河南省紫荆黄萎病菌的分离和鉴定

为明确河南省郑州市紫荆山公园紫荆植株枯死的病因,采集具有典型黄萎病症状的紫荆植株,采用组织分离法分离出2株病原菌Vcg1和Vcg4,并进行鉴定。该病原菌在PDA培养基中菌落菌丝灰白色,分生孢子梗轮生,后期产生微菌核。PCR扩增菌株Vcg1和Vcg4 r DNA-ITS区段并测序,序列比对结果表明其与大丽轮枝菌(V.dahliae Kleb.)同源性最高。通过分生孢子悬浮液伤根接种法测定目标菌株在紫荆幼苗上的致病性,结果发现该病原菌能引起紫荆发病,维管束变褐色,严重的导致紫荆植株死亡。以上结果表明引起郑州市紫荆山公园紫荆枯死的病原菌为大丽轮枝菌。

Isolation and Identification of Verticillium dahliae on Chinese Redbud in Henan

The leaves of Chinese redbud in Zhengzhou Chinese Redbud Mountain Park turned yellow,and the vascular turned brown,with seriously disease plants dead. In order to determine the cause of death, Chinese redbud with the Verticillium wilt symptom was collected and two isolates of Vcg1 and Vcg4 were isolated from infected Chinese redbud stems. The colonies of isolates on PDA showed gray white first, later formed microsclerotia,and the conidiophores were verticillate.The rDNA-ITS of Vcg1 and Vcg4 was amplified by PCR and sequenced. The sequence blast resulted in the highest sequence homology with V. dahliae Kleb. . The pathogenicity of isolates was tested by dipping Chinese redbud seedlings roots in conidial suspensions. The pathogens could infect Chinese redbud,and made the vascular bundle brown, seriously causing plant wilted and dead. The results showed that the pathogen causing Chinese redbud wilt in Zhengzhou Chinese Redbud Mountain Park was V. dahliae Kleb. .