Gallagher, Joseph , Chester, Michael , Symonds, V. Vaughan , Veruska C. Silva, Ana , Mavrodiev, Evgeny , Leitch , Andrew R. , Soltis, Pamela , Soltis, Douglas .
Are independently derived populations of Tragopogon miscellus Ownbey (Asteraceae) reproductively isolated?
Tragopogon miscellus is an allopolyploid that has formed recently (fewer than 80 years ago) in the Palouse region of Washington and Idaho. Previous studies have shown that the species has formed multiple times. So far, evidence for genetic exchange between independently derived populations has been equivocal. That is, based on microsatellite data, some co-occuring individuals with distinct genotypes have resulted from separate origins (with one genotype a recent migrant to the location) with no clear evidence of subsequent hybridization and recombination between these genotypes. In contrast, hand-pollination between T. miscellus individuals of distinct origins results in viable F1 hybrids. Here we survey populations across an urbanized area in the north of the Palouse where T. miscellus has become one of the most prevalent weeds. In this area there may be more opportunities for inter-population gene flow due to the closer proximity among populations. To determine if gene flow is occurring between independently derived T. miscellus populations we used genomic in situ hybridization (GISH) to generate karyotypes for a large number of individuals from seven localities. Translocations appear to be fixed in some populations. We used nuclear microsatellites to examine genetic structure among these same individuals. By combining these data, we are able to determine which individuals within these populations are migrants from another population, which individuals are the results of crossing, and what effects karyotypic variation may have on gene flow among independent origins. This study will help estimate the prevalence of crossing between recent allopolyploid populations with different origins.
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1 - University of Florida, Department of Biology, Gainesville, FL, 32611, USA
2 - Massey University, Institute of Molecular Biosciences, Palmerston North, New Zealand
3 - Embrapa Coastal Tablelands, Aracaju, 49025, Brazil
4 - University of Florida, Florida Museum of Natural History, Gainesville, FL, 32611, USA
5 - Queen Mary University of London, School of Biological and Chemical Sciences, Mile End Road, London, E1 4NS, UK
genomic in situ hybridization
Presentation Type: Poster:Posters for Sections
Location: Khorassan Ballroom/Chase Park Plaza
Date: Monday, July 11th, 2011
Time: 5:30 PM