Submitted to: Symposium Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 4/1/2007
Publication Date: 6/24/2007
Citation: Holmquist, K.G., Brunet, J. 2007. The effect of landscape and pollinator features on contemporary gene movement in Aquilegia coerulea [abstract]. 9th International Pollination Symposium on Plant-Pollinator Relationships - Diversity in Action, June 24-28, 2007, Ames, Iowa. p. 133-134.
Technical Abstract: As a consequence of distinct pollen dispersal curves which may result from differences in grooming and foraging behavior, different pollinators may differentially affect patterns of pollen-mediated gene flow, and ultimately the effective neighborhood size and genetic structure of a population. In addition, for a given pollinator, patterns of pollen-mediated gene flow will be affected by the ecological context of pollination, which includes the density and distribution of potential pollen donors and recipients. In this study we examine the impact of two distinct pollinators, hawkmoths and bumblebees, on pollen movement on a large geographic scale (40 km2). We also contrast the impact of these two pollinators on pollen-mediated gene movement under two different ecological contexts, by contrasting gene flow in geographical areas with different degrees of plant aggregation. We set up five patches of approximately six geo-referenced pollen traps (mothers) with two pollination treatments per patch (J ' 30 mothers/treatment) within a 40 km2 area of the Grand Canyon National Park on the eastern edge of the Kaibab Plateau of Arizona where plants are at low density in isolated patches. Using the inter-plant distances obtained for the approximately 60 pollen traps deployed on the Kaibab Plateau, we generated a replicate distribution of pollen traps within a 40 km2 area of the western edge of the Markagunt Plateau of Utah extending into the Cedar Breaks National Monument, an area where plants are denser and more uniformly distributed. The gynoecia of plants in the bumblebee only treatment were capped with thin-wall PCR tubes in the evening to exclude any hawkmoth visitors and exposed during the day. The opposite capping regime was done for the hawkmoth only treatment plants in order to exclude bumblebee visitors during the day. A random sample of approximately 25 seeds per pollen trap (female) were run at five microsatellite loci in order to obtain progeny genotypes, for a total sampling effort of roughly 3000 individuals (750 individuals/treatment * 2 Treatments (bumblebee versus hawkmoth pollination) * 2 replicate distributions of pollen traps (Kaibab Plateau versus Markagunt Plateau)). Two-Generation Analysis was performed using the GeneticStudio v2.0 software in order to estimate 'FT and subsequently calculate the effective number of males and estimate the spatial extent of the mating neighborhood for each pollination treatment within each ecological context.