Agricultural landscapes and the Loire River influence the genetic structure of the marbled newt in Western France

Jean-Marc Costanzi (1) , Pascal Mège (2) , Alexandre Boissinot (3) , Francis Isselin-Nondedeu (4) , Sandra Guérin (2, 5) , Olivier Lourdais (3) , Audrey Trochet (6, 7) , Quentin Le Petitcorps (2) , Agathe Legrand (2) , François Varenne (8) , Pierre Grillet (9) , Sophie Morin-Pinaud (10) , Damien Picard (2)

1 Faculty of Technology, Natural Sciences and Maritime Sciences [Norway]
2 Département de Biologie UFR Sciences - Université d'Angers [France]
3 CEBC - Centre d'Études Biologiques de Chizé - UMR 7372
4 CITERES - Cités, Territoires, Environnement et Sociétés
5 CEFE - Centre d’Ecologie Fonctionnelle et Evolutive
6 EDB - Evolution et Diversité Biologique
7 SETE - Station d'écologie théorique et expérimentale
8 LPO - Ligue pour la Protection des Oiseaux
9 Pierre Grillet
10 Unité Avifaune migratrice, Direction de la Recherche et de l’Expertise (ONCFS France]

Amphibians are particularly sensitive to landscape fragmentation. Potential barriers between breeding sites can negatively influence the dispersal of individuals and increase genetic structure between populations. In this study, we genotyped 10 microsatellites for 334 marbled newts (Triturus marmoratus) at 11 different locations in Western France. Samples were collected in different regions with contrasting agricultural landscapes (low and high proportion of arable land in the north and south, respectively). We found a strong genetic structure between the northern and southern sampling sites. Isolation by distance was recorded after 62 km, but within the northern region, little or no genetic structure was detected over large distances (up to 114 km). Genetic structure at shorter distance (43 km) was found between sites situated in landscapes with larger amounts of arable lands. A significant positive relationship was found between the pairwise genetic distance (Fst) between sites and the amount of arable land together with the distance between sites. Our results suggest that the Loire River might act as a corridor for the marbled newt, while arable land might act as a barrier. Finally, although a large city is located between sampling sites, no effect was detected on population structure

Domaines: Sciences de l'environnement

Jean-Marc Costanzi, Pascal Mège, Alexandre Boissinot, Francis Isselin-Nondedeu, Sandra Guérin, et al.. Agricultural landscapes and the Loire River influence the genetic structure of the marbled newt in Western France. Scientific Reports, 2018, 8 (1), pp.14177. ⟨10.1038/s41598-018-32514-y⟩. ⟨hal-02197281⟩