PNW 98 Session - Full Abstracts
Full Abstract
1) Contact Author: Alan C. Yen
2) Institution:University of Washington
3) Mailing Address: Department of Botany, Box 355325, Univ. of Washington, Seattle, WA 98195-5325
4) Phone #:206-616-7156
5) Email: alanyen@u.washington.edu
6) Presenter: Alan C. Yen
7) Paper or Poster: paper
8) Equipment needs other than standard slide and overhead projector:
9) Contributed session 1st choice:Functional
10) Contributed session 2nd choice:Functional
11) Do you want your oral or poster presentation judged for a student award (yes or no)?: Yes
12) Would you like to be a judge for Student Awards (yes or no)?:No
13) Keywords:Carex, DNA, Phylogeny
14) Authors:
ALAN C. YEN (1)
Richard G. Olmstead (1)
15) Affiliation/institution:
(1) Dept. of Botany, University of Washington, Seattle, WA
16) Abstract Title:
Molecular systematics of Carex (Cyperaceae) based on chloroplast DNA sequences
17) Abstract Text:
_Carex_ (Cyperaceae) is an important genus in temperate wetlands in providing forage material, wildlife shelters, storm water retention, and the maintenance of important wetland functions. _Carex_ is also known for its taxonomic difficulties due to the size of the genus, the similarity among species, and the complex morphology. We use comparative DNA sequencing techinques to reconstruct the phylogeny for _Carex_ and tribe Cariceae in order to identify monophyletic lineages and to evaluate the usefulness of morphological characters in delimiting monophyletic groups. Analyses based on 33 taxa and 3,300 bp of chloroplast DNA sequences from _ndh_F, Leucine tRNA (_trnL_) intron, and the intergenic spacer region between _trn_L and _trn_F (Phenylalanine), suggest the monophyly of Cariceae, with _Schoenoxiphium_, a South African genus, at the base of the tribe. The remaining members of the Cariceae form three unresolved clades consisting of _Kobresia_, _Carex_ subgenera _Carex_/_Indocarex_/_Vignea_, and subgenus _Primocarex_/_Uncinia_/_Cymophyllus_. The monophyly of _Schoenoxiphium_, _Carex_ subgenus _Vignea_, subgenera _Carex_/_Indocarex_, and _Uncinia_ is strongly supported. The relationships among _Kobresia_, subgenus _Primocarex_, and _Uncinia_ are ambiguous at present. The weak bootstrap support for several internal nodes and the high consistency index (0.7 on average) suggest recency of ancestry within these groups. The high consistency index suggests low homoplasy within the data and the suitability of these cpDNA regions for studies at the generic and subgeneric levels.
18) Comments/Requests: