A SINGLE-LOCUS MINISATELLITE DISCRIMINATES CHINOOK SALMON (ONCORHYNCHUS-TSHAWYTSCHA) POPULATIONS

A knowledge of genetic structure in natural populations is often neces sary for conservation and management purposes, especially in declining Pacific salmon populations. To test for genetic differentiation betwe en nine populations of chinook salmon, Oncorhynchus tshawytscha, from south-western British Columbia, Canada, DNA was extracted from 603 fis h and hybridized with a single-locus minisatellite probe. Multivariate statistical analyses of the resulting allele size data permitted succ essful overall population identification of 52% (individual population range: 24-78%; P < 0.005), indicating a high level of genetic differe ntiation among the nine populations. Two of the nine populations were further analysed using data from a second minisatellite locus. The dis crimination success rate improved from 81.1% (one-locus analyses) to 9 0.0% (two-locus analyses), indicating the potential for greatly increa sed resolution gained by the addition of more loci. These results indi cate that variation at minisatellite loci can be used for assessing po pulation-level genetic structure, even with artificial gene flow.