Genome-wide assessment of Quercus pedunculiflora differentiation within the Quercus robur (Fagaceae) species complex—implications for forest management in Central-Eastern Europe

Bibliographic Data

ID24234183
AuthorsIvett Hegedüs, Denes Bartha (0000-0001-7106-7614), Nozim Shodiev, Gábor Sramkó (0000-0001-8588-6362)
Year2026
Volume28
Pages101528
Publication date2026-11-01
Open AccessYes
TypeARTICLE
VenueTrees Forests and People (JOURNAL)
Journal identifiersISSN: 2666-7193 • E-ISSN: 2666-7193
PublisherElsevier BV (PUBLISHER)
DOI10.1016/j.tfp.2026.101528
OpenAlexW7221796677
LanguageEN
References cited81

Climate change is expected to increase drought stress across large parts of Central Europe, raising the question of whether southern oak populations may represent valuable genetic resources for future climate-adaptive forest management. In this exploratory study, we investigated genomic relationships among Quercus robur (pedunculate oak), Q. pedunculiflora (greyish oak), and morphologically transitional individuals sampled from Bulgaria, Romania, and Hungary using low-coverage whole-genome resequencing. Genome-wide analyses revealed weak but consistent nuclear genomic differentiation within the Q. robur complex, consistent with the recognition of Q. pedunculiflora as a differentiated lineage. Within the limitations of the present sampling design, this pattern is compatible with subspecific rank rather than treatment as a separate species or a simple ecological variant of Q. robur . No genomic evidence was found for the occurrence of Q. pedunculiflora in the sampled Hungarian material, including individuals previously assigned to this taxon based on morphology. Phylogenomic analyses indicated heterogeneous chromosome-level signals, while morphologically transitional individuals did not form a separate genomic lineage. Analyses of 21 previously identified drought-responsive candidate genes showed substantial overlap in normalised mapped dosage between taxa and geographic groups, with no statistically supported differences. Together, these results provide no evidence that systematic dosage differences in the examined drought-responsive candidate genes underline the observed genomic differentiation. From an applied perspective, Balkan oak populations represent candidates for further evaluation in provenance and assisted gene-flow trials, rather than genetically demonstrated sources of drought-adaptive variation for immediate operational deployment.

assisted gene flow · Drought stress · genomic differentiation · Phylogenomics · provenance trials · Quercus robur · Chromosomal and Genetic Variations · Genetic diversity and population structure · Genetic Mapping and Diversity in Plants and Animals

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