Study of Genetic Diversity of Micro-planktonic Eukaryotes in South China Sea by ITS and 5.8s rRNA Gene Cloning and Sequencing

Marine eukaryotic organisms are fundamental components of marine planktonic systems, and are significant fraction of the biomass and activity in marine system. Their diversity in South China Sea, however, has remained elusive, since the small cells lack morphologicalfeatures features for identification. We studied small eukaryotic organisms (planktonic protists) genetic diversity in South China Sea by using ITS and 5.8s rRNA Gene Cloning. 12 clone libraries of the marine small eukaryotes were constituted, and except 238 metazoan clones, 301 clones were identified within alveolates (nearly 57.8%), Chlorophyta, Stramenopiles, Rhizaria, Haptophyceae and fungi. The diversification of length and sequence is so variation in ITS, most of the sequence in our clone libraries were less than 98% similar to any sequence in gene bank. Many noval clones were detected in our clone libraries. Despite 3um prefiltration, we recovered ITS and 5.8s rRNA gene sequences notably chlorophyta, dinoflagellates and cilites. High diversity and abundance of small eukaryotes in South China Sea were revealed again.