Allozymic variation in some Norway spruce populations of the international IUFRO provenance-testing programme of 1964/1968

Isoenzyme-polymorphisms of Norway spruce populations from the spruce regions of Central and Southeastern Europe were compared with those from Northern and Northeastern Europe. To do this, the electrophoretically detectable geneticvariation was assayed at 19 coding gene loci (10 enzyme systems) for 15 provenances of the international IUFRO provenance-testing programme of 1964/1968. The results can be summarized as follows: 1. For the gene loci SKDH-A, IDH-A, LAP-A and GDH-A some alleles showed a marked geographic pattern. 2. The measures of genetic diversity as the mean number of alleles per locus (AIL), the proportion of polymorphic loci (P%), the expected heterozygosity (He) and the hypothetical gametic multilocus-diversity according to GREGORIUS (1978) all showed lower values in Southern and Central than in Northern and Northeastern Europe. Thereby, the genetic variation within the populations increased in going from the southwest to the north or northeast, although two provenances fr;om the Balkans showed higher values as well. Hence, the conclusions of other authors could be confirmed. 3. For most provenances significant to highly significant correlations were found between the genetic distances and the geographic distances of the provenances. 4. The subpopulation differentiation (Dj), i.e. the genetic distance between each individual provenance and the complement of all other provenances, was highest for the most southerly provenances (Southwestern France and Northern Greece) and one Eastern Russian provenance. In the discussion of the results it is pointed out that, along the altitude gradients and depending on the geographic latitude, numerous ecological adaptations advantageous for the species have arisen during the reinvasion into the Central European area after the last Ice Age. Thus, despite limited genetic variation at the experimentally accessible gene loci, the Norway spruce in Central Europe has demonstrated a good adaptive capacity.