Abstract
A filamentous fungus whose taxonomical name is not yet known has been suspected as the causal fungus of mass mortality of Quercus trees, because it is specifically found in the dead trees. This fungus is referred to as QM fungus in this paper. In order to utilize the dead trees, cultural features of Lentinula edodes (shii-take mushroom) and QM fungus were examined and L. edodes was cultivated using dead logs and their wood meal. Mycelia of L. edodes managed to grow even on the medium contained in the test tube in which QM fungus was vigorously growing. In a mycelial bed culture test, mycelia of L. edodes also grew well on the mycelial bed prepared with wood meal obtained from dead trees. Harvested fruit bodies showed no difference in number and weight between cultures made from dead trees and healthy trees. In a bed log culture test, mycelia of L. edodes spread in dead logs much more broadly than in healthy logs, even though QM fungus had infested dead logs at the time of inoculation. These results indicate that Quercus trees killed en masse can be used for both mycelial bed culture and bed log culture of L. edodes satisfactorily.
