Abstract Detail

Development and Structure

Cooper, Toby [1], Krosnick, Shawn Elizabeth [1].

Preliminary examination of extrafloral nectariferous structures in Passiflora incarnata L. (Passifloraceae).

The family Passifloraceae provides many notable examples of plant-animal coevolution, from complex parasite-host interactions to mutualisms between plant and pollinators. Within this family, the genus Passiflora is particularly rich in specialized adaptations to animal mutualists such as bats, hummingbirds, and numerous species of wasps and bees. Passiflora incarnata is a common representative of this genus in the southeastern US. A trailing or climbing perennial vine, P. incarnata grows quickly in open habitat, colonizing roadsides, agricultural sites, and other disturbed areas through a combination of sexual and vegetative reproductive strategies. P. incarnata possesses large, conspicuous, androgynophorous flowers particularly suited to pollination by large solitary bees such as Xylocopa or Bombus species. In addition to reproductive structures facilitating species mutualisms, the plant produces extrafloral nectaries on leaf petioles and the lamina of floral bracts. These structures secrete sugars that are known to attract multiple species of ants which, in turn, provide varying levels of protection from herbivores such as the caterpillar of the gulf fritillary (Agraulis vanillae). The mechanisms of secretion have been examined in the petiolar and laminar nectaries of several related species within this genus. In those species, sugars translocated to the nectary structures appear to be eccrine-secreted into the apoplastic space below the cuticle where they accumulate until nectar secretion. The present study attempts to build on this understanding of Passiflora extrafloral nectaries by examining the ultrastructure of nectary tissues and vasculature in Passiflora incarnata and comparing these to the structures previously documented in Passiflora auriculata, P. biflora, P. caerulea, P. edulis, P. helleri, P. ligularis, P. quadrangularis, P. seemannii, and P. warmingii. Extrafloral nectaries at various stages of development were collected from P. incarnata and sections were studied using light microscopy. These are compared and contrasted with the structures of similar species previously described.

1 - Tennessee Tech University, Dept. of Biology, 1100 North Dixie, Cookeville, TN, 38505, USA

Keywords:
Extrafloral nectary
Coevolution
plant-insect interactions
Passiflora incarnata.

Presentation Type: Poster
Session: P, Development and Structure: Posters
Location: Exhibit Hall/Savannah International Trade and Convention Center
Date: Monday, August 1st, 2016
Time: 5:30 PM This poster will be presented at 5:30 pm. The Poster Session runs from 5:30 pm to 7:00 pm. Posters with odd poster numbers are presented at 5:30 pm, and posters with even poster numbers are presented at 6:15 pm.
Number: PDS009
Abstract ID:855
Candidate for Awards:Developmental and Structural Section best poster