Microsatellite Analysis for Differentiation and Identification of the Source Tree of Fagus orientalis Lipsky

The present study describes approaches for the identification of individual beech trees using maternal tissues from their seeds or fruits. Four microsatellite markers were used for genetic analysis of seedlots from Fagus orientalis Lipsky, a highly out-crossing tree species. Seeds from 11 single-tree harvests belonging to one population, (7 seeds from each), as well as non-paranchymatic maternal tissues of the seeds (single woody pericarps) were genotyped. No prior information about the genotypes of the mother trees was available for the seedlot samples. Two methods for detection of mother tree genotypes were adopted; (1) analysis of woody pericarps and their applicability for a direct molecular identification of the mother trees; and (2) analysis of maternal half-sib families and usefulness contaminations and inference of the seed parents from the offspring. A comparison of the multi-locus genotypes from pericarps with those of the inferred from the offspring revealed absolute identity. Analysis of the half-sib families revealed that the maternal genotypes can be inferred from offspring genotypes due to codominant Mendelian inheritance of the microsatellites. Differences among the seeds from the same mother tree suggested that paternal genotypes and gene flow have more influence on differentiation. The results of this research show that microsatellite analysis is a suitable means to monitor the number of trees included in commercial seedlot samples and detect seed contaminations.