The Netherlands
March 16, 2022
A new version of the CPVO lettuce protocol will be published in April 2022. It includes some changes for the Bremia isolates. The isolate Bl:36 is included in the protocol and some obligations of other isolates are skipped.
In the International Bremia Evaluation Board (IBEB) an epidemiological survey and yearly evaluation of Bremia isolates is done and if appropriate according to their procedures, new isolates can be denominated and included in the ISF/IBEB differential table.
Once a new isolate is denominated, and after evaluation of the data, the Vegetable Expert Meeting (VEM) of CPVO decides if this isolate can be used in DUS testing. If so, it will be included in a new version of the CPVO lettuce protocol.
What are the changes to the CPVO lettuce protocol from April 2022?
In the past years the isolates Bl:36 and Bl:37 were denominated. Last November the VEM decided to include Bl:36 in the protocol. To prevent that the number of races used in DUS testing becomes too large, it was also decided to skip some obligations (asterisk) of other isolates. For newly added resistance characteristics, a phasing in period of 5 years applies, so that companies can prepare themselves for evaluation and use in DUS testing.
The following changes will be included in the new version to be published in April 2022:
- The asterisk conditional to Bl:16 will disappear for Bl:20, 21, 26. This means that these isolates are no longer obligatory in DUS.
- The asterisk will disappear for Bl:27, 30 and 31. This means that also these isolates are no longer obligatory in DUS.
- Bl:36 is added as Bl:29-conditional asterisk (with phasing in as usual for new resistance characteristics). This means that Bl: 36 testing will be obligatory for lettuce applications that are resistant to Bl: 29.
- Phasing in for Bl:33 and Bl:35 has ended on 1-1-2021
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