| Abstract Detail
Systematics Wefferling, Keir [1], Hoot, Sara [1]. Disentangling the subalpine marshmarigold polyploid complex: Phylogeography of Caltha leptosepala s.l. (Ranunculaceae). The western North American subalpine marshmarigold (Caltha leptosepala, Ranunculaceae) polyploid complex has a cytotype distribution that suggests refugial persistence in the Pacific Northwest, to the south of Last Glacial Maximum (LGM) icesheets. Two morphologically and genetically distinct hexaploid subspecies are distributed allopatrically in the US Rockies and Cascade-Sierra axis. Allododecaploids apparently formed repeatedly between the hexaploid taxa, and now are mainly distributed in the north of the complex’s range. Our most recent work estimates the timing of divergence between the hexaploid subspecies, the age(s) of allopolyploids, and infers patterns of recolonization of deglaciated terrain post-LGM. Using morphology (leaf and pollen), chromosome counts, flow cytometry, and DNA sequence data (nuclear ribosomal ITS and chloroplast), we aim to infer the most likely LGM refugia and recolonization routes of subalpine marshmarigolds. A fossil-calibrated phylogeny of the buttercup order Ranunculales was used to estimate the age of Caltha and close outgroups, and these age estimates were used as secondary calibrations (or age distributions) for the Caltha leptosepala polyploid complex. Structured coalescent analysis of the C. leptosepala complex supports recolonization of deglaciated northern regions (present-day British Columbia and Alaska) mainly from the North Cascades, and limited dispersal between the Rockies and Cascade-Sierra axis. Log in to add this item to your schedule
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1 - University Of Wisconsin-Milwaukee, Biological Sciences, Lapham Hall S394, PO Box 413, Milwaukee, WI, 53201, USA
Keywords: allopolyploid Polyploid Complex hybrid Pacific Northwest cytogeography Ranunculaceae Ranunculales coalescent Pleistocene Last Glacial Maximum refugia.
Presentation Type: Oral Paper Session: 19, ASPT Cooley Awards Location: Sundance 5/Omni Hotel Date: Tuesday, June 27th, 2017 Time: 10:15 AM Number: 19009 Abstract ID:369 Candidate for Awards:George R. Cooley Award |