Testa - EPPO Conference on diagnostics for plant pests


2015-11-30/12-02, Angers Conference Centre (FR)

- and associated workshops -
2015-12-03/04, GEVES, Beaucouzé, Angers (FR)







The EPPO-TESTA Conference was organized in Angers on 2015-11-30/12-02 at the kind invitation of the Agence nationale de sécurité sanitaire de l’alimentation, de l’environnement et du travail (ANSES, FR) and of the Groupe d'Etude et de contrôle des Variétés et des Semences (GEVES, FR).

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This Conference followed in the sequence of EPPO Conferences on new methods of diagnosis in plant protection, previously held in the Netherlands, in 1985, 1994, 2000, 2004 and 2012) and in the United Kingdom in 2009. This Conference was attended by more than 100 participants from 21 countries (including non EPPO countries: Brazil, Republic of Korea, South Africa). Most participants were experts in the field of diagnosis of plant pests, and representatives of private companies were also present.



Conference Angers

Participants - View more pictures >


Testa project


The outcomes of the TESTA EU FP7 project ‘Seed health: development of seed treatment methods, evidence for seed transmission and assessment of seed health’ were presented during the first part of the meeting. Presentations covered the following topics:


Introduction to Testa
Welcome and introduction to the TESTA project Christine Henry (FERA)
Testa Work Package 2: Sampling Roy Macarthur (FERA)
Seed transmission  
Efficiencies of bacterial transmission from plants to seeds and from seeds to plantlets Marie-Agnès Jacques (INRA)
Colonization routes of Xanthomonas campestris pv. campestris in Brassica plants that can result in seed infection Jan van der Wolf (DLO)
Diversity of seed-borne bacteria and consequences for detection strategies Marie-Agnès Jacques (INRA)
Diagnostic methods  
Testa WP1 task 1.2: Protocols for assessing Tilletia spp. transmission rates Geoffrey Orgeur (GEVES)
Novel molecular diagnostic methods for seed transmitted pathogens of tomato Peter Bonants (DLO)
Comparison of three DNA extraction kits suitable for PCR-based detection of Acidovorax citrulli in watermelon and melon seeds Emilio Stefani (UNIMORE)
“Dead or alive” that is the question, with examples of CGMMV and Xcc
part one | part two
Theo van der Lee & René van der Vlugt (DLO)
Cereal grain mycoflora on single seeds: comparison of metabarcoding and VideometerLab for pathogen detection on cereal grain Mogens Nicolaisen (AU)
Implementation of the detection protocol for Xanthomonas euvesicatoria in pepper seeds Emilio Stefani (UNIMORE)
Pathoscreen, a new approach in non-destructive quantitative detection Theo van der Lee on behalf of Els Verstappen (DLO)
Diagnostic method validation  
Culture-free rapid molecular detection of Clavibacter michiganensis subsp michiganensis in seeds of tomato Harrie Koenraadt (Naktuinbouw)
Comparison of detection methods for Ditylenchus in alfalfa and faba bean seed lots and method validation Valérie Grimault (GEVES)
Validation of a RT Taqman PCR for detection of pospiviroids in tomato seeds Maaike Bruinsma (Naktuinbouw)
Seed treatment  
Validation study of alternative seed treatments for Xanthomonas campestris pv. campestris on Brassica Gloria Mandiriza (UP)
Validating a thermotherapy seed-treatment against Ditylenchus dipsaci associated with alfalfa seeds Edgar Mangwende (UP)




Conclusions and recommendations from the TESTA part of the Conference


  • Welcomed the outcomes of the TESTA project in particular the activities related to test development and validation, methods to determine if the pest is viable, and validation of extraction methods for nematodes.
  • Were satisfied that consideration had been given to the establishment of sampling plans taking into account variation in the sample and performance of a test. They reiterated the recommendations made at the previous Conference on Diagnostics that sampling methodology prior to testing was critical and recommended that this should be given more attention.
  • Noted that there is a need for further collaboration between the public and private sector for test development, as well as for internationally interlaboratory validated tests. They noted that tests developed in TESTA will be considered for inclusion in EPPO and ISTA protocols.
  • Agreed that it would be valuable to prolong the collaboration initiated in TESTA through other mechanisms e.g. Euphresco, ISHI, ISTA, EPPO.
  • Agreed that it would be valuable to further disseminate the knowledge acquired through the project.
  • Noted that the issue of biological relevance of a level of detection was a complex issue but should be considered when developing and using tests.






