Format: ORAL

Benjamin S. Lazarus1, Ash Kerber2, Csar Arvelos3, Fabian Michelangeli4, Agnes Dellinger1

1 Department für Botanik und Biodiversität, Universität Wien, Wien, Österreichische 2 University of Colorado - Boulder, Department of Ecology and Evolutionary Biology, Boulder, Colorado, USA 3 Programa de Pós - Graduação em Ecologia, Conservação e Biodiversidade, Universidade Feredal de Uberlândia, Uberlândia, Minas Gerais, Brazil 4 Institute of Systematic Botany, New York Botanical Garden, New York City, New York, USA

Flowers that are buzz-pollinated have evolved restricted, poricidal anthers that are most effectively pollinated by bees rapidly vibrating the stamens to extract pollen. This functionally specialized pollination strategy has evolved repeatedly in approximately 8% of angiosperms, and dominates in the plant family Melastomataceae, with around 96% of species exhibiting buzz pollination. Within Melastomataceae, a vast diversity of anther shapes and configurations have emerged and have been equated to an adaptive plateau of morphologically successful phenotypes. In this study, we explore the biomechanics of different anther structures and their effects on pollen release dynamics. Using CT scans and artificial buzzing experiments of morphologically distinct Melastomataceae species, we relate vibration parameters (frequency, amplitude, and number of pulses) and anther structure to pollen release rates. We will present results from convergent and divergent anther types found in different genera across three different Melastomataceae communities. We will then interpret these results in their pollination-ecological context, i.e., whether Melastomataceae species visited by a larger diversity of bee species also show high pollen release rates across a larger range of vibration parameters. This work is done with the aim of contributing to the fields understanding of the evolution and functioning of stamen trait diversity and subniche partitioning within the buzz-pollination syndrome, as well as to pinpoint potential evolutionary trajectories towards convergent or divergent floral phenotypes.