eng Abstract: The results of selection of plus trees of sessile oak (Quercus petraea (Matt.) Liebl.) as a base for establishing a seed orchard are presented in this paper. The research included 86 trees of phenotypically highest quality, selected based on morphological and physiological criteria, in order to preserve and improve the genetic diversity of the species. Morphological characteristics of leaves and acorns were analysed, including dimensions, mass and the ratio of certain parameters. The results of one-way analysis of variance showed that there are statistically significant differences among the trees for all observed characteristics (p < 0.01), which indicates a high level of genetic and morphological variability. The obtained results confirm that selected plus trees represent a suitable source of reproductive material for establishment of seed orchard of sessile oak. This way a basis for long-term conservation of genetic potential and adaptive capacity of the species is created. Popović, Vladan Lazić, Sanja Lučić, Aleksandar Rakonjac, Ljubinko Pižurica, Radojica Ivanović, Boris Petrović, Aleksandra info:eu-repo/semantics/article Selection of sessile oak (Quercus petraea (Matt.) Liebl.) plus trees for seed orchard establishment Institute of forestry https://unilib.phaidrabg.rs/o:8884 doi:10.5937/SustFor2592011P ISSN: 1821-1046 2025 Sustainable Forestry volume: 92 startpage: 11 endpage: 27 application/pdf 658818 bytes Keywords: Quercus petraea, plus trees, morphological variability, acorn, leaf, seed orchard, genetic diversity http://creativecommons.org/licenses/by/4.0/legalcode