Graduation Year


Document Type




Degree Name

Master of Science (M.S.)



Degree Granting Department


Major Professor

Bruce J. Cochrane, Ph.D.

Co-Major Professor

Richard P. Wunderlin, Ph.D.

Committee Member

Frederick B. Essig, Ph.D.


Chrysopsis fioridana Small (Asteraceae) is a federally endangered plant endemic to the Tampa Bay area of west central Florida. It is confined to the sand pine scrub community, growing in open, sunny, and sandy areas or in disturbed areas at the edges of scrub. As a means ofassessing the genetic variability ofthis species, eight populations in Hillsborough County were compared with a seed stock collection housed at Bok Tower Gardens in Lake Wales using random amplification for polymorphism detection (RAPD). The objectives of this study were to (I) describe the overall genetic variation among and within populations and subpopulations of C. floridana, (2) compare the variation ofthe seed stock collection to that of the natural populations, and (3) to apply this information to reintroduction programs for this species.

The average genetic diversity was relatively high for an endemic species with geographically isolated populations. The Bok Tower Garden population exhibited a level of variation and polymorphism comparable to those of wild populations. The sampled populations do not appear to be highly structured. The majority of the variation was attributed to within population differences and only 20 percent of the variance could be attributed to genetic variation between the populations. This distribution of variance indicates that this species is rather homogeneous and suggests considerable gene flow occurs between populations.

My results suggest that conservation plans for C. fioridana should focus on the total number of individuals rather than the number of populations. As there appears to be little genetic differentiation between populations and polymorphism levels are comparable in most populations, seed from different populations could be used in recovery programs without the fear of loss of genetic information. Preservation and proper management of the natural habitat is also important to insure suitable sites for existing and introduced populations.

Included in

Botany Commons