Submitted to: New Phytologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/14/2005
Publication Date: 1/1/2006
Citation: Barthelmess, E.L., Richards, C.M., McCauley, D.E. 2005. Relative effects of nocturnal vs diurnal pollinators and distance on gene flow in small silene alba populations. New Phytologist 169:689-698 Interpretive Summary: The authors report experimental results on gene flow dynamics that is part of a larger study on population extinction and colonization processes in the short lived perennial Silene alba. Specifically, the experiments use arrays of genotyped control populations to examine the rate of pollen meditated gene flow in diurnal and nocturnal pollinator guilds. These data underscore the importance of nocturnal pollinators in moving genes among populations.
Technical Abstract: · Silene alba exists in natural metapopulations throughout its range and is visited by a suite of both diurnal and nocturnal pollinators. Pollen-mediated gene flow may help reduce genetic isolation of subpopulations. We compared the relative effects of nocturnal vs. diurnal pollinators on pollen-mediated gene flow in subpopulations separated by two distance treatments. · We established populations consisting of genetically marked individuals in an old field in Tennessee. Electrophoretic examination of seedlings produced by plants exposed to nocturnal, diurnal and control pollinator treatments and separated by either 20 or 80 m allowed us to directly measure pollen-mediated gene flow. · Gene flow was more common between populations separated by only 20 m. Nocturnal pollinators were responsible for most gene flow between populations, regardless of distance. Diurnal pollinators played only a small role in pollen-mediated gene flow. · Nocturnal pollinators are better than diurnal pollinators at moving pollen between small S. alba subpopulations. However, their effectiveness declines as the distance between subpopulations increases, making them relatively ineffective at moving genes between isolated subpopulations.