Spatial genetic differentiation among poulations of european beech (fagus sylvatica L.) in western germany as identified by geostatistical analysis
Résumé
The spatial genetic differentiation among European beech stands in western Germany was analysed by a new method. The genetic structure at 8 enzyme gene loci of 100 sampled populations was used as data base. The data represent authors' own results and published data from 8 different studies. For 10 geographic distance classes [h] from 0 to 500 km, the average genetic distance between the populations for each single gene locus, a gene-pool distance and the semivariances of genetic diversity gam were computed. Significant deviation from random spatial genetic structure was tested by permutation analysis. In many cases (Lap-B, Mdh-B, Mdh-C and 6Pgdh-C) the mean genetic distance between stands with spatial distance up to 200 km was significantly smaller and the genetic distance between stands with geographic distances of 200 and 400 km was significantly greater than expected for random spatial genetic structure. Similar tendencies were found for the gene-pool distance and the semivariances of diversity. Kriging, as a method for spatial interpolation, was used to draw synthetic maps of the spatial patterns of allelic frequencies and genetic diversity. The influence of postglacial recolonisation and regeneration with foreign seed material on the spatial genetic patterns are discussed