30余种植物病原真菌体内的病毒或类病毒粒子已有报道。有的还进行了病毒对真菌致病力影响的研究。一些真菌衰退病有人报道过,但几乎没有报道植物病原真菌表现出退化型症状。Castanho和Butler认为,在立枯丝核菌常规移植过程中,从健壮分离体中获得的严重罹病分离体表现出一种衰退现象。这种衰退常与三个大小不同的双链RNA(ds RNA)之一些片断有关;在一 More than 30 kinds of plant pathogenic fungi in vivo virus or viroid particles have been reported. Some also carried out the virus on the fungal pathogenicity of the study. Some fungal recessions have been reported, but few phytopathogenic fungi have been reported to exhibit degenerative symptoms. Castanho and Butler argue that the severely diseased isolates from robust isolates showed a regression during routine Rhizoctonia solani grafting. This decline often associated with three different sizes of double-stranded RNA (dsRNA) some of the pieces; in a