12th Meeting of the EPPO Panel on Diagnostics in Virology and Phytoplasmology

Braunschweig (DE), 2026-10-20/22

The EPPO Panel on Diagnostics in Virology and Phytoplasmology met in Braunschweig, Germany, at the kind invitation of Julius Kühn-Institute (JKI). This Panel serves as EPPO’s technical body responsible for preparing and reviewing Diagnostic Standards for viruses, viroids and phytoplasmas. The meeting was attended by 25 Panel members and one observer, and was chaired by Ms Trontin (EPPO Secretariat), with the support of Mr Aoutil (EPPO Secretariat).

Revised EPPO Diagnostic Standards reviewed during the meeting

The Panel reviewed three revised Diagnostic Standards.

PM 7/133 Phytoplasmas

The Standard was approved in September 2026. The Panel discussed a comment received from the Czech Republic during the final approval stage concerning the interpretation of results obtained using a molecular test (Christensen et al., 2004). The Panel agreed that the addition of a note to cover the concern raised was not needed. The Standard will be published in the coming months.

PM 7/079 Grapevine flavescence dorée phytoplasma

The Panel reviewed the comments received during the first stage of the country consultation. The main points discussed included the addition of the detection of Palatinate grapevine yellows phytoplasma to the flow diagram (as the detection tests also detect this phytoplasma), the need to provide examples of kits for nucleic acid extraction, and the clarification of result interpretation for the real-time PCR-based test (IPADLAB). A new version of the Standard that takes into account the discussions of the Panel will be prepared and sent for the final approval stage.

PM 7/139 Tospoviruses (Genus Orthotospovirus)

The Panel reviewed the comments received during the first stage of country consultation. The main discussion points focused on the flow diagram, the use of bioassays for detection, the use of the test of Boonham et al. (2002) for the identification of Tomato spotted wilt virus, clarification of the PCR cycling conditions for certain molecular tests, and the inclusion of a new molecular test (real-time RT-PCR test for Chrysanthemum stem necrosis virus; Naktuinbouw, 2025). A revised version of the Standard incorporating the Panel’s comments and discussions will be prepared and sent for the final approval stage.

The progress made on the revision of the following Standard was also discussed:

PM 7/132 Andean potato latent virus and Andean potato mild mosaic virus: An expert from JKI (DE) provided updates on tests that can be used for the detection and identification of the two viruses. A new version of this Standard will be prepared for the next Panel meeting.

New EPPO Diagnostic Standards reviewed during the meeting

The Panel reviewed two new Diagnostic Standards.

PM 7/NEW Ilarvirus ApNMV (apple necrotic mosaic virus), Ilarvirus APLPV (American plum line pattern virus), Ilarvirus SNSV (strawberry necrotic shock virus) and potato yellowing virus.

The Panel reviewed the draft of the Standard prepared by experts from CREA-DC (IT), NIVIP-NVWA (NL), ILVO (BE), JKI (DE), SASA (GB), and VNIIKR (RU). The main discussion points included changing the title from Ilarvirus to the specific names of the virus species addressed in the Standard; summarizing the introduction section; adding sequence analysis of RT-PCR products (Thekke Veetil et al., 2016) to confirm the detection and identification of strawberry necrotic shock virus; including high-throughput sequencing (HTS) for identification; and harmonizing the RNA extraction appendix with other Standards. A new version of the Standard that takes into account the discussions of the Panel will be prepared and sent for the first stage of country consultation.

PM 7/NEW Nepoviruses

The Panel reviewed the draft of the Standard prepared by experts from NIVIP-NVWA (NL), Naktuinbouw (NL), Fera Science Ltd (GB), SASA (GB) and VNIIKR (RU). The discussion focused on changing the title to highlight that only some Nepoviruses are covered in the Standard; further considering the addition of nematodes as a matrix; checking the availability of validation data for serological and HTS tests for identification, and revising the RNA extraction procedure. A new version of the Standard that takes into account the discussions of the Panel will be prepared, further reviewed by the Panel by email and sent for the first stage of country consultation.

The progress made on drafting of the following new Standard was also discussed:

PM 7/NEW Carlaviruses: An expert from CRA-W (BE) presented the generic and species-specific serological and molecular tests to be included in the Diagnostic Standard. A draft for this Standard will be prepared for the next Panel meeting.

Plans for future development and revisions of Diagnostic Standards

The Panel agreed to revise Diagnostic Standard PM 7/152 Begomoviruses and to develop a new Standard for Ipomovirus lycopersici (Tomato mild mottle virus) and potentially for Ipomovirus cucurbitavenaflavi (Squash vein yellowing virus), subject to approval by the Working Party on Phytosanitary Regulations. At the next Panel meeting (2028), developing Standards for Grablovirus vitis (Grapevine red blotch virus) and some torradoviruses will be further considered.

12th Meeting of the EPPO Panel on Diagnostics in Virology and Phytoplasmology

Braunschweig (DE), 2026-10-20/22

Revised EPPO Diagnostic Standards reviewed during the meeting

New EPPO Diagnostic Standards reviewed during the meeting

Plans for future development and revisions of Diagnostic Standards

Other topics