Masu salmon,
Oncorhynchus
masou masou
, is one of the most valuable fishery species that has been introduced to China,
though to date no studies on the genetic diversity and genetic relationship among hatchery populations has been performed with
molecular markers. We undertook such a study and sampled 120 individuals from three hatchery stocks and analyzed 20
microsatellite loci. All loci were polymorphic and a total of 91 alleles were detected. A relatively low level of genetic diversity was
revealed with effective number of allele of 3.1094, 3.3299 and 3.1894 and expected heterozygosity of 0.6600, 0.6648 and 0.6638 in
the three stocks, respectively. Deviations from Hardy-Weinberg equilibrium were found due to heterozygote deficit. Accordingly,
evidence of genetic bottlenecks were found in the three stocks. An individual assignment test demonstrated that 85% of individuals
were correctly assigned into their original stocks. Pairwise
Fst revealed that significant differentiation occurred between these three
stocks. The results of the study indicated that disequilibrium of genetic structure and differentiation has occurred in all three stocks.
This information collectively provides a basis for measures to avoid of loss of genetic diversity and introgression in Chinese
aquaculture.
