Does lack of pollination extend flower life?

by Hannah F. Fung, James D. Thomson

Flower of Gentianopsis detonsa (Gentianaceae), the species that showed the strongest extension of floral longevity  (2.7 days).  Photograph by Barbara A. Thomson

The longevity of a flower will be determined partly by genetically determined factors, but may also have a plastic component.  In particular, various authors have reported that floral senescence can be delayed if pollination is withheld.  Such extensions are particularly noteworthy in orchids.  In some orchid species, flowers will remain fresh and receptive for weeks if unpollinated, but will wither in a day or two after being pollinated. In non-orchids, reported extensions are shorter.   However, even modest extensions take on new interest in the context of climate change.  There is concern that changing seasonal cues may cause “phenological dislocations” between the flowering times of plants and the activity periods of their pollinators.  But plants that can extend the lives of unpollinated flowers would be more resilient to such changes. 

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To promote  more systematic study of this phenomenon, we conducted experiments on a local collection of nine species from various plant families. 

Read the whole summary in: English!
Read the scientific publication in JPE.

 

Comparing pollen deposition and pollen germination

by Rob Patchett, Gavin Ballantyne and Pat Willmer

Counting the number of pollen grains deposited on a flower stigma after a single visit by an animal – normally an insect - is a method commonly used to compare the performance of pollinators.

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Syrphid fly on a turnip (Brassica rapa) flower.

Here, we investigated whether counting the number of pollen grains deposited by different insect visitors placed them in the same order of pollinator performance compared to counting the number of germinated pollen grains. We chose the turnip as a study plant because it is self-incompatible – self-pollen will not germinate.

Read the whole summary in: English!
Read the scientific publication in JPE.