Figure 3

Maximum likelihood (ML) phylogeny of rbc L gene sequences for 15 Heterococcus strains. Twelve other strains had sequences identical to one of the 15 shown (Additional file 3). Sequences without accession numbers are reported for the first time. Sequence names highlighted in blue indicate authentic reference strains; names used in the tree are those used to identify the original cultures (see text). Capital letters in filled blue circles indicate the seven species apart from H. fuornensis resolved by the psbA/rbcL spacer and ITS2 sequence analyses (see text). The names next to the tree represent clades and lineages recovered in the phylogenetic analyses. Thick lines indicate internal branches resolved by maximum likelihood, maximum parsimony, minimum evolution distance and Bayesian analyses and with significant statistical support (bootstrap >95%, posterior probability = 1.0). Black filled circle marks the branch indicating the monophyletic origin of Heterococcus that was significantly supported (bootstrap >95%, posterior probability = 1.0) except for the maximum likelihood analyses. The phylogeny shown is part of a larger ML phylogeny (calculated with GARLI v0.96 [25, 26]) based on a rbcL data set (1325 bp long, 517/418 variable/parsimony informative sites) consisting of 15 Heterococcus sequences and 32 other Xanthophyceae sequences corresponding to clades C, B, T, and V as defined in [14] (see Additional file 1) as well as two outgroup taxa. Scale bar, substitutions per site.