Date of Graduation

Spring 2009

Degree

Master of Science in Plant Science (Biology)

Department

Biology

Committee Chair

L. Michelle Bowe

Abstract

Asclepias meadii, or Mead's milkweed, was once a widespread tallgrass prairie species but is now a federally threatened species due to habitat destruction. In 2006, Missouri Department of Conservation began introducing new plants from Kansas and other Missouri populations into the Wahkon-tah prairie system. The purposes of this study are: 1) to assess the genetic diversity of five Missouri populations/prairies of A. meadii; 2) compare the genetic diversity of Asclepias meadii to three widespread congeners, Asclepias incarnata, A. tuberosa, and A. viridis; and 3) to assess the changes, if any, that have occurred in the clonal structure of A. meadii at Wah'kon-tah and Niawathe prairies using amplified fragment length polymorphisms (AFLP). This is a relatively quick technique that yields a large number of polymorphic fragments useful for population genetic studies. Unlike previous studies, there were no clones detected at any of the prairies. Rockhill Prairie showed the most AFLP diversity (Shannon's diversity; I=0.164), and South Fork had lowest (I=0.096). Proffit Mountain showed the highest unbiased He (0.094) and South Fork the lowest (0.066). Compared to other Asclepias species, A. meadii showed the least genetic diversity (I=0.127 and UHe=0.081) whereas A. tuberosa showed the most (I=0.256 and UHe=0.167). Both A. meadii and A. tuberosa maintain more genetic variation, AMOVA, within populations (93% and 94%) than do A. incarnata and A. viridis (88% and 87%). To maintain sexually viable populations, management should be aimed at maintaining or increasing genetically diverse populations.

Keywords

Asclepias meadii, conservation genetics, AFLPs, rare, Asclepias incarnata, Asclepias tuberosa, Asclepias viridis

Subject Categories

Plant Sciences

Copyright

© Jason Ray Comer

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