NUCLEAR RIBOSOMAL-RNA SEQUENCES FOR INFERRING TRIBAL RELATIONSHIPS WITHIN ONAGRACEAE

Relationships among tribes within the evening-primrose family, Onagraceae, were inferred from 18S and 26S ribosomal RNA sequences. Of 1819 nucleotide positions sequenced, 17 were phylogenetically informative. With Lythrum (Lythraceae) as the outgroup, one most parsimonious cladogram was derived (length = 28; consistency index = 0.75) using computer-assisted phylogeny inference software. The cladogram supported Ludwigia as the sister group to Onagraceae and provided strong evidence for the monophyly of Oenothera-Epilobium and Circaea-Fuchsia. The placements of Hauya and Lopezia were not well supported by the data as indicated by examining trees which were one step longer than the most parsimonious tree.