Genetic variation of the silver fir Abies alba was investigated at the protein level. Buds in winter dormancy, harvested in six different regions of Austria, were analyzed electrophoretically. Allelic frequencies of the polymorphic enzyme loci IDH-1, IDH-2, LAP-1, and 6-PGDH-1 were determined. The results indicate a clear genetic differentiation between the provenances from western and eastern regions of Austria. In all four loci, west-east frequency clines could be observed. The amount of genetic variation measured as average heterozygosity is higher in the western provenances. The relationship between the observed frequency clines and reimmigration routes of Abies alba the last glacial period and different conditions of competition by other forest tree species is discussed.
