An extensive survey on phylogeny and pathology of fungi associated with the oak decline in Zagros forests located in Western Azarbaijan, Kurdistan, Kermanshah, Lorestan, and Ilam provinces, a large number of collected fungal isolates seventeen isolates morphologically resembled the members of Phaeoacremonium. Similar DNA fingerprinting patterns were generated for all isolates using M13 primer. Thus, one representative isolate (IRAN 4348C) was analyzed based on tub2 sequence data using maximum parsimony and neighbor-joining algorithms and identified as Phaeoacremonium tuscanicum. Pathogenicity was confirmed following Koch’s postulates on two-year-old Quercus brantii seedlings under greenhouse conditions. To our knowledge, it is the first time Ph. tuscanicum is reported from oak trees and confirmed as a pathogenic fungal species on Q. brantii in the world.
