Andrea Southgate
Graduate Student
Plant Biology & Conservation
Program
Northwestern University
2205 Tech Drive
Evanston, IL 60208
a-southgate@northwestern.edu
Echinacea Project Research Assistant
Chicago Botanic
Garden asouthgate@chicagobotanic.org
|
Plant Biology & Conservation
|
My ResearchAlthough there are many ecological consequences of habitat fragmentation on plants (i.e. disruption of pollinator relationships, competition with invasive species), my research at Northwestern and the Chicago Botanic Garden uses the native plant Echinacea angustifolia to investigate one of the genetic issues. Under the guidance of Dr. Stuart Wagenius, I study inbreeding and how it relates to Echinacea population size in fragmented prairies. The anthropogenic fragmenting via roads, railroads, agricultural fields, and residential areas of the once continuous tall grass prairie has created smaller, more isolated plant populations that may suffer from a reduction in fitness due to inbreeding depression. A single generation of outcrossing may increase fitness for a population suffering from inbreeding depression by increasing heterozygosity which masks deleterious alleles; however, if isolated populations are locally adapted, the hybridization between populations may also show a decrease in fitness due to outbreeding depression. Additionally, the effective population size of a remnant may influence the effects of inbreeding and outbreeding depression. To investigate this, Echinacea angustifolia plants were hand-pollinated to produce three randomly mated crosses: within the population, inbred - within family, and outbred - between populations. Paternal plants originated from seven different prairie remnants in rural western Minnesota and had populations of various sizes (Ne = 6 to Ne = over 1000). Seeds from the crosses were weighed, germinated, and grown in a greenhouse environment. Cotyledons were scored for abnormalities and photographed to determine area and symmetry. Leaf heights were measured on days 14, 21, 28, and 35. Seedlings were then planted in a common garden in Kensington, MN. Approximately two months later leaf heights were measured, and plants were scored for herbivory damage and presence of insects. I hope to submit the results of this study to a peer-reviewed journal in the Spring of 2007.
|
Additional Information Poster: Inbreeding and outbreeding in seven populations of Echinacea angustifolia. Presented at Janet Meakin Poor research Symposium, Chicago Botanic Gardens, October 20, 2006. |
|
21 day old Echinacea seedlings (photo: Andrea Southgate) |
|
Collecting Phlox at Northwestern University (photo: Hank Southgate) |
|
CBG volunteer Char Schweingruber and I planting germinated Echinacea seedlings (photo: Stuart Wagenius) |
