Phylogenetics of Paniceae (Poaceae)
Date
2001-11Author
Duvall, Melvin R.
Noll, Jeffrey D.
Minn, Alexandra
Metadata
Show full item recordAbstract
Paniceae demonstrate unique variability of photosynthetic physiology and anatomy, including both non-Kranz and Kranz species
and all subtypes of the latter. This variability suggests hypotheses of independent origin or reversals (e.g., from C4 to C3). These
hypotheses can be tested by phylogenetic analysis of independent molecular characters. The molecular phylogeny of 57 species of
Paniceae was explored using sequences from the grass-specific insert found in the plastid locus rpoC2. Phylogenetic analyses confirmed
some long-recognized alliances in Paniceae, some recent molecular phylogenetic results, and suggested new relationships. Broadly,
Paniceae were found to be paraphyletic with Andropogoneae, Panicum was found to be polyphyletic, and Oplismenus hirtellus was
resolved as the sister group to the remaining ingroup species. A particularly well-supported clade in the rpoC2 tree included four
genera with non-Kranz species and three with distinctively keeled paleas. As previously suggested, the PCK (phosphoenol pyruvate
carboxykinase) C4 subtype arose once within Paniceae. All clades with non-Kranz species had Kranz ancestors or sister taxa suggesting
repeated loss of the Kranz syndrome.