ToBRFV resistance in grafted tomato plants?

The problem of the tomato rough leaf spot virus ToBRFV is still very topical in the Spanish tomato sector. The good news is that we will soon have a wide catalogue of tomato varieties of all types that are highly resistant to ToBRFV(HR).

Tests carried out in a growth chamber over a period of six weeks showed that ToBRFV could not multiply in tomato varieties highly resistant to HR.

The test was carried out on ungrafted plants. After all, resistance to ToBRFV is not yet available in grafted tomato varieties.

There are still many uncertainties about the role of the rootstock in this story. For example, the rootstock may still be infected with ToBRFV and that would lead to a continuous virus pressure on the highly resistant upper stem.

A continuously high virus pressure also carries the risk that resistance will break down more quickly. To avoid such scenarios, it is very important to maintain a high level of hygiene, even when switching to ToBRFV-resistant varieties. The effect of a ToBRFV-infected rootstock on a highly resistant variety is one of the things we will try to find out in a forthcoming research.

Although ToBRFV could not develop in the three tested varieties for which high resistance to ToBRFV is claimed, good hygiene is still extremely important.

For more information, analysis and tips on how to win the battle against the rugose virus we recommend the following link: 

https://www.nunhems.com/gb/en/solutions/winthebattleagainstrugosevirus.html