Document: ISA-3-25-2
Gene flow and local adaptation: Effect of spatial scale on the usefulness of genetic markers for measuring the evolutionary potential of endangered species.
PETIT, C.* 1, H.FRÉVILLE 1, A.MIGNOT 1, B.COLAS 2, M.RIBA 3, E.IMBERT 1, S.HURTREZ-BOUSSÈS 4, M.VIREVAIRE 5 and I.OLIVIERI 1
Institut des Sciences de l'Evolution, Université Montpellier 2 1
Institut d'Ecologie, Université Paris 6 2
CREAF, Universitat Autonoma de Barcelona 3
Institut de Recherche pour le Développement, Montpellier 4
Conservatoire Botanique National Méditerranéen, Ile de Porquerolles 5
Abstract:
In order to detect the evolutionary potential of two endangered species, Brassica insularis and Centaurea corymbosa, genetic variation in quantitative traits in seedlings and adult plants, and in allozymic markers was examined within and among four populations of each species. In contrast to previous studies in outcrossing plant species, population structure for quantitative traits (Qst) was generally lower than spatial differentiation of genetic variation in allozymes (Fst). This result suggest strong homogeneous selection pressures in populations of each species. High values of Fst (0.213 and 0.364 for B. insularis and C. corymbosa respectively) suggest low gene flow among populations. Moreover, the genetic distance based on allozymes (estimated by the ratio Fst/1-Fst) is positively associated with the geographical distance, suggesting that these populations are isolated by distance. In contrast, Qst's are statistically independent from geographical distance. We argue that Fst should not be always considered as conservative estimates of Qst to evaluate the evolutionary potential of endangered species.
Keywords: Population structure - Neutral markers - Quantitative genetics - Geographical distance - Adaptive potential
This abstract is being presented at: 10:00 AM in session:
Symposium # 26: Conservation of Ecologically Important Variation: Comparing Molecular Markers and Ecological Traits.