Arceo Gomez, Gerardo , Ashman, Tia-Lynn .
Local co-flowering community diversity influences pollen receipt, female reproductive success and mediates selection on flower longevity in Mimulus guttatus.
Even though individual plant species occur within complex plant-pollinator communities we know little about how co-flowering community attributes such as species diversity and composition affect pollinator preference and behavior.Co-flowering species vary in the amount, quality and type of floral rewards and thus pollinators could discriminate among flowers or visit indiscriminately leading to high levels of heterospecific pollen (HP) transfer. Highly competitive pollination environments, in particular, may impose strong selective pressures on traits that improve the frequency and/or efficiency of pollination such as flower size, longevity and stigma-anther distance. However, how floral traits and their potential adaptive value vary in response to variation in plant species diversity among communities has not been evaluated. In this study we determined how local co-flowering community diversity influences pollinator visitation,conspecific pollen (CP) and HP receipt in Mimulusguttatus flowers by conducting pollinator observations and collecting styles after one day of pollination in two high and two low diversity sites. We explore covariation in floral traits (flower size, longevity and stigma-anther distance) with co-flowering species richness across 23 M. guttatus populations, and found one trait with significant variation (floral longevity). Lastly, we evaluated whether the adaptive value flower longevity changes in high versus low diversity co-flowering communities using a reciprocal transplant experiment. Pollinator visitation rate was higher and HP receipt lower at low versus high diversity sites but no difference in CP deposition was found. Our reciprocal transplant experiment showed that flowers on plants originally from high diversity co-flowering communities lived longer, received more CP and produced more seeds than those on plants from less diverse communities, but these benefits were only seen at high diversity sites. Overall, our results revealed that differences in co-flowering community diversity result in differences in the pollination environment, that longer lived flowers are adaptive at high diversity sites but not at low diversity sites, a result that parallels the pattern of genetic differentiation in floral longevity. This study is the first to show that community context, i.e., species richness,represents a distinct selective environment that mediates selection on floral traits.
Log in to add this item to your schedule
1 - University of Pittsburgh, Biological Sciences, 4249 Fifth Avenue, Pittsburgh, PA, 15260, United States
2 - University Of Pittsburgh, Department Of Biological Sciences, 4249 Fifth Avenue & Ruskin, Pittsburgh, PA, 15260, USA
Heterospecific pollen receipt
Presentation Type: Poster:Posters for Topics
Location: Battelle South/Convention Center
Date: Monday, July 9th, 2012
Time: 5:30 PM