b'FEATURE ARTICLE Towards Safer Seeds: The Changing Landscape of Seed Health TestingNicolas Denanc1 and Jaiana Malabarba2GEVES, National Seed Testing Station (SNES), Beaucouz, France1nicolas.denance@geves.fr2jaiana.malabarba@geves.frTHE MAIN STAPLE FOODS, AND A VARIETY OF PLANTthe identification of causative fungal agents and methods of seed testing, PRODUCTS THAT ARE CONSUMED IN THE WORLD, share thelike the well-known standard blotter method (Doyer, 1938, 1948). Over time, same origin: a seed. More than ever, seeds are globetrotters: they arethe toolbox for detecting pathogens has expanded. One can distinguish moved across the world for various goals (crop production, breeding, seedbetween direct and indirect techniques. Direct techniques aim to detect multiplication, commercialisation, research trials, etc.). There is a hugeviable pathogens using biological approaches (i.e. morphological, number of seeds traded each year: 7 660 613 metric tons exported in 2022biochemical and pathological characteristics; bioassays) while indirect for a value of 16 230.2 million USD (ISF, 2025). In such a dynamic economictechniques aim to detect particles of the pathogens using serological sector, circulating safe seeds is therefore crucial to secure plant health.or molecular approaches (i.e. antigen/antibody recognition; nucleic However, introductions of pests in new countries due to infested seedssequences). As an example, in bacteriology, analytical workflows typically were recorded all over the world as early as the 1880s (Baker and Smith,combine a three-step process composed of a dilution plating assay and a 1966; Neergaard, 1977), confirming that seeds can be a pathway for pestmolecular approach followed by a pathogenicity assay. Therefore, a strain dissemination. Fortunately, from that period to today, the seed sector hasisolated from a seed sample whose identity is confirmed by polymerase made impressive progress in improving seed health quality. This articlechain reaction (PCR, or derivate) will be considered as a true target, only offers a concise overview of seed health testing, highlighting key historicalif it induces disease symptoms on the host plant. If no pathogenicity is and technical developments through a personal perspective. observed, the analysis will be concluded as negative. Such a decision-based scheme aims to reflect biological relevance, to avoid declaring Foundations of Seed Health Testing positive samples in the case of the presence of non-pathogenic strains, with Since the early ages of agriculture, farmers have brought attention to thelimited epidemiological threats in the field. On the contrary, it ignores the value of their seeds: there is no good crop production without seeds of highbiological possibility of disseminating non-pathogenic microorganisms or good quality. To our knowledge, the most recent in-depth investigationinto geographical areas where they could recombine with local pathogens on the history of seed testing in its broader sense is the fruit of Anas Gotsand acquire pathogenic characteristics, as has already been shown, for PhD thesis (Got, 2024). Facing the need for controls to ensure farmers haveinstance, with Xanthomonas (Jacques et al., 2016; Merda et al., 2016).access to biological material that satisfies a certain level of performance, the first seed testing station was established in 1869 in Germany by the botanist Friedrich Nobbe, mostly focusing on germination and purity analyses. TheThe history of seed pathology has been first seed health testing laboratory was established around 50 years later, in 1918, in The Netherlands. However, phytosanitary issues were alreadyreviewed through multiple lenses, including being scrutinised, as Nobbe reported in his handbook of seed science, on the occurrence of sclerotia and smut balls observed accompanying seedtechnical advancements, regulatory samples (Nobbe, 1876). From then on, there was a general awareness that certain pathogens could be carried with or inside seeds. This led to the publication of successive lists of seed-borne pathogens, including, but notframeworks and economic implications.restricted to, those by Charles Bessey in 1886, Annie Lorrain Smith in 1903, and Nora Lilian Alcock and Clayton Roberts Orton in 1931. The significance of seed health was later recognised, most notably by Mary Noble andISTA has been involved in validating and publishing seed health methods Paul Neergaard, who coined the term seed pathology while promotingfor field crops, vegetables and forest trees for over 25 years and in 2025, initiatives around the world and advising the way forward for seed testingthe Association released the first ISTA Handbook on Seed Health Testing. (Noble, 1951, 1957; Neergaard, 1986). The history of seed pathology hasSupported by pertinent illustrations, this resource gives key information been reviewed through multiple lenses, including technical advancements,on how to assess seed health, considering hygiene and safety rules, regulatory frameworks and economic implications (Neergaard, 1977;general methods and specificities according to the type of pests (ISTA, McGee, 1981; McGee, 1995; Maude, 1996; Agarwal and Sinclair, 1997;2025). Validating a method for diagnostics or purposes requires fulfilling Gitaitis and Walcott, 2007; Munkvold, 2009; Goswami et al., 2020; Kumarperformance criteria. Basically, validation is the process that determines and Gupta, 2020; Srivastava et al., 2020; Munkvold et al., 2025). the suitability of a test through an in-depth analysis of various parameters to guarantee its performance for a specific use. The validation process relies Seed Health Testing Methods on the prior optimisation and standardisation of the method to ensure that Assessing seed health requires specifically designed facilities andit is ready for implementation and quality is guaranteed. In the literature, workflows to ensure reliable and contamination-free testing (FAO andthere are plenty of protocols elaborated by individual laboratories, most ISTA, 2023). There is a large arsenal of techniques or methods (includingoften without extensive comparative tests. The scientific community combinations of techniques) suitable for the detection of all kinds of pests inis increasingly concerned with establishing guidance for diagnostic seed samples. Lucie Doyer, who served as the first Chair (19281949) of theprotocols to avoid misinterpretation and to increase the confidence in and ISTA Seed Health Committee (referred to as the Plant Disease Committeerepresentativeness of published data (Cardwell et al., 2018; Massart et al., at that time), paved the way for the determination of seed-borne diseases,2022a; Massart et al., 2022b; Cardwell et al., 2023). International authorities, 8 SEED TESTING INTERNATIONAL www.seedtest.org'