Genetic structure of Dolly Varden (Salvelinus malma walbaum) populations from southeastern sakhalin and the southern kuril islands

摘要

The genetic structure of Dolly Varden (Salvelinus malma Walbaum) population form six rivers of southeastern Sakhalin and six rivers of the Kuril Islands was examined using electrophoretic, analysis or 22 enzyme systems encoded b 45 loci. In all populations, mean heterozygosities (0.044-0.105), mean numbers of alleles per locus (1.15-1.52), and proportions of polymorphic loci (18.2-39.4%) were estimated for all loci that had clear resolution. Highly significant heterogeneity of allele frequencies was detected among populations of both Sakhalin and the Kuril islands. By means of cluster analysis and multidimentional scaling, all populations were divided into the Sakhalin and Kuril groups. Within the groups, no association of genetic similarity with geographic distance between populations was observed. Although the average genetic diversity was similar in these regions, the relative interpopulation diversity was almost three times higher in the Kuril (17.6%) than in the Sakhalin (6.5%) groups. In all, the proportion of genetic diversity between regions (8.4%) was somewhat lower than the proportion of mean interpopulation diversity (11.3%). In small populations isolated form the sea, genetic variation was lower than in nonisolated populations. Allozyme differences between the northern and the southern forms of Dolly Varden are discussed.