PM 7/90 (2) Anisogramma anomala

Specific scope: This Standard describes a diagnostic protocol for Anisogramma anomala.1 This Standard should be used in conjunction with PM 7/76 Use of EPPO diagnostic protocols.

Specific approval and amendment: Approved in 2009–09. Revision approved in 2024–03. Authors and contributors are given in the Acknowledgements section.

Anisogramma anomala (Peck) E. Müller in E. Müller & Arx (Diaporthales) was first described by Peck as a pathogen of the native American hazelnut (also called American filbert), Corylus americana Walt. (Gottwald & Cameron, 1979). It is considered as an endemic pest of C. americana, but on the European (cultivated) hazelnut, C. avellana L., it causes eastern filbert blight, a devastating disease producing perennial cankers on limbs. Already reported as early as 1892 in the North-East USA (Halsted, 1892), the pathogen later caused serious problems on cultivated hazelnut in the North-West USA. Since its first detection in South-West Washington State in 1970 (Davison & Davidson, 1973), A. anomala has spread southwards into the Willamette Valley of Oregon and can now be found throughout the entire valley (OSU, 2023). This pathogen is distributed in Canada and the USA and information on its population structure (based on SSR markers) can be found in Cai et al. (2013). For an updated geographical distribution consult EPPO Global Database (EPPO, 2022). A. anomala has no known hosts other than Corylus spp.

Anisogramma anomala systematically colonizes the phloem, cambium and the outer xylem of branches and produces cankers after an incubation period of at least 14 months. The average growth of cankers in European hazelnut is 31 cm per year (Gottwald & Cameron, 1980), girdling branches, causing canopy dieback and death of trees (Johnson et al., 1996). The wild American hazelnut, Corylus americana Marshall, is generally resistant or highly tolerant of infection.

The pathogen infects actively growing shoots and buds from budbreak to early shoot elongation. It has the typical characteristics of an obligate, biotrophic parasite.

A flow diagram describing the diagnostic procedure for A. anomala is presented in Figure 1.

Name: Anisogramma anomala (Peck) E. Müller.

Synonyms: Apioporthe anomala (Peck) Höhn.

Cryptosporella anomala (Peck) Sacc.

Diatrype anomala Peck.

Cryptospora anomala (Peck) Ellis & Everh.

Taxonomic position: Fungi: Ascomycota: Diaporthales.

EPPO Code: CRSPAN.

Phytosanitary categorization: EPPO A1 list no. 201, EU A1 Quarantine Pest (Annex IIA).

No reference material available.

GenBank accession EU683064 (partial LSU gene) can be used as a reference.

Guidance on reporting and documentation is given in EPPO Standard PM 7/77 Documentation and reporting on a diagnosis.

When performance characteristics are available, these are provided with the description of the test. Validation data are also available in the EPPO Database on Diagnostic Expertise (http://dc.eppo.int), and it is recommended to consult this database as additional information may be available there (e.g. more detailed information on analytical specificity, full validation reports, etc.).

Further information on this organism can be obtained from:

Molnar TJ, Rutgers, The State University of New Jersey 59 Dudley Road, New Brunswick, NJ 08901-8520 (US) ([email protected]).

If you have any feedback concerning this Diagnostic Protocol, or any of the tests included, or if you can provide additional validation data for tests included in this protocol that you wish to share, please contact [email protected].

An annual review process is in place to identify the need for revision of diagnostic protocols. Protocols identified as needing revision are marked as such on the EPPO website. When errata and corrigenda are in press, this will also be marked on the website.