부산대학교 도서관

Serious seedling decline of Zamia furfuracea was found at Tsaotuan, Nantow in the summer of 2001. The leaves of the affected seedlings became smaller and yellow at the early stage and their root systems were necrotic and seriously rotted. The internal tissues of affected stems turned brown and soft with gummosis. The diseased plants grew slowly and died eventually. Three isolates of Phytophthora were isolated and all of them caused disease symptoms similar to those appearing in the field on the inoculated young seedlings. The same fungi were reisolated from the inoculated diseased seedlings. The isolated Phytophthora grew on V-8 agar at temperature ranging from 8-32°C with the optimum temperatures of 24-28°C. The fungal colonies showed rosette pattern on PDA plates. Hyphal swellings were spherical, irregular to coralloid, clustered or single. Sporangia were not formed on agar plates but were produced abundantly in soil extract solution or washed with mineral solution. Sporangia, 42.5-(53.5)-65.0 X 27.5-(32.1)-35 µm, were non-papillate and non-deciduous, and displayed nested and extended proliferation in water. The ratios of L/B were 1.21-(1.67)-2.7. Chlamydospores, 25-(31)-35 µm, were spherical and thin-walled. All of the three Phytophthora isolates belonged to A mating type. None of them form oospores themselves when paired with A2 type of P. parasitica. However, they were able to stimulate A2 to initiate sexual reproduction. The Phytophihora was identified as Phytophthora cinnamomi Rands according to Waterhouse key. This is the first report of Phytophthora disease of Zamia furfuracea in Taiwan as well as in the world.