Cotton leaf curl Rajasthan virus infecting tomato in Pakistan

Tomato plants showing phenotypically symptoms of tomato leaf curl disease (ToLCD) were collected in Faisalabad, Pakistan. These exhibited a severe downward leaf curling with enation on the lower side of the leaf. In order to identify the begomovirus components associated with the disease phenotypes, DNA extracted from them was screened by PCR using specific primers for ToLCNDV DNA A and DNA B and a universal beta satellite primer pair (designed to detect all beta satellite). Tomato sample was found positive for ToLCNDV DNAA and beta satellite. The fragments amplified were cloned and sequenced. The begomovirus sequence obtained showed the highest levels of sequence identity (99%) to cotton leaf curl Rajasthan virus (CLCuRV), a virus previously identified in cotton showing symptoms of cotton leaf curl disease (CLCuD). The sequence of beta satellite showed 99% identity to the beta satellite associated with CLCuD. This is the first time CLCuRV has been identified in tomato and indicates that this host can serve as a reservoir for the agent causing CLCuD. Partial repeat constructs for Agrobacterium-mediated inoculation have been produced to show infectivity of these clones (to fulfill Koch's postulates), for studying their host range and potential threat to crops.