Figure 3.

Maximum likelihood phylogeny of 564 aligned nucleotides of psbA genes. Maximum likelihood approximate likelihood-ratio test (aLRT) support values are indicated at the nodes. psbA sequences amplified in this study are indicated in bold and are labelled with the location (LO=Lake Ontario), the date of sample collection, and an arbitrary clone number. The letter following the clone number is an arbitrary label for the OTU (that is, group of sequences >97% identical) that corresponds the labels in Figure 4. Only a single representative sequence from each OTU was used for the phylogenetic analysis. Sequence groups containing potential chimeras are indicated with an ^* after the clone name. The scale bar indicates the proportion of substitutions per site.