Skip to content
University of Maryland LibrariesDigital Repository at the University of Maryland
    • Login
    View Item 
    •   DRUM
    • Theses and Dissertations from UMD
    • UMD Theses and Dissertations
    • View Item
    •   DRUM
    • Theses and Dissertations from UMD
    • UMD Theses and Dissertations
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Elucidating the Macro- and Micro-evolutionary Relationships of the Federally Listed Endangered Species Agalinis acuta (Orobanchaceae)

    Thumbnail
    View/Open
    Pettengill_umd_0117E_11083.pdf (4.477Mb)
    No. of downloads: 666

    Date
    2010
    Author
    Pettengill, James Beaton
    Advisor
    Neel, Maile C
    Metadata
    Show full item record
    Abstract
    <italic>Agalinis acuta<italic> (Orobanchaceae) is a federally listed endangered plant species native to the mid-Atlantic and northeastern coastal plains of the United States. Due to morphological ambiguity and molecular similarity between <italic>A. acuta<italic> and <italic>Agalinis tenella<italic> and <italic>Agalinis decemloba<italic> a conservation priority is to determine whether <italic>A. acuta<italic> represents an evolutionarily distinct entity worthy of protection under the Endangered Species Act. To resolve this question, a phylogenetic study was first conducted based on seven chloroplast DNA loci and the nuclear DNA locus ITS from 79 individuals representing 29 <italic>Agalinis<italic> species. A study evaluating the utility of those cpDNA loci and three analytical techniques for the purpose of DNA barcoding was also conducted. The phylogenetic study indicated that A. acuta was perhaps evolutionarily indistinct from<italic> A. decemloba<italic> and <italic>A. tenella<italic>. Based on the results of subsequent analyses of 21 microsatellite loci and morphological data evaluated under myriad species concepts, <italic>A. acuta<italic>, <italic>A. decemloba<italic>, and <italic>A. tenella<italic> best represent a single species with two subspecies; the former two putative species would constitute a subspecies called <italic>A. decemloba ssp. decemloba<italic> and <italic>A. tenella<italic> would be <italic>A. decemloba ssp. tenella<italic>. With evolutionary distinct entities described, a phylogeographic study was conducted to determine the extent to which historical processes rather than contemporaneous events can explain extant patterns of genetic and phenotypic diversity within <italic>A. decemloba<italic>. The dispersal of a few individuals out of southern refugial populations likely represents the process through which northern populations were established; however, recent anthropogenic effects that disproportionately affected northern populations may have also contributed to extant patterns of diversity. Neutral or adaptive explanations for phenotypic variation among populations are also investigated. The conservation implications of population genetic analyses were assessed for members of <italic>A. decemloba ssp. decemloba<italic>. Despite the evidence that this taxon is self-compatible, the high levels of inbreeding and low levels of heterozygosity are of such a magnitude in certain populations that genetic factors may be negatively impacting fitness. Because of the small effective population sizes and degree of isolation, all populations should be managed to reduce the risk of extinction associated with demographic and environmental stochasticity.
    URI
    http://hdl.handle.net/1903/10259
    Collections
    • Biology Theses and Dissertations
    • UMD Theses and Dissertations

    DRUM is brought to you by the University of Maryland Libraries
    University of Maryland, College Park, MD 20742-7011 (301)314-1328.
    Please send us your comments.
    Web Accessibility
     

     

    Browse

    All of DRUMCommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsThis CollectionBy Issue DateAuthorsTitlesSubjects

    My Account

    LoginRegister
    Pages
    About DRUMAbout Download Statistics

    DRUM is brought to you by the University of Maryland Libraries
    University of Maryland, College Park, MD 20742-7011 (301)314-1328.
    Please send us your comments.
    Web Accessibility