Population Genetics of the Cedar-Glade Endemic Astragalus bibullatus (Fabaceae) Using Isozymes

The rare cedar-glade endemic Astragalus bibullatus (Fabaceae) has low levels of genetic variability both within and among populations. Within-population means across 15 isozyme loci resulted in estimates of 1.4 alleles per locus, 25.6% polymorphic loci, and 0.064 for observed heterozygosity. Populations are genetically very similar, with a low FSTand genetic identity values ranging from 0.981 to 1.000. Sites where this species naturally occurs should be protected, but, considering the low levels of population differentiation, the source of transplants or seeds needed to establish new populations may not be the most critical concern.