Genetic Diversity of Asian Chum Salmon Oncorhynchus keta (Salmonidae, Salmoniformes) and the Dynamics of Gene Pools in Sakhalin Populations under Artificial Reproduction

摘要

The estimates of genetic diversity in populations of chum salmon Oncorhynchus keta from different regions of Sakhalin Island, Iturup Island, and the Anadyr' River were obtained on the basis of analysis of alloz-yme variability. These estimates together with our published earlier data on chum salmon from the Amur River basin and the rivers of the northern coast of the Sea of Okhotsk demonstrate pronounced regional genetic differentiation in the Asian part of the fish range. The intraregional level ofinterpopulation genetic diversity was maximum on Sakhalin Island (G_(ST) = 6.6%) and was small on Iturup Island (G_(ST) = 0.9%) and the northern coast of the Sea of Okhotsk (G_(ST) = 0.6%). Interpopulation genetic diversity of Sakhalin chum salmon was almost commensurable to the diversity of the whole pool of studied Asian populations (G_(ST) = 7.6%) and would be presented more completely in baselines assigned for genetic identification of mixed stocks. It was demonstrated that the character and degreeof genetic differentiation between populations of chum salmon from the main hatcheries situated in different regions of the Sakhalin oblast and connected to one another by numerous transplantations of fertilized eggs did not change significantly during an approximately 20-year period of our observation, and this fact suggests low efficiency of such transplantations.