Differences in pollination syndromes and the frequency of autonomous delayed selfing between co-flowering Hibiscus aponeurus (Sprague and Hutch) and H. flavifolius (Ulbr) from Kenya

Authors

  • Juan Carlos Ruiz Guajardo The University of California in Davis Department of Evolution and Ecology Center for Population Biology Storer Hall, Davis, CA 95618
  • Andrew Schnabel Department of Biological Sciences Indiana University South Bend South Bend, Indiana, IN 46634.
  • Britnie McCallum Belk College of Business University of North Carolina at Charlotte, Charlotte, NC 28223
  • Adriana Otero Arnaiz Office of Agricultural Affairs USDA, U.S. Embassy Mexico City
  • Katherine C. R. Baldock School of Biological Sciences University of Bristol Bristol BS8 1TQ
  • Graham N Stone Institute of Evolutionary Biology University of Edinburgh Edinburgh EH9 3JT

DOI:

https://doi.org/10.26786/1920-7603(2018)three

Abstract

Delayed autonomous selfing offers a mechanism for seed production when pollination levels are low or unpredictable. At Mpala Research Centre (MRC) in Kenya, we examined the relationships between floral attraction, insect visitation, and delayed autonomous selfing through backwards stylar curvature in the co-flowering Hibiscus aponeurus and H. flavifolius. Despite producing similar pollen and nectar rewards, visitation rates and the composition of floral visitor guilds varied significantly between these species. Across four years of observations, floral visitation in H. flavifolius was dominated by bees, and in H. aponeurus by a mixture of bees, butterflies and beetles. Visitation rates to H. flavifolius flowers (range 0.17 - 2.1 visits flr-1hr-1) were two times greater than to H. aponeurus flowers (range 0 - 2.7 visits flr-1hr-1), which resulted in significantly higher pollen deposition and removal rates in H. flavifolius than in H. aponeurus. Field crosses demonstrated little pollen limitation in either species. In open-pollinated flowers, H. aponeurus displayed significantly greater stylar curvature and apparent self-pollination than did H. flavifolius.  Floral attributes in H. aponeurus, such as a smaller corolla size and a downwards orientation of the stylar column, also suggest that delayed selfing is a more important mechanism of reproductive assurance in this species than in H. flavifolius. Determining whether these differences in insect visitation and stylar curvature are characteristic for these species or are unique to MRC will require comparison with populations located in other parts of the ranges, genetic tests of selfing rates, and chemical analyses of nectar, pollen, and floral volatiles.

 

Author Biographies

Juan Carlos Ruiz Guajardo, The University of California in Davis Department of Evolution and Ecology Center for Population Biology Storer Hall, Davis, CA 95618

Postdoctoral International Scholar

 

 

Andrew Schnabel, Department of Biological Sciences Indiana University South Bend South Bend, Indiana, IN 46634.

Professor of Biological Sciences 

Britnie McCallum, Belk College of Business University of North Carolina at Charlotte, Charlotte, NC 28223

Masters Student 

Adriana Otero Arnaiz, Office of Agricultural Affairs USDA, U.S. Embassy Mexico City

Philosophy Doctor in Biology 

Katherine C. R. Baldock, School of Biological Sciences University of Bristol Bristol BS8 1TQ

Postdoctoral Researcher 

Graham N Stone, Institute of Evolutionary Biology University of Edinburgh Edinburgh EH9 3JT

Professor of Ecology 
Hibiscus aponereus mature dehisced flowers and developing fruit. Photo taken at Mpla Reserach Centre by Juan C. Ruiz Guajardo

Published

2018-03-05

How to Cite

Ruiz Guajardo, J. C., Schnabel, A., McCallum, B., Otero Arnaiz, A., Baldock, K. C. R., & Stone, G. N. (2018). Differences in pollination syndromes and the frequency of autonomous delayed selfing between co-flowering Hibiscus aponeurus (Sprague and Hutch) and H. flavifolius (Ulbr) from Kenya. Journal of Pollination Ecology, 22, 21–34. https://doi.org/10.26786/1920-7603(2018)three

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Section

Articles