キノリン系合成化合物であるオキソリニック酸(5-ethyl-5,8-dihydro-8-oxo [1,3] dioxolo [4,5-g] quinoline-7-carboxylic acid,スターナ®)は,植物病原細菌のうちグラム陰性細菌,とくにPseudomonas glumae, P. plantarii, P. avenae, P. solanacearumなどのPseudomonas属菌やErwinia属菌に高い抗菌活性を示した。P. glumae各分離株に対するオキソリニック酸のMICは0.1-0.4μg/mlであった。その作用性は,誘導期に対しては殺菌作用が強く,対数増殖期初期に対しては増殖抑制効果が強いが,対数増殖中期以降に対する効力は低いことが明らかとなった。また,オキソリニック酸処理によって, P. glumaeの細胞形が異常に伸長する現象が認められた。
Rice plants fixed in glutalaldehyde were cut into 30μm thickness with Automatic MT-2 (Nihon-Ika). The cross sections were immersed in the fluorescent antibody labelled with FITC against Pseudomonas glumae and observed under a fluorescent microscope. Specific fluorescences derived from the bacteria were found in and on an upper and lower epidermis, in a parenchyma and in a sclerenchyma of palea and lemma of grain. They were found in an upper and lower epidermis and a vascular bundle sheath of a flag leaf blade, and around a vascular bundle and a lysigenous aerenchyma of a flag leaf sheath. These results suggest that this immunofluorescent antibody technique is useful for detecting P. glumae on rice plants.
Viral wilt in cucumber plants grafted on squash rootstocks occurred in summer and autumn in Kagawa prefecture, whereas no viral wilt was observed in winter and spring. Mosaic disease occurred at a high percentage in summer and autumn. Both cucumber mosaic virus (CMV) and zucchini yellow mosaic virus (ZYMV) were detected in the grafted cucumber plants showing viral wilt in the fields at a high frequency. The inoculation with the samples containing CMV and ZYMV caused severe wilt on the grafted cucumber plants.