The causal bacterium of rice grain rot entered to the lemmata and paleae through the stomata, and multiplied in the intercellular spaces of the parenchyma. Stomata are mainly opened on the inner surfaces of lemmata and paleae, a few on outer surfaces of lemmata and they are connected each others through the intercellular space of parenchyma. The bacteria multiplied on the surface of albumen and embryo, but never invaded them.
1983年に福井県内のオオムギおよびコムギ畑において既知の雪腐病とは異なる雪腐症状の発生を認めた。融雪直後の茎葉は暗緑色に腐敗しており,乾くと灰白色ないし黄白色になる。生き残った葉には楕円形の病斑が形成される。病斑の周囲には明瞭な褐色のふちどりがあり,中央部に灰白色ないし淡褐色の菌糸塊が見られる。菌糸融合などの諸性質を検討した結果,病原菌はムギ類の株腐病をおこすCeratobasidium gramineum Oniki, Ogoshi et Araki (Syn. Corticium gramineum Ikata et T. Matsuura)と同一種であることが明らかになった。
Bacterial blight of lilac (Syringa vulgaris L.) was found in Nagano Pref., Japan. The disease first appears on shoot as water-soaked small spot. Those spots rapidly enlarge in size and become sunken, blackish and elliptical lesions. The lesions usually elongate longitudinally to form irregular-shaped stripes. Affected young shoots bend over at the lesions, wither and often die. The pathogenic bacterial isolates were identified as Pseudomonas syringae pv. syringae van Hall 1902 from the results of pathogenicity and bateriological tests.
Occurrence of Japanese pear rust on Japanese pear trees planted in the flat and extensive rice field (about 5km×4km) was generally severe in the area within 100m away from the infected trees of Chinese juniper as rust inoculum and gradually decreased with increase of distance up to 1, 500m. Under the climatically satisfactory condition to dispersal of sporidia such as heavy rainfall and strong wind, the trees planted within 1, 000m were rather severely diseased. The following relationships were detected between the distance of sporidial dispersal (x) and the percentage of diseased leaves (Y):Y=124.297e-0.002x in 1977, and Y=54.361e-0.002x in 1979. Therefore, it is concluded that the distance of sporidial dispersal for practical control may be about 1, 500m.
Citrus tatter leaf virus (CTLV) was purified by molecular permeation chromatography on controlled pore glass beads after preliminary partial purification from infected leaves of Chenopodium quinoa. CTLV had very flexuous filamentous particles 600 to 650nm long and 13nm wide. In uranyl acetate, the particles were constructed with a pitch of 3.4nm and showed two types of fine structure, cross-banding and criss-cross pattern. The virus had a single RNA species with a mol. wt. of 2.83×106 and produced a single protein band (mol. wt. 27, 000) in SDS-PAGE. CTLV showed a serological relationship to apple stem grooving virus which is a member of the capillovirus group. These findings suggest that CTLV is a capillovirus.