13th Conference on Medicinal and Aromatic Plants of Southeast European Countries (CMAPSEEC 2026)

Background: Helichrysum italicum (Roth) G.Don (Asteraceae) is a Mediterranean aromatic and medicinal species valued for its essential oil, which is widely used in the cosmetic, pharmaceutical, and perfumery sectors. Rising commercial demand during the early 2000s led to intensified harvesting of wild populations, particularly along the eastern Adriatic coast. In combination with ongoing habitat degradation, this pressure has raised concerns about potential losses of genetic diversity and reduced adaptive capacity in H. italicum. To address these concerns, this study investigates how overexploitation may have influenced the genetic diversity of H. italicum across its native range.
Material and Methods: In this study, we investigated the genetic diversity and population structure of H. italicum using microsatellite markers (SSRs) to analyze twenty populations spanning the entire eastern Adriatic coast.
Results: Fifteen microsatellite loci were successfully amplified and genotyped for all individuals. Expected heterozygosity ranged from 0.662 to 0.776 (mean HE = 0.724), reflecting moderate to high genetic diversity. Population differentiation was low (mean FST = 0.037), and AMOVA indicated that most genetic variation occurred within populations. Despite the low overall structure, significant φST values revealed detectable differentiation among populations. Bayesian clustering analysis identified four genetic clusters, with extensive admixture among populations. A significant correlation between genetic and geographic distances supported an isolation‑by‑distance pattern.
Conclusion: H. italicum populations maintain substantial genetic diversity and exhibit low genetic differentiation, consistent with the characteristics of an outcrossing species. The predominance of within-population genetic variation and the extensive admixture among genetic clusters indicate ongoing gene flow and strong connectivity among populations. These findings suggest that the intensive exploitation of natural populations has not had a lasting negative impact on the genetic diversity of H. italicum populations in the study area.