Amplified fragments length polymorphism between populations ofAmblystegium tenaxexposed to contrasting water chemistries

Amplified fragments length polymorphism (AFLP) was used to study the genetic differentiation between five populations of Amblystegium tenax from areas experiencing contrasting water chemistries, by comparing their AFLP patterns with those of two populations of the closely related species A. fluviatile. The pair of AFLP primers Eco-AGG/Mse-CAT provided 35 scorable fragments among which 30 were polymorphic. The main division in the phylogenetic tree occurred between the populations coming from the classical area of distribution of the species in Belgium and the populations having recently colonized new areas. The genetic differentiation was higher within these two clades of A. tenax than between the two species A. tenax and A. fluviatile. The consequences of such a level of genetic differentiation in systematics, biomonitoring and biological conservation are discussed.