Circulifer haematoceps, THE VECTOR OF THE BEET CURLY TOP IRAN VIRUS

Beet curly top is a disease of sugar beet which has been in the center of attention due to its unpredictable epidemics and its economic importance. It has been shown that due to short life cycle and high populations of the leafhopper vector, the disease often spreads very rapidly in a region. At least five virus species of the genus Curtovirus (Geminiviridae) are recognized as the cause of beet curly top disease. Two of these species, namely, Beet severe curly top virus (BSCTV) and Beet curly top Iran virus (BCTIV) have been reported from Iran. Two leafhopper species, Circulifer haematoceps and C. tenellus, have been reported as the vector of Beet curly top virus before recognition of different species (Fattahi et al., 2010). Therefore, it was not certain whether one or both viruses are transmitted by the leafhoppers. Recently, it was shown that C. haematoceps could transmit BSCTV from sugar beet plants infected via an infectious clone of the virus. In the present study, the possibility of transmission of BCTIV by C. haematoceps was examined. Leafhoppers were collected in sugar beet fields of northern Fars province using D-Vac. The dominant species was C. haematoceps. The leafhoppers were allowed to breed on healthy sugar beet in the greenhouse. The newly born nymphs were placed on sugar beet plants previously agroinoculated with an infectious clone of BCTIV (Zarghan isolate) for an acquisition access period of four days, and then transferred to healthy seedlings at 2-leaf stage (5 leafhoppers / 3 seedlings). Typical symptoms of curly top appeared on all inoculated seedlings after two weeks. Presence of BCTIV in symptomatic test plants was verified by PCR using specific BCTIV primers. The experiment was repeated two more times with similar results. It is concluded that like BSCTV, BCTIV is transmitted by C. haematoceps ‌under greenhouse condition.