS rRNA genes. All coral species harbored Symbiodinium clade C through PCR-RFLP analysis of large subunit rRNA. Moreover sequencing of polymerase chain reaction-amplified fragments of ITS rRNA genes showed that the clade C sequences were clustered with a previous studied group Symbiodinium subclade C1. The results suggested that the high-resolution genetic marker such as ITS genotypes might represent ecologically or physiological distinct Symbiodinium. Low diversity of symbiotic dinoflagellate suggested that the coral-Symbiodinium holobionts had low adaptation to environmental stress.