Japanese isolates of Verticillium dahliae were examined for vegetative compatibility relationships using nitrate-nonutilizing mutants. Four levels of vegetative compatibility were differentiated according to the degree of compatibility between the tester mutants of nit1 and NitM. Wild-type growth with a complementation line greater than 5 mm wide was defined as "strong reaction (-I-+)", i.e., compatible. Ten out of 15 isolates showed compatibility and were separated into three groups, provisionally designated as VCGJ1, VCGJ2, and VCGJ3, depending upon their reactions. This method was used to estimate genetic diversity within a local population of V. dahliae. Another 12 isolates from Gunma Pref. were paired with tester isolates of the three vegetative compatibility groups proposed, Eight Gunma isolates were assigned to VCGJ1 or VCGJ2. Two isolates were incompatible with all testers. The remaining 2 isolates were self-incompatible. Thus, 18 out of 27 Japanese isolates of V. dahliae were assigned to VCGs: 8 to VCGJ1,7 to VCGJ2, and 3 to VCGJ3. VCGJ1 was compatible with both VCGJ2 and VCGJ3, but VCGJ2 and VCGJ3 showed a weak reaction with each other. Japanese isolates of V. dahliae were thus demonstrated to form a VC group comprising three subgroups.

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In 1998, Verticillium sp. (CE98Vt1 and CE98Vt2) were isolated from discolored vascular structures of potato tubers sold at a market in Chiba Prefecture. These isolates were identified as Verticillium tricorpus on the basis of cultural and morphological characteristics and PCR diagnosis. This observed vascular discoloration of the potato tuber was demonstrated in three cultivars (Touya, Toyoshiro, and Waseshiro) among eight cultivars by inoculation to seedlings. External and internal symptoms of these isolates were not distinct in potato plants. The virulence of these isolates to potato was very low as compared with Verticillium dahliae. These two isolates were not pathogenic to Chinese cabbage, eggplant, green pepper, larkspur, parsley, snapdragon, soybean, tobacco, and tomato. This is the first report of V. tricorpus from potato in Japan.

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Two Exobasidium species causing Exobasidium leaf blister on Rhododendron spp. are described. An Exobasidium leaf blister on Rhododendron yedoense var. yedoense f. yedoense has been recognized in Hokkaido Prefecture, Japan, since the first report was issued in 1950. The causal fungus is identified with Exobasidium dubium from the morphology of its hymenial structure and mode of germination of the basidiospores. Another Exobasidium leaf blister on Rhododendron dauricum has been observed in Hokkaido Prefecture, Japan. In comparison with morphology based on hymenial structure and mode of germination of the basidiospores of the 100 validly described taxa, this fungus differs from those known taxa in the size of basidia and basidiospores, the numbers of sterigmata and septa of basidiospores, and the mode of germination of basidiospores. Thus, a new species, Exobasidium miyabei, is established and illustrated.

The expansions of communities and cities over the last two decades have led to the increase of the number of health care facilities, and thus, clinical wastes are generated in significant amounts. Clinical wastes are a potential source for many pathogens such as viruses, parasites, fungi and bacteria. Therefore, clinical wastes should be treated before disposal into the environment. The incineration is the most common technology applied for the treatment process. However, the negative effects of incineration on humans and the environment have led scientists to define alternative technologies for the safe disposal of clinical waste. Numerous treatment technologies have been investigated as an alternative for incineration, such as autoclave and microwave. These technologies generally depend on temperature while the recent direction is to use a non-thermal sterilization processes. SC-CO 2 is one of the nonthermal sterilization technologies, which depends on pressure and low temperature. Currently, SC-CO 2 has been extensively used for the inactivation of microorganisms in food and pharmaceutical industries. However, the application of SC-CO 2 in treating clinical wastes has been on a rise. Studies conducted on the inactivation of fungi in food, normal saline and growth media indicate that SC-CO 2 has the ability to inactivate these organisms. In clinical wastes, SC-CO 2 has been found to be effective in the inactivation of pathogenic bacteria. Therefore, this review paper focuses on the potential of using SC-CO 2 as alternative technology for inactivating fungi in clinical wastes.

Witches" broom on Rhododendron wadanum has been observed since 1994 in Nagano Pref. and recently, in 2000, it was found at Mt. Tsukuba, Ibaraki Pref., Japan. in comparison with the morphology, the mode of germination of basidiospores and the cultural characteristics of the 99 validly described taxa, this fungus was considered as a new species and named Exobasidium nobeyamense. (Ezuka, 1990).However, no species was reported to cause witches' broom in Sect. Brachycalyx.Therefore, we carried out morphological comparisons of the specimens collected in Ibaraki and Nagano Pref. with other Exobasidium spp. on Rhododendron spp.We propose the fungus producing witches' broom on Ft.wadanum as a new Exobasidium species. Materials and MethodsMorphological observations Fresh specimens on R. wadanum collected in the field were used for morphological observations. Specimens examined are listed in the description of the species. Morpho~ogica~ observations were conducted by light and scanning electron microscopy. The basidiospores and conidia or thin sections of hymenia were mounted in Shear's solution on glass slides for LM observations. For SEM, the infected leaves with hymenia stored in FAA were used. Samples for SEM were prepared by modifying a standard procedure (Tanaka, 1992), using a glutaraldehyde (2~ v/v) fixation procedure, dehydration, then t-butyl alcohol freeze-drying and coating with platinum-palladium in a high vacuum with a Hitachi E-1030 ion sputter. They were examined with a Hitachi S-4200 SEM operating at 15 kV. Taxonomy

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