[Molecular genetic diversity of phytoplankton rbcL gene in Jiaozhou Bay]

The variants of a 500 base pair fragment of RubisCo large subunit gene (rbcL) from the phytoplanktonic DNA of Jiaozhou Bay surface seawater were amplified by using polymerase chain reaction and cloned. Twenty-eight clones were randomly selected and sequenced, which were further used to determine the molecular genetic diversity of the phytoplankton of Jiaozhou Bay surface seawater. Systematic analysis showed that the clones representing cryptophyta counted for 28.6%, Stramenopiles 32.1%, Haptophyta 28.6%, Rhodophyta 3.6% and Chlorophyta 7.1%. The sequences from Cryptophyta, Stramenopiles, Haptophyta and Rhodophyta belonged to type D of Form I rbcL and Chlorophyta to type B, indicating that the dominant phytoplankton were those represented by type D rbcL. The genetic diversity index and the reversely translated amino acid sequence diversity of Jiaozhou Bay phytoplankton were 2.85 and 0.20, which were determined by the abundances of operational taxonomy units and the reversely translated amino acid sequences respectively.