金钗石斛茎腐病病原菌的分离与鉴定

Isolation and identification of pseudobulb rot pathogen of Dendrobium nobile

为确定金钗石斛Dendrobium nobile茎腐病的病原菌,采用子实体分离、组织分离、致病性测定、形态学鉴定及rDNA-ITS序列分析方法对病原菌进行研究。结果表明:离体测定、活体测定2种接种方式,金钗石斛植株均表现出水渍状腐烂病斑、软化症状,均与基地驯化苗病株症状一致。经鉴定,金钗石斛茎腐病的病原菌为尖孢镰刀菌Fusarium oxysporum Schltdl,子实体为尖孢镰刀菌无性阶段的分生孢子座。

To determine the pathogen causing pseudobulb rot disease of Dendrobium nobile,sporophore isolation,tissue isolation,pathogenicity test,morphological study and rDNA−ITS sequence analysis were performed.The results showed that in vitro and vivo test,the leaves and pseudobulb of D.nobile both were infected in the form of water stains and softening,which were consistent with the symptoms of domesticated seedlings in the base.Fusarium oxysporum Schltdl was identified as the pathogen causing pseudobulb rot in D.nobile,and the sporophore is sporodochium of the asexual stage of F.oxysporum.