Ansell, Stephen , Grundmann, Michael , Schneider, Harald , Russell, Stephen J. , Vogel, Johannes C. .
Biogeography of Italian mountain ranges: evidence from Arabis alpina.
Arabis alpina is a widespread plant in European arctic and alpine environments, including all major mountain ranges in Italy. We sampled populations from Sicily in the south to Lake Garda in the north, studying nuclear and cpDNA diversity. Populations in the Alps had significantly lower levels of nuclear genetic variation (P, Ae, Ho, and gene diversity) compared to the Italian peninsular populations. Both the Western and Eastern Alps had significant departures from Hardy-Weinberg Equilibrium expectations (FIS=0.368 and 0.598), suggesting a breakdown in self-incompatibility (possibly coinciding with leading-edge colonisation), while the Italian peninsular populations were all outbreeding (FIS=0.076). Genetic variation was strongly partitioned between the Alps and the Italian peninsular (FST=0.430) and local differentiation was detected at all geographic scales. We conclude that Arabis alpina initially colonised the Italian peninsular during the early Quaternary, and remnants of that original colonisation are still found in Sicily. Climate oscillation, range fragmentation and genetic drift resulted in the formation of multiple refugia along the Italian peninsular. The western Alps were probably re-colonised from a northern Italian gene pool, but the eastern Alps population probably originate from a very recent postglacial expansion from outside the Italian refugia.
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1 - Natural History Museum, Department of Botany, Cromwell Road, London, SW7 5BD, England
2 - Natural History Museum, Cromwell Road, London, SW7 5BD, UK
Presentation Type: Poster:Posters for Topics
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM