Genetic diversity and conservation ofIpomoea microdactyla(Convolvulaceae): an endemic vine from the Bahamas, Cuba, and southeastern Florida

Abstract

Ipomoea microdactyla Griseb. (Convolvulaceae) is restricted to the Bahamian archipelago, Cuba, and southeastern Florida. The species is listed as a state endangered species in Florida, where it is mostly restricted to the hyperfragmented pine rockland of Miami‐Dade County. Using seven DNA microsatellite loci, we assessed levels of genetic diversity for 12 populations of this species from Andros Island in the Bahamas (six sites), Cuba (one site), and Florida (five sites). We found significantly greater mean numbers of alleles, and higher mean values for both observed and expected heterozygosity in populations from the continuous forest on Andros than those from the habitat fragments in Florida. It is unknown if these patterns of genetic diversity in the Florida populations are the result of habitat fragmentation or founder effects. The population from Cuba exhibited relatively high levels of genetic variation, suggesting that this island is a major center of diversity and dispersal for this species. It appears that hybrid introgression for I. carolina alleles within I. microdactyla individuals occurred at a single site on Andros Island. Overall, the mean inbreeding coefficient value was 0.089, suggesting low levels of inbreeding. The highest inbreeding coefficient values were mostly recorded in Florida. Two groups were revealed, one containing the populations from Florida, and the second one encompassing those from the Bahamas and Cuba. Our results highlight the negative genetic consequences of habitat fragmentation and support initiatives recently established to establish corridors to connect the remnants of the pine forest of the Miami‐Dade County.

Genetic Diversity and Conservation of Pseudophoenix (Arecaceae) in Hispaniola

“…As noted by Geiger et al (2014), few population genetic studies have been conducted in these islands.…”

“…They focused on Ipomoea microdactyla Griseb. (Convolvulaceae) (Geiger et al 2014), Pinus caribaea Morelet var. bahamensis (Griseb.)…”

“…In the last six years a consortium of Caribbean and US scientists has been studying the conservation status of the Caribbean flora (Francisco-Ortega et al 2007;Maunder et al 2008;Oleas et al 2013;Carey et al in press), using molecular techniques to address conservation questions (e.g., Meerow and Nakamura 2007;Namoff et al 2011;Meerow et al 2012;Geiger et al 2014). The consortium has also conducted molecular phylogenetic research relevant to the taxonomy and management strategies of Caribbean Endangered and Critically Endangered plant species (reviewed in Oleas et al 2013).…”

“…These molecular markers can help to understand the biological features and the evolutionary history of a particular taxon (Fernandez-Silva et al 2013). Recent examples of how SSRs have had a direct application for Caribbean endemic plants were reported for Ipomoea L. (Geiger et al 2014), Pinus L. (Pinaceae) (Sanchez et al 2014), Pseudophoenix (Namoff et al 2011), Pterocarpus Jacq. (Fabaceae) (Muller et al 2009), and Zamia L. (Meerow et al 2012;.…”

“…(Fabaceae) (Muller et al 2009), and Zamia L. (Meerow et al 2012;. In these studies microsatellites have provided phytogeographical insights (Meerow et al 2012;Geiger et al 2014;Sanchez et al, 2014), have helped to define conservation management units for Critically Endangered species , have revealed high levels of inbreeding in threatened species (Namoff et al 2011), and have demonstrated limited gene flow among populations (Muller et al 2009). …”