Spatial and microgeographical genetic differentiation of black alder (Alnus glutinosa Gaertn.) populations

Three Alnus glutinosa populations from central Slovakia were investigated by means of isozyme analysis. The average expected heterozygosity ranged from 0.151 to 0.173. Despite significant differences in allele frequencies among populations, genetic differentiation was low (F-ST = 0.022). Intrapopulation fixation indices indicate no or very slight deviation from panmictic expectations towards the heterozygote deficiency. No indications were found that the investigated populations have experienced recent bottlenecks in population size. A spatial autocorrelation analysis based on Moran's I indicates the existence of a spatial genetic structuring in the population Kral'ova. Patch size was estimated to be 70-100 m, which is more than observed in other broadleaved tree species. This difference is explained by the linear shape of alder populations and a higher mobility of seeds. (C) 2002 Elsevier Science B.V. All rights reserved.