Genetic Marker Development and Diversity Analysis of Post Oak (Quercus stellata)

The American Cross Timbers forest ecosystem consists of a strip of land running from southeastern Kansas to Central Texas.  It is primarily a Post Oak (Quercus stellata) and Blackjack Oak (Quercus marilandica) forest.  This ancient forest currently occupies only about 1.6% of its ancestral range due to human settlement and development over the last several centuries. Little ecological or genetic research has been performed on this old-growth ecosystem. Genetic diversity of these forest remnants needs to be examined in order to determine their genetic health and to select regions of highest conservation priority. We developed genetic markers to facilitate the examination of the genetic diversity of 14 remnant populations of Post Oak (Q. stellata) spanning the range of the present day Cross Timbers. SSR markers were generated using a genomic reduction protocol combined with 454 pyrosequencing. SSR markers were filtered from the 454 data using the computer program MISA, and potential polymorphic markers were then identified and screened. Of the 48 markers tested, 24 were polymorphic.  Seventeen SSR markers were fluorescently labeled and used to determine population diversity within the species.