Study Of Genetic Diversity Of Algae Dna Viruses In The North Yellow Sea

Virioplankton, viruses in aquaic ecosystem, are now considered to be one of the most abundant and active components of microbial communities. Viroplankton play an important role in the microbial loop, biogeochemical cycles, structure and diversity of microbial community. Studying of the abundance and diversity of viroplankton in different locations and environment will help in understanding of the rules of the distribution and the ecological status of viroplankton. And it will also help to understand population structure of biology and provide reference numerical dates and theoretical basis for environmental assessment.The North Yellow Sea represents an important type of marine ecosystem of the north temperate zone. There were just a few reports about the abundance of virioplankton in the North Yellow Sea using epiflororence microscopy(EFM). In this paper, we studied the abundance of virioplankton by flow cytometry(FCM), and analyzed the correlation between virioplankton and environmental parameters in the North Yellow sea. Viral abundance ranged from 2.76×106 to 3.97×107 particles mL-1(2.12×107 particles mL-1 on average). In horizontal distribution, the area of the high viral abundance existed the southeast area of investigation area. In vertical distribution, there was no significant difference of virioplankton abundance in each water layer. In daily variations of virioplankton, its highest virioplankton abundance existed at the 30m water layer at 19:00, while the lowest abundance existed at the 10m water layer at 4:00. The abundance of virioplankton appeared uptrend from 10:00 to 19:00 in all layers. Virioplankton abundance has obvious positive correlation with heterotrophic bacteria, Synechococcus(Syn) and picoeukaryotes(Euk), however, there was no correlation between virioplankton abundance and VBR. The virioplankton abundance was positively correlated with temperature, while it has negative correlation with depth and salty.The diversity of algae DNA viruses are extremely rich in the oceans, but there was no any reports about the study of viroplankton diversity in China. The diversity of algae DNA viruses in the North Yellow Sea and Qingdao coastal waters was analysed by denaturing gradient gel electrophoresis (DGGE). The amount of operational taxonomic units (OTUs) in the North Yellow Sea was 10,8,8 at stations of A604, B107 and C803, respectively, and it was 6 in ZQ station. These results implicated that the diversity of algal viruses was not the same in different waters, which was higher in the North Yellow Sea and lower in ZQ station. Furthermore, the diversity of algal viruses was also different in the three stations of the North Yellow Sea. And 2 similar OTUs were found throughout the whole four stations, suggesting that some kinds of genetically identical algal viruses have a ubiquitous distribution in the seas。DGGE map indicated the diversity of algae DNA viruses in the North Yellow Sea and Qingdao coastal waters, but it was preliminary. In order to define the members and classification of virus, the target segments were sequenced and were used in sequence analysis. In this paper, we studied the genetic diversity of algae DNA viruses in the North Yellow Sea by PCR-RFLP.329 positive clones were digested by HaeⅢand MspⅠ, and we obtained 18 operational taxonomic units(OTUs). The 18 OTUs were attributed to three cluster. Cluster I was most closely related to DNA pol sequences of HaV01 which belongs to Raphidovirus. Cluster II was most closely related to DNA pol sequences of FsV which belongs to Phaeovirus. Cluster III was attributed to uncultured viruses, and its definite position in classification need further research. No member of Chlorovirus, Prasinovirus, Prymnesiovirus and Coccolithovirus was discovered in this study.