Genetic structure profile of rainbow trout (Oncorhynchus mykiss) farmed strains in Greece

Abstract

The rainbow trout, Oncorhynchus mykiss, comprises a non-indigenous species of the European freshwater ecosystem. Due to its remarkable advantages of fast-growing and facultative adaptability in various habitats under different conditions, it has become the most dominant commercially reared species of freshwater aquaculture in Greece. Despite its economic importance, there is a dearth of population genetic studies regarding the origin of any posterior introduction by the private aquaculture sector. In this study, a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay was used, in order to assess variation in five mitochondrial DNA protein-encoding regions and the control region, covering more than 5,500 bp of the 16,600 bp total mitochondrial genome size. The samples derived from 10 rainbow trout farms throughout Greece representative of the freshwater aquaculture sector. The conducted population structure analysis revealed two major clusters among the farmed-rainbow trout populations. Moreover, the overall genetic diversity was substantially attributed to the diversity within populations rather than among them. In any case, both factors obtained from AMOVA analysis were statistically significant. The obtained haplotype network reinforced the existence of two central haplotype clusters among the farmed-rainbow trout populations in the Greek freshwater aquaculture sector. © Published by Central Fisheries Research Institute (CFRI) Trabzon, Turkey.