Other Apscaviroids Infecting Pome Fruit Trees

Apple dimple fruit viroid, first reported in Italy, was later identified in Lebanon, China, and Japan, always in apple trees affected by dimple fruit disease. It has been found recently in fig in Italy, but not associated with a specific symptom. Apple fruit crinkle viroid was first reported in apples showing fruit crinkle disease in Japan. Other isolates were reported in hops with symptoms of stunting and leaf curling, and in asymptomatic Japanese persimmons, both cultivated in Japan. Pear blister canker viroid naturally infects pear and quince. It has been reported worldwide, particularly in the Mediterranean basin, although the economic impact is limited because most pear cultivars are tolerant. Apscaviroids infecting pome fruit trees can be detected readily by molecular hybridization and RT-PCR, and controlled by using viroid-free propagation material.