Recent Topics Posters
Rodrigues, Anuar , Colwell, Alison , Stefanovic, Sasa .
Phylogeography of the parasitic plant genus Conopholis (Cancer-Root; Orobanchaceae).
Little is known of the evolutionary relationship among the species and populations of the genus Conopholis as well as their post-glacial history. In the most recent taxonomic treatment of the genus, Haynes (1971) described it as having two species, C.americana and C.alpina, based on geographic distribution, morphology, reproductive isolation and host specificity. Using sequences derived from the plastid genome (clpP gene/intron and the trnfM-E intergenic spacer) of individuals sampled from across the entire range of these species, we reconstructed a molecular phylogeny for the genus. The results reveal that reciprocal monophyly between the two proposed species has not yet been achieved. Conopholis americana is found to be monophyletic while the data for C. alpina show evidence of at least two distinct lineages indicating that there could be three species within the genus. Further morphological and molecular analyses will reveal whether a taxonomic realignment is warranted. In addition, to further investigate the glacial refuges, biogeography and post-glacial migration of C.americana, an in-depth haplotype analysis approach was taken. The results reveal 23 distinct haplotypes. A place-holder from each type was then chosen and the relationships among them were reconstructed. Upon analysis, five groups of haplotypes are evident and those largely coincide with their geographic distribution. When northern haplotypes are defined as those found at any location above where the previous ice cap was located at the last glacial maximum (~18,000ya), 75% of all haplotypes are located in the south while only 25% are found in the north. This is in accordance with the Southern Refugia Hypothesis, which predicts that southern populations are the most genetically diverse and that as populations migrate north they lose their genetic diversity. More dense taxonomic sampling and better resolution could reveal migration routes taken by these populations.
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1 - University of Toronto at Mississauga, Biology, 3359 Mississauga Road North, Mississauga, Ontario, L5L 1C6, Canada
2 - Western Ecological Research Center, US Geological Survey, Yosemite Field Station, 5083 Foresta Rd, El Portal, CA, 95318
3 - University of Toronto at Mississauga, Biology, 3359 Mississauga Rd N, Mississauga, Ontario, L5L1C6, Canada
Southern Refugia Hypothesis.
Presentation Type: Recent Topics Poster
Location: Ball Room & Party Room/SUB
Date: Monday, July 28th, 2008
Time: 12:30 PM