Tomato brown rugose fruit virus (ToBRFV) is an emerging pathogen affecting tomato-production systems in several countries, including Mexico. This situation involves challenges due to the negative ...impact on yield and the lack of disease-management measures. This work analyzes the spatiotemporal distribution of ToBRFV in commercial tomato greenhouses. The presence or absence of diseased plants was evaluated weekly, assigning a location in space (x, y). Temporal analysis consisted of fitting the incidence to the monomolecular, logistic, log-logistic, Gompertz, exponential, Weibull, and Richard models, evaluated using the Akaike information criterion, significance, correlation, coefficient of determination, and root mean square error. Spatial analysis consisted of determining spatial aggregation using the Moran, Fisher, and Lloyd indices. In addition, spatial distribution was assessed by sequence observations, point patterns using the inverse distance index, and analysis by SADIE distance indicators. Results indicated that the logistic models (log-logistic and logistic) best described the temporal progress of ToBRFV. This disease also had slightly aggregated patterns in the initial phase, highly aggregated in the exponential phase, and uniform in the deceleration and stationary phases. This study demonstrates that the spatial and temporal dynamics of ToBRFV have important implications for the monitoring, diagnosis, management, and risk prediction of this disease.
Tomato is one of the most important crops worldwide, with a production of ≈190 million tons, but it is constantly threatened by several viral diseases. Tomato brown rugose fruit virus (ToBRFV), ...identified in 2014 on tomato plants and subsequently reported in many countries, represents one of the major threats to tomato crops, due to production losses, different transmission modes and its rapid spread. This work aimed to evaluate 37 local Sicilian tomato ecotypes against ToBRFV infection. After a preliminary screening by molecular analyses for tomato mosaic virus (ToMV) and pepino mosaic virus (PepMV), and ToBRFV detection, tomato plants were grown in a greenhouse for their morphological characterization and for evaluating resistance and tolerance to ToBRFV. Resistance and tolerance levels were estimated by mechanical inoculation with ToB SIC01/19 ToBRFV isolate in ten plants per ecotype and evaluating virus accumulation by RT-qPCR and visual observation of symptoms. All ecotypes were infected with ToBRFV, showing several symptoms with different disease severity. No tomato ecotype showed a high level of resistance, but two ecotypes, Pop27 and Pop35, showed very moderate symptoms and therefore a high tolerance. These Sicilian tomato ecotypes could be used in genetic breeding programs as parental ones to obtain cultivars tolerant to ToBRFV.
The 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 production due to its ...ability to break the resistant genes (
,
,
) in tomatoes. The objective of this work was to identify new resistant source(s) of tomato germplasm against ToBRFV. To achieve this aim, a total of 476 accessions from 12
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 resistant/tolerant, including thirty-one accessions of
, one accession of
, four accessions of
, three accessions of
and five accessions of
subsection
hybrid. Further analyses using serological tests identified four highly resistant
lines, PI 390713, PI 390714, PI 390716, and PI 390717. The inheritance of resistance in the selected lines was verified in the next generation and confirmed using RT-qPCR. To our knowledge, this is a first report of high resistance to ToBRFV in
. These new genetic resources will expand the genetic pool available for breeders to develop new resistant cultivars of tomato against ToBRFV.
The tomato brown rugose fruit virus (ToBRFV), a formidable tobamovirus, poses a significant threat to tomato production globally. This comprehensive study is dedicated to establishing an integrated ...control strategy for ToBRFV, encompassing the entire tomato cultivation process from seed to harvest. Initial investigations revealed a 0.8% seed transmission rate of ToBRFV, with viral presence detected in endosperms but not in seed embryos. Employing a multifaceted approach, infected seeds underwent a meticulous disinfection process. Gradual heating in a rotating thermal machine from 20 °C to 72 °C for 3 days resulted in a remarkable 0.3% contamination rate, rendering the virus non-infectious. Furthermore, ToBRFV-infected seeds underwent UV light treatment at 254 nm for 30 min, resulting in a 50% reduction in contamination rates. Chemical disinfectants, including 1% Tsunami 100 (comprising 30–60% acetic acid, 15.2% peroxyacetic acid, and 11.2% hydrogen peroxide) and 1% Biocon A (a combination of potassium peroxymonosulfate with buffer and organic acid), exhibited notable success. This study not only unravels the intricate dynamics of ToBRFV transmission and inactivation but also underscores the efficacy of integrated control measures. The findings provide valuable insights for the sustainable management of ToBRFV, contributing to the resilience of global tomato cultivation against this viral menace.
Symbiotic interaction between plants and microorganisms in the rhizosphere is an important factor affecting plant growth and fitness. Arbuscular mycorrhiza fungi symbiosis increases resistance of the ...plants to stress factors, including pathogens. Tomato brown rugose fruit virus (ToBRFV) is an important destructive virus damaging tomatoes and peppers with losses that can reach 100%. It is listed on the list of current quarantine organisms in the Czech Republic. The aim of this study was to evaluate influence of root colonization with Funneliformis mosseae or/and Azospirillum brasilense on ToBRFV symptoms and viral titre reduction. Plants treated with arbuscular mycorhizal fungi (AMF) had lower symptom emergence after 14 dpi, however there was no difference in symptoms emergence after 21 dpi within all treatments. The highest colonization intensity by Funneliformis mosseae was detected in ToBRFV negative plants treated with both AMF and Azospirillum (AZO) and the lowest in ToBRFV positive plants with the same treatment (AMF + AZO). Colonization intensity of Azospirillum brasilense in all treated variants went from 20% to 41%. Results suggest that the combination of those two beneficial microorganisms in ToBRFV-infected plants negatively affected AMF colonization.
