ALLOZYME VARIATION AND GENETIC DIFFERENTI ATION IN POPULATIONS OF ARCTIC CHAR SALVELINUS-ALPINUS FROM THE BALTIC SEA-TAIMYR PART OF THE RANGE

Genetic variation and differentiation of Arctic Char populations from the part of the range extending from the Baltic Sea to Taimyr was anal yzed on the basis of our own and published data. Among 34 enzyme loci examined, only EST-2 and MDH-3,4 exhibited high frequencies of alterna tive alleles. Genetic differentiation was relatively low (D = 0.000-0. 092; D = 0.035). All sympatric forms also showed low levels of diverge nce (D = 0.000-0.005). However, in some cases, differences in allele f requencies of polymorphic loci were significant, indicating their repr oductive isolation. Dispersal of Arctic char over the range examined p robably occurred in the postglacial period. It consisted of several wa ves of migration from the Baltic Sea basin, to the south of which one of the main refugiums was located during the glaciation period. Origin and phylogeny of various Arctic char forms, including Alpine populati ons, are discussed.