Decline of Phellodendron amurense in Tokyo: Associated Fungi and Pathogenicity of Associated Cylindrocladium spp. Tsuneo Watanabe, Forestry and Forest Products Research Institute, P.O. Box 16, Tsukuba Science City, Ibaraki 305, Japan. Shinsuke Hagiwara, The Institute for Nature Study, National Science Museum, 5-21-5, Shiroganedai, Minato-Ku, Tokyo, Japan; and Itsumi Narita, Saitama Prefectural Ornamental Plants Research Center, Kushibiki, Fukaya, Saitama 366, Japan. PLANT DIS. 79:1161. Accepted for publication 22 May 1995. Copyright 1995 The American Phytopathological Society. DOI: 10.1094/PD-79-1161.

Three Cylindrocladium species were isolated from Phellodendron amurense seedlings together with fungi belonging to 24 genera, and 11 genera from the tree roots. The three species were tested for pathogenicity on leaflets and seedlings of P. amurense. Cylindrocladium colhounii caused leaf blight and subsequent abscission of leaflets of seedlings, saplings, and trees, and damping-off of potted seedlings, but C. camellea and C. tenue were not pathogenic. The significance of Cylindrocladium species in relation to decline of P. amurense trees in Tokyo is discussed.