b'FEATURE ARTICLE[The Seed Health Test Image Database] aimsConclusionIn todays rapidly changing world, plant disease emergences can occur to provide concise, clear descriptions of whateverywhere, for multiple reasonsclimate change, global trade or evolving agricultural practices. Disease emergences require a rapid reaction time. seed-borne pests look like, based on theTherefore, there is a need for a faster delivery of seed health knowledge: which pests are associated with which seeds, and which detection method is most appropriate? Looking ahead, whatever the pests, the future of seed amalgamation of high-quality images takenhealth testing seems to give great emphasis to molecular approaches. There are many advantages for such methods, like the speed of results and reviewed by seed pathology experts. delivery and their sensitivity and specificity. However, there is no universal solution existing today. Direct methods will still be needed to confirm the presence of viable pathogens in a seed sample. This reinforces the need The objective is to connect these resources as much as possible in the nearfor well-trained analysts that are aware of what they are looking for, how future, with the ISTA-IDB covering all the pests with existing ISTA seedthey can recognise the pests and how they can assess their tests efficiently. health methods. So far, 24 pathogens with existing methods are illustratedSeed health testing requires a combination of highly technical skills that in the ISTA-IDB. Notably, pest images cover all the methods for barley,are at some point universal, as indirect techniques like enzyme-linked wheat, flax, bean, soybean, sunflower and brassicas, or partially for rice,immunosorbent assay (ELISA) or qPCR are conducted in the same way carrot and pea. The aim is also for the ISTA-IDB to later include most of thewhatever the pest. In contrast, direct methods are very specific, like the pests inventoried in the ISTA-RPL. The number currently stands at 84 frommorphological identification of bacteria or fungi, involving symptom the ISTA-RPL. No viruses are included in the ISTA-IDB, which makes senserecognition in a pathogenicity assay that implies a range and level of as they cannot be observed like fungi or bacteria. However, offering imagescompetence to distinguish pathogen species. Proficiency in recognising of symptoms on bioassays or indexing would also be of interest for theone fungal species does not imply being competent for all fungi. This is community. Although the effort required to better connect and strengthencase-by-case knowledge that must be recognised and qualified accordingly. the three tools is high, the expected benefits are even greater. Together,ISTA tools, such as the Reference Pest List, validated seed health methods, they form a package that will confer a better understanding and therefore,and the Seed Health Test Image Database, play a key role in improving seed a better awareness of all actors of the seed sector, for a more efficienthealth testing and will continue in the future, engaging more accredited management against harmful seed-borne pests. laboratories and expert analysts, ultimately strengthening global efforts to protect seed and plant health.What Does the Future Hold for Seed Health Testing? AcknowledgmentsPests never walk alone. Just like any other crop compartment, theWe would like to thank past and current people involved in the ISTA-RPL spermosphere is a paradise for many organisms. Over the last decade,project: Giulia Farinaro, Caroline Bellenot and Eduardo Glvez Sotelo, all there has been growing evidence that seed microbiota is contributingthe international experts and Seed Health Committee members for their to seed performance, and that is driven by several factors (e.g. species,reviews, and ISTA for financial support. Having ISTA seed health methods terroir, culture history, technical plan for cultivation, etc.) (Klaedtke etwould not be possible without the contribution of colleagues from all over al., 2016; Simonin et al., 2022). Part of these microbial communities canthe world. The ISTA-IDB would not have been released without Nicole be transmitted through seeds to the next generation (Abdelfattah et al.,Callious leadership. We also thank Ruud Barnhoorn for critical review of 2023). The main challenge in seed testing is to detect and identify, amongthis article.this microbial diversity, seed-borne pathogens whose negative impact on the crop would be significant. It can be very costly to perform seed healthReferencestesting for several pests on seeds for one seed lot. Offering combined1.Abdelfattah, A., Tack, A.J.M., Lobato, C., Wassermann, B. and Berg, G. analyses for several pests at once is a means for seed companies to optimise(2023). From seed to seed: the role of microbial inheritance in the assembly the number of seeds that are required for testing. Multiplexing severalof the plant microbiome. Trends in Microbiology, 31(4):346355. doi.targets in a qPCR analysis is already used as routine for several pests.org/10.1016/j.tim.2022.10.009Developing approaches without a priori as a pre-screening step may be the2.Agarwal, V.K. and Sinclair, J.B. (1997). Principles of Seed Pathology, 2nd next way to go in seed testing. For instance, proof of concept on the use ofedn. CRC Press, Boca Raton, FL, 539 pp.high-throughput sequence has already been performed in virology (Maree3.Baker, K.F. and Smith, S.H. (1966). Dynamics of seed transmission et al., 2018; Olmos et al., 2018; Lebas et al., 2022). The ISTA Seed Healthof plant pathogens. Annual Review of Phytopathology, 4, 311332. doi.Committee also has ongoing projects for complex taxa like that on Fusariumorg/10.1146/annurev.py.04.090166.001523metabarcoding. Other initiatives may be running in various laboratories4.Calliou, N. (2024). Seed health test image database: the full story. Seed outside the scope of ISTA (e.g. coupling detection of bacteria and fungi orTesting International, 168, 1315.other pests). As mentioned above, developing detection methods for insects5.Cardwell, K., Dennis, G., Flannery, A., Fletcher, J., Luster, D. et al. (2018). is under consideration to offer a methodological response in accordanceDiagnostic assay validation terminology. The Plant Health Instructor. doi.with phytosanitary issues. org/10.1094/PHI-I-2018-0709-016.Cardwell, K.F., Harmon, C.L., Stack, J.P. and Sharma, P. (2023). Focus issue articles on diagnostic assay development and validation: the science Offering combined analyses for several of getting it right. PhytoFrontiers, 3(1), 58. doi.org/10.1094/PHYTOFR-02-23-0014-FIpests at once is a means for seed companies 7.Denanc, N. (2024). Seed pathway for tree pest dissemination: gathering knowledge to improve forest health management. Proceedings of the 26th to optimise the number of seeds that areInternational Union of Forest Research Organizations World Congress (IUFRO), Stockholm, Sweden. Zenodo, Switzerland. doi.org/10.5281/zenodo.12592306required for testing. 8.Denanc, N. and Grimault, V. (2022). Seed pathway for pest dissemination: the ISTA Reference Pest List, a bibliographic resource in non-vegetable crops. EPPO Bulletin, 52, 434445. doi.org/10.1111/epp.12834SEED TESTING INTERNATIONAL OCTOBER 2025 13'