Population Genetics of Scaevola on Culebra, Puerto Rico.

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On the islands of Puerto Rico, a native species of coastal shrub, Scaevola plumieri, co‐occurs with an invasive species, Scaevola taccada, introduced from the indo‐pacific islands. We are interested exploring the genetic diversity of both S. plumieri and S. taccada on the island of Culebra, PR in order to characterize the differences in genetic variation of an endemic species versus an invasive species. We hypothesize that the S. plumieri will have a greater amount of genetic diversity than the invading species due to S. taccada's more recent establishment on the island. Previous studies in our lab have shown that the alleles for two microsatellite regions were distributed across all populations on Culebra and had no correlation between distance and genetic diversity. To improve our characterization of diversity, we developed novel species‐specific microsatellite primers for S. plumieri using whole genome sequencing data. Six pooled samples from different beaches across Culebra were sent for Illumina MiSeq paired‐end sequencing and a Python computer code was written to identify potential microsatellites from the raw sequencing data. Leaf samples from both S. plumieri and S. taccada populations were collected from Culebra during January of 2015 and March of 2017, dried with silica gel, and the genomic DNA from each leaf was extracted. Microsatellites in the S. plumieri samples were amplified using the newly developed primers whereas microsatellites in S. taccada were amplified using previously developed primers. Fragment peaks from analysis by capillary gel electrophoresis were investigated using the program Geneious and peaks representing the fragment size of the microsatellite alleles were identified and recorded for each individual. These data were then evaluated through the program Arlequin which implements a series of tests to determine molecular variance (AMOVA), identify deviations from Hardy Weinberg Equilibrium and correlate geographic distance and genetic variation. In the future we plan to further expand our analysis using these novel S. plumieri primers to incorporate plant samples form Vieques, PR and mainland PR for a complete characterization of Scaevola diversity across all islands of Puerto Rico.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.