Abstract
1. In the peresent paper the results of the writer's investigation on the cultural characters of three wood-rotting fungi, Lenzites abietina FR., L. subferruginea BERK. and L. trabea (PERS.) FR., causing the brown rot of various coniferous trees were described.
2. The growth habit of the mycelium on seven different media were compared. Among the agar media used, the malt decoction agar and the SAITO's soy decoction agar proved to be the best for all fungi tested, being followed by the Koji decoction agar, the potato decoction agar and the exocarp of citrus decoction agar. The mycelial growth was generally more vigrous in Lenzites trabera and L. subferruginea than L. abietina. At the beginning of their growth the colonies were white changing afterward slowly to light yellowish brown, yellowish brown or dark brown.
3. The relation of temperature to mycelial growth was investigated by culturing the mycelium on poured plates of three agar media incubated at different temperatures. Repeated experiments indicated that the optimum temperature for the mycelial growth of Lenzites abietina seemed to lie at the temperatures from 26°C. to 28°C. It was found also that the mycelium of L. subferruginea and L. trabea grew very vigorously at the temperatures from 32°C. to 36°C. and the optimum temperature was approximately 34°C.
4. The relation of hydrogen-ion concentration to mycelial growth was studied using the potato decoction agar at 28°C. The mycelia of three fungi tested seemed to be able to grow between pH 2.6-3.0 and pH 8.0, and the optimum pH value for the mycelial growth seemed to lie at pH 5.6 (Lenzites abietina) pH 6.2 (Lenzites subferruginea and L. trabea).
5. By BAVENDAMM's method, the writer obtained negative reaction indicating these three fungi as belonging to the group of cellulose dissolving fungi.