Tomato brown rugose fruit virus (ToBRFV) is a recently emerged serious viral threat to tomato production. The virus is named after its symptoms consisting of characteristic brown wrinkled (rugose) ...patches on the fruits of infected tomato plants. ToBRFV is a member of the genus Tobamovirus and a very stable mechanically transmitted virus. So far, most tomato cultivars are susceptible, enabling a swift spread of ToBRFV. In this review, we present strategies to halt devastating disease outbreaks of ToBRFV based on the collective research data of various tobamovirus–plant interactions. Viruses, like ToBRFV, are biotrophic pathogens with small genomes. Hence viral proliferation depends on various host factors, also termed susceptibility (S) genes. However, S genes often have an intrinsic function for the host plant. Thus, mutations in S genes may lead to pleiotropic phenotypes. Therefore, identifying mutant variants of S genes with no pleiotropic effects is essential for exploring impaired S genes in breeding tomatoes resistant to ToBRFV.
Tomato brown rugose fruit virus (ToBRFV), a newly identified Tobamovirus, has recently emerged as a significant pathogen of tomato plants (Solanum lycopersicum). The virus can evade or overcome the ...known tobamovirus resistance in tomatoes, i.e., Tm-1, Tm-2, and its allele Tm-22. ToBRFV was identified for the first time only a few years ago, and its interactions with the tomato host are still not clear. We investigated ToBRFV’s presence in the reproductive tissues of tomato using fluorescent in situ hybridization (FISH) and RT-PCR. In infected plants, the virus was detected in the leaves, petals, ovary, stamen, style, stigma, and pollen grains but not inside the ovules. Fruits and seeds harvested from infected plants were contaminated with the virus. To test whether the virus is pollen transmitted, clean mother plants were hand pollinated with pollen from ToBRFV-infected plants and grown to fruit. None of the fruits and seeds harvested from the pollinated clean mother plants contained ToBRFV. Pollen germination assays revealed the germination arrest of ToBRFV-infected pollen. We concluded that ToBRFV might infect reproductive organs and pollen grains of tomato but that it is not pollen transmitted.
species represent a threat to solanaceous crops worldwide, due to their extreme stability and because they are 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 gained 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 the tomato brown rugose fruit virus target on the CP-3'NTR region, which was previously validated as a single assay. The performance of this test was evaluated, displaying analytical sensitivity 10
-10
-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.
In 2020, a test performance study (TPS) for the specific detection of tomato brown rugose fruit virus (ToBRFV) was organized in the frame of the H2020 Valitest project. Since no validated tests were ...available, all the protocols reported in the literature were at first screened, performing preliminary studies in accordance with the EPPO standard PM 7/98 (4). Five molecular tests, two conventional RT-PCR and three real-time RT-PCR were found to be suitable and were included in the TPS. Thirty-four laboratories from 18 countries worldwide took part in TPS, receiving a panel of 22 blind samples. The panel consisted of sap belonging to symptomatic or asymptomatic leaves of
and
. The results returned by each laboratory were analyzed and diagnostic parameters were assessed for each test: reproducibility, repeatability, analytical sensitivity, diagnostic sensitivity and diagnostic specificity. All the evaluated tests resulted in being reliable in detecting ToBRFV and were included in an EPPO Standard PM 7/146-Diagnostics.
During the growing season of 2021-2022, a total of 145 symptomatic tomato leaf and fruit samples were collected from different locations in Riyadh Region, Saudi Arabia, showing a moderate-to-severe ...mosaic with dark green wrinkling, blistering, narrowing, and deformation with necrosis spot on tomato leaves, while irregular brown necrotic lesions, deformation, and yellowing spots rendering the fruits non-marketable were observed on tomato fruits. These samples were tested serologically against important tomato viruses using enzyme-linked immunosorbent assay (ELISA), and the obtained results showed that 52.4% of symptomatic tomato samples were found positive for Tomato brown rugose fruit virus (ToBRFV), wherein 12 out of 76 samples were singly infected; however, 64 out of 145 had mixed infection. A sample with a single infection of ToBRFV was used for mechanical inoculation into a range of different host plants; symptoms were observed weekly, and the presence of the ToBRFV was confirmed by ELISA and reverse transcription-polymerase chain reaction (RT-PCR). A total RNA was extracted from selected ELISA-positive samples, and RT-PCR was carried out using specific primers F-3666 and R-4718, which amplified a fragment of 1052 bp. RT-PCR products were sequenced in both directions, and partial genome nucleotide sequences were submitted to GenBank under the following accession numbers: MZ130501, MZ130502, and MZ130503. BLAST analysis of Saudi isolates of ToBRFV showed that the sequence shared nucleotide identities (99-99.5%) among them and 99-100% identity with ToBRFV isolates in different countries. A ToBRFV isolate (MZ130503) was selected for mechanical inoculation and to evaluate symptom severity responses of 13 commonly grown tomato cultivars in Saudi Arabia. All of the tomato cultivars showed a wide range of symptoms. The disease severity index of the tested cultivars ranged between 52% and 96%. The importance ToBRFV disease severity and its expanding host range due to its resistance breaking ability was discussed.
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