Changes in genetic structure of sessile oak (Quercus petraea [Matt.] Liebl.) natural regeneration in relation to maternal trees

The genetic variability of sessile oak (Quercus petraea L.) mature stand and its natural progeny was investigated. Comparison between genetic structure of parental and progeny trees was based on frequencies of nuclear microsatellite (SSR) alleles occurring in three DNA loci. A slight (4%) increase of gene pool between oak mature and progeny trees was revealed by heterozygosity level estimation, maintaining 86.3% of genetic similarity between generations. Also allele richness, partition probability of basic clustering and inbreed coefficient proved the high genetic similarity between parental and progeny of investigated oak trees. The gene flow occurred within the stands as far as rare alleles were transmitted or new ones appeared in the progenies. The results highlight the necessity of such a study for silvicultural measures taken in order to proceed natural or artificial regeneration in forest tree stand.