Conservation Biology of Eastern Tallgrass Prairie: Integrating Issues of Management and Restoration for the 21st Century
Bell, Timothy , Zettler, Lawrence , Bowles, Marlin .
Restoration implications of the breeding system of the federal threatened Eastern Prairie Fringed Orchid (Platanthera leucophaea): Crossing effects on seed viability, germination, protocorm growth and population viability.
Eastern Prairie Fringed Orchid (Platanthera leucophaea) is a federally threatened prairie perennial in which restoration is an important recovery planning objective. Use of multiple versus single seed sources for restoration is of concern due to the potential for outcrossing and inbreeding depression. To address this issue, we compared seed viability, germination and protocorm growth for progeny from flowers that were either selfed (S), outcrossed within the same population (OW) or outcrossed between populations (OB). The experimental pollination was repeated over three years using populations separated by as much as 309 km. In all three years, seed viability was significantly lower for S progeny but there was no significant difference between OW and OB progeny. Germination differed significantly among all three crossing treatments with germination rates highest for OB progeny, intermediate for OW progeny and lowest for S progeny. This same ranking pattern continued for the growth of protocorms into larger pre-photosynthetic stages. Demographic matrix models, using different seed germination and protocorm transitions based on crossing treatments, were used to compare viability for simulated populations. Preliminary results indicate that populations having OB transitions have the highest growth rate, OW are intermediate and S have the lowest population growth rate. Although the effects of outbreeding depression may not appear for several generations, our short-term results indicate that starting a new population of Eastern Prairie Fringed Orchid by introducing seeds from multiple populations should maximize initial population growth rate.
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1 - Chicago State University, Biological Sciences, 9501 South King Drive, Chicago, Illinois, 60628, USA
2 - Illinois College, Biology, 1101 West College Ave., Jacksonville, Illinois, 62650, USA
3 - The Morton Arboretum, 4100 Illinois Route 53, Lisle, Illinois, 60532, USA
Presentation Type: Symposium or Colloquium Presentation
Location: Williford B/Hilton
Date: Wednesday, July 11th, 2007
Time: 3:00 PM