Ornithogalum mosaic virus (OrMV) occurred in Akita Prefecture. An OrMV isolate obtained from a diseased O. thyrsoides could infect not only O. thyrsoides and O. dubium but also five dicot plants (Nicotiana clevelandii, Gomphrena globosa, Chenopodium amaranticolor, C. quinoa and Tetragonia tetragonoides). Another isolate from a diseased O. dubium, by contrast, was transmissible via sap inoculation to the two Ornithogalum plants but not to any dicot plants tested. The two isolates caused mosaic symptoms on the two Ornithogalum plants. This is the first report on the occurrence of OrMV in Japan.
Isolates of a Fusarium graminearum species complex causing Fusarium head blight on wheat and barley were collected from the western part of Japan in 2002, and their mycotoxin productivity on a rice medium for deoxynivalenol (DON), nivalenol (NIV), T-2 toxin and zearalenone (ZEA) was examined using liquid chromatography/mass spectrometry. Fifty-eight percent of the isolates produced more NIV than DON; none of the isolates produced T-2 toxin and 96% produced ZEA. Among nine selected NIV-producing isolates, eight were significantly more virulent than isolate H-3 of a highly virulent DON chemotype, and all the NIV-producing isolates produced NIV in wheat grains obtained from a field inoculation test.
An outbreak of a new fungal disease of poinsettia (Euphorbia pulcherrima Willd. ex Klotzsch) was recorded in Hyogo Prefecture (2003) in Japan and caused dark, gray necrosis on stem and wilt. The pathogen reproduced the original symptoms after inoculation of whole plant of poinsettia. Then it was identified as Phytophthora nicotianae van Breda de Haan (1896). The name Phytophthora blight of poinsettia, in Japanese “Eki-byo” is proposed for the disease.
A new disease of wax gourd (Benincasa cerifera Savi) characterized by scab of fruit was observed in Okayama Prefecture, Japan in July 2003. Fungal isolates frequently obtained from diseased fruits of the plants were identified as Rhizoctonia solani AG-4 HG-I based on hyphal anastomosis and cultural morphology. In inoculation tests, these isolates were pathogenic on fruits of wax gourd and caused the same symptoms, and were re-isolated from the lesions of the diseased fruits. This is the first report of a fruit disease of wax gourd caused by R. solani. Therefore, the name brown scab of wax gourd is proposed for the new disease.