泽泻斑点病病原菌鉴定及防治药剂初筛

Identification of the pathogen of leaf spot of Alisma orientale(Sam.)Juzepcz.and fungicide screening in laboratory

泽泻[Alisma orientale(Sam.)Juzepcz.]是我国传统中药材之一,在栽培过程中叶部易受斑点病为害而导致产量严重受损。对分离自病叶的真菌进行形态学和分子生物学鉴定,结合柯赫氏法则证实其致病性,明确了泽泻斑点病的病原菌为链格孢(Alternaria alternata),此为国内首次报道链格孢侵染泽泻引起叶部斑点病。同时采用菌丝生长速率法开展了防病药剂的室内筛选,结果表明,在5种供试药剂中,啶酰·肟菌酯和咪鲜胺的抑菌作用明显,对病原菌的EC_(50)分别为0.006 mg/L和0.016 mg/L,可为泽泻斑点病的防治提供用药参考。

Alisma orientale(Sam.)Juzepcz.is one of the traditional Chinese herbs of great medicinal value,of which the leaves are susceptible to spot disease,leading to severe yield loss.Morphological and molecular biological techniques were used to identify the pathogen causing spot disease in Alisma orientalis.The pathogenicity of the isolated fungi was determined according to Koch’s postulates.The results showed that the pathogen was Alternaria alternate.It was the first time that Alternaria alternate was reported to cause Alisma orientalis leaf spot in China.The fungicides were further screened.Among the five fungicides tested,the inhibitory effects of boscalid+trifloxystrobin and prochloraz were significant,with EC_(50) of 0.006 mg/L and 0.016 mg/L,respectively.The results provided a theoretical basis for the prevention and control of A.orientale spot disease.