Document: JOH-3-25-3

Conserving important genetic variation in the rare Sapphire Rockcress, Arabis fecunda (Brassicaceae).

MCKAY, J.K.* ^1,2 and T.MITCHELL-OLDS ^1,2

Division of Biological Sciences, University of Montana, Missoula, MT, USA ¹
Dept. Genetics and Evolution, Max Planck Institute of Chemical Ecology, Jena, Germany ²

Abstract:
In conservation, knowing the degree to which rare populations are locally adapted is crucial for management decisions concerning translocation and restoration, as well as for avoiding outbreeding depression and determining the evolutionary potential of species of concern. We integrate ecology, physiology and genetics to assess variation within and among populations of Arabis fecunda Rollins, a rare perennial plant endemic to SW Montana, USA. Despite small effective population sizes, common garden screening revealed populations from different elevations to be genetically differentiated for functionally important quantitative traits. We contrast this quantitative variation with genetic variation in only 1 of 14 allozyme markers suggesting conservation strategies based on molecular markers alone may fail to detect important heritable differentiation. We tested hypotheses that particular traits were adaptive based on evolutionary (Qst/Fst) and functional (phenotypic selection) consequences of this genetic variation. We conclude that preserving genetic variation for traits involved in drought tolerance may allow these populations of concern to persist in the face of spatial and temporal environmental variation.

Keywords: neutral markers, quantitative genetics, local adaptation, evolutionary potential, drought tolerance

This abstract is being presented at: 9:15 AM in session:
Symposium # 26: Conservation of Ecologically Important Variation: Comparing Molecular Markers and Ecological Traits.