Mycobiota in the seeds of narrow-leaved ash (Fraxinus angustifolia Vahl)

Abstract

Narrow-leaved ash (Fraxinus angustifolia), currently the most damaged forest tree species in the Republic of Croatia, is suffering from dieback primarily caused by pathogenic fungus Hymenoscyphus fraxineus. Since health status of seeds is very important for future seedling production, objective of this study was to screen narrow-leaved ash seeds for presence of this main pathogen and other potentially parasitic fungi. Seeds were collected from five locations and analysed using three different methods. Results revealed relatively good health status of inspected seeds, with total of 15 different fungal taxa identified in less than 40% of samples and no confirmation of Hymenoscyphus fraxineus presence. Most frequently detected fungi were various species of genus Alternaria and species Sphaerulina berberidis, while other taxa occurred rarely. Although identified fungal species haven't caused visible symptoms on seeds after one to two months of storage, many of them are known seed pathogens or opportunistic ash (Fraxinus spp.) pathogens and could have a negative effect on seeds after longer period of storage or storage in unfavourable conditions.