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Apple scar skin viroid (ASSVd) is the type species of genus Apsacaviroid in family Pospiviroidae The ASSVd infections can induce severe apple fruit cracking, scarring and distortion or color dappling, depending on the cultivar.In pear, its infections are usually symptomless except for rusty skin and Japanese pear fruit dimple.Previously, pear plants carrying ASSVd was suggested as a pathogen source for apple scar skin or dappling occurred widely in China.