From a local discovery to global disruption
It started as a small infection in Israel back in 2014 and it quickly spread around the country and its neighbours (Jordan, Syria, Saudi Arabia…). The infection was described by a Jordanian team as a new virus in 2015 and it was given the name of Tomato Brown Rugose Fruit Virus (ToBRFV). This virus belongs to the Tobamovirus family, which includes well-known viruses such as the Tobacco Mosaic Virus (TMV) and the Tomato Mosaic Virus (ToMV). Both viruses have been fought over a 50-year period with varieties with resistances coming from the gene Tm-22. . With the appearance of the ToBRFV, they realised that the resistance given by the Tm-22 had been broken and, therefore, the ToBRFV became a great threat for tomato producers due to its high transmission, causing it to spread all over the planet.
Today, the ToBRFV is a true challenge for tomato crops all over the world as its effects have an impact on the crop’s yield and on the quality of the fruit, or they mean a decrease in production, but to a large extent, it also has an impact on post-harvest quality, which is much more difficult to detect with the naked eye and, therefore, to guarantee of the supply. Over the past eight years, the tomato industry has changed, as it has affected over 35 countries, leading to the search for solutions such as new plant protection protocols, additional work force, an increase in crop rotations… However, these steps are not enough to mitigate the impact of ToBRFV. A gene needed to be found that would provide resistance to the virus.
Together, we can stop the spread
Since the virus appeared, Enza Zaden started its research work to find a gene that would provide resistance to ToBRFV and, consequently, be able to develop varieties with this resistance. Once the gen was found, the company’s improvement team started the introgression of the gen into the parental lines in order to subsequently start with the first crosses and obtain hybrids. The results from this research were highly promising, not only due to their resistance, but also due to the agronomical characteristics of these varieties, in addition to the flavour, colour, post-harvest, production…
All Enza Zaden’s varieties resistant to ToBRFV are marketed under the HREZ brand.
Hypersensitivity reaction: The HREZ varieties act in such a way that when a virus particle enters a plant, the cells around the virus die and consequently the virus also dies. This means that the virus does not multiply, and the plant is not a focus of infection. Using a different source of resistance, the virus slows down its multiplication, but it does not disappear and, therefore, the virus concentration continues to grow in the crop and the plants continue to be a focus of infection, giving rise to production losses, post-harvest problems of the fruit and a greater uncertainty regarding the following campaigns.
Today, Enza Zaden has commercial varieties of HREZ available in the main types of tomatoes that make up a complete portfolio for Spain, adapted to the different production areas. For the Plum Cherry segment, they have Pascua and Ponza, with resistance to ToBRFV, TYLCV and Ff (Fulvia fulva). Their high productivity stands out, in addition to good Brix levels. In the case of plum tomatoes, HREZ offers Cedros and Azores. And in the Beefsteak segment, they have Arkoi and Lanzarote for harvesting green and with calibres of over 200 grams, which are ideal for the demand on the Spanish home market.
In addition to the varieties already mentioned, this year Enza Zaden has introduced two new vine and loose tomato varieties that have hit the market with force and have been very well-accepted. They will soon have commercial names and are already available for sale.
Alongside these varieties, Enza Zaden continues working to extend its HREZ portfolio and to have commercial varieties in all the different tomato typologies.
HREZ, synonymous with success
HREZ, along with the recommended plant protection steps, is the only solution available in the industry to effectively fight against ToBRFV as it provides a protection that prevents the virus’ propagation, allowing all the interested parties in the industry to look to the future confidently, without the crop losing any of its potential. Together, we can stop the propagation.
