Plant traits diversify rapidly in response to different pollinator species shows a study published in Nature Communications this week. After only 11 generations of pollination by either bees or hoverflies, plants had diverged in height, flower fragrance, flower colour, and reliance on the pollinator for reproduction. The study suggests that changes in pollinator communities can have rapid consequences on the evolution of plant traits.
Previous studies of plant evolution in response to pollinators have been conducted in the field, where other factors could also drive changes in plant characteristics. By using an experimental system, the current study makes it possible to isolate the effects of pollinator identity on plant evolution.
Daniel Gervasi and Florian Schiestl grew the plant Brassica rapa in greenhouses with pollination performed by either bumblebees or hoverflies. Compared to hand-pollinated plants, bumblebee-pollinated plants evolved to be taller and have more fragrant flowers with more ultraviolet colour, whereas hoverfly-pollinated plants evolved to be shorter and less fragrant.
At the end of the experiment, plants from the bumblebee treatment were more successful at attracting bumblebee pollinators. Meanwhile, plants from the treatment with hoverflies, which are much less effective pollinators, were better able to self-pollinate (fertilize seeds without the aid of a pollinator). These findings highlight the need for more work on the evolutionary implications of changed pollinator environments in natural habitats, the authors conclude.