Etiological Studies on the Banana Bunchy Top

Abstract

Hand-section of tissues of bunchy top diseased banana plants were examined under a reflecting fluorescence microscope. A distinctly specific bright fluorescence was observed in these phloem tissues of lamina veins, midribs, sheaths, corms and roots. Symptomless suckers taken from infected stool also gave a weak fluorescent reaction. These specific reactions were phloem-limited, and were not observed in the healthy banana plants. Leaf sections prepared from both diseased and healthy plants of banana were also examined under light microscope after treatment with Dienes’ stain. No specific blue staining was noticed in these phloem tissues. These results indicated that the banana bunchy top disease is probably not of a mycoplasmal etiology and that a phloem-limited etiology may possibly be involved. 香蕉萎縮病病株組織之徒手切片，經反射型螢光顯微鏡觀察結果，在葉片、主脈、葉鞘、球莖、根部及病株之無病徵吸芽的篩管細胞，呈現顯著特殊螢光反應。這些特殊螢光反應局限於篩管組織。健全蕉株之篩管組織則無此反應。同時香蕉病株與健株葉部切片，亦以 Dlenes' stain 染色處理後，經光學顯微鏡觀察，結果在該篩管組織皆無特殊性藍色染色反應，此項結果表示本病病原並非擬菌質體。本病病原或其與寄主植物反應生成物分佈於香蕉病株之葉部、葉鞘、球莖、根部及病株之無病徵吸芽苗之篩管組織。