Potentially invasive fungal pathogens in forests of Nepal

Potentially invasive fungal pathogens of tree species in Nepal were isolated and identified in this study. A survey was conducted throughout the country, and the infected parts of different host trees were cultured in potato dextrose agar medium to isolate the pathogenic fungi. Altogether, 10 fungal pathogens were identified as causing foliar and trunk diseases. Two of the pathogens, Nectria sp. (stem canker) and Phytophthora alni subsp. alni (bleeding canker), were reported from the stems and trunks of Alnus nepalensis and Shorea robusta, respectively. The pathogens Neonectria neomacrospora (needle cast), Aureobasidium apocryptum (anthracnose), Golovinomyces cichoracearum (powdery mildew), Calonectria reteaudii (blight), Dothistroma septosporum (needle cast), Calonectria indusiata (spot), Olivea tectonae (rust) and Rhytisma acerinum (tar spot) were isolated from the foliar part of the host trees Abies spectabilis, Acer laevigatum, Alnus nepalensis, Eucalyptus camaldulensis, Pinus roxburghii, Rhododendron arboreum, Tectona grandis and Toona ciliata, respectively. These species could be the potential invasive forest pathogens in Nepal. An effective long-term future plan needs to be developed for managing these forest diseases to maintain the forest health of the country.