PHYLOTRANSCRIPTOMICS, TAXONOMY, AND ECOLOGY OF THE CARIBBEAN-ENDEMIC MISTLETOES DENDROPEMON (LORANTHACEAE)
Restricted (Penn State Only)
- Author:
- Caraballo-Ortiz, Marcos A
- Graduate Program:
- Biology
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- December 12, 2017
- Committee Members:
- Tomas A Carlo-Joglar, Dissertation Advisor/Co-Advisor
Andrew George Stephenson, Committee Chair/Co-Chair
Claude Walker Depamphilis, Committee Member
Heather M Hines, Committee Member
David Michael Geiser, Outside Member - Keywords:
- Loranthaceae
Viscaceae
Santalaceae
Arceuthobium
Phoradendron
Dendrophthora
Psittacanthus
Oryctanthus
Passovia
Dendropemon
Endemism
West Indies
Phylogenetics
Transcriptome
Antilles
Fruit Dispersal
Parasitic Plants
Caribbean Islands
Caribbean Flora
Endemic Plants - Abstract:
- This dissertation is about the diversity, taxonomy, and ecology of mistletoes of the Caribbean Islands. The main topics treated here are: (1) a summary of the diversity of mistletoes from the Caribbean Islands, discussing our current knowledge of their taxonomy, ecology, and conservation; (2) a reconstruction of the phylogenetic relationships among the endemic Caribbean mistletoes Dendropemon (Santalales: Loranthaceae) using modern molecular tools and the proposal of taxonomic and nomenclatural updates; and (3) an ecological study exploring the interactions between a species of Dendropemon mistletoes with local trees and bird dispersers. In the first part, a brief introduction to the Caribbean Islands is presented, including its geologic history and biological diversity. Then, mistletoes from the Caribbean are introduced, and their biology, ecology, and conservation discussed. A dichotomous key for all genera is provided as well as a taxonomic summary of all currently recognized species, which includes their general distributions. The second part shows a study focused on the utility of multiple transcriptomes over DNA barcoding for resolving phylogenetic relationships at and below species level and testing monophyly of species using the Caribbean-endemic mistletoes Dendropemon (Santalales: Loranthaceae) as study case. Dendropemon is the most diverse of the over 180 regionally endemic genera, and the only one present in most of the major islands across the Caribbean. The results demonstrate the capacity of transcriptomes to discern among closely related species and even within a species, and shows that not all species of Dendropemon were monophyletic. A time tree analysis also shows that Dendropemon is a young genus that experienced short speciation periods and rapid diversifications. Based on the results, an updated taxonomic treatment is presented which includes a dichotomous key and descriptions for the forty species of Dendropemon proposed here. In the third part, an ecological study was conducted exploring the interplay between a species of mistletoe (Dendropemon caribaeus) with local trees and frugivorous birds in Puerto Rico. In this study, phenological data of local trees were combined with inoculation experiments of mistletoe seeds on branches of trees to determine whether capacity to establish seeds versus ability to be dispersed onto those trees via birds is what limits host distribution of D. caribaeus. Results show that the compatibility between the host and the mistletoe is more important than seed dispersal explaining the local abundance of mistletoe. However, the availability of fruits modulates the behavior of birds, and trees with short fruiting phenologies are less prone to receive mistletoe seeds than trees with extended fruiting phenologies, even when they are compatible hosts for the mistletoe. In summary, the diversity, taxonomy, and ecology of the Caribbean mistletoes were examined with a focus on the regionally endemic genus Dendropemon by combining modern molecular techniques for phylogenetic inferences, traditional taxonomy, field experiments, and ecological modelling. The information presented here aims to provide an updated taxonomic summary of Caribbean mistletoes, which comprise a fascinating but understudied group of plants in one of the top biodiversity hotspots in the world.