| Abstract Detail
Systematics Section Peterson, Paul M. [1], Romaschenko, Konstantin [1], Johnson, Gabriel [2]. A phylogeny of the Chloridoideae (Poaceae) based on plastid and nuclear DNA sequence data. The subfamily Chloridoideae includes more than 1420 species worldwide and share only a few structural characters: all exhibit Kranz or C4 leaf anatomy (except Eragrostis walteri Pilg.), and most have chloridoid bicellular microhairs and chloridoid embryos. We conducted a molecular phylogenetic study of the Chloridoideae (including 100 genera) using a total of 265 species (five species were used as outgroups) based on six plastid DNA sequences (ndhA, ndhF, rps16-trnK, rps16-intron, rps3, and rpl32-trnLUAG) and a single nuclear ITS DNA sequence. Our parsimony analysis of DNA sequences provides support for the monophyly of the Chloridoideae; followed by, in order of divergence: a Neyraudia and Triraphis clade with all taxa apparently having panicoid-like microhairs (elongated, slender, and thin-walled terminal cells); an Eragrostideae clade with the Cotteinae (includes Enneapogon) sister to the Uniolinae (incudes Entoplocamia), and a terminal clade of Ectrosia, Harpachne, and Psammagrostis embedded in a polyphyletic Eragrostis; a Zoysieae clade that includes Urochondra, Spartina, Calamovilfa, Pogoneura, Crypsis, Zoysia, and a polyphyletic Sporobolus; and a very large Cynodonteae clade that includes monophyletic clades of (in alphabetical order) Aeluropus, Astrebla (includes Schoenefeldia), Blepharidachne, Boutelouinae, Brachyachne s.s., Chloris (includes Lintonia), Cleistogenes, Ctenium, Cynodon (includes two species of Brachyachne), Dactyloctenium, Dignathia, Enteropogon (includes one species of Eustachys), Eustachys s.s., Hilariinae, Lepturus, Melanocenchris, Microchloa, Monanthochloinae (includes Distichlis, Reederochloa, and Monanthochloë), Mosdenia, Muhlenbergiinae, Munroinae, Orcuttiinae, Orinus, Perotis (includes Craspedorhachis and Lopholepis), Traginae (includes Monelytrum, Polevansia, Tragus, and Willkommia), Trichloris, Trioidia, and Tripogon (includes Eragrostiella). Clearly, many of these purported relationships are tenuous and in the future we hope to obtain greater sampling of African taxa.
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1 - Smithsonian, Department of Botany, National Museum of Natural History, P.O. Box 37012, Washington, DC, 20013, USA
2 - Smithsonian, Department of Botany and Laboratories of Analytical Biology, Museum Resource Center, 4210 Silver Hill Road, Suitland, MD, 20746, USA
Keywords:
classification
Chloridoideae
grasses
ITS
phylogeny
plastid DNA
Poaceae
taxonomy.
Presentation Type: Array
Session: 68
Location: Cottonwood D/Snowbird Center
Date: Wednesday, July 29th, 2009
Time: 4:30 PM
Number: 68014
Abstract ID:437 |
