New, emerging and re-emerging fungal diseases on medicinal and aromatic plants in European domain
Plant diseases cause agricultural and economic loss and impact negatively on human and animal health through mycotoxins and allergens produced by them. They also have consequences for biodiversity conservation. The pathogens could be classified in five categories: new - detected within the last five years; emerging - have always been present in an area but have grown in importance over the years; re-emerging - have been previously controlled but are once more a major problem associated with chemical resistance or changes in management or cultivars; threatening - not reported or limited in distribution in Europe and chronic-spreading – known for longer than 20 years and causing increased concern. Diseases emerge or re-emerge due to changes in farming practices, development of new strains of the pathogen, climate change, introduction of the pathogen to new geographical locations, or introduction of more efficient pathogen vectors. During the last years emerging infectious diseases (EIDs) are of special concern to researchers. Among all pathogens fungi are responsible for the greatest damage to plants in both agricultural and natural ecosystems. They represent over 70 % of all plant pathogens and over 30 % of plant EIDs. Surveys on fungal diseases of medicinal and aromatic plants have been carried out in the framework of several research projects between Germany, Bulgaria, Lithuania and Poland in the last two decades. EIDs have been reported, either as novel pathogens or as familiar pathogens affecting new host species. The importance of the problem could be illustrated by such examples as some phytopathogenic fungi on Apiaceae and Lamiaceae hosts discussed in the present work.