Tomato is one of the most important vegetable crops grown worldwide. Tomato brown rugose fruit virus (ToBRFV), a seed-borne tobamovirus, poses a serious threat to tomato productions due to its ability to break the resistant genes (Tm-1, Tm-2, Tm-22) in tomato. The objective of this work was to identify new resistance source(s) of tomato germplasm against ToBRFV. To achieve this aim, a total of 476 accessions from 12 Solanum species were tested with the ToBRFV US isolate for their resistance and susceptibility. As a result, a total of 44 asymptomatic accessions were identified as resistance/tolerance, including 31 accessions of S. pimpinellifolium, one accession of S. corneliomulleri, four accessions of S. habrochaites, three accessions of S. peruvianum and five accessions of S. subsection lycopersicon hybrid. Further analysis using serological tests identified four highly resistant S. pimpinellifolium lines, PI 390713, PI 390714, PI 390716 and PI 390717. The inheritance of resistance in the selected lines was verified in next generation and confirmed by RT-qPCR. To our knowledge, this is a first report of high resistance to ToBRFV in S. pimpinellifolium. These new genetic resources will expand the genetic pool available for breeders to develop new resistant cultivars of tomato against ToBRFV.

Tobamovirus species represent a threat to solanaceous crops worldwide, due to their extreme stability and being seed-borne. In particular, recent outbreaks of tomato brown rugose fruit virus in tomato and pepper crops led to the establishment of prompt control measures, and the need for reliable diagnosis was urged. Another member of the genus, tomato mottle mosaic virus, has recently risen attention due to reports in different continents and its common features with tomato brown rugose fruit virus. In this study, a new real-time RT-PCR detection system was developed for tomato brown rugose fruit virus and tomato mottle mosaic virus on tomato leaves and seeds using TaqMan chemistry. This test was designed to detect tomato mottle mosaic virus by amplifying the movement protein gene in a duplex assay with tomato brown rugose fruit virus target on the CP-3’NTR region, which was already validated as a single assay. The performance of this tests was evaluated, displaying analytical sensitivity 10-5-10-6-fold dilution for seeds and leaves, respectively, and good analytical specificity, repeatability, and reproducibility. Using the newly developed and validated test, tomato brown rugose fruit virus detection was 100% concordant with previously performed analyses on 106 official samples collected in 2021 from different continents.