新疆巩留县杏果实斑点病病原菌鉴定

目的]鉴定引起新疆巩留县杏树果实斑点病病原菌，研究造成杏树果实病害的原因，为当地杏树防治工作提供依据。方法]采用常规组织分离法分离得到罹病杏真菌菌株，利用传统形态学观察和分子系统学分析相结合的方式对所分离出菌株进行分类鉴定及其致病性检测。结果]杏果病斑处的病原菌在显微镜下观察到分生孢子形态与经PDA培养基培养后观察到分生孢子形态均与Thyrostroma carpophilum（Lév.） B.Sutton所产生分生孢子一致；将分离获得的3株真菌的rDNA-ITS片段测序后与NCBI参考序列进行多重序列比对的结果显示，其序列与T.carpophilum一致性为100%；在基于ITS基因序列构建的系统发育树中，3株菌与T.carpophilum聚在同一分支。在接种了T.carpophilum后，杏果实和叶片均产生明显病斑并且从其所产生的病斑上再次分离到所接菌，满足柯赫氏法则。结论]从新疆巩留县杏果实病斑处分离获得的3株真菌，经鉴定为引起杏穿孔病的病原菌T.carpophilum。这是该菌首次在该地区发现并报道。

The Pathogen Identification of Apricot Fruit Spots Disease in Gongliu County, Xinjiang

Objective] This study aims to identify the pathogen of apricot fruit spots disease in Gongliu County, Xinjiang, and to find the causes of apricot fruit diseases, so as to provide a reference for the disease prevention and control of local apricot trees.Method] The fungal strains on the infected apricot were isolated by using conventional tissue separation method, and the isolates were identified by morphological observation, phylogenetic analysis and pathogenicity.Result] The morphological feature of conidia developed on apricot fruit lesions and PDA medium were consistent with the conidia produced by Thyrostroma carpophilum (Lév.) B. Sutton. Furthermore, sequence identity comparison showed that all the three strains obtained were 100% identical in rDNA-ITS sequences with the NCBI reference sequence of T. carpophilum, and the three strains grouped into one consensual cluster with the reference isolates of T. carpophilum in the phylogenic tree based on rDNA ITS sequence. After inoculation of the obtained isolate, both apricot fruits and leaves produced obvious lesions, and the pathogen were again isolated from the lesions, thereby satisfying Koch''s postulate.Conclusion] The three strains isolated from the apricot fruit spots in Gongliu County were identified as T. carpophilum. This is the first report of this disease presence in Xinjiang Uygur Autonomous Region.