Fraxinus excelsior seed is not a probable introduction pathway for Hymenoscyphus fraxineus.
We investigated the transmission of Hymenoscyphus fraxineus from infested seed to germinating seedlings of common ash (Fraxinus excelsior) in order to determine the potential risk associated with intra- and intercontinental movement of seed. Neither fungal isolations from necrotic or healthy embryos nor PCR testing with H. fraxineus-specific primers detected the pathogen. Similarly, H. fraxineus was not detected in axenically grown seedlings generated from infested seed lots. The results help clear up prior confusion of the pathogen being seed-borne. Any remaining surface contamination by pathogen spores could be washed off seeds as a quarantine measure.