FIG. 6.

Electropherograms of bacterial and plastid rDNA diversity in unfiltered (A) and filtered (B) seawater at a depth of 10 m from 8 km off the coast of Yaquina Head, Oreg. SSU rRNA genes were amplified with the 27F and 338R primer pair, and amplicons were separated by natural length polymorphisms. Peaks E, F, G, and I were removed by filtration through a 0.8-μm-pore-size polycarbonate filter. Peaks E, F, and G have been identified as plastid genes (prymnesiophytes, bacillariophytes, and prasinophytes, respectively). Peak I is unidentified.