Harmorescoll: a harmonized collection of reference isolates, controls and differentials to facilitate disease resistance testing

Abstract

Plant breeding for resistance to pests is a commercial activity that benefits from a regulatory framework that promotes steady progress. In Europe, a significant part of this framework is applied by national variety examination offices and provided by the Community Plant Variety Office, CPVO. In the vegetable sector, disease resistances are commonly used as characteristics for establishing distinctness, uniformity and stability (DUS) of new cultivars. CPVO has published official protocols for resistance testing, of which many have been harmonized between European countries and seed companies over the last 15 years. As a next step, we now propose to improve information on the availability and quality of the most essential reference materials (controls, differentials, and isolates) for relevant vegetable crops. The Harmorescoll project involves examination offices, accredited examination centres, seed companies and trade associations. The inventory of the reference materials described in CPVO protocols and guidelines of UPOV, the International Union for the Protection of New Varieties of Plants, contains materials already available through existing initiatives (i.e., IBEB, IWGP, MATREF, Plantum), and some missing materials. In this new initiative, a series of experimental validations will be performed on prioritized pathosystems, respecting some criteria to consider the materials as a reference. The aim of the manuscript is to present the project, next steps, and its benefits. Harmorescoll will build a new network by using the experience obtained in existing initiatives that serve the same purpose in different European countries. Harmorescoll wishes to become a user-friendly platform providing reliable information on reference materials for a given resistance test, and how to obtain it. The aim is to improve efficiency and trust in DUS resistance tests. Having a harmonized system ensuring access to high quality reference material will be an asset for breeders worldwide to characterize vegetable genetic resources for disease resistance.We thank all people involved in the project as representatives of their company and/or initiatives, among them Ton Allersma (Bayer/Euroseeds), Cécile Collonnier (CPVO), Carole Constant (Sakata/UFS), Pascal Coquin (GEVES), Perrine David (HM.CLAUSE), Michel de Lange (Syngenta/IBEB/IWGP), Raphaël Fernandez (GEVES), Eelco Gilijamse (Rijk Zwaan/Plantum), Aurélia Gouleau (GEVES), Monique Hoogenboom (Naktuinbouw), Catherine Langat (Euroseeds), Christelle Lavaud (GEVES), Claudius Marondedze (Euroseeds), Lesley McCarthy (SASA), Bertrand Monsimier (Vilmorin Mikado), Céline Morineau (CPVO), Raquel Piqueras (INIA-CSIC), Rose Souza Richards (ISF), Monique van Vegchel (Plantum). We thank the providers of reference materials in the initiatives, partners that store back-up of the isolates and the initiatives’ members for daily care of the reference material. The Harmorescoll project has received co-funding from the Community Plant Variety Office (CPVO) under grant agreement N°7515996.Peer reviewe