EPPO Bulletin最新文献

This Standard describes the purpose and use of EPPO Diagnostic Standards. Definitions used in these Standards are given in Appendix 1. This Standard is based on ISPM 27 (IPPC, 2006).

Approved in 2006-09. Revised in 2010-09, 2014-09, 2016-11, 2018-09 and in 2024-09.

This Standard is designed to be used in conjunction with the EPPO Standards of series PM 7 on diagnostics.

Diagnostic tests have different performance characteristics (e.g. levels of analytical sensitivity and analytical specificity resulting in different risks of false-positive and false-negative results), speed and cost. These elements are taken into account by the customer and the laboratory when choosing a test or a combination of tests for the diagnosis of a pest in specific circumstances of use.

The reliability of a test depends on its performance characteristics, obtained from validation and verification studies. Information on how to perform validation and verification is provided in PM 7/98 Specific requirements for laboratories preparing accreditation for a plant pest diagnostic activity (EPPO, 2021). Validation data is not available for all tests that are currently widely used in plant pest diagnostic laboratories. Lack of validation data is, in particular, often the case for routine tests such as ELISA or morphological analyses. However, there is often a long period of experience of use of such tests and it is usually possible for the laboratory to qualify the reliability of such tests (e.g. based on the number of years of experience, the number of samples tested, the use of controls and participation in proficiency tests). It is nevertheless recognized that performance characteristics allow a better understanding of the reliability of the tests. There are cases where a combination of tests is used to increase the overall accuracy and confidence in the diagnosis (e.g. see Section 4).

It should be noted that the result of a test or a combination of tests also depends on the proficiency of the laboratory.

Critical cases:

The circumstances of use described in the latter three bullet points (in bold) are considered in this Standard as critical cases where additional confidence in the outcome of the diagnosis will be required (see Section 2.1). The detection of a pest in a consignment declared to have been submitted to a phytosanitary treatment is also considered to be a critical case (see also Section 5.3.2).

The European Union (EU) regulation for fruit flies (Diptera: Tephritidae) was modified in 2022, and the broad ‘non-European Tephritidae’ group was replaced by a list of 75 regulated taxa (66 species and nine genera). The National Reference Laboratories in the EU must now be able to identify all of them, whatever the development stage, in order to carry out official surveillance. To help laboratories, the European Union Reference Laboratory for Insects and Mites developed an interactive and multi-entry online key called Q-Tephrikey. The key is now freely available on the XPer3 website. It covers a total of 113 tephritid taxa, encompassing the regulated ones, 12 species listed as non-regulated exceptions and the species that have been intercepted in Europe. The taxa are encoded in two morphological matrices for adults and for larvae. This latter one is less extensive because only 38 species among the 113 taxa are described at the larval stage. To help the diagnosticians, the morphological matrices are accompanied by a pathway matrix encoded for the distributions and host ranges of each taxon. We present here the detailed content and functioning of Q-Tephrikey, and discuss its strengths and weaknesses in terms of its objectives. The key is available at https://q-tephrikey.identificationkey.org/mkey.html.

Xylella fastidiosa has been identified as the causal agent of several horticultural plant diseases that have resulted in major economic and cultural heritage losses. In the last decade, X. fastidiosa emerged as a destructive phytopathogen on olive trees in the Apulia region, Italy, prompting widespread surveillance throughout the Mediterranean basin. The present paper reports monitoring efforts for X. fastidiosa in Palestine on olive for 5 years (2017–2022) and 1 year (2022) on stone fruit trees, as a result of international collaboration projects. No signs of olive quick decline syndrome were observed on olive trees in all the Palestinian olive-growing lands. This observation was confirmed by molecular tests using LAMP technology and PCR. In addition, 500 leaf samples from stone fruit trees (almond, apricot, peach, nectarine and plum) were tested using LAMP and PCR. All of these samples were negative for X. fastidiosa, even though few of the samples from almond trees in Idna (Hebron governorate) and apricot trees in Bal'a (Tulkarm governorate) showed leaf scorch-like symptoms. This study provides confirmation that these important horticultural crops in Palestine (olive and stone fruits) are still free of X. fastidiosa. Preventive measures and surveillance of these and other horticultural crops such as grapevine and citrus trees are strongly recommended.

Pepino mosaic virus (PepMV) is known to cause a wide range of symptoms in cultivated tomato plants, damaging fruits and crops. Currently, five genotypes of PepMV are known (US1, CH2, EU, LP and PES), which can all infect tomato plants. Tomato seed is a proven pathway for PepMV, and the virus is known to easily spread mechanically during crop handling. A multiplex real-time reverse transcriptase-polymerase chain reaction (RT-PCR) test was developed and validated for the specific identification of PepMV isolates from tomato seeds. This test is designed to be used for diagnostics and seed health tests as a pre-screen to distinguish negative PepMV samples from suspect samples or as a confirmation test of a positive ELISA or bioassay test result. The multiplex real-time RT-PCR test consists of two PepMV-specific real-time RT-PCR tests and a Bacopa chlorosis virus real-time RT-PCR test as an internal amplification control. The analytical specificity of the developed test was evaluated by in vitro and in silico analyses. The analytical sensitivity was evaluated by creating three dilution series of naturally PepMV-infected leaf tissue in healthy tomato seed extracts and the diagnostic specificity and sensitivity were validated on a collection of seed lots.