Abstract Detail

Reproductive Processes

Sharrett, Lucas [1], Steven, Janet [2].

The role of volatile organic compound emissions in the development of a hummingbird pollination syndrome in Silene virginica.

Olfactory signaling as a method for pollinator attraction is common in flowering plants, and pollinator-specific signaling can be a crucial factor in speciation. In this research, we are quantifying the volatile organic compounds (VOC) that serve as olfactory signals in three species of Silene (Caryophyllaceae). The species included are Silene virginica, Silene stellata, and Silene caroliniana which are closely related. The main pollinators of these three species are hummingbirds, moths, and large bees, respectively. S. virginica produces red flowers and is a diurnal specialist primarily pollinated by the ruby-throated hummingbird Archilochus colubris. S. stellata has white flowers and is a nocturnal specialist primarily pollinated by Hadena ectypa. S. caroliniana produces pink flowers and is a diurnal generalist pollinated by large bees and diurnal lepidopterans. In the floral attraction of lepidopterans and bees, VOCs play a significant role in guiding pollinators towards a nectar reward. Therefore, S. stellata and S. caroliniana should produce scent unique to their pollinator syndrome. However, little research has been conducted on the olfactory capabilities of hummingbirds and it is assumed that hummingbird pollinated species do not produce specific scent compounds used in the attraction of their pollinators, solely relying on color and other visual cues. Therefore, the hummingbird pollination syndrome is currently expected to be unaccompanied by a pattern of VOC emissions in S. virginica with little evidence for the utilization of scent assisted foraging behaviors in A. colubris. The floral scent composition of the three species will be compared to determine the extent to which VOC emissions have diverged among their different pollination syndromes. The role of VOCs in S. virginica will be the primary focus in comparison of these three closely related species due to its unique pollination syndrome. If S. virginica is found to emit the same or less floral compounds at lower concentrations than its sister species, then we can understand that the scent profile of S. virginica is the result of a degradation in scent, due to a lack of selection pressures for unique VOCs in the adaptation of a hummingbird pollination syndrome. If we find that S. virginica expresses unique floral VOCs apart from its sister species, then we can infer that the selection of these compounds was pressured by A. colubris in the adaptation of the hummingbird pollination syndrome.

1 - Christopher Newport University, Department of Organismal and Environmental Biology, 1 Avenue of the Arts, Newport News, Virginia, 23606, United States
2 - Christopher Newport University, Department Of Organismal And Environmental Biology, 1 Avenue Of The Arts, Newport News, VA, 23606, United States

Hummingbird Pollination
Volatile Organic Compounds
Pollination syndromes
plant-pollinator interactions.

Presentation Type: Oral Paper
Number: RP4005
Abstract ID:908
Candidate for Awards:None

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