Conference on diagnostics


Presentations for the EPPO Diagnostics part of the Conference were on the state of the art of diagnostics in the EPPO region and were divided into the following sessions:


New molecular and bio-analytical identification tools
Multiplex detection of plant pathogens Jan Bergervoet (Wageningen University, NL)
Development of a polyvalent detection method for Begomoviruses presenting a threat to the European tomato industry Pascal Gentit (ANSES, FR)
Generic RT-PCR tests for detection and identification of Tospoviruses Marcel Westenberg (NPPO, NL)
Detection and identification of Meloidogyne enterolobii in complex DNA-backgrounds using LNA-probe based real-time PCR assays Sebastian Kiewnick (Agroscope, CH)
New diagnostic tools for improved diagnostics of grapevine phytoplasmas Natasa Mehle (NIS, SI)
Improvements in challenging diagnostic of Pepino mosaic virus and Potato spindle tuber viroid in tomato seeds for better sensitivity Natasa Mehle (NIS, SI)
Development of a loop-mediated isothermal amplification assay for rapid detection of Fusarium oxysporum f.sp. cubense tropical race 4 through Diversity Array Technology sequencing Cor Schoen (Wageningen UR, NL)
New tools for better morphological identification  
Quick identification of commonly intercepted Tephritidae in Europe: How does molecular identification help the morphology? Valérie Balmès (ANSES, FR)
Application of digital microscopy for the remote identification of invertebrate pests Dom Collins (Fera, GB)
Improved approaches for early detection  
Proposed EPPO validation of plant viral diagnostics using next generation sequencing Ian Adams (Fera, GB)
Development of high-throughput sequencing (HTS) based sentinel tools for the detection and early warning of airborne fungal pathogens Jaime Aguayo (ANSES, FR)
Tree disease surveillance: metabarcoding to identify fungi in spore traps Ian Adams (Fera, GB)
NGS applications in plant pathogen diagnostics Annette Dullemans (Wageningen UR, NL)
Biological and epidemiological studies of Pseudomonas syringae pv. actinidiae and Pseudomonas syringae pv. actinidifoliorum pathogenic on kiwifruit to improve their detection Amandine Cunty (ANSES, FR)
Unravelling the Synchytrium endobioticum genome: working towards reliable and rapid molecular pathotype identification Bart Van de Vossenberg (NPPO, NL)
Improved pathogen management in crops using rapid in-field diagnostics Catherine Harrison (Fera, GB)
Deployment of loop-mediated isothermal amplification (LAMP) assays for rapid pest and pathogen identification in the UK Ian Adams (Fera, GB)
Assessment of performance criteria of ‘Candidatus Liberibacter solanacearum' detection methods Marianne Loiseau (ANSES, FR)
New approaches for detection and characterization of Xanthomonas arboricola pv. pruni on stone fruits and almond Maria López (IVIA, ES)
New approaches for the early detection of tree pests and pathogens Rick Mumford (Fera, GB)
Xylella fastidiosa outbreak in Europe: new genotypes in Corsica Valérie Olivier (ANSES, FR)
Potential of spiral plating and digital real-time PCR for improved seed health testing Manca Pirc (NIB, SI)
Enrichment procedures to improve detection of Clavibacter michiganensis subsp. michiganensis in seed extracts with a dilution plating, a TaqMan PCR and a LAMP assay Flavia Vieira Lelis (Wageningen UR, NL)
Beyond the science - Collaborative approaches to early detection of pests Rehema White (St Andrews University, GB)
Other topics of importance in diagnostics  
A flexible scope on phytosanitary diagnostics Arjen Werkman (NRC, NPPO, NL)
Obtaining an ISO17025 accreditation for PCR-sequencing: experiences of the Dutch NPPO Bart van de Vossenberg (NPPO, NL)
Comparison and implementation of detection tests for ‘Candidatus Liberibacter solanacearum’ in plant tissue samples Leon Tjou-Tam-Sin (NVWA, NL)
Results of the Euphresco- SENDO project: improving diagnostics in Synchytrium endobioticum Gerard van Leeuwen (NPPO, NL)
Results of the Q-collect project Peter Bonants (Wageningen UR
Euphresco Baldissera Giovani (Euphresco Co-ordinator at EPPO)



