接种枯萎病菌香蕉苗病症及其组织病理特征

The symptom observation and tissue pathogenic characteristics of banana seedlings after inoculation with Fusarium oxysporum f.sp. cubense

用枯萎病菌4号生理小种接种香蕉苗后,观察发现:香蕉苗在发病初期出现了黄叶、球茎组织变褐症状;发病中期出现了叶片萎蔫、球茎组织变褐、假茎可见斑点状或线条状褐色病变、根变黑褐症状;发病后期出现了植株萎蔫、枯死等症状.采用组织病菌分离法,发现病菌从香蕉根部侵入后,由香蕉组织下部向上部传导,并在根、球茎和假茎中稳定定殖.用组织切片法观察发现病菌能使香蕉苗球茎组织产生褐变,引起细胞壁木质素增加及淀粉颗粒减少.

Banana seedlings inoculated with Fusariurn oxysporum f. sp. cubense race 4 appeared some symptoms, such as yellow leaves, browning corm tissue （occured in the earlier period）, wilting leaves, browning corm and pesudostem tissue, blacking roots （occured in the middle period）, and wilting, dying plants （occured in the latter period）. By using the method of plant tissue pathogen isolation, it was found that pathogen invading injured roots could transmit upwards in banana plants, and colonized in roots, corms and pesudostems tissue of banana. These pathogenic characteristics that could cause corm tissue to bring browning reaction, lignose of cell wall to increase, and faecula granule to decrease, were also observed by using tissue sectioning.