Genetic analysis of populations of brown trout (Salmo trutta L.) from the Romanian Carpathians

The Carpathian Mountains are one of the most complex orogenetic areas of Europe, with unique fauna, including the brown trout (Salmo trutta ). In this study we performed population genetic analysis of 12 different S. trutta populations using two types of molecular markers: nine microsatellites and mitochondrial D-loop sequences. The following working hypothesis was considered: the Romanian Carpathians and their surrounding lowlands can be key relief units based on which the S. trutta genetic diversity, spread, distribution, connectivity, relative isolation and genetic divergence can be at least partially explained. The phylogenetic analysis revealed that the majority of sequences were grouped in the Danubian clade. The high haplotype diversity of the 12 analyzed brown trout populations can be explained by the high nucleotide diversity. The microsatellite analysis revealed an inbreeding event for all the loci and for the populations analyzed. The Romanian Carpathians' shape and geographic orientation play a zoogeographical key role driving force in respect to the S. trutta populations.