東洋ラン(Cymbidium sp.)から分離されたOrchid Fleck Virusの性状について

Orchid flck virus (OFV) was isolated from Oriental Cymbidium (Cymbidium sp.),showing chlorotic flecks on leaves. The virus was transmitted mechanically to Chenopodium quinoa,C.murale and Beta vulgaris by sap-inoculation and caused systemic infection. Local lesions were produced on C.amaranticolar, Petunia hybrida, Tetragonia expansa and Vigna sinensis. Sap from infected T.expansa was still infective after 10 mim at 40℃ but not after 10 min at 45℃, at a dilution of 10-3 but not 10-4, and after 30 min at room temperature but not after 60 min. The isolate of OFV had non-enveloped, bullet-shaped patricles measuring about 40×120－150 nm in dip preparations. However, bacilliform particles about 40×120-140 nm were observed in ultrathin sections. In ultrahtin sections of virus-infected tissues, virus patricles were detected both in the nuclei and in the cytoplasm. Moreover, the inclusions of low electron density(viroplasm) were also observed in the nuclei.Virus particles were found to attach at one end to the inner nuclear membrane. A number of particles surrounded by the inner membrane often showed an appearance like a spoked wheel.