珠芽黄魔芋软腐病病原菌分离与鉴定

为了对引种驯化的珠芽黄魔芋软腐病病害进行有效防控，采集陕西省镇巴县有软腐病发病症状的珠芽黄魔芋叶柄进行病原细菌分离纯化、致病性检测、分离菌株的菌落形态特征观察、生理生化特征及16S rDNA序列比对分析。试验结果表明，从软腐病症状的珠芽黄魔芋叶柄中分离获得了不同形态的15株细菌，致病性试验发现其中的ZYH1菌株可使珠芽黄魔芋、花魔芋、胡萝卜和白菜离体组织表现出软腐症状，并导致珠芽黄魔芋和花魔芋植株发病。分离的ZYH1菌株单菌落圆形突起，乳黄色，边沿光滑整齐，杆状菌体，16S rDNA序列分析结果表明，该菌株与已报道的胡萝卜软腐果胶杆菌(Pectobacterium carotovorum)亲缘关系最近，相似度为99.6%。这是陕南地区首次报道由胡萝卜软腐果胶杆菌引起的珠芽黄魔芋软腐病害，该研究结果有助于为引种驯化的珠芽黄魔芋软腐病害防治提供理论依据。

Isolation and Identification of a Pathogen of Amorphophallus bulbifer Soft Rot in Zhenba County of Shaanxi

In order to more effectively control the soft rot disease of Amorphophallus bulbifer during introduction and domestication, the pathogen of A. bulbifer petiole was isolated from Zhenba county, Shaanxi Province, and the pathogenicity of plant tissues and konjac plants were detected. The morphological characteristics, physiology and biochemistry analysis, and 16S rDNA sequence of the strain were analyzed. The results showed that a total of 15 strains of different bacteria were isolated from the bulbs of A. bulbifer soft rot. The infection test showed that the ZYH1 strain could cause soft rot symptoms in isolated tissues of A. bulbifer, konjac, carrot and Chinese cabbage, and cause soft rot disease of A. bulbifer and konjac plants. The ZYH1 strain was rod-like with round protuberance, milky yellow, smooth and neat border. The 16S rDNA sequence analysis showed that this strain was closely related to Pectobacterium carotovorum strain SXR1 with 99.6% similarity. This is the first report about A. bulbifer soft rot disease caused by Pectobacterium carotovorum in Southern Shaanxi Province. The results provide a theoretical basis for the prevention and control of the soft rot disease of A. bulbifer.