Distribution of marine Synechococcus assemblage in Qiongdong upwelling in northwestern South China Sea
HOU Qinghua，YE Yingyi
Laboratory for Coastal Ocean Variation and Disaster Prediction，College of Oceanography and Meteorology，Guangdong Ocean University，Zhanjiang 524088，China
Abstract: In order to explore the distribution characteristics and coexistence relationship of marine Synechococcus assemblage on the precise spatial scale in the coastal upwelling area from 18°30′-20°30′N to 110°00′-111°30′E, the horizontal and vertical spatial distribution of ten clades of Synechococcus was investigated in the water of the Qiongdong upwelling area in the northwest of the South China Sea in summer by 16S-23S rDNA internal transcribed spacer (ITS) quantitative polymerase chain reaction (qPCR) technology. The results showed that the ten clades of Synechococcus were widely distributed in Qiongdong upwelling water, and presented obvious spatial niche partitioning in the horizontal and vertical directions. The dominant clades were Ⅱ, Ⅲ, Ⅹ and CRD1 (Costa Rica dome), and the maximal average abundance of all the ten Synechococcus was cladeⅡ in the Qiongdong upwelling water. Types Ⅱ, Ⅲ, Ⅳ and Ⅹ were highly abundant in the surface water and coexisted with each other. The isolines of clades Ⅱ, Ⅲ and Ⅳ abundances were significantly elevated to the near-shore subsurface water, with positively correlated with temperature and dissolved oxygen (DO)level, and negatively correlated with salinity, reflecting the influence of upwelling dynamic processes on their coexistence. There was the peak abundance of clades Ⅰ, Ⅷ and Ⅹ in the surface water of the coastal estuary, which was mainly affected by river runoff. The distribution of CRD1, CRD2, ⅩⅤ and ⅩⅥ types in the subsurface water of Qiongdong area were co-occured, without significant correlation relationship with temperature, DO and salinity on the whole. There were different ecological clades of Synechococcus in different niches. Temperature, salinity, DO, upwelling dynamic process and river flow affected the different niche partitioning of Synechococcus assemblage in the Qiongdong upwelling area. The findings provided theoretical foundation for further study on the function of marine Synechococcus assemblage.
侯庆华, 叶映仪. 海洋聚球藻生态类群在南海西北部琼东上升流区的分布特征[J]. 大连海洋大学学报, 2023, 38(5): 753-762.
HOU Qinghua, YE Yingyi. Distribution of marine Synechococcus assemblage in Qiongdong upwelling in northwestern South China Sea. Journal of Dalian Ocean University, 2023, 38(5): 753-762.
2023, Vol. 38 
