The spatial genetic structure and diversity of cedar (Cedrus sp.) from Türkiye and Cyprus: evidence from nSSRs

Abstract Lebanon cedar ( Cedrus libani ) is a keystone conifer of eastern Mediterranean mountains, and an important species for forest conservation and restoration. However, range-wide patterns of population structure in C. libani remain poorly resolved, limiting evidence-based management and conservation efforts. In this study, we investigate the genetic structure and diversity of C. libani across its main distribution range of Anatolia and its closely related taxon, C. brevifolia (Cyprus cedar). Using 15 nuclear microsatellite markers (nSSRs), we analyzed seed lots from 14 stands across Türkiye and trees from one natural population of C. brevifolia in Cyprus. Our results reveal a significant genetic differentiation between C. brevifolia and C. libani (pairwise FST 0.063 to 0.114), as well as high genetic diversity within both taxa (mean expected heterozygosity H E ≈ 0.507; mean allelic richness Ar = 6.97). STRUCTURE analyses identified K = 3 as the primary level of population subdivision, separating C. brevifolia from C. libani and revealing a clear east–west separation within Anatolian C. libani . Subsequent hierarchical analyses resolved five genetically distinct clusters of C. libani , corresponding to major geographic regions of the Taurus Mountains (Antalya, Isparta, Konya, Mersin, and Kahramanmaraş). These clusters reflect pronounced spatial structuring and region-specific genetic diversity potentially influenced by macro-scale tectonic and climatic barriers. This study provides a comprehensive assessment of the spatial genetic structure of C. libani in Anatolia offering valuable insights for sustainable forest management and gene conservation.