2020/08/19 by Kai Hao, Zhi-Xi Tian, Zichen Wang +3 · 10 citations
Agricultural and Biological Sciences · Environmental Science · #Biology #Botany #Ecology #Ecology and Vegetation Dynamics Studies #Foraging #Interspecific competition #Plant Parasitism and Resistance #Plant and animal studies #Pollen #Pollen source #Pollination #Pollinator #Zoophily
paper · pdf · doi:10.1098/rspb.2020.1191
openalex publication_date 2020/08/19 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Angiosperm pollen grain diameter varies greatly from a few microns to over 100, but the selective forces driving the interspecific variation in pollen size remain unclear. Although both pre- and post-pollination hypotheses have been proposed, empirical evidence remains scarce. Here we propose that visits by pollen-foraging pollinators have selected against large pollen grains. An association between pollinator behaviour and pollen grain size was confirmed by field studies of 80 flowering species in natural communities, showing that pollinators positively collected pollen in those species with relatively smaller pollen grains but rarely did so in species with larger ones. Allowing for the confounding effects of pollinator type, flower size or style length and pollen grain number, we found a significant effect of pollen-foraging behaviour on variation in pollen grain size, particularly in bee-pollinated plants. While these results suggest that many plant species whose pollen is collected or consumed by pollinators produce small pollen grains, it remains unclear whether pollen grain size is directly affected by pollinator foraging habit or indirectly mediated by pollen number trade-offs.