SSRs Are Useful in Characterizing Genetic Diversity in Endangered Magnolia ashei

Magnolia ashei Weath., or Ashe’s magnolia, is an endangered species endemic only to the Florida Panhandle. M. ashei is sometimes listed as a variety of the closely related bigleaf magnolia, M. macrophylla Michx., which has a wider and less well-documented distribution. An understanding of the genetic diversity of the native populations of M. ashei will enable effective conservation of the species, as well as provide insight into the relationship between this species and M. macrophylla. We collected leaf samples from wild-growing M. ashei plants in eight sites in Florida, as well as from cultivated plants from botanic gardens or nursery sources. Thirty-one SSR primer pairs from published Magnolia SSR studies were evaluated for amplification of polymorphic loci in M. ashei. While many of the primers tested were not effective in amplifying polymorphic loci, the primers did work in M. ashei indicate that individuals in the populations are genetically distinct. Additional sampling and polymorphic loci will be needed to determine whether each population has a distinct genetic makeup. We plan to collect and voucher more samples of M. ashei and M. macrophylla as we work to characterize and conserve this important native plant.