Indagini di genetica molecolare su popolazioni selvatiche e di allevamento di Salmo [trutta] marmoratus (Cuvier, 1817) per la gestione e la conservazione dei ceppi autoctoni del Friuli Venezia Giulia.

In this study was investigated the genetic variability of breeding and natural populations of Salmo [trutta] marmoratus (marble trout) ten years after the beginning of the recovery and conservation project of the two local races in danger of extinction in Friuli Venezia Giulia (Tagliamento and Isonzo rivers). The wild population was precisely collected in the river Fella (Tagliamento basin). We tested the applying of RAPD-PCR for the individuation of diagnostic markers which discriminate between S [t] marmoratus and S. [t] trutta (brown trout), between Tagliamento and Isonzo marble trout races, and to test also the degree of genetic variability in breedingpopulations. We totally analysed 66 samples (58 marble trout and 8 brown trout). The obtained results confirm not only an expected genetic differentiation between marble and brown trout, but also the existence of a real genetic separation between Tagliamento and Isonzo marble trout. The polymorphic patterns obtained by use of five RAPD-primers on breeding samples, and also intrapopulation similarity diagrams, prove that they have maintained a fair degree of genetic variability, even though inbreeding risk and physiological mortality.