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ToBRFV was discovered in 2014 and has been damaging the tomato sector ever since. The consequences of Tomato Brown Rugose Fruit Virus have been significant for many growers. The highly contagious virus can cause a lot of damage to the cultivation. But where does ToBRFV come from? How did it spread across the world and is there light at the end of the tunnel?
A new tomato virus was discovered in Israel in 2014. This new virus broke the ToMV/TMV resistance mediated by the Tm-22 gene. This new virus was first described in a paper by Salem et al. in Nov. 2015 and named Tomato Brown Rugose Fruit Virus (ToBRFV)
Soon after its discovery, this new virus became a global concern. The mechanically transmitted virus spread rapidly from grower to grower, country to country, and continent to continent. Nowadays, the virus pressure is especially high in the unheated and heated greenhouse markets. Regions with high virus pressure includes North America, the Middle East and West Europe.
Symptoms are only visible after three weeks, making it difficult to keep up with the virus. Signalling and locating is only possible when the first symptoms are visible - yellow spots, wrinkled patches and brown scars that render the tomato fruits unsellable. It is an uphill battle to contain a localised spread once it begins. Enza Zaden heard about this new virus through contacts in the Middle East. Rapidly the connection was made to other tobamoviruses, such as Tomato Mosaic Virus (ToMV) and Tobacco Mosaic Virus (TMV). Being a mechanically transmitted virus, the Enza Zaden teams already feared at the time that it would spread all over the world.
In 2018, ToBRFV was spotted for the first time in Europe and America, followed by Asia.
Tomato brown rugose fruit virus is not currently listed as Union quarantine pest under Regulation (EU) 2019/2072 , however, the pest is regulated by emergency measures in Commission Implementing Regulation (EU) 2020/1191 . These emergency measures state that ToBRFV should not be introduced into or moved within the EU territory. (source:www.storymaps.arcgis.com)
The tomato industry had a solution against Tomato Mosaic Virus (ToMV) and Tobacco Mosaic Virus (TMV) — a resistance gene called Tm-22 that has been used for more than 50 years to stop these two viruses.
However, Tomato Brown Rugose Fruit Virus broke this resistance gene. The search for a new source of resistance began. Enza Zaden screened around a thousand accessions in their gene bank. A gene bank is a large collection of wild tomato seeds that can naturally be crossed with cultivated tomato. Herein lay the answer: we identified a new gene that gives high resistance (HR) to ToBRFV.
Newly developed tomato varieties with High Resistance have been extensively tested in North America and West Europe. The plants and tomatoes do not show ToBRFV symptoms under normal virus pressure. The solution to fight against ToBRFV lies in a multi-layered approach that combines (high) resistance and sanitary measures.
In the past 2 years, thanks to a close collaboration across the globe with tomato growers and other professionals, the tomato industry knows better how to deal with ToBRFV. Experience shows that sanitary measures play a key role in maintaining the virus pressure down.
Enza Zaden has a long history in breeding tomatoes. “We have a very wide range of tomato varieties, from large beef tomatoes to tasty vine tomatoes (truss tomatoes) and from baby plum tomatoes to pink tomatoes. This basis of high performing varieties combined with the newly discovered gene will enable us to deliver high performing varieties with High Resistance to ToBRFV” explains Kees Konst – Tomato Crop Research Director at Enza Zaden.
HREZ is a growing collection of Highly Resistant varieties. The first HREZ varieties are now commercially available – our ambition is to incorporate ToBRFV-HR into the entire Enza Zaden tomato portfolio.
You can read more about HREZ against ToBRFV here.
Data information and illustration provided by Enza Zaden on this webpage are provided to assist professional growers and users and, are based on Enza Zaden’s assessment of its test results and practical experience however without any guarantee, representation or warranty regarding accuracy thereof or purpose and/or performance of the HREZ variety in practice. Environmental conditions must be taken into account. Under no circumstances shall Enza Zaden be liable to the professional grower or user for results deviating from that information.