IDENTIFICATION OF WHITEFLY-TRANSMITTED TOMATO YELLOW LEAF CURL GEMINIVIRUS FROM IRAN AND A SURVEY OF ITS DISTRIBUTION WITH MOLECULAR PROBES

A virus causing a disease of tomato, prevalent in the southern provinc es of Iran, with symptoms of leaf-curling, stunting, reduction of leaf size, leaf corrugation, shortening of internodes and severe reduction in fruit yield, was shown to bz transmissible to healthy tomato plant s by grafting and by whiteflies (Bemisia tabaci), but not by sap inocu lation. Geminivirus DNA was detected in extracts of diseased tomato pl ants by dot-blot hybridization assays using as probes full-length clon ed DNA of Australian, Italian (Sardinian) or Jordanian strains of toma to yellow leaf curl virus (TYLCV). Geminivirus coat protein was detect ed in whitefly inoculated plants by clot immunobinding assay using pol yclonal antibody raised against Jordanian TYLCV, A limited survey usin g the dot-blot hybridization assay for virus detection indicated the p resence of the virus: in tomato-growing provinces of southern but not northern Iran. Whitefly transmission experiments to tomato under contr olled greenhouse conditions showed that some isolates of TYLCV-like ge miniviruses from different parts of Iran differ in symptomatology.