Abstract Detail

Pollination Biology

Spigler, Rachel [1].

Effects of pollination conditions on floral longevity and display and the cost of delaying pollination in the self-compatible biennial Sabatia angularis (Gentianaceae).

Plasticity of floral traits in response to pollination can enable plants to maximize opportunities for pollen import and export under poor pollination conditions, while minimizing costs under favorable ones. Both floral longevity and display are key traits influencing pollination. Although pollination-induced flower witling is widely documented, comparatively little is known about plasticity in response to other dimensions of pollination, the costs (gains) of plastically extended (reduced) longevity, and pollination-induced changes in floral display. I addressed this gap using a set of comprehensive and complementary experiments testing plasticity of floral traits in the self-compatible biennial Sabatia angularis. Specifically, plasticity of floral longevity was evaluated in response to multiple axes of pollination: pollen addition, removal, type (self vs. outcross), and composition (single vs. multiple donors) and timing of pollination. The cost of delaying pollination was evaluated by comparing seed set from early and late pollinations. Finally, I evaluated plasticity of floral display metrics (peak floral display, time to peak flower, flowering duration, mean flowering rate) in response to pollination. Floral longevity was highly plastic in response to pollen addition and dose-dependent, but insensitive to the type and composition of pollen deposited. Pollen removal tended to extend floral longevity, but only insofar as it precludes self-pollination and thus pollination-induced wilting. The wilting response was faster under delayed pollination, and no cost was detected for delayed pollination. Pollinated plants had reduced peak floral displays and condensed flowering periods compared to control plants. Plasticity in floral longevity and display as demonstrated here could optimize fitness in S. angularis, a species prone to pollen limitation and high inbreeding depression. Under pollinator scarcity, extended floral longevities offer greater opportunities for pollen receipt and export at no cost to seed set, reproductive assurance via delayed autonomous self-pollination, and larger, more attractive floral displays. Under high pollinator availability, shortened longevities lead to smaller displays that should lower the risk of geitonogamy.

1 - Temple University, Biology, 1900 N. 12th Street, Philadelphia, PA, 19122, USA

Keywords:
Floral display
Floral longevity
Plasticity
Autogamy
Autonomous selfing
pollination
Corolla wilting.

Presentation Type: Oral Paper
Session: 36, Pollination Biology
Location: 203/Savannah International Trade and Convention Center
Date: Wednesday, August 3rd, 2016
Time: 8:45 AM
Number: 36004
Abstract ID:349
Candidate for Awards:None