Causal Agent and Some Important Characters of Tomato Leaf Curl Disease

Abstract

Symptoms of tomato leaf curl disease in Thailand resemble those of tomato leaf curl and tomato yellow leaf curl in the other countries. The cause of which is still uncertain. No low molecular weight nucleic acid was detected from infected tomato Tbe extracted nucleic acid did not infect either tomato or Gynura sp. through mechanical inoculation. Infected tomato did not response to tetracycline treatment. Ultrastructural study of phloem tissue of infected plant revealed virus-like spherical particle of 17-20 nm in diameter aggregated in cluster. Same type of particle was found both singly and in pairs in the partially purified virus suspension. It is thus concluded that the causal agent is a virus in the geminivirus group. The virus could be transmitted through tissue implantation and Bemisia tabaci Genn. Its host range included Datuva stramonium L. and Nicotiana glutinosa L. Tomato "Sida" and "Morglobe" varieties were infected at the rate of 65-70%. No resistant variety was found.