桑里白粉病菌重寄生真菌的分离与鉴定

Isolation and Identification of Hyperparasitic Fungi in Phyllactinia moricola on Mulberry

为了解桑里白粉病菌的重寄生真菌种类,通过分离和寄生性验证,获得2个桑里白粉病菌重寄生真菌菌株HP8和HP9,这两个菌株寄生闭囊壳后,子囊及子囊孢子溃解。菌株HP8菌落绿色,菌丝体无色至褐色,菌丝有隔膜,分生孢子梗结节状膨大,分生孢子椭圆形、单胞、褐色或无色,ITS序列(MT463536)与尖孢枝孢Cladosporium oxysporum(MF135506)同源性为100%,系统进化树分析发现菌株HP8与尖孢枝孢(MF135506)聚在一起;菌株HP9菌落白色,菌丝无色,分生孢子月牙形、单胞、无色,ITS序列(MT463537)与刀孢蜡蚧菌Lecanicillium psalliotae(KC881072)同源性为99%,在系统进化树中,菌株HP9与刀孢蜡蚧菌(KC881072)聚在一起。结合形态特征和ITS序列分析,鉴定出菌株HP8和HP9分别为尖孢枝孢和刀孢蜡蚧菌。高通量测序结果表明,病桑叶在室内保存4个月后,桑里白粉病菌的重寄生真菌为刀孢蜡蚧菌。

To understand the species of hyperparasitic fungi of Phyllactinia moricola,fungal isolation from P.moricola and hyperparasitism verification were conducted,and two hyperparasitic fungal strains HP8 and HP9 were obtained.In cleistothecia of P.moricola parasitized by strains HP8 or HP9,the asci and ascospores were destroyed.The colonies of strain HP8 were green in color,the mycelia were brown or colorless,with septa,conidiophores with nodular swellings on the septa,conidia oval,unicellular,brown or colorless.ITS sequence(MT463536)had 100%identity to that in Cladosporium oxysporum(MF135506).In phylogenetic tree,ITS sequence of strain HP8 clustered together with C.oxysporum(MF135506).The colonies of HP9 strain were white in color,the mycelia were colorless,conidia crescent,unicellular and colorless.ITS sequence(MT463537)had 99%identity to that in Lecanicillium psalliotae(KC881072).In phylogenetic tree,ITS sequence of strain HP9 clustered together with L.psalliotae(MT463537).Combined with morphological characteristics and ITS sequence analysis results,strains HP8 and HP9 were identified as C.oxysporum and L.psalliotae,respectively.The results of high-throughput sequencing showed that L.psalliotae was the main hyperparasitic fungal species on P.moricola in diseased mulberry leaves.