曾报道苹果锈果病的病原为类病毒,称为苹果锈果类病毒(Apple Scar SkinViroid,ASSV)。在分类上与已知的几组类病毒均不同,其侵染性也已得到证实。50年代已观察到由梨树园改栽的苹果园,或梨树与苹果混栽的果园中,苹果锈果病发病率较高,但梨树却未见任何症状。其后,曾用十几个品种的梨(包括产于未栽过苹果的梨产 It has been reported that the pathogen of apple rust disease is a type of virus called Apple Scar Skin Virus (ASSV). In classification and known several groups of viruses are different, its infectivity has also been confirmed. In the 1950s, apple orchards replanted by pear orchards, or pear orchards mixed with apples, were found to have a higher prevalence of rust and rust, but no symptoms were observed in pear trees. Since then, more than a dozen varieties of pears have been used (including those produced on unripened apples