Germination Self-lnhibitors from Colletotrichum gloeosporioides f. sp. Jussiaea. Tetsu Tsurushima. Faculty of Commerce, Han-nan University, Amamihigashi 5-4-33, Matsubara City, Osaka 580, Japan. Tamio Ueno(2), Hiroshi Fukami(2), Hiroshi Irie(3), and Masafumi Inoue(4). (1) Faculty of Commerce, Han-nan University, Amamihigashi 5-4-33, Matsubara City, Osaka 580, Japan; (2)Department of Agriculture Chemistry, Faculty of Agriculture, Kyoto University, Kitashirakawa Sakyo-ku, Kyoto 606, Japan; (3) Faculty of Pharmaceutical Science, Nagasaki University, Nagasaki 852, Japan; (4) Dainihonjocyugiku Company Limited, Toyonaka, Osaka 561, Japan. MPMI 8:652-657. Accepted 23 May 1995. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1995.

Three self-inhibitors of conidial germination were isolated from Colletotrichum gloeosporioides f. sp. jussiaea and identified as (E)- and (Z)-3-ethylidene-l, 3-dihydroindol-2-one and (2R)-(3-indolyl) propionic acid. These compounds were named CG-SI (C. gloeosporioides-self-inhibitor) 1, 2 and 3, respectively. The inhibitors reduced the germination of conidia with ED50 values of 3 (g/ml for CG-SI 1, 5 ug/ml for CG-SI 2, and 100 to 150 (u)g/ml for CG-SI 3. Among 16 tested species of anthracnose fungi, CG-SI 1, 2, and 3 were only detected from C. gloeosporioides f. sp. jussiaea and C. fragariae. Activity of the self-inhibitors was greater for germination than for germ tube growth and the effects were greatest against the fungal species that produced them. The evidence indicates that CG-SI 1, 2, and 3 are physiologically important as germination self-inhibitors in these fungi.