Recommendations from the EPPO Diagnostics part of the Conference


  • The capability to quickly and reliably detect and identify pests is critical for effective phytosanitary measures to be taken. Laboratories are increasingly working under quality assurance systems (including accreditation) and need to have access to validated tests. In order to ensure proper development, validation and effective and reliable use of tests, access to reference material is essential. It is essential that the infrastructure in Plant Health is strengthened. In this respect the results of the Q-collect were noted.
  • New technology and tools can present many advantages (for example speed, high sensitivity, adaptability for high throughput) but also presents new challenges such as how to validate them & use under accreditation. Examples of ways to address some of these new challenges and of the new types of controls that will be needed (for example for sequencing including data analysis) were appreciated and will be considered when revising PM 7/98(2) Specific requirements for laboratories preparing accreditation for a plant pest diagnostic activity.
  • At the EPPO Diagnostics Conference in 2012 it was stated that: The consequences of continuing evolution in diagnostic techniques and taxonomy on phytosanitary regulations should be considered further. The Participants agreed that this recommendation is still valid and encouraged EPPO to stimulate exchanges of views on this issue in its meetings.
  • The circumstances of use of on-site analysis versus laboratory analysis require further discussion with NPPOs.
  • The Conference considered that it is essential that the development of harmonized diagnostic protocols continues.
  • It was noted that it is important that tests are validated in other laboratories, not just in the laboratories in which they were developed. This is one of the reasons test performance studies are so important.
  • The importance of social engagement, in particular the need to consider stakeholder involvement, in the development and testing of new technologies, was recognised in order to optimise uptake and longer term collaboration.


Warm thanks are due to the session leaders: Nathalie Franquet (ANSES, FR), Géraldine Anthoine (ANSES, FR), Rick Mumford (Fera, GB), Christine Henry (Fera, GB), Peter Bonants (PRI, NL), Françoise Petter (EPPO), Michel Ebskamp (Naktuinbouw, NL), Marie-Agnès Jacques (INRA, FR).





WorkshopThe Conference was followed by Workshops which were attended by 40 participants from 14 countries. Following the Welcome speech by Arnaud Deltour (Director-General of GEVES) participants took part in lectures and practical sessions and also had a laboratory visit. The following sessions were held:


Detection of tomato pathogens by molecular methods

  • Introductory Lecture
  • Lecture on Luminex
  • Demonstration Practical Extraction
  • Lecture on LAMP
  • Demonstration Practical Luminex
  • Lecture on TaqMan
  • Demonstration Practical LAMP
  • Lecture on NGS / Live-Dead
  • Demonstration Practical TaqMan


Detection of Ditylenchus dipsaci on alfalfa and faba bean by sieving method and confirmation by PCR

  • Lecture
  • Demonstrations and Practical sessions


Detection of Phoma lingam on brassicas by blotter and media methods and confirmation by PCR and pathogenicity test

  • Lecture
  • Demonstrations and Practical sessions


Warm thanks are given to the organisers of the Testa Workshops: Valerie Grimault (GEVES, FR), Geoffrey Orgeur (GEVES, FR), Peter Bonants (Wageningen UR, NL), Jan Bergervoet (Wageningen UR, NL), Willem Stol (Wageningen UR, NL), Jose Van Beckhoven (PRI, NL) and Els Verstappen (Wageningen UR, NL).