Why Resistant Rootstock Can Be a Game Changer in Fighting ToBRFV

By Marco Antonio Mammella and Frank Millenaar  

As tomato experts, we've been closely monitoring the ongoing fight against Tomato Brown Rugose Fruit Virus (ToBRFV). A key question, which is currently subject to some debate, is whether resistant rootstocks play a significant role in combating this virus. At BASF I Nunhems, we not only believe that resistant rootstocks are a powerful tool in the battle against ToBRFV, we know it! 

Our research indicates that tomato plants are much less likely to be infected by ToBRFV if they consist of a resistant rootstock variety and a resistant scion. While it’s true that the scion largely determines the visible symptoms of the virus, the role of the rootstock should not be underestimated. This is particularly true in scenarios where crop residues from a previous infection are left in the soil.  

Imagine investing substantial effort into sanitizing your greenhouse and following stringent hygiene protocols, only to discover that the virus has infiltrated your plants through the roots. All that hard work would have been in vain. This underscores the importance of resistant rootstocks, which act as a crucial barrier to prevent the virus from spreading through the plant's system. 

The combination of a resilient rootstock and a resistant scion result in a stronger, more robust plant capable of withstanding disease pressures while also ensuring better yield and quality. It’s essential to remember that the synergy between resistant rootstocks and scions is key in tomato cultivation. Many virus transmission events are linked to mechanical infections caused by common agronomic practices, such as pruning or harvesting. 

Our resistant rootstocks have been shown to retain less virus in the roots, leading to reduced viral multiplication compared to standard rootstocks. This conclusion is supported by our findings from both artificial inoculation studies and conditions resembling commercial environments. By limiting the circulation of the virus, we can effectively lessen its harmful impact on the fruits when paired with a resistant scion. 

At BASF I Nunhems, we have developed Dreampower, our first ToBRFV-resistant rootstock, which can be paired with any of our over 25 resistant tomato varieties. We are committed to helping our customers find the best combinations to meet their specific needs. Our ongoing efforts are directed towards developing additional resistant rootstock varieties, with plans to unveil the next generation next year. These forthcoming rootstocks will further enhance their capabilities, utilizing diverse resistance mechanisms to decrease both the multiplication and movement of the virus. 

In summary, the fight against ToBRFV is ongoing, and we at BASF I Nunhems are dedicated to providing innovative solutions that empower tomato growers to thrive in this challenging landscape.