Arabidopsis arenosa represents a promising model for studying the mechanisms underlying the adaptation to serpentine soil. Genetic basis of serpentine adaptation is still poorly known and A. arenosa possesses many advantages as a tool to complete that knowledge. The first step of this study was to reveal the presence of a local adaptation to serpentine soil in a population of A. arenosa. To do so, I used the data from a reciprocal transplant experiment realized between a Czech pair of serpentine - non-serpentine populations and I explored the phenotypes associated with the adaptation. Subsequently, I produced the F2 hybrids coming from crosses between serpentine - non-serpentine parents and I studied the expression of fitness traits in F2 plants growing in serpentine in order to estimate the number of loci underlying the adaptation which I compared with other studies. I confirmed the presence of a local adaptation, with the population of serpentine origin performing better than the non-serpentine population in the serpentine substrate of origin, associated with accumulation of heavy metals in the leaves. Analyses of the soil composition revealed differences in heavy metals and nutrients contents, Ca/Mg ratio and pH between the two localities. Those results fitted with the function of the candidate...

La survie et la croissance des plantes sont essentielles afin d’assurer l’efficacité des protocoles de phytoremédiation et la décontamination des friches contaminées. La survie des saules et leur adaptation aux contaminants dépendent de la nature et de la concentration des contaminants. L’objectif de l’étude est d’identifier les cultivars ayant les meilleurs rendements, mais aussi de déterminer si la provenance des boutures (milieu contaminé ou milieu non contaminé) pourrait influencer la survie, la croissance et la phytoextraction (Cd, Cr, Cu, Ni, Pb, Zn) des saules. Nous avons comparé ces différents paramètres pour des boutures de dix cultivars de saules dans un milieu industriel fortement contaminé par les composés organiques et dans un milieu non-contaminé. Les variations dans la réponse des cultivars selon la provenance des boutures (milieu contaminé ou milieu non-contaminé) ont aussi été analysées dans chacun des sites d’étude. Selon nos résultats, le cultivar ˈ5005ˈ (Salix alba) est très productif en milieu extrêmement contaminé. Le cultivar ˈS25ˈ (Salix eriocephala) est aussi un choix très intéressant en phytoremédiation, puisqu’il produit près de deux fois plus de biomasse racinaire comparativement aux autres cultivars. La provenance des boutures n’a pas d’impact significatif sur la survie, la croissance et la phytoextraction pour la majorité des cultivars sauf pour le cultivar ‘Millbrook’, où les individus provenant du milieu contaminé ont produit significativement plus de biomasse aérienne lorsqu’ils poussaient en sol contaminé comparativement aux individus qui n’ont jamais été en contact avec les contaminants. Ces résultats pourraient aider à planifier des protocoles de phytoremédiation plus efficaces, en sélectionnant les cultivars de saule les plus adéquats et en élaborant l’échantillonnage des boutures utilisées dans les sites appropriés. / Plant survival and growth are essential parameters to monitor the effectiveness of phytoremediation protocols and the eventual decontamination of brownfields. The ability of different willow cultivars to survive and adapt to contaminants in polluted soils depends on the nature and concentration of the contaminants. The objective of the study was to identify the cultivars with the highest yields, but also to determine whether the origin of the cuttings (contaminated site or not) might influence survival, growth and phytoextraction of willow cultivars. We compared survival, growth and phytoextraction (Cd, Cr, Cu, Ni, Pb, Zn) of cuttings of ten willow cultivars in a highly organic-contaminated industrial environment and in an uncontaminated soil. Variations in the response of the cultivars according to the origin of the cuttings were also analyzed for each sites. According to our results, cultivar ˈ5005ˈ (Salix alba) was very productive in an extremely contaminated environment. Cultivar ˈS25ˈ (Salix eriocephala) was also a relevant choice, as it produced nearly twice more root biomass compare to other cultivars. The origin of the cuttings did not have significant influence on survival, growth and phytoextraction for almost all cultivar except the ˈMillbrookˈ cultivar: individuals originating from the contaminated environment produced significantly more aboveground biomass when growing in the contaminated environment compared to individuals who had never been in contact with contaminants. These results could help build more effective phytoremediation protocols in highly contaminated environments by selecting adequate willow cultivars and sampling cuttings in an appropriate environment.