Two generic PCR primer sets for the detection of members of the genus Torradovirus

Abstract

Two degenerate primer pairs were designed for the universal detection of members of the genus Torradovirus. Primer pair Torrado-1F/Torrado-1R was designed based on the RNA-dependent RNA polymerase region located in RNA1 and primer pair Torrado-2F/Torrado-2R based on a region overlapping the two first coat proteins Vp35 and Vp26 in RNA2. The primers were used in two-step and one-step RT-PCR protocols. Both primer pairs were able to detect 14 out of 15 isolates belonging to the two torradovirus species Tomato torrado virus (ToTV) and Tomato marchitez virus (ToMarV) and the two tentative species Tomato chocolate spot virus (ToChSV) and Tomato chocolàte virus (ToChV). Due to poor sample quality, one isolate of ToTV was detected with primer pair Torrado-2F/Torrado-2R and not with primer pair Torrado-1F/Torrado-1R, suggesting that the latter primer pair was less sensitive. Nevertheless, both primer pairs proved to be suitable for the universal RT-PCR detection of torradoviruses and can be deployed for the detection of all currently known torradoviruses and possibly for the detection of new members of this group.