Systematics/Phytogeography / Taxonomie/ Section
Gillespie, Emily , Kron, Kathleen A. .
Evolution and Biogeography of the Genus Phyllodoce and its Close Relatives (Ericaceae: Phyllodoceae) based on seven molecular markers.
Four closely related genera (Phyllodoce, Kalmiopsis, Epigaea and Rhodothamnus) form a small but morphologically and biogeographically diverse clade within the tribe Phyllodoceae (subfamily Ericoideae). These genera of ericaceous alpine/subalpine shrubs are distributed at high latitudes in the Northern hemisphere. Phyllodoce (approx. 7 spp.) is distributed circumboreally as far south as the Sierra Nevada Mountains (California, USA) and Manchuria (northern China), with the highest diversity in northwestern North America. Kalmiopsis (1-2 spp.) is known only from Oregon, USA. Rhodothamnus (2 spp.) is narrowly distributed in the Alps and Caucasus Mountains in Eurasia. Epigaea (3 spp.) occurs narrowly in Japan, in the Caucasus, and broadly in eastern North America. The wide variety of distributions in this clade provide an opportunity to ask interesting biogeographical questions in a phylogenetic context. Phylogeny reconstruction was accomlished within both Parsimony and Bayesian frameworks using seven nuclear and chloroplast DNA regions, including nrITS, GBSS-1 (waxy), LEAFY, matK, rbcL, ndhF and trnS-G intergenic spacer. Outgroups were chosen based on larger analyses of the subfamily Ericoideae, and include representatives of Kalmia, Elliottia, Bejaria and Rhododendron. Biogeographical analyses were conducted using MacClade and DIVA. Current phylogenetic analyses suggest that Epigaea and Rhodothamnus form a clade together, which is sister to a clade formed by Kalmiopsis and Phyllodoce. All genera appear to be monophyletic as traditionally circumscribed, although a single Phyllodoce sp. (P. breweri) resolves as more closely related to Kalmiopsis under particular analytical conditions. Biogeographic analyses indicate that the Kalmiopsis + Phyllodoce clade originated in northwestern North America, while the Epigaea + Rhodothamnus clade originated in the mountainous areas of southern Europe and western Asia.
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1 - Wake Forest University, Department of Biology, PO Box 7325, 226 Winston Hall, Winston-Salem, North Carolina, 27109-7325, USA
Northern hemisphere biogeography
Presentation Type: Oral Paper:Papers for Sections
Location: Room 3/Woodward
Date: Monday, July 28th, 2008
Time: 5:00 PM