ARS | Publication request: A MOLECULAR PHYLOGENY OF THE SUBFAMILY ARUNDINOIDEAE (POACEAE) BASED ON THESEQUENCES OF RDNA (ITS)

Submitted to: Australian Systematic Botany
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 21, 1997
Publication Date: N/A

Interpretive Summary: The Arundinoideae is one of seven subfamilies of the grass family. The presence of many heterogeneous morphological characters within the subfamily cause taxonomic difficulty and confusion. The boundary of the subfamily as well as the generic rankings are uncertain in current grass classifications. We used ribosomal DNA sequence data to determine genetic relationships. Our data identified three major groups corresponding to the tribes, Aristideae, Arundineae, and Danthonieae, which are supported by evidence from cryptic anatomical structures and geographical distributions. Some species with no obvious close relatives were clearly placed in correct taxonomic groups. Our results have clarified many of the taxonomical problems of the Arundinoideae.

Technical Abstract: Phylogenetic relationships of the whole Poaceae family inferred from the sequence data of rDNA (ITS) support the hypothesis that the arundinoids are monophyletic, contrary to the polyphyly as previously indicated. The ITS sequence phylogeny of 43 arundinoid species recognizes the early divergence of the Aristideae and three major groupings, corresponding loosely to the tribes Arundineae and Danthonieae. The Arundineae are resolved into two paraphyletic clades: Arundo, Monachather, and Dregeochloa are the sister group to Amphipogon, and Diplopogon in one clade. Phragmites, Molinia, Gynerium, Thysanolaena, Spartochloa, and Cyperochloa are the sister group to Eriachne and Micraira in the other clade. Arundo is not closely related to Phragmites. The Danthonieae clade, including taxa from Africa, Australia, New Guinea, New Zealand, the South American Cortaderia, and the North American Danthonia, appears to be monophyletic. However, the genus Merxmuellera is polyphyletic.