Abstract Detail

Systematics

Pichardo, Fritz Jose [1], Roncal, Julissa [2].

Phylogeny and divergence times of the Neotropical palm tribe Euterpeae.

Tribe Euterpeae is a group of Neotropical palms that comprises 33 species in 5 genera distributed from Central America to Southeastern Brazil and Bolivia, including the Caribbean islands. Some species are important elements of Amazonian forests since they can be among the 10 most abundant trees. Some members of this tribe are economically important for their oil production and edible palm heart. In this study we aimed to clarify the intergeneric and interspecific relationships within tribe Euterpeae and estimate the time of origin of its taxa. We reconstructed a phylogenetic tree with maximum likelihood and a dated Bayesian phylogenetic tree using one plastid (trnD-trnT) and four low-copy nuclear DNA regions (CISP4, PHYB, RPB2, and WRKY6). We used five fossil and two secondary calibration points to estimate divergence times. We successfully amplified sequences from 26 Euterpeae species including 7 infra-specific taxa, and 41 outgroup taxa. The tribe and each genus were monophyletic with high support. The most basal genus was Hyospathe. Euterpe was sister to Neonicholsonia, and Prestoea was sister to Oenocarpus. The hippuriform (horsetail shape) inflorescence of Oenocarpus, previously thought to originate from Euterpe’s inflorescence by loss of the adaxial rachillae was not supported because these two genera appeared in two different sister clades. Some widely distributed species (Euterpe precatoria, Prestoea acuminata and Hyospathe elegans) were not monophyletic, which invites a revision of these species circumscriptions. Tribe Euterpeae diverged from its sister tribe Areceae at around 46 million years ago (Ma), while the crown age of the Euterpeae was estimated at around 40 Ma. Although tribe Euterpeae’s origin occurred in the Eocene most of the extant genera had crown ages after the middle Miocene (<17 Ma) with some species originating later during the Pliocene to Pleistocene. This work represents the most complete molecular phylogeny of the group, and inclusion of the few missing narrow endemic taxa will provide a more complete understanding of the interspecific relationships of the tribe.

1 - Memorial University of Newfoundland, Department of Biology, 232 Elizabeth Ave., St. John's, NL, A1B 3X9, Canada
2 - Memorial University Of Newfoundland, 232 Elizabeth Avenue, St. John\'s, N/A, A1B 3X9, Canada

Keywords:
Euterpeae
phylogeny
molecular dating
palms
Neotropics.

Presentation Type: Oral Paper
Session: 14, Systematics I: Basal Dicots, Monocots & Rosids
Location: Sundance 1/Omni Hotel
Date: Monday, June 26th, 2017
Time: 2:45 PM
Number: 14006
Abstract ID:186
Candidate for Awards:None