Abstract
A Tospovirus was isolated by mechanical sap transmission from potato plants showing leaf and stem necrosis symptoms and identified as Tomato yellow fruit ring virus (TYFRV) based on biological, serological and molecular studies. In mechanical transmission trials, a wide range of indicator plants, including members of the Amaranthaceae, Chenopodiaceae, Cucurbitaceae, Fabaceae and Solanaceae, closely similar to that of the not-infecting Nicotiana isolates of the same virus, was infected. The isolates under study strongly reacted with TYFRV antibodies, but not with the specific antibodies of the other tospoviruses tested (Groundnut ringspot virus, Impatiens necrotic spot virus, Iris yellow spot virus, Tomato chlorotic spot virus, Tomato spotted wilt virus and Watermelon silver mottle virus). In reverse transcription-polymerase chain reaction (RT-PCR), using specific primers for TYFRV-N gene, a DNA product with the expected size of approximately 1,200 bp was amplified from infected plants. The sequence analysis of this fragment showed a high identity with the corresponding region of TYFRV and confirmed the presence of this virus in Iranian potato crops. In this study, the transmission of TYFRV through potato tubers, even if at very low extent, was evidenced for the first time.