Chau, Marian , Ranker, Tom , Morden, Clifford .
Bottlenecks and founder effects in the endangered Hawaiian fern 'ihi'ihi (Marsilea villosa).
Restoration of endangered plant species can be achieved by reintroducing plants or propagules to suitable areas within a natural historical range. Understanding the genetic structure of plant populations is critical to ensure that sampling for reintroduction captures sufficient genetic diversity to allow for environmental adaptation in new populations. Marsilea villosa ('ihi'ihi) is an endangered, endemic Hawaiian fern with seven remaining populations in ephemerally flooding drylands on the islands of O'ahu and Moloka'i. Among its uncommon traits are long-lived sporocarps (i.e., highly modified leaves containing sporangia and spores), a requirement of flood and drought to complete its sexual life cycle, and extensive vegetative growth. We used RAPD markers to assess population genetic structure across the full range of M. villosa. Using a Bayesian modeling approach in the program Structure, we inferred three optimal clusters. Cluster assignment was mixed in most O'ahu populations, while Moloka'i populations and one small, recently outplanted population on O'ahu (Hanauma Bay) fell distinctly within clusters. Within Moloka'i, populations from the northwest were distinct from a population in the southwest. Since Hanauma Bay is known to have been established from few individuals, the distinction is likely due to a genetic bottleneck. Strong population structure within Moloka'i is also indicative of founder effects. A higher degree of genetic variation on O'ahu and the distinction between regions within Moloka'i suggest two separate colonizations from O'ahu to Moloka'i. Restoration efforts that include M.villosa reintroduction should take into account the results of this study, and best sampling practices for outplanting are likely to differ between islands.
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1 - University Of Hawaii, Department Of Botany, 3190 Maile Way, HONOLULU, HI, 96822-2279, USA
2 - National Science Foundation, Division Of Environmental Biology, 4201 Wilson Blvd, Room 635N, Arlington, VA, 22230, USA
Presentation Type: Oral Paper:Papers for Sections
Location: Union E/Hyatt
Date: Monday, July 9th, 2012
Time: 9:30 AM