Meerow, Alan , Francisco-Ortega, Javier , Stevenson, Dennis Wm. .
Microsatellite DNA studies in the Caribbean Zamia pumila complex (Zamiaceae).
The Zamia pumila complex (Cycadales: Zamiaceae) is a monophyletic, diploid (2n = 16) and distinctive assemblage of cycad populations restricted to the West Indies and southeastern U. S. that has been treated as comprising as many as 14 or as few as one species. We have developed a microsatellite (simple sequence repeat, SSR) DNA library from Z. integrifolia that we will use to investigate various evolutionary and biogeographic questions. Our overall goal is to document the patterns of microsatellite DNA variation across populations of the Zamia pumila complex throughout its range, infer population structure and biogeographic and demographic history of the complex, and attempt to understand the processes of speciation within the group. We will sample individuals from populations from each island in the West Indies known to harbor extant Zamia populations [Bahamas (Andros, Eleuthera, Grand Bahama, Great Abaco, Long Island, New Providence), Cuba, Grand Cayman, Jamaica, Hispaniola, Puerto Rico], and 15-20 populations from Florida and southeast Georgia in the southeast U. S. We hypothesize that Zamia in the Caribbean will exhibit conformance to the stepping stone model, given the limited gene flow exhibited by most cycad species. We further hypothesize that we will uncover genetic evidence of bottlenecks within some populations, apropos to the history of the Greater Antilles. Finally, we intend to address the hypotheses that the Z. pumila complex represents more no less than five species, that pollinator mediated isolation restricts gene flow between species in the complex, and that every species in the Z. pumila complex will have a unique pollinator association. We have already designed 17 SSR primer pairs that are successfully capturing polymorphism in Zamia (including species from Central and south America), and have only screened 20% of our library of potential SSR containing clones.
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The Cycad Pages
1 - U.S. Department of Agriculture, Agricultural Research Service, National Germplasm Repository, 13601 Old Cutler Road, Miami, Florida, 33158, USA
2 - Dept. Biological Sciences, Florida International University, Fairchild Tropical Botanic Garden, Miami, Florida, 33199, USA
3 - New York Botanical Garden, Institute of Systematic Botany, 200Th Street & Southern Boulevard, Bronx, New York, 10458-5126, USA
Presentation Type: Oral Paper
Date: Monday, August 15th, 2005
Time: 8:00 AM