Mechanically Transmitted Virus Disease of Citrus New To India

Some trees of sweet orange and Kagzi lime at Kodur and Shrirampur, Lisbon lemon at Indian Agricultural Research Institute, New Delhi, and lemon and Lisbon lemon trees at Chethali, Karnataka, showing yellow vein flecking symptoms in leaves were indexed for the infectious variegation virus, a strain of psorosis virus, by grafting, mechanical sap inoculation, and by aphids into seedlings of sweet orange, Lisbon lemon, lemon, and Kagzi lime. The disease was readily transmitted by grafting as well as by mechanical sap inoculation to sweet organge cv. Mosambi and Pineapple, but was not transmitted by aphids. All the three strains were purified and isolated free from all other viruses by inoculating them from the parent source trees by mechanical sap inoculation into sweet orange seedlings. This is the first record from India of mechanical sap transmission of the psorosis virus strain to citrus seedlings.