Posdoctoral fellow Carnegie Science Palo Alto, California
Body of Abstract: Sida fallax (Malvaceae) is the most widespread and variable taxon of Malvaceae in the Hawaiian Islands, growing with a diversity of morphological forms and in different habitats of Midway Atoll, Nihoa, and all the main islands. Morphological variation exists both within and among populations. The low elevation and mountain ecotypes are two extreme ecological forms of S. fallax with many intermediate morphological types existing between them. This study objective was to investigate the genetic variation within and among populations from the various habitats and geographic locations throughout the Hawaiian range of S. fallax. To do this, populations were collected from six of the main Hawaiian Islands (Kauaʻi, Oʻahu, Maui, Molokaʻi, Lānaʻi, and Hawaiʻi) and Nihoa in the Northwestern Hawaiian Islands. Multiplexed ISSR genotyping by sequencing (MIG-seq) were used to detect single nucleotide polymorphisms (SNP). Genetic differences among individuals and populations were evaluated using PCO analyses. The relationship of FST with the geographical distance between the populations was assessed using the Mantel test. Results showed that populations on a single island were more closely related to each other and to populations on islands within their respective groups than they were to populations on other islands. The beach ecotype populations of all islands showed somewhat closer relationships to each other than to mountain ecotype populations and provided some continuity among all the island groups. The overall genetic relationships among islands were to a large extent predictive based on island position within the chain, and, to a lesser extent, within island topography.