Community Structure And Ecological Significance Of Zooxanthellae Around Luhuitou Reef In Sanya

The zooxanthellae was in the coral play an important role in the adaptations of coral reef ecosystem to global climate change and its adaptability to environment.There are 48 samples as massive?dendritic and lobate corals include in 6 families,9 genus,9 species collected in coral reefs area of Sanya Luhuitou Bay,Hainan Province,China.Firstly,genomic genomic DNA was extracted from all samples using a plan tissue DNA extraction kit.according to the manufacturer's instructions.Secondly,the ITS2 gene sequence was amplified by using the gene specific primers of zooxanthellae.Thirdly,based on the Miseq platform,high-throughput sequencing was carried out on the gene sequence of the expanded zooxanthellae,meanwhile,nutrient and heavy metal concentration were tested in the seawater samples collected synchronously in the coral reef area of the deer.Bioinformatics analysis based on the gene sequence of the zooxanthellae and seawater environmental factors.The main conclusions are as follow:(1)From the diversity analysis of zooxanthellaewas in coral OTU level and the study of the clade and the subclade to zooxanthellae,the zooxanthellae diversity of OTU level have difference in spatial and interspecies of coral.The clade mainly including clade C and clade D but other clades have extremely low abundance.The subclade constituents is relatively abundant,and the dominant subclades with relatively high abundance are subclade C1,C15,C3u,D1,D1a,and Cspc.(2)The study of the community structure of zooxanthellae in different spatial shows that there is no obvious difference(P>0.05).For some subclades only in some regions but not in others.The relative abundance of some zooxanthellae subclade have most difference in all areas.The community structure of zooxanthellae subclades are nearest among same coral hosts(P=1).In different coral hosts,the community structure of zooxanthellae subclades have obvious difference(P<0.01).In addition,the spatial structure of the symbiotic zooxanthellae of the Porites lutea is different from other coral hosts.The community structure of zooxanthellae subclades have very obvious difference in the different morphology coral(P<0.01).The constituents of zooxanthellae subclades in massive and dendritic coral are more abundant to lobate coral.(3)Base on the analysis of community structure among coral symbiotic zooxanthellaewas in coral reefs area of Sanya Bay,we conclude that the community structure in coral symbiotic zooxanthellae subclades are associated with coral host and environmental conditions.(4)From the correlation analysis of the relationship between coral symbiotic zooxanthellae subclades and enviroment factors,different zooxanthellae subclades have different adaptability to different environmental factors within a certain range.(5)The main reasons for the occurrence of a large number of clade D in this region are the increase of SST and sea water turbidity caused by long-term engineering construction and other environmental changes.