Applying microsatellites in two commercial strains of Arctic charr (Salvelinus alpinus): Potential for a selective breeding program

Genetic variability was estimated at eight microsatellite loci in two strains of Arctic charr (Salvelinus alpinus) available in Québec (Buteux and Fraser) to evaluate their potential in a selective breeding program. Both strains showed restricted genetic diversity with a mean number of alleles per locus of 6.28 and 4.28 for the Buteux and the Fraser strains, respectively. The two strains had significantly different allelic and genotypic distribution Genetic variability was lower in the Quebec domesticated strains than in wild populations of the same species (Kruskall–Wallis H=15.227; df=4 and P=0.0042) and in other broodstock of the same strain (Kruskall–Wallis H=12.60; df=4 and P=0.0134). The Fraser strain appeared more inbred than the Buteux with mean relatedness values (r-value) of −0.082 and −0.160, respectively. Surprisingly even with a restricted genetic diversity, r-value estimates showed that a high percentage of all possible crosses are not a risk for inbreeding in both strains (61% and 71% for the Fraser and the Buteux strains, respectively). These results have shown that genetic variability assessed by microsatellites was low in both strains. However, genotyping microsatellites could minimize inbreeding risks by crossing most genetically distinct breeders.