An Exploratory Analysis of Genetic Structure and Introgression in Salmo trutta Populations from Campania Rivers

Abstract

Simple Summary In Italy, the native Mediterranean trout populations are threatened by the introduction of hatchery-reared trout of Atlantic origin, which can cause hybridization and loss of local genetic biodiversity. This study aimed to provide a preliminary genetic characterization of the trout populations in selected river basins of Campania region (southern Italy), and to determine whether morphological differences between Atlantic and Mediterranean trout are also supported by the genetic analyses of the LDH-C1* gene and microsatellite markers. The results showed a complex genetic structure among Campanian trout populations, with evidence of Atlantic genetic introgression in different rivers; and that the analysis of multiple genetic markers is important for accurately identifying hybridization and assessing trout ancestry. However, trout specimens from rivers such as Imperatore, Sava, and Volturno showed genetic characteristics consistent with Mediterranean ancestry. These findings can contribute to the conservation of native Mediterranean trout, the preservation of local genetic diversity, and the development of more effective restocking strategies based on genetically appropriate local populations.