Abstract
A filamentous fungus has been isolated from wood killed by mass mortality of Quercus trees. Effects of four edible mushrooms, Lentinula edodes, Pholiota nameko, Naematoloma sublateritium, and Flammulina velutipes on mycelial growth of this unidentified oak pathogenic fungus were estimated on dual culture in petri dish. The results showed that only L. edodes inhibited the mycelial growth of the pathogenic fungus. Subsequently, we selected an excellent strain by carrying out dual culture between the pathogenic fungus and 73 strains of L. edodes. This strain is expected to be useful to control mass mortality.