Abstract Detail



Ericaceae: Systematics, Ecology and Evolution

Gillespie, Emily [1], Madsen-McQueen, Tesa [2], Eriksson, Torsten [3], Madritch, Michael [4], Murrell, Zack [5].

Evidence of considerable population divergence in Sandmyrtle (Kalmia buxifolia, Ericaceae).

Sandmyrtle, Kalmia buxifolia (Bergius) Gift & Kron, exhibits a disjunct distribution in eastern North America. Extant populations occur in the New Jersey Pinelands (NJP), the Southern Appalachian Mountains (SAM), and the Sandhills/Cape Fear Arch (SCFA) region of the Carolinas. There is no present-day biogeographic connection between NJP and SCFA populations, and very little between the SAM and SCFA populations. Despite relatively close geographic proximity, the SAM and SCFA populations are dissimilar in terms of habitat; SAM populations typically occur on rock outcrops and SCFA populations occur in wet pinelands that are ecologically similar to the northern NJP populations. Individual plants also vary morphologically, with SAM and NJP plants tending to be somewhat mat-forming and SCFA plants tending to be taller and spindly. Over the last 150 years, experts have recognized between one (current consensus) and three species based on a combination of morphology and habitat. We developed microsatellite DNA markers for Sandmyrtle using an Illumina sequencing dataset, sampling from three populations representing the three main parts of the Sandmyrtle distribution. We also tested these markers in several individuals from the closest relative, Alpine Azalea (Kalmia procumbens (L.) Gift, Kron & P.F. Stevens ex Galasso, Banfi & F. Conti) and single individuals from the remaining eight Kalmia species. We then applied several of the most variable and robust of these markers to an additional eight K. buxifolia populations and a full (N=24) population of K. procumbens in order to gain landscape-level insights into Sandmyrtle’s genetic variability and structure, deviation from Hardy-Weinberg assumptions, and phylogeographic history. We sequenced one nuclear and one chloroplast marker for eight individuals from each population as a complementary dataset and generated a fossil-calibrated phylogeny. We also examined trait evolution and niche partitioning within a phylogenetic context. Our current dataset reveals considerable divergence at the population and/or physiographic level. SCFA and NJP populations are more genetically similar to each other overall, somewhat aligning with the taxonomic boundaries suggested by JK Small in the 1930s. The emerging patterns are consistent with a late Miocene SAM origin of Sandmyrtle, followed by subsequent fragmentation and range expansion in response to climate change events leading into the Pliocene and Pleistocene.


1 - Butler University, Biological Sciences, 4600 Sunset Ave., Biology, Indianapolis, IN, 46208, United States
2 - University of California, Riverside, Department of Evolution, Ecology, and Organismal Biology, 900 University Avenue, Riverside, CA, 92521, USA
3 - University Of Bergen, University Museum, Department Of Natural History, Postboks 7800, Bergen, N-5007 , Norway
4 - Appalachian State University, Department of Biology, 572 Rivers Street, Boone, NC, 28608, USA
5 - Department Of Biology, Appalachian State University, 572 Rivers Street, Boone, NC, 28608, United States

Keywords:
Ericaceae
Kalmia buxifolia
Microsatellite DNA
phylogeography
Pine Barrens
Sandhills
Sandmyrtle
Southern Appalachian Mountains.

Presentation Type: Colloquium Presentations
Number:
Abstract ID:418
Candidate for Awards:None


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