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144368 - Mechanisms of male-male interference during dispersal of orchid pollen.pdf (1.65 MB)

Mechanisms of male-male interference during dispersal of orchid pollen

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posted on 2023-05-20, 23:21 authored by Harder, LD, Shane RichardsShane Richards, Agren, J, Johnson, SD
Siring success of flowering plants depends on the fates of male gametophytes, which compete for access to stigmas, stylar resources, and ovules. Although rarely considered, pollen may often compete during dispersal, affecting the processes required for export to stigmas: pollen pickup, transport, and deposition. We quantified dispersal interference by tracking bee-mediated dispersal of stained Anacamptis morio (Orchidaceae) pollen from individual donor flowers and inferred the affected dispersal mechanisms on the basis of the fit of a process-based model. During individual trials, all recipient flowers were either emasculated, precluding interference with donor pollen, or intact, adding potentially interfering pollen to the pollinator. The presence of competing pollinaria on bees reduced pickup of additional pollinaria, doubled the overall proportion of lost donor pollen, and reduced total pollen export by 27%. Interference specifically increased loss of donor pollen between successive flower visits and variation in deposition among trials, and it likely also reduced pollen contact with stigmas and pollen deposition when contact occurred. Thus, by altering pollen removal, transport, and deposition, male-male interference during pollen dispersal can significantly—and perhaps commonly—limit plant-siring success.


Publication title

The American Naturalist








School of Natural Sciences


Univ Chicago Press

Place of publication

1427 E 60Th St, Chicago, USA, Il, 60637-2954

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Copyright 2021 by The University of Chicago. This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License (CC BYNC 4.0), (, which permits non-commercial reuse of the work with attribution.

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  • Open

Socio-economic Objectives

Expanding knowledge in the biological sciences