Abstract Detail



Macroevolution

Schenk, John [1], Botnaru, Lucia [2].

Staminode Evolution in Mentzelia Section Bartonia (Loasaceae) and their Impact on Insect Visitation Rates.

Staminodes are infertile stamen that have evolved numerous times across angiosperms; however, very little is known about the evolutionary transitions of staminodes, especially among close relatives.  We studied staminode evolution in Mentzelia section Bartonia to determine how many times staminodes have been gained or lost.  A maximum-likelihood approach identified ten transitions, in which staminodes evolved at least five times and were reversible.  We then examined the visitation consequences of staminode evolution by quantifying how staminodes affect visitation rates.  A population of Mentzelia multiflora was used in an experimental study where visitation of control flowers (staminodes present) was compared to treatment flowers (staminodes removed).  The only pollinator was Apis mellifera (Apidae), who significantly hovered above and landed on control more than treatment flowers.  Despite the preference to land on staminodial flowers, once landed, pollinators spent an equal time on control and treatment flowers.  We hypothesize that the increased visitation of staminodial flowers likely offsets the loss of the reproductive function in stamens.


1 - Georgia Southern University, Department Of Biology, 4324 Old Register Road, Biological Sciences Building, Statesboro, GA, 30458, United States
2 - Georgia Southern University, Department of Biology, Statesboro, GA, 30458, USA

Keywords:
Ancestor character estimation
androecium
floral evolution
staminode
Mentzelia
Loasaceae
Pollination
functional cooption
macroevolution
phylogenetic comparative methods.

Presentation Type: Oral Paper
Number:
Abstract ID:136
Candidate for Awards:None


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