Incidence of Fruit Trees Viroid Diseases by Tissue Print Hybridization in Egypt

Direct tissue printing on membranes has been applied on a large scale for an initial detection of CEVd, HSVd and PLMVd in fruit trees in Egypt. CEVd was detected mainly in sweet orange trees and occasionally in grapevine and mango. The principal characteristics of the disease on sweet orange trees. It was incidence with 15.4, 4.5 and 1.5%, respectively. HSVd was detected mainly in sweet orange trees and occasionally in apple, apricot, mandarin, grapevine, mango, peach, pear and plum trees with 25.2, 2.2,7.2, 10.5, 12.4, 15.7,65.6, 40.5 and 5.7%, respectively. The principal characteristics of the disease on sweet orange trees. PLMVd was detected mainly in peach and occasionally in apple, apricot, grapevine, mango, pear and plum with 45.0, 5.4, 2.5, 0.5, 13.5, 23.4 and 3.5% incidence. The principal characteristics of the disease on peach trees. The three viroids; CEVd, HSVd and PLMVd were detected frequently in sweet orange and peach occasionally in grapevine, pear, mango, plum and apricot in Egypt.