A MOLECULAR PHYLOGENY OF THE GELIDIALES (RHODOPHYTA) BASED ON ANALYSIS OF PLASTID RBCL NUCLEOTIDE-SEQUENCES

Parsimony analyses of rbcL nucleotide sequences were used to develop h ypotheses of relationships among taxa in the taxonomically difficult o rder Gelidiales including species from seven currently recognized gene ra: Capreolia, Gelidiella, Gelidium, Onikusa, Pterocladia, Ptilophora, and Suhria. Nucleotide sequences of rbcL from red algae are variable and provide a large number of informative characters Sor phylogenetic analysis, yet the absence of insertion/deletion mutations allows for t he unambiguous alignment of sequences. Species were resolved into 10 w ell-supported major clades representing genera and species complexes. The topological positions of these 10 clades within trees are also wel l supported and indicate that Gelidium and Pterocladia as currently ci rcumscribed are not monophyletic. These results call for a revision of the classification of the Gelidiales.