Time dependent attachment properties of pollen grains in anemophilous plants tested by the mass centrifugation method

The process of pollen release, transfer and capture is the most critical step in reproduction of higher plants and requires several steps of detachment and reattachment of pollen grains to different surfaces. As a response to their specific biotic or abiotic factors, pollen grains have developed a huge variability of size, shape and surface structure, which affects their adhesion properties in a specific manner and contributes to the pollination syndrome of a plant. However, despite decades of research and a great public awareness, these adhesion forces have rarely been measured directly. In the present paper, we used a mass centrifugation setup with glass as a standard substrate, to characterize time dependent adhesion properties of pollen grains from four anemophilous species and compared them to the results of previous studies. Our results show strong differences in adhesion between species studied in fresh and aged state, which can be related to their respective pollination ecology. We discuss the species-specific adhesive properties of pollen grains and highlight methodological aspects, to establish centrifugation method as a standard approach, in order to collect a broad set of quantitative data about adhesion properties of pollen grains and to understand their role in the process of pollination.