Survey of Brazilian Peppertree Genetic Diversity by qaz91038

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									       Improving Biological Control of
        Brazilian Peppertree through
       Characterization of the Genetic
             Diversity in Florida

            W. A. Overholt, K. T. Gioeli,
             J. P. Cuda, C. R. Hughes
                 and D. A. Williams

This
 History of Brazilian Peppertree
    Introduction into Florida
• Date of first introduction uncertain, possibly
  as early as 1884, more likely around 1900
• Popularized as an ornamental by George
  Stone in Punta Gorda starting in 1926
• Recognized as a serious invasive beginning
  in the 1950s / 60s
• Currently estimated to occupy ~ 1,000,000
  acres in Florida
• Distribution in north Florida appears to be
  limited by lack of cold tolerance
  Problems associated with
Brazilian Peppertree in Florida

• Displacement of native plant species
• Poor wildlife habitat
• Human/livestock health concerns
  Classical Biological Control
Native home                Invaded area




              Biological




              Control
    Rationale for examining BP
         genetic diversity
• Classical biological control rests on the
  premise that exotic organisms often reach
  higher densities in invaded areas because
  their natural enemies are left behind in the
  native home.
• The most promising candidate biological
  control agents are those which have co-
  evolved with the specific genotype(s) that
  have invaded the new area.
• Thus, identifying the genetic diversity of BP
  in Florida, and comparing it to diversity in S.
  America, will help to better target foreign
  exploration for biological control agents.
    Genetic diversity of BP in
     South America (Barkley 1944)

• Schinus terebinthifolius
• S. terebinthifolius var. acutifolius (Brazil)
• S. terebinthifolius var. pohlianus (Brazil,
  Paraguay, Argentina)
• S. terebinthifolius var. raddianus (Brazil)
• S. terebinthifolius var. rhoifolius (Brazil)
Native Distributions of Schinus terebinthifolius taxa (NYBG 2003)



                                                                       -5o




                                                                      -32o
                                  f



pohlianus   acutifolius   raddianus    rhoifolius   terebinthiolius
        Diversity in Florida ?
• Schinus terebinthifolius
• Schinus terebinthifolius var. raddianus




   Variation in Leaflet Morphology & Number
       Research Questions
• Do two or more distinct varieties occur in
  Florida?
• Is there evidence of hybridization between
  varieties in Florida?
• Can we identify the probable native home of
  Florida’s genotypes?
• Do new genotypes exist in Florida which do
  not occur in South America?
• Are different genotypes adapted to various
  habitat types in Florida?
• Are genotypes at the colonizing front different
  from those in areas where BP has been long
  established?
           Procedures
• Collect Samples of BP Shoot Tips in
  South America and Florida
• Perform Genetic Analyses on Samples
• Use Results for Biotype Matching of
  Natural Enemies with BP Populations
        Sample collection
• Statewide sampling coordinated by Bill
  Overholt & Ken Gioeli in Saint Lucie County
• Assistance solicited from the network of
  Extension Agents
• A minimum of 10 samples collected from each
  county where BP occurs in Florida
• Efforts are made to distribute sample sites
  over representative habitat types
• Terminal buds removed and placed in vials
  with 95% alcohol
• Sites are geo-positioned and GIS Mapped
• DNA (8 microsatellite loci) will be analyzed
        Survey in Brazil
• 30 samples collected in Parana, Minas
  Gerais and Santa Catarina states in
  March 2003
• Collaborations being initiated to
  expand sampling to other areas (e.g.,
  Argentina, Paraguay)
           Progress to date
• Samples received from   Vouchered specimens
  25 counties             Institute for Systematic Botany)
• 398 individual trees
Survey in Brazil



                             Palmital (25-30)



                            Curitiba (16-22)

                      Balneario Camboriu (23-24)

                      Irati (1-6)


     Riozinho (7-9)
Preliminary analysis (125 samples):
  Distance between samples and
            relatedness
                  0
Log Fst (Theta)




                             y = 2.6234x - 6.0178
                  -1              2
                                 R = 0.6769
                  -2
                  -3
                  -4
                  -5
                       0.5              1           1.5         2   2.5
                                              Log distance Km
          Tentative conclusion

• Preliminary analysis suggests that the Brazilian
  Peppertree population in Florida is the result of a
  single introduction
• If this holds true after further analyses, it
  simplifies the search for well-adapted biological
  control agents
           Collaborators
• University of Florida Department of
  Entomology and Nematology
• University of Florida Cooperative
  Extension Service
• University of Miami
• Saint Lucie County
• Florida Assn. Of Natural Resource
  Extension Professionals (FANREP)
Brazilian Collaborators
•   Federal University of Parana
•   University of Blumeneau
•   University Centro Oesti, Irati
•   University of Vicosa
Thank you!
      John Alleyne        Pinellas
      Adrian Hunsberger   Miami-Dade
      Kim Gabel           Monroe
      Frank Mellon        Manatee
      John Brenneman      Polk
      David Griffis       Volusia
      Stephen Brown       Lee
      Dan Culbert         Okeechobee, Indian River
      Liberta Scotto      Broward
      Sharon Ewe          Brevard
      Mack Sweat          Desoto
      Kenny Smith         Hernando
      Brian Suber         Seminole
      Steve McGuffey      Martin
      Melissa Hennig      Collier
      Dean Vanderbleek    Lake
      James Boggs, Jr.    Hardee
      Gene McAvey         Hendry
      Tony Pernas         Dade, Monroe, Collier

								
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