17 September 2026 News
At Enza Zaden, clear and transparent communication about resistance claims is essential. As part of an industry-wide harmonization effort coordinated through Euroseeds and aligned with the International Seed Federation (ISF) the terminology used to communicate resistance to Lettuce Mosaic Virus (LMV) in lettuce has been updated. As a result of this harmonization, varieties previously carrying the resistance designation LMV:1 will now be communicated as LMV:2.
The change relates solely to the way resistance is described and communicated.
Historically, many lettuce varieties were marketed with the resistance claim LMV:1. Following a review of resistance classifications, the European seed sector agreed to align its terminology with the ISF differential set. Under this harmonized approach, the common type of LMV isolates for which resistance claims are made is now designated as race 2 (LMV:2).
As a consequence, resistance claims previously communicated as LMV:1 will gradually be updated to LMV:2 across product information, catalogues, technical sheets, labels, and other materials.
Importantly, nothing changes in the genetics or performance of the varieties themselves.
This update does not indicate:
• A new resistance source
• A change in the effectiveness of the resistance
• A modification of the variety's genetic makeup
• Any change in how the variety performs in the field
The update is intended to improve consistency and transparency in resistance communication across the vegetable seed industry.
Over the coming months, customers may encounter both designations while materials are being updated.
For example:
• LMV:1 in older materials
• LMV:2 in newly updated materials
In these cases, both references relate to the same resistance claim and should be considered equivalent during the transition period.
Enza Zaden supports industry initiatives that improve clarity and consistency for growers and the value chain. By aligning our resistance terminology with the updated ISF and Euroseeds standards, we aim to ensure that resistance information is communicated clearly and consistently across all markets.
If you have questions about this update or about resistance claims in our lettuce portfolio, please contact your local Enza Zaden representative.
Discover our Global Lettuce portfolio here: Lettuce Varieties | Enza Zaden
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