Studies on Tomato yellow leaf curl begomoviruses in Jordan
Several viruses have been reported to cause tomato yellow leaf curl disease, in particular Tomato yellow leaf curl begomovirus (TYLCV – EPPO A2 list*) and Tomato yellow leaf curl Sardinia begomovirus (TYLCSV). In Jordan, the disease was first reported in 1978. Since then, it has spread to all tomato-producing regions where it has become a limiting factor to tomato production in summer and autumn (in some cases, up to 100 % yield losses have been observed). Surveys were conducted in 2002/2003 in 3 tomato-growing regions (Jordan Valley, Al-Mafraq and Amman). Leaf samples (78 samples in 2002 and 259 in 2003) showing symptoms of curling, yellowing and stunting were collected and tested by dot blot hybridization and PCR. Results showed that Tomato yellow leaf curl begomovirus (TYLCV) was widespread in the main tomato-growing regions. The highest rate of TYLCV was recorded in Al-Mafraq (76%), whereas samples collected from the Northern Jordan Valley showed the lowest virus incidence (13%). Tomato yellow leaf curl Sardinia begomovirus (TYLCSV) was also detected but with a lower incidence (6% in Al-Mafraq and 27% in central Jordan Valley). In 2003, both viruses were detected again, sometimes in mixed infections. This is the first report of TYLCSV in Jordan.
The situation of Tomato yellow leaf curl begomovirus in Jordan can be described as follows: Present, widespread in the main tomato-growing regions.
The situation of Tomato yellow leaf curl Sardinia begomovirus in Jordan can be described as follows: Present, first detected in 2002/2003 with a low incidence.
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* At present, only Tomato yellow leaf curl begomovirus is listed as such but with the description of several virus species involved in tomato yellow leaf curl disease, this entry may need to be revised.
Sources
Anfoka GH, Abhary M, Nakhla MK (2005) Molecular identification of species of the Tomato yellow leaf curl virus complex in Jordan. Journal of Plant Pathology 87(1), 65-70.