稻曲病不同抗性水稻品种的组织化学及分生孢子侵染途径的初步观察

 稻曲病菌分生孢子悬浮液对抽穗期水稻进行接种,观察分生孢子及其侵染途径.结果发现,分生孢子在颖壳表面可萌发形成菌丝,在颖口内侧可以见到菌丝伸向谷颖内部,可能为分生孢子直接侵染稻穗提供了一定证据.对抗、感品种谷粒的组织化学研究结果表明:抗病品种的颖壳中含有大量的木质素,感病品种中的木质素较少;在抗病品种谷粒的颖壳中的红色荧光物质远远多于感病品种;在抗病品种谷粒表皮的胚乳细胞中也含有多酚类物质,这层细胞较正常细胞大,在感病品种中没有发现.稻曲球切片的紫外光观察可发现每一个稻曲球中存在6个"蝴蝶"型荧光结构,染色剂染色后观察证明该结构不含过氧化物酶、单宁类物质、木栓质和木质素.

Histochemical observation on the resistant and susceptible varieties to Ustilaginoidea virens (Cooke) Tak and way of conidia

Infection of U. virens was observed with microscope on various rice cultivars inoculated with conidia suspension at the heading stage. The results showed that the conidia could germinate and form mycelia on the surface of glume and further extend inside the glume hull,which may provided evidence of infecting panicle by conidia directly. By histochemical observation on the grains,a higher level of lignin content was found in the resistant variety Shuijing 3 (R) than in the susceptible variety 9522 (S). Abundant polyphenolic compounds in epidermis and endosperm of grain were detected in R,but not in S. A sort of "butterfly" structure was repeatedly observed under the UV light in each sclerotium of U. virens. No peroxidase,tannins,suberines or lignins was found in the "butterfly" structures by histochemical observation.