花楸烂皮病病原菌鉴定

Identification of Pathogen of Cytospora Canker of Sorbus

为了鉴定花楸(Sorbus pohuashanensis (Hance) Hedl)烂皮病的病原,在东北林业大学校园采集到带病植物标本,进行了病原菌的分离和纯化;通过孢子悬浮液对花楸树健康枝条刺伤接种,完成了病害柯赫氏法则的验证。通过观察菌株菌落的宏观和微观形态,对比相关参考文献对病原菌进行了形态学鉴定;提取供试菌株DNA,进行r DNA-ITS序列的PCR扩增与测序,对比NCBI数据库对病菌进行分子鉴定。结果表明:孢子悬浮液接种在花楸枝条上发病的病症与自然条件下病症相同;与NCBI数据库比对,病原菌与普尔松白孔座壳菌(Leucostoma persoonii (Nitschke) H9hn.)在覆盖度为96%的范围内相似度为99%。因此,鉴定引起花楸烂皮病的病原菌为普尔松白孔座壳菌,其无性型为核果壳囊孢(Cytospora leucostoma (Speg.) Sacc.)。该病害为花楸上的国内新病害。

With Sorbus pohuashanensis(Hance)Hedl bark rot from the campus of Northeast Forestry University,the pathogens were isolated and refined by tissue separation,tested by the Koch’s postulation methods,and identified by morphological characteristics and internal transcribed spacer regions(ITS).Pathogenicity test showed that S.pohuashanensis isolates caused the symptoms originally observed on those of naturally infected plants,and ITS sequences were 99%homologous to Leucostoma persoonii(Nitschke)H hn.as determined by a BLAST search in the NCBI database.So,the causal fungus was identified as L.persoonii,and its anamorphic species is Cytospora leucostoma(Speg.)Sacc.This represents the first report of the disease and the pathogen in China.