Genetic variation between phenotypically different native and introduced brown trout in Slovenia

Abstract

The aim of the study was the identification of genetic polymorphism enabling a discrimination between Slovenian native (Danubian) and introduced (Atlantic) brown trout (Salmo trutta) populations. Within the mitochondrial DNA D-loop region three polymorphic sites with four different genotypes were found, two of them being characteristic for the Danubian brown trout, and the other two for the Atlantic and the Ohrid trout, respectively. Analyzing microsatellite DNA one informative locus was found, revealing four alleles which enabled the discrimination among the Danubian, the Atlantic and the Ohrid type of brown trout. Using these genetic markers it was confirmed that the genetic and phenotypic identity of Slovenian native brown trout is endangered with non-native one, especially at districts being intensively stocked with hatchery-reared brown trout.