| Abstract: | Genetic variation in 24 populations of Siberian fir Abies sibirica Lebed. from the Urals, West Siberia, East Siberia, South Siberia, and the Baikal region were examined using allozyme markers. Three out of fifteen allozyme loci proved to be polymorphic. Heterozygosity He was 6.6-9.6%, which is substantially lower than that in other widely spread boreal conifers. Our results suggest that the Siberian fir populations are subdivided into four geographic groups: (1) the Baikal Lake group, (2) the Sayan and the Altai group, (3) the Middle and Southern Urals group, and (4) Subpolar and Northern Urals group. This pattern of geographic differentiation may be explained by the preservation of the Siberian fir during the last glacial maximum (18 000-22000 years B.P.) in isolated refugia with subsequent recolonization of the present area. FST in the populations examined was 10.16%, which is comparable to the estimate for Larix sibirica (7.9%), a conifer species having a similar range and pattern of geographic population differentiation. |
