Straub, Shannon C.K. , Doyle, Jeff J. .
Conservation genetics of Amorpha herbacea var. crenulata (Fabaceae), including assessment of the genetic success of ex situ and restoration conservation efforts.
Genetic factors, including loss of genetic diversity, can play a major role in the extinction of species as population numbers decline, but are often unattainable components of conservation management plans. Amorpha herbacea var. crenulata is a federally endangered legume endemic to Dade County, Florida, with only four natural and two reintroduced populations remaining. Fairchild Tropical Garden also maintains a large ex situ collection of individuals from both extant and extirpated populations. The objectives of the project were twofold: first to assess genetic diversity and differentiation within the species as a whole through comparison with the more widespread variety, Amorpha herbacea var. herbacea; and second, to evaluate the success of current conservation efforts from a genetic perspective. Chloroplast haplotypes and nuclear microsatellite markers were used to assess genetic diversity and population structure in wild populations, ex situ collections, and restored populations of A. herbacea var. crenulata in Florida and wild populations of A. herbacea var. herbacea spanning its geographic range. Analyses suggest that A. herbacea var. crenulata and A. herbacea var. herbacea differ in ploidy and are strongly genetically differentiated from one another, with the endangered variety harboring considerably more genetic diversity than the widespread variety. A. herbacea var. crenulata does not appear to be suffering from loss of genetic diversity, which may be being maintained due to polyploidy or differences in breeding system as compared to A. herbacea var. herbacea. Additionally, the longevity of these perennial plants may be slowing the appearance of the genetic signature of habitat loss and fragmentation. Current conservation outplantings of A. herbacea var. crenulata have captured approximately 80% of the variation observed in source populations, so there is room for improvement in future efforts to increase the genetic diversity found in restored populations in order to preserve evolutionary potential.
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1 - Cornell University, L.H. Bailey Hortorium, Department of Plant Biology, Ithaca, New York, 14853, USA
Presentation Type: Oral Paper:Papers for Topics
Date: Monday, July 28th, 2008
Time: 1:45 PM