Tomato Brown Rugose Fruit Virus (ToBRFV)

ToBRFV in susceptible tomato varieties

The symptoms of ToBRFV can be similar to those of other Tobamoviruses and of PepMV. Symptoms of ToBRFV can range from mild to severe and depend on the time of infection, environmental conditions and varietal susceptibility.

Fruits
Fruit coloration is affected. ToBRFV causes a pale colour, green stripes or yellow spots on fruits which may develop into brown lesions and necrosis. Fruits become rough and stay unripe. A reduced number of fruits are produced. Fruit deformation can occur from early to late stages.

Calyx
Symptoms include distinct discoloration (browning) of the veins of the calyx in an early stage, or drying out and browning of the end of the calyx tips.

Leaves
Leaves of infected tomato plants can show yellowing of the veins, mosaic patterns and other Tobamovirus-like symptoms with occasional leaf narrowing and lumps.

Origin and spread

ToBRFV was first reported in Jordan and Israel in 2014. Since then, the virus has been detected in the US, Mexico, China and several countries in Europe and the Middle East. Since 1 November 2019, ToBRFV has had quarantine status (Q-status) within the EU.For updates on current outbreaks, please visit https://gd.eppo.int/taxon/TOBRFV/reporting. 

Characteristics

ToBRFV belongs to the group of Tobamoviruses and is closely related to the Tobacco mosaic virus (TMV) and Tomato mosaic virus (ToMV). Its primary hosts are tomatoes and peppers. ToBRFV is able to overcome the Tobamo resistances in tomato (Tm2², Tm1). This means that all tomato varieties released before 2022 are susceptible.

Transmission

ToBRFV is transmitted mechanically. This means that any contact with the virus can spread the disease. Handling activities such as transplanting, pruning, tying, cultivation, spraying and harvesting are ways to transmit the virus. Materials such as clothes, shoes, equipment and tools can also carry and spread the virus. Additionally, the transmission can take place via insects, such as bumblebees. Just like other Tobamoviruses, ToBRFV is very stable and very infectious. It can survive in water, on surfaces and in the absence of plant material for a long time without losing its virulence.

Minimising the risk of spread

Switching to High Resistance (HR) tomato varieties is the best way to prevent the consequences of a ToBRFV infection. Resistant tomato varieties provide extra protection, but it remains important to minimise the risk of infection. Therefore, it is still important to adhere to strict hygiene measurements in the case of Rugose Defense varieties. For example, people moving among locations have the potential to spread all sorts of viruses. Avoid unnecessary visits to the crops and ensure that plants are not touched unless absolutely necessary. The sharing of equipment and materials (such as reusable plastic fruit crates) between facilities can also spread the virus.

Clean seeds

Only use tomato seeds from reliable sources that have been tested for ToBRFV:

• Rijk Zwaan always upholds high hygiene standards in all its facilities to prevent the outbreak of diseases.
• Representative samples of all Rijk Zwaan tomato and pepper seed batches are tested for ToBRFV by Naktuinbouw-accredited laboratory tests. This includes all trial seeds. Seeds are only supplied if absence of ToBRFV has been confirmed.