Physiological, Phylogenetic And Ecological Characteristics Of Cultured Isolates Of Marine Synechococcus Genus

1. Variations in the spatial and temporal distribution of the Synechococcus population in the Jiaozhou Bay were investigated between July 2005 and April 2006. The centre of Synechococcus concentration in every month has a dramatic change was ranged from outside to inside, and then from inside to outside. Reported data indicate that the average concentration of Synechococcus can range from 66 cells/ml (March) to 4.87×103 cells/ml (September). Our methodology combined a survey of the physical structure and nutrient contents of the water column with the complete characterization of the phytoplankton community structure at 0 m and 30 m depth in D5. The N/P ratio appeared to be an accurate clue to the phytoplankton composition with predominance of Synechococcus 51.6% (September),98.5% (October) , when the N/P ratio was between 10 and 30 in the September and October. Picoeukaryotes predominated 92.1% (August), 84.8% (November) when the N/P ratio was below 10 or above 30, special in August or November. Further characterization of picophytoplankton from samples collected during summer and fall. When the N/P ratio reached 33 suggested the existence of two Synechococcus subpopulation. After the analysis of nitrogen, when the Synechococcus subpopulation existed, the NO3-N/PO4-P ratio reached 14.