Abstract Detail

Ecology

Foster, Olyvia [1], Caruso, Christina [1].

Delayed pollen receipt extends floral longevity and reduces seed production in an Eastern North American wildflower.

Plants may be able to respond to declines in pollination services through plasticity in traits such as floral longevity that can increase the opportunity for pollination. While plastically extending longevity could prolong the opportunity for pollination, it may reduce seed production by decreasing the carbon available to mature ovules. This decrease in seed production could be larger for hermaphrodite than female flowers if more carbon is required to maintain the larger corollas of hermaphrodite flowers. To test whether delayed pollination caused by pollinator declines could increase floral longevity and decrease seed production, we manipulated the timing of pollination for female and hermaphroditic Lobelia siphilitica plants. We hand-pollinated two flowers per plant either on day-1 or day-5 of the female phase. For each flower, we measured the number of days from corolla opening to wilt and the number of seeds per fruit. The timing of pollination affected both floral longevity and seed production: L. siphilitica flowers pollinated on day-5 had an average corolla longevity of 2.2 days longer than flowers pollinated on day-1 and produced 34.1% fewer seeds. However, the effect of delayed pollination on seed production did not differ between female and hermaphrodites, suggesting that more carbon is not required to maintain the larger corolla of hermaphrodite flowers. Overall, our results suggest that L. siphilitica could respond plastically to delayed pollination caused by declines in pollination services by extending floral longevity. This ability to extend longevity could aid L. siphilitica plants during declines in pollination services, but only if the costs of corolla maintenance are outweighed by the benefits of a prolonged opportunity for pollination. Although further study of plasticity in additional floral traits is required to understand plant responses to declines in pollination services, our findings demonstrate how plants can be active participants in the plant-pollinator relationship through plasticity in floral longevity.

1 - University Of Guelph, Department Of Integrative Biology, Guelph, ON, N1G 2W1, Canada

Keywords:
Floral longevity
pollination
Gynodioecy
Resource allocation trade-offs
Plasticity.

Presentation Type: Poster
Session: P1, Ecology Posters
Location: Virtual/Virtual
Date: Monday, July 19th, 2021
Time: 5:00 PM(EDT)
Number: P1EC002
Abstract ID:256
Candidate for Awards:Phytochemical Best Poster Award