Effects of Open Pollination, Selfing, Inbreeding, and Outbreeding on Seed Set and Viability in Spiraea virginiana Britton (Rosaceae)

UNCA Author/Contributor (non-UNCA co-authors, if there are any, appear on document)
Kristin Emery, Student (Creator)
University of North Carolina Asheville (UNCA )
Web Site: http://library.unca.edu/
Jennifer Rhode Ward

Abstract: Spiraea virginiana Britton (Virginia spiraea), an endangered riparian shrub found in the Appalachian and Blue Ridge Mountains, reproduces primarily via asexual reproduction. Sexual reproduction is rare under field conditions, but it is unclear whether pollen limitation or genetic incompatibilities are the underlying cause. Open, selfed, inbred, and outbred pollination treatments were applied to populations of S. virginiana from three Western North Carolina counties. Stigmas from open pollinated treatments were collected to quantify pollen loads. Flowers from pollination treatments were collected 90-120 days later, and a subset of seeds were stratified for three months before monitoring germination rates. In addition, 100 seeds from each replicate were tested for viability using TTC. Both foreign and conspecific pollen loads on Graham County stigmas were significantly lower (P=0.0001) than pollen loads on stigmas from other populations. Seed set from Ashe County plants was significantly lower than other populations (P=0.0001), but treatment had no significant effect on seed set (P=0.18). Only the Ashe County population produced viable seeds (0.44%). Because seed set was not correlated with pollen load, variation in reproductive success could be due to other factors. Genetic variation within and among populations is currently being investigated to see if it could help explain differential seed production.

Additional Information

UNC Asheville - Journal of Undergraduate Research
Language: English
Date: 2014
Spiraea virginiana Britton (Virginia spiraea), Appalachian mountains, Western North Carolina, open pollination, seeds

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