Studies On Genetic Diversity Of Eukaryotic Ultraplankton In Western Xiamen Waters

A fingerprint technique PCR-DGGE which was based on the theory of small subunit ribosomal RNA (SSU RNA, 18S rRNA) gene analysis was developed by using molecular techniques which include DNA extraction, PCR amplification, Denaturing Gradient Gel Electrophoresis (DGGE), Clone-sequencing and some other techniques to explore the genetic diversity of eukaryotic ultraplankton assemblages in western Xiamen Waters. The preliminary study was carried out on genetic diversity, temporal and spatial distributions of eukaryotic ultraplankton assemblages in four typical stations of western Xiamen Waters, relationship between genetic structure and environmental factors would be discussed, . Main conclusions were as following:1. The genetic diversities of the eukaryotic ultraplankton assemblages in western Xiamen Waters were very high and the main groups were Chlorophyta, Stramenopiles, Haptophytes, Dinophyceae, Novel Alveolates and unidentified groups. Chlorophyta, Novel Stramenopiles, Novel Alveolates and unidentified groups which were the most extensively distributed and relatively abundant have played very important roles in dynamics and other aspects of eukaryotic ultraplankton assemblages in the study area.2. The genetic structures of eukaryotic ultraplankton assemblages have showed a seasonal variations in some degree in western Xiamen Waters, and the seasonal changing patterns of genetic structures in Stn 23 was the most prominent one amid that of those other three stations and it indicated that the genetic structures of the monthly samples which have high-temperature features are relatively similar in some degree, while the genetic structures of the monthly samples which have low-temperature features also showed a similar pattern in Stn 23, these trends can also be applied to other three stations in different degrees. Some OTUs(operational taxonomic units ) can be correlated with the high-temperature featured monthly samples, and the low-temperature featured monthly samples separately inside different corresponding stations.Variations of assemblages'genetic structures among different geographical stations indicated that the patterns of assemblages stability among the four stations are different, the assemblages'structure are relatively stable in Stn 26, while the assemblages'structures of Stn 27 are very unsteady; Different groups of OTUs were specific correlated with different stations and the stations which shares the same genetic structure patterns .3. Relativity analysis between environmental factors and assemblages'structures indicated that different OTUs were significantly correlated with different environmental factors (such as temperature, salinity and nutrients), and the temperature might be one of the most important environmental factors which influenced the genetic structures of eukaryotic ultraplankton assemblages in western Xiamen Waters.