Systematics/Phytogeography / Taxonomie/ Section
Le Clerc-Blain, Jessica , Saarela, Jeffery M. , Starr, Julian R. .
Barcoding sedges (Carex and Kobresia; Cyperaceae) of the Canadian Arctic Archipelago.
As the largest (2,000 spp.) and most widespread flowering plant genus, Carex and its allies in tribe Cariceae (sedges) represent one of most taxonomically challenging and ecologically significant of all angiosperm groups. This is particularly true in Arctic ecosystems where sedges represent ca. 10% of the vascular flora and form the dominate component of most habitats. We have taken a geographical approach to determine if sedges (Carex and Kobresia) from the Canadian Arctic Archipelago can be distinguished with a DNA barcoding approach. We have obtained sequence data for the coding regions matK, rbcL, rpoB and rpoC1, representing a subset of the plastid loci being considered as plant barcoding regions. We sampled multiple (2–8) individuals from 15–20 species for each marker, and compared parsimony analyses for regions alone and in combination (2–3) with results assessed by the percentage of species resolved as monophyletic and with bootstrap support ≥ 70%. Individual regions recovered the monophyly of 20–75% (5–50% with support ≥ 70%) of the possible species sampled, with rpoB and matK resolving the largest percentage of species when used alone. Combining loci (matK + rpoB, matK + rpoC1, rpoB + rpoC1, matK + rpoB + rpoC1) does not improve the percentage of species resolved in trees (between 36.8% and 68.1% of species with bootstrap support ≥70%). However, while matK resolves the greatest number of species (75%), combined analyses of rpoB + matK resolve the highest percentage species with bootstrap support ≥70% (68.4%). Several of the species that were not resolved as monophyletic in any analyses are either very closely related or taxonomically problematic.
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1 - University of Ottawa, Department of Biology, P.O. Box 450, Station A, Ottawa, Ontario, K1N 6N5, Canada
2 - Canadian Museum of Nature, P.O. Box 3443, Station D, Ottawa, Ontario, K1P 6P4, Canada
Presentation Type: Poster:Posters for Sections
Location: Ball Room & Party Room/SUB
Date: Monday, July 28th, 2008
Time: 12:30 PM