GENETIC-VARIATION OF THE CROATIAN BEECH STANDS (FAGUS-SYLVATICA L) - SPATIAL DIFFERENTIATION IN CONNECTION WITH THE ENVIRONMENT

Thirty-five beech stands located in Croatia, (Yugoslavia) have been analysed using 6 polymorphic enzymatic loci. Three of them (PX-1, PX-2, GOT-1) seem to be more or less influenced by selection since their allelic frequencies are related to climatic conditions. The total gene diversity is higher for only 1 out of 6 loci in the continental region. Discriminant analyses on allelic frequencies show that the Mediterranean Seslerio-Fagetum which grows in rather dry conditions, is an association apart; and a significant difference exists between 2 groups of Mediterranean beechwoods located in the highlands and on the plain, respectively. A general tendency towards a heterozygotic deficit occurs with the same significance in both regions. Multilocus F-statistics reveal that the total genotypic differentiation and its 2 components (intra- and interpopulations) do not differ between the 2 regions.