Systematics Section / ASPT
Sangaumphai, Akanita , Derieg, Nathan , Campbell, Jackie , Bruederle, Leo P. .
Evolutionary Potential in Carex lutea, a rare North American Endemic.
Carex lutea LeBlond (Cyperaceae) was first described in 1994 from the Atlantic Coastal Plain of North Carolina, where it occupies wet sandy soils underlain by coquina limestone in rare savannas. The golden sedge is a narrow endemic that is restricted in distribution to approximately ten populations distributed in Pender and Onslow Counties. Its closest relatives include C. cryptolepis Mack., a broadly distributed North American endemic, and the widespread C. flava L., both of which belong to section Ceratocystis of the genus; genetic data presented herein support recognition of C. lutea as distinct within the section. Although expected to exhibit relatively low levels of genetic diversity, in general, endemics have proven to be unpredictable. Carex lutea, with its restricted distribution; small, isolated populations; and caespitose habit was expected to meet expectations of low genetic diversity. The objective of this research was to describe population genetic diversity and its apportionment within and among populations of C. lutea, a species of special concern. Genotypic data were collected from five populations for each of 20 putative allozyme loci using standard population genetic techniques; these data were analyzed to obtain common measurements of genetic diversity, e.g. expected heterozygosity, and test for significant deviations from Hardy-Weinberg expectations; F-statistics were used to assess population subdivision. In comparison to other caespitose carices, C. lutea exhibits a moderate level of genetic diversity, e.g., He = 0.0570, which exceeds that reported for North American populations of C. cryptolepis and C. flava. Contributing to this diversity is significant population differentiation (Fst = 0.3237), as well as population subdivision.
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1 - University of Colorado at Denver and Health Sciences Center, Biology, Campus Box 171, P.O. Box 173364, Denver, Colorado, 80217, USA
Presentation Type: Poster
Location: Salon C, D & E - Gov Ballroom/Hilton
Date: Tuesday, August 16th, 2005
Time: 12:30 PM