The founding of Mauritian endemic coffee trees by a synchronous long-distance dispersal event.

Published

Journal Article

The stochastic process of long-distance dispersal is the exclusive means by which plants colonize oceanic islands. Baker's rule posits that self-incompatible plant lineages are unlikely to successfully colonize oceanic islands because they must achieve a coordinated long-distance dispersal of sufficiently numerous individuals to establish an outcrossing founder population. Here, we show for the first time that Mauritian Coffea species are self-incompatible and thus represent an exception to Baker's rule. The genus Coffea (Rubiaceae) is composed of approximately 124 species with a paleotropical distribution. Phylogenetic evidence strongly supports a single colonization of the oceanic island of Mauritius from either Madagascar or Africa. We employ Bayesian divergence time analyses to show that the colonization of Mauritius was not a recent event. We genotype S-RNase alleles from Mauritian endemic Coffea, and using S-allele gene genealogies, we show that the Mauritian allelic diversity is confined to just seven deeply divergent Coffea S-RNase allelic lineages. Based on these data, we developed an individual-based model and performed a simulation study to estimate the most likely number of founding individuals involved in the colonization of Mauritius. Our simulations show that to explain the observed S-RNase allelic diversity, the founding population was likely composed of fewer than 31 seeds that were likely synchronously dispersed from an ancestral mainland species.

Full Text

Duke Authors

Cited Authors

  • Nowak, MD; Haller, BC; Yoder, AD

Published Date

  • June 2014

Published In

Volume / Issue

  • 27 / 6

Start / End Page

  • 1229 - 1239

PubMed ID

  • 24797428

Pubmed Central ID

  • 24797428

Electronic International Standard Serial Number (EISSN)

  • 1420-9101

International Standard Serial Number (ISSN)

  • 1010-061X

Digital Object Identifier (DOI)

  • 10.1111/jeb.12396

Language

  • eng