occurrence of tomato brown rugose fruit virus in lorestan province tomato greenhouses: a first report

Tomato brown rugose fruit virus (tobrfv) is a recently identified, highly contagious, and destructive tobamovirus that primarily infects tomatoes. to investigate the presence of this virus, forty leaf samples were collected from plants exhibiting viral symptoms such as mosaic, leaf malformation, and blistering from the tomato greenhouses in lorestan province in 2024. mechanical inoculation on nicotiana benthamiana and solanum lycopersicum was done, and symptoms appeared as a systemic mosaic on n. benthamiana seven days post-inoculation (dpi), while tomato plants exhibited mosaic, blistering, severe deformation, and shoestring-like symptoms, particularly in apical leaves, by 10dpi. then, an rt-pcr assay was operated on the samples, and a 623-base pair fragment was successfully amplified utilizing tobrfv-specific primers corresponding to the coat protein gene region. sequence blast analysis confirmed that the lorestan isolates exhibited a nucleotide sequence identity ranging from 99.32% to 99.83%, as did other isolates in genbank. the phylogenetic tree generated using mega11 software indicated that tobrfv isolates clustered into two distinct groups, with the isolates from lorestan province classified as group ii. within group ii, two lorestan isolates clustered alongside three other iranian isolates. the length of the branches in this group suggests that mutations are present in these isolates compared to group i. isolates from other countries were classified into a distinct subgroup within the group i. the two-by-two comparison of nucleotide sequences using sdt v1.2 software demonstrated the lorestan isolates exhibited the highest genetic similarity to the iranian isolates zar-k-20 and zar-kp, with identities ranging from 99.30% to 99.50%. in contrast, the lorestan isolates demonstrated the greatest genetic distance from the peru isolate, which had an identity of 98.80%. this report represents the first documented tobrfv detection instance in lorestan province tomato greenhouses.