狭叶十大功劳白粉病发生调查及其病原鉴定

Occurrence of Powder Mildew of Mahonia fortunei and Identification of Its Pathogen

对江西农业大学校园内狭叶十大功劳白粉病症状进行描述,调查发生情况,并对其病原菌进行了形态和分子生物学鉴定。狭叶十大功劳白粉病主要为害叶片,通常在叶片正面形成白色粉状霉层,严重时导致叶片变形;该病终年可见,新叶、嫩枝于4月上句开始发病,8-11月为发病盛期,空旷处植株发病重于树荫处。对该病菌的有性态和无性态进行了观测,其有性态和无性态分别与文献对多丝叉丝壳Microsphaera multappendicisZ.Y.Zhao & Yu和亚麻粉孢Oidium lini Skoric的描述相吻合;对该病菌的rDNA-ITS区段进行了PCR扩增、序列测定和序列分析,发现该序列与GenBank中多丝叉丝壳对应序列的同源性达99%。根据对病菌的形态和分子生物学鉴定结果,认为江西农业大学校园内狭叶十大功劳白粉病的病原为子囊菌门多丝叉丝壳M.multappendicis,其无性态为半知菌类亚麻粉孢Oidium lini。

The symptoms of powder mildew of Mahonia fortunei on the campus of Jiangxi Agricultural University（JXAU） were described,its incidence and severity were investigated,and its pathogen was identified by using morphological and molecular biological method.The results showed that powder mildew of Mahonia fortunei occurred mainly in leaves.The diseased leaf usually displayed a layer of powdery white mold on its front side,and the severely diseased leaf often became deformaed.The disease occurred all the year,with new leaves and new shoots being infected in early April,and with August to November as the peak period of the disease.The disease in sunshine was more severe than in shadow.The morphological characteristics and size of the teleomorph and anamorph of its pathogen were microscopically observed and measured,and they were in coincidence with description of Microsphaera multappendicis Z.Y.Zhao Yu and Oidium lini Skoric in existing literatures,respectively.The rDNA-ITS region of the pathogen was PCR-amplified,sequenced and sequence analyzed,the sequence had 99%homology with corresponding sequence of M.multappendicis.Based on the results of the morphological and molecular biological identification of the pathogen,M.multappendicis in ascomycota is considered as the pathogen of powder mildew of Mahonia fortunei on the campus of JXAU, and O.lini in imperfect fungi is anamorph of the pathogen.