2018 ESA Annual Meeting (August 5 -- 10)

PS 16-62 - Creating a pollen library as a tool to determine heterospecific pollen load and diversity for insect-pollinated species in a serpentine seep community

Tuesday, August 7, 2018
ESA Exhibit Hall, New Orleans Ernest N. Morial Convention Center
Rebecca A Hayes, Rainee Kaczorowski and Tia-Lynn Ashman, Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA
Background/Question/Methods

Understanding the ways in which different plant species interact with each other via shared pollinators is integral to understanding a community’s dynamics. One way to monitor these interactions is by tracing heterospecific pollen transfer between co-flowering plants. Plants may have different traits that influence pollinator accessibility of reproductive structures (e.g., flower shape, corolla size, tube opening diameter, stigma/anther distance, or stigma/stamen exertion) or the effect that heterospecific pollen can have on a recipient species (e.g., style length or stigma size). We sought to answer the question of whether the likelihood of receiving heterospecific pollen was correlated with these traits. To address this, we created a pollen reference library categorized by size and morphological characteristics for a community of 96 angiosperms in serpentine seeps at the McLaughlin Natural Reserve in Lower Lake, California. The pollen library was then used to identify heterospecific pollen species found on the stigmas of plants throughout the community.

Results/Conclusions

Pollen lengths ranged from that of the diminutive Plagiobothrys stipitatus (3.75±0.478 μm) to the colossal grains of Clarkia concinna (104±0.958 μm). Species were divided into categories based on pollen length and 19 general morphological shapes (e.g., round, oval, dumbbell, triangular, spiky) with specific features (e.g., surface texture, aperture type/number). Stigmas from 67 species were examined thus far to determine the identity and quantity of different pollen types, which will allow for categorization of species into groups with varying quantities and diversities of heterospecific pollen receipt. Heterospecific pollen loads and diversity for each species will be presented. This information will be used to determine which traits are important for mediating the effects of heterospecific pollen receipt, which will be important for understanding community dynamics.