SALMONID PHYLOGENY INFERRED FROM RIBOSOMAL DNA RESTRICTION MAPS

Genomic DNA was isolated from 17 salmonid species including six species of Salvelinus (S. namaycush, SL. fontinalis, SL. leucomaenis, SL. confluentus, S. malma, and S. alpinus), two species of Salmo (S. trutta and S. salar), eight species of Oncorhynchus (O. mykiss, O. clarki, O. masou, O. tshawytscha, O. kisutch, O. keta, O. nerka, and O. gorbuscha), and one species of Hucho (H. perryi). Restriction maps of the ribosomal DNA were prepared by using probes to the 18S and 28S coding regions of the rDNA. Phylogenies were constructed from this data using both cladistic and distance methods. Results supported the recent placement of the Pacific trouts in the genus Oncorhynchus. The phylogeny obtained for the genus Salvelinus suggested that S. confluentus from North America may be more closely related to S. leucomaenis from Japan than to species in the S. malma - S. alpinus complex. Fixed differences in restriction sites were found among the major subgroups within the S. malma -S. alpinus complex.