Patron géographique de la variation génétique chez la perchaude (Perca flavescens) et impacts du paysage du fleuve Saint-Laurent

Authors: Leclerc, Émilie
Advisor: Bernatchez, Louis
Abstract: Landscape genetics is being increasingly applied to elucidate the role of environmental features on the population structure of terrestrial organisms. However, the potential of this framework has been little explored in aquatic ecosystems such as large rivers. Here, we used a landscape genetics approach in order to: i) document the population structure of the yellow perch (Perca flavescens) by means of genetic variation at microsatellite markers, ii) assess to what extent the structure was explained by landscape heterogeneity, and iii) interpret the relevance of interactions between genetics and landscape for management and conservation. Analysis of the genetic variation revealed a relatively modest overall level of genetic structuring (FST = 0.039), with three zones of restricted gene flow defining four distinct populations. Physical barriers played a more important role on gene flow and genetic structure than waterway geographic distance. We found correlations between genetic differentiation and presence of distinct water masses in the sector of Lake Saint-Louis (r = 0.7177, P = 0.0340) and with fragmentation of spawning habitats in the sector of Lake Saint-Pierre (r = 0.8578, P = 0.0095). Our results support the treatment of four distinct biological units, which is in contrast with the current basis for yellow perch management. Finally, this study showed that landscape genetics is a powerful means to identify environmental barriers to gene flow causing genetic discontinuities in apparently highly connected aquatic landscapes.
Document Type: Mémoire de maîtrise
Issue Date: 2007
Open Access Date: 13 April 2018
Grantor: Université Laval
Collection:Thèses et mémoires

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