金银花黑斑病病原菌番茄匍柄霉的分离与鉴定

Isolation and Identification of Pathogenic Fungus Stemphylium lycopersici Causing the Black Spot Disease on Honeysuckle(Lonicera japonica Thunb.)

[目的]分离并鉴定引起金银花黑斑病的病原菌,为该病害的有效防控提供理论依据。[方法]采用常规组织分离法对发病金银花叶片进行分离,结合形态学、多基因序列分析(ITS、gpd和EF-1α序列)和致病性测定进行病原物种鉴定。[结果]在形态学上,分离获得的菌株YP4在PDA培养基上的菌落呈灰白或黄白色棉毛状,与番茄匍柄霉的菌落特征相符;在基于ITS、gpd和EF-1α序列联合构建的3种系统发育树中,供试菌株YP4均以较高支持率与番茄匍柄霉(Stemphylium lycopersici)聚在同一分支上;致病性接种实验结果表明,菌株YP4接种至金银花叶片上和番茄叶片上均可产生病斑,并可再分离获得其纯菌株;因此,结合形态学、分子系统发育学以及致病性测定,该病原真菌被鉴定为番茄匍柄霉。[结论]本研究明确了引起河北省金银花黑斑病的病原菌为番茄匍柄霉,这是该病菌在我国危害金银花的首次报道。

[Objective]To clarify the pathogen causing black spot disease on Lonicera japonica,and to provide a theoretical basis for effective prevention and control of this disease.[Method]The strains of the pathogen were isolated by conventional tissue plate method,and were identified by the morphological characters and phylogenetic analysis of ITS,gpd and EF-1αsequences.Its pathogenicity was tested through in vitro inoculating healthy leaves of L.japonica and Solanum lycopersicum.[Result]The isolated fungal strain YP4 morphologically formed greyish to yellowish white,cottony colonies on Potato Dextrose Agar,which were consistent with published descriptions of Stemphylium lycopersici.In the three phylogen-etic trees based on ITS,gpd and EF-1αsequences,the isolate YP4 fell into the S.lycopersici clade with strong support.Based on the pathogenicity measurement of Koch's rule,the strain YP4 was pathogenic to leaves of L.japonica and S.lycopersicum.[Conclusion]Combined with the morphological characteristics,the pathogenicity determination and phylogenetic analysis of ITS,gpd and EF-1αsequences,the patho-gen causing black spot disease on honeysuckle is identified as S.lycopersici.To our knowledge,this is the first report of S.lycopersici causing black spot of L.japonica in China.