Abstract Detail

Pollination Biology

Zweck, Justin [1], Muniz, Paige [2], Arduser, Mike [3], Bernhardt, Peter [4].

AN INVESTIGATION OF POLLINATION AND FLORAL FORM CHANGE IN AMORPHEAE (Fabaceae); FROM SPECIALIZATION TO GENERALIZATION.

The floral morphologies of several species in the Amorpheae tribe of legumes differ dramatically from the typical papilionoid legume floral form from which these species are derived. While typical papilionoid species enclose their sexual organs within the petals, these Amorpheae species feature flowers in which the sexual organs are exposed, potentially affecting reproduction mode by permitting pollination by a greater range of taxa. We tested this hypothesis by comparing pollination and reproduction in 4 Amorpheae species versus 4, co-occurring, papilionoid legumes species at the Shaw Nature Reserve in Summer 2015. Results indicate that the Amorpheae species did in fact feature a more generalized pollination system (beetles, wasps, bees) than their papilionoid counterparts (primarily bees), and also featured doubly higher insect visitation rates. Correspondingly, Amorpheae species also featured significantly higher reproductive rates than papilionoid species in each comparison (p values 9.923e-8, 1.102e-5, 2.2e-16, and 1.045e-9). Amorpheae species were more likely to feature heterospecific pollen deposition than their papilionoid counterparts, however, suggesting the possibility of a tradeoff accompanying the shift to generalized pollination. Generalized pollination systems are predicted to be favored in variable environments, and when the primary pollinator (i.e. bees) is limited due to competition or scarcity. Therefore, we predict that the generalized Amorpheae species studied will here be more robust to the effects of climate change and habitat fragmentation than their papilionoid counterparts, which rely exclusively on bees for reproduction.

1 - Saint Louis University/Missori Botanical Garden, Biology, Macelwane Hall 3507 Laclede Avenue, St Louis, MO, 63103, USA
2 - Saint Louis University, Biology, Macelwane Hall 3507 Laclede Avenue
3 - Missouri Department of Conservation
4 - Saint Louis University, Department Of Biology, 3507 Laclede Avenue, St. Louis, MO, 63103, USA

Keywords:
Generalist vs. Specialist
Fabaceae
Pollination Shift
Zygomorphy
Actinomorphy.

Presentation Type: Oral Paper
Session: 36, Pollination Biology
Location: 203/Savannah International Trade and Convention Center
Date: Wednesday, August 3rd, 2016
Time: 10:30 AM
Number: 36009
Abstract ID:519
Candidate for Awards:None