Abstract Detail

Systematics Section

Margenthaler, Elaina [1], Benzing, David H. [2], Holst, Bruce K. [3], Summers, Carly F. [1], Clark, John L. [4], Clark, John R. [1].

Comparative phylogenetic analysis of the origin and frequency of epiphytism among three disparate plant families: Bromeliaceae, Gesneriaceae, and Orchidaceae.

Epiphytism has evolved numerous times across disparate plant lineages including mosses, ferns and seed plants. Although thousands of species exhibit epiphytism and many of these have a high tolerance for the often xeric environment of forest canopies, no single character is unique to epiphytic plants. Adaptations that counter aridity are numerous (e.g., CAM metabolism, drought-deciduousness, etc.) and are shared by epiphytes and terrestrials alike. However, by retracing and studying the evolutionary history of epiphytes, we may identify unique combinations of characters or heretofore unknown factors affecting the success of these plants. In this study, we utilize phylogenetic comparative methods to explore the independent origin and evolution of epiphytism among three disparate plant families, each containing a relatively large number of epiphytic genera: Bromeliaceae (Poales), Gesneriaceae (Lamiales), and Orchidaceae (Asparagales). By providing a phylogenetic framework to study epiphytism, we may better understand how these species are both similar and radically different from one another. Using extensive sampling across bromeliads, gesneriads, and orchids from Marie Selby Botanical Gardens living collection, and sequence data from GenBank, we analyze plastid and nuclear ribosomal genic regions using maximum likelihood and Bayesian phylogenetic methods to construct phylogenetic trees. Parsimony, likelihood and Bayesian methods are then used to reconstruct the origin and evolution of various structures and physiologies along these evolutionary topographies. We interpret the evolution of epiphytism in terms of shared, derived characters and the frequency and distribution of these characters among the three families. We also compare various methods for reconstructing life history traits and the relative strengths and weaknesses of these methods are explored.

Broader Impacts:

1 - Marie Selby Botanical Gardens, Gesneriad Research Center, 811 S. Palm Ave., Sarasota, Florida, 34236, USA
2 - Marie Selby Botanical Gardens, 811 S. Palm Ave., Sarasota, Florida, 34236, USA
3 - Marie Selby Botanic Gardens, 811 South Palm Avenue, Sarasota, Florida, 34236-7726, USA
4 - University of Alabama, Department of Biological Sciences, Box 870345, Tuscaloosa, AL, 35487, USA

Keywords:
epiphyte
evolution
Bromeliaceae
Gesneriaceae
Orchidaceae
phylogenetics
character evolution
modeling.

Presentation Type: Poster:Posters for Sections
Session: P
Location: Hall A/Convention Center
Date: Monday, August 2nd, 2010
Time: 5:30 PM
Number: PSY038
Abstract ID:588