玉米顶腐病鉴定

Studies on the symptoms and pathogen identification of maize top rot disease

报道了玉米顶腐病发生的系统性症状特点及病原菌鉴定的结果。玉米顶腐病抽穗前主要表?叶缘缺刻、叶片枯死、扭曲卷裹、弯头、顶叶丛生;抽穗后表?为叶片基部腐烂,叶鞘、茎秆腐烂,植株畸形。叶缘缺刻和叶片撕裂是顶腐病区别于其他病害的鉴别性特征。引起玉米顶腐病的病原菌小分生孢子呈假头状着生,而不是串珠状着生,因此,将该病原菌鉴定为亚粘团镰孢霉[Fusarium subglutinans(Wr.&Reink.)Nelson,Toussoun&Marasas]。引起茎、叶部两种症状的亚粘团镰孢霉同源性很高,在遗传上具有较高的相似性,是同一病原。与串珠镰孢霉复合侵染可加重病害的发生,其发病率较单独接菌高11.1%。

The systematic symptoms and pathogen of maize top rot were studied. The results showed that the symptoms were as followed： leaf lobes, leaf necrosis and twist malformation in seedlings and leaf rot, stalk rot and plant stunt after heading stage. Leaf lobes were the symptom that could be used to distinguish this disease from other diseases. The pathogen of maize top rot had no rosary traits. So it was identified as Fusarium subglutinans （Wr. Reink. ） Nelson, Toussoun ＆ Marasas. Fusarium, causing leaf rot and stalk rot, were highly homologous with high similarity in inheritance. The compound infection of F. subglutinans and F. moniliforme produced additive effects on symptoms. The disease incidences of compound infection were 11.1%0 higher than that of single infection by one of two pathogens.