New strains of potato spindle tuber viroid and tomato Australian leaf curl bigeminivirus from a wild Solanum sp. in Australia
Leaf curl is a severe disease of tomato in the Northern part of Australia. It can induce leaf curl, yellowing, upward leaf rolling and cessation of fruit production. This disease has appeared each year since 1970, causing complete crop failure in some early plantings in the coastal area. In Northern Territory, studies were carried out to identify wild plants which could act as natural reservoirs of the Australian tomato leaf curl bigeminivirus (TLCV-Au). Many wild plants were tested for the presence of the virus. As a result, three distinct virus-like agents were isolated from a wild, symptomless Solanum sp. Two of them were identified as geminiviruses which are related but distinct from TLCV-Au. These viruses were not mechanically transmissible. A third agent, mechanically transmissible, was also found, and it caused stunting, shoot elongation and hairlessness on tomato plants. A circular RNA was isolated from these tomato plants and analysis revealed that the RNA sequence was a variant of potato spindle tuber viroid (EPPO A2 quarantine pest). Potato spindle tuber viroid had been found in Australia in 1982 on potato breeding material, it was successfully eradicated in 1987 and is now considered of plant quarantine importance for Australia. The authors pointed out that there is no evidence of field infection by potato spindle tuber viroid.
Behjatnia, S.A.A.; Dry, I.B.; Krake, L.R.; Condé, B.D.; Connelly, M.I.; Randles, J.W.; Rezaian, M.A. (1996) New potato spindle tuber viroid and tomato leaf curl geminivirus strains from a wild Solanum sp.
Phytopathology, 86(8), 880-886.