金边露兜叶斑病病原菌鉴定及生物学特性研究

Identification and biological characteristics of pathogenic fungus of leaf spot disease of Pandanus pygmaeus

为明确广东省金边露兜(Pandanus pygmaeus)叶斑病病原菌及其生物学特性,采用组织分离法从罹病叶片获得菌株t1.通过致病性测定、菌株形态观察和分子生物学测定,对其进行了种类鉴定和生物学特性研究.结果表明,引起金边露兜叶斑病的致病菌为暹罗炭疽菌(Colletotrichum siamense).病原菌株t1生长最佳条件为:温度28℃,pH 7,可利用各种碳源和氮源;产孢的最适条件为:温度28℃,pH 10,连续光照,碳源和氮源分别为纤维素和蛋白胨.黑暗条件下24 h有利于菌丝生长,连续光照24 h时产孢量最大.病原菌菌丝致死温度为55℃、10 min.这是国内首次报道暹罗炭疽菌引起的金边露兜叶斑病的研究,这将有助于了解该病害生物学特性,为其防治提供参考.

To identify the potential pathogen and test its biological characteristics of Pandanus pygmaeus,the pathogen strain t1 was isolated and purified from the infected leaves of P.pygmaeus by tissue isolation method.The species specification and biological characterization were determined by pathogenicity assay,morphological observation and molecular biology assay of the strain.The results showed that the pathogen causing P.pygmaeus leaf spot was Colletotrichum siamense.The optimal conditions for the growth of pathogenic strain t1 were 28℃,pH 7,and various carbon and nitrogen sources were available;the optimal conditions for sporulation of C.siamense production were 28℃,pH 10,continuous light,and the carbon and nitrogen sources were cellulose and peptone,respectively.Mycelial growth was favored under dark conditions for 24 h,while the maximum sporulation was achieved under continuous light for 24 h.The pathogenic mycelium was killed at 55℃and 10 min.This is the first study on P.pygmaeus leaf spot disease caused by C.siamense in China,which will help to understand the biological characteristics of the disease and provide reference for its control.