进境西葫芦种子蔓枯病菌的分离与鉴定  

Isolation and identification of Didymella bryoniae of imported zucchini seed

作　　者：文朝慧 尤佳 王溪桥 何苏琴[2] WEN Zhaohui;YOU Jia;WANG Xiqiao;HE Suqin(Gansu Exit-Entry Inspection and Quarantine Bureau,Lanzhou 730010,Gansu,China;Institute of Plant Protection,Gansu Academy of Agricultural Sciences,Lanzhou 730070,Gansu,China)

机构地区：[1]甘肃出入境检验检疫局,兰州730010 [2]甘肃省农业科学院植物保护研究所,兰州730070

出　　处：《中国瓜菜》2018年第12期15-18,共4页China Cucurbits And Vegetables

基　　金：甘肃省自然科学基金项目(1506RJZA183);甘肃出入境检验检疫局科技计划项目(2015GK001)

摘　　要：为了检测进境植物种子中携带的病原真菌,对一批籽粒颜色不正常的意大利西葫芦(Cucurbita pepo L.)种子进行了病原菌分离、致病性测定、PCR检测及rDNA ITS序列分析。结果表明,在种子样品中分离到1株疑似蔓枯病菌Phoma cucurbitacearum的分离物ZuSc-1,分离物ZuSc-1在PDA培养基上菌落圆形,背面初期白色,后期变为灰黑色,菌落表面略隆起,不形成子囊座和分生孢子器。该分离物人工接种西葫芦胚根产生蔓枯病的典型症状。特异性引物DB17F/DB17R扩增分离物ZuSc-1的DNA得到预期556 bp的产物,分离物rDNA ITS序列与蔓枯病菌(序列号EU167573、GU045304和AY293804)的序列相似性为100%。根据分离菌株形态学特征、致病性测定、PCR检测及rDNA ITS序列分析,将该菌株鉴定为瓜类黑腐球壳菌Didymella bryoniae (Auersw.) Rehm,其无性型为Phoma cucurbitacearum(Fr.:Fr.)Sacc.。In order to detect seed-borne fungal pathogens in imported seeds, PCR and agar plate methods were used to detect discoloured zucchini seeds imported from Italy. One isolate ZuSc- 1 was intercepted from the seeds through the PDA plate method. This isolate showed similar morphological characteristics with Phoma cucurbitacearum, the colony was round, the back was white at the early stage, and turned gray and black at the later stage, the surface of the colony was slightly swell, without the formation of ascomycetes and conidia. Pathogenicity was confirmed on zucchini radicles by artificial inoculation with typical symptoms of gummy stem blight. The result of PCR detection showed that the isolate ZuSc-1 could be amplified by P cucurbitacearum-specific primer DB17F/DB17R with a product of 556 bp. The sequence analysis revealed that ITS sequence of the isolate ZuSc- 1 shared 100% sequence identity with P cucurbitacearum （GenBank Accession No. EU167573, GU045304, and AY293804）. The isolate ZuSc-1 was identified as Didymella bryoniae （anamorph： Phoma cucurbitacearum） based on its morphological characteristics, rDNA ITS sequence analysis and the results of pathogenicity test.

关 键 词：西葫芦种子 瓜类蔓枯病 瓜类黑腐球壳菌 

分 类 号：S436.429[农业科学—农业昆虫与害虫防治]