Phylogenetic affinities of the Trentepohliales inferred from small-subunit rDNA.

Phylogenetic analyses of the nuclear-encoded small-subunit rDNA sequences from taxa representing all of the major lineages of green algae, including new sequences for the Trentepohliales, consistently indicated that the subaerial Trentepohliales are closely related to ulvophycean marine green algae, particularly to the siphonous and hemisiphonous orders. The presence of phragmoplast-type cytokinesis in the order Trentepohliales remains enigmatic, and it is interesting that this type of cell division is associated with terrestrial (subaerial) habits.