Reconstructing euglenoid evolutionary relationships using three genes: nuclear SSU and LSU, and chloroplast SSU rDNA sequences and the description of Euglenaria gen. nov. (Euglenophyta)

Abstract

Using Maximum Likelihood and Bayesian analyses of three genes, nuclear SSU (nSSU) and LSU (nLSU) rDNA, and chloroplast SSU (cpSSU) rDNA, the relationships among 82 plastid-containing strains of euglenophytes were clarified. The resulting tree split into two major clades: clade one contained Euglena, Trachelomonas, Strombomonas, Colacium, Monomorphina, Cryptoglena and Euglenaria; clade two contained Lepocinclis, Phacus and Discoplastis. The majority of the members of Euglena were contained in clade A, but seven members were outside of this clade. Euglena limnophila grouped with, and was thus transferred to Phacus. Euglena proxima was a single taxon at the base of clade one and is unassociated with any subclade. Five members of Euglena grouped together within clade one and were transferred into the newly erected genus Euglenaria. The monophyly of the remaining genera was supported by Bayesian and Maximum Likelihood analyses. Combining datasets resolved the relationships among ten genera of photosynthetic euglenoids.