Molecular Ecology and Evolution
Li, Pan , Wan, Ying , Cameron, Kenneth , Fu, Chengxin .
Phylogeography of the North American Herbaceous Smilax (Smilacaceae).
The herbaceous Smilax (sect. Nemexia) exhibit a classic East Asian-North American phytogeographic disjunction. While the two East Asian species are well defined by morphological and molecular evidence, the North American species are more taxonomically confused and treated as 1 to 9 species by different authors. Recent studies of chloroplast and nuclear DNA have shown that North American herbaceous Smilax are monophyletic, but failed to resolve the phylogenetic relationships among them. To elucidate these relationships, we reconstructed a phylogeny of Smilax sect. Nemexia using amplified fragment length polymorphism (AFLP) data. 325 individuals from 49 populations of all the nine North American species + the two East Asian species were sampled across the whole geographic range. Individuals of S. jamesii from western North America formed a cluster distinct from the eastern North American species. Within the eastern clade, a population of "S. biltmoreana" from the southern Appalachians formed a basal clade. The remaining samples showed a pattern related to geography rather than morphology or taxonomy. To supplement these data we also sequenced three plastid loci (ycf6, trnG and rpoc1). The cpDNA and AFLP results both support our former hypothesis that herbaceous Smilax first arrived into western North America via the Bering land bridge, and then spread eastwards, followed by isolation between them. Eastern herbaceous Smilax may have localized in glacial refugia in southern Appalachia, then expanded rapidly to the north in order to achieve their present distribution.
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1 - Zhejiang University, College Of Life Sciences, 388 Yuhangtang Road, Hangzhou, Zhejiang, 310058, China
2 - Wisconsin State Herbarium, Department Of Botany, 154 Birge Hall, 450 Lincoln Drive, Madison, WI, 53706, USA
Presentation Type: Poster:Posters for Topics
Location: Khorassan Ballroom/Chase Park Plaza
Date: Monday, July 11th, 2011
Time: 5:30 PM