Pate, Sarah , Godsmark, George , Murrell, Zack .
Phylogeography and Mating System of Spiraea virginiana Britton.
Spiraea virginiana Britton is a threatened shrub endemic to second and third order drainages in the southern Appalachians and Cumberland Plateau. Because little is known about the species,characterization of its mating system, potential for sexual reproduction, and evolutionary relationships within the species could lead to improved conservation management. In order to examine genetic structure across the species' range, we conducted aphylogeographic study using a multi-locus approach. A phylogenetic analysis based on maximum parsimony of Inter Simple Sequence Repeats (ISSRs) revealed similarity within drainages, as well as monophyly of the species. To assess maternal relationships within the species, three regions of non-coding chloroplast DNA were sequenced, and a Bayesian phylogenetic analysis was conducted. Mapping of a haplotype network and the major clades identified in the Bayesian analysis revealed little structure within drainages and potential relatedness across elevational gradients. These conflicting genetic signatures are difficult to interpret, but studies of the species' reproductive biology provide some clues. Pollination treatments were conducted in a common garden setting and in three wild populations along the New River in Ashe County, NC. Results from these treatments tentatively suggest the species has a mixed mating system, and can reproduce sexually, contrary to prior observations. However, seed size, seed weight, and fruit set were variable among populations and germination rates were low. Based on our observations and the patterns revealed by the phylogeography, sexual reproduction in the species may be more possible than previously thought and seed may be wind-dispersed.
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1 - Appalachian State University, Biology, 572 Rivers Street , Boone, NC, 28608-2027, USA
Presentation Type: Oral Paper:Papers for Topics
Location: Forsyth Room/Chase Park Plaza
Date: Monday, July 11th, 2011
Time: 10:45 AM