A SURVEY OF BANGIALES (RHODOPHYTA) BASED ON MULTIPLE MOLECULAR MARKERS REVEALS CRYPTIC DIVERSITY

The Bangiales is a diverse order consisting of 28 species in Canada. Morphological simplicity and similarity among species has led to taxonomic confusion and the need for molecular techniques for species identification. This study is the first to employ the standardized DNA barcode marker COI-5P in a broad floristic survey of the Bangiales in Canadian marine waters. A total of 37 species were ultimately sequenced, 29 of which occurred in Canada. Molecular results led to the synonymization of Wildemania cuneiformis with W. amplissima, as well as the description of two new species: Porphyra corallicola sp. nov. and Pyropia peggicovensis sp. nov., and discovery of another five putative new species. Comparison of the performance of COI-5P as a species identification tool relative to rbcL (large subunit of ribulose-1,5-bisphosphate carboxylase oxygenase) and the UPA (universal plastid amplicon) revealed that, although each marker had strengths and weaknesses, the COI-5P showed the highest species-discriminatory power due to its high level of interspecific variation. The rbcL was further used to place the new species into a phylogenetic context, whereas UPA was not recommended for species identification in the Bangiales owing to within-individual heterogeneity between the two copies present in the plastid genomes in some lineages.