b'FEATURE ARTICLEFigure 1. Scope of the ISTA seed health methods in the International Rules for Seed Testing, showing diversity of (A) pathogens (fungi, oomycetes, bacteria, viruses and nematodes), (B) plant species (vegetables, cereals, legumes, forest trees and oilseed crops), and (C) pesthost combinations, covered by the 36 methodslike the European and Mediterranean Plant Protection Organizationsector, it is essential that all stakeholders along the value chain are fully (EPPO), are publishing standards (PM7 series; gd.eppo.int/standards/ informed about any treatments applied. This awareness is critical, not only PM7/). Focusing on seed health testing, ISTA and the International Seedfor hygiene, safety and protection (human health), but also for accuracy. Federation (ISF) also already have their own guidelines to set up andIndeed, the efficiency of the detection methods can be negatively impacted validate methods (ISTA, 2021; ISHI, 2025). Using appropriate statisticalby different treatments, which can yield false negative results and the tools, the main steps include: (i) method development and in-house datarelease of infected seed lots. To counteract such possibilities, some internal development by one laboratory (may include pre-collaborative studies); controls may be added to the analysis when the current method is not (ii) multi-laboratory study design (test plan); (iii) multi-laboratoryapplicable to treated seed. collaborative study; and (iv) study analysis and method validation report. Currently, the ISTA seed health methods preferentially target fungal pathogens (n=28), but also bacteria and viruses at a lower level (n=8 of each), ISTA has been involved in validating andand a few nematodes (n=3). There is considerable scope to further diversify the types of pests targeted by ISTA seed health testing, to include those that publishing seed health methods for field crops,are currently under-represented or absent. For instance, the relationship between insect pests and seeds is becoming an increasing concern, vegetables and forest trees for over 25 years. especially in an environment of changing climate, which is rapidly altering pest distribution worldwide. As a consequence, countries are imposing increasingly strict restrictions on the import of seed lots. The recent As of January 2026, ISTA will publish 36 seed health methods in theworkshop organised in March 2025 by the ISTA Seed Health and Advanced International Rules for Seed Testing (ISTA Rules), concerning 47 pathogens,Technologies Committees on Insect Detection in Seed Testing is a good including the recently approved method for Fusarium oxysporum f.sp.example of ISTAs commitment to aligning itself with phytosanitary issues. lycopersici in tomato (Fig. 1). In their current versions, the ISTA seed healthThe great ideas discussed during the workshop round table, as well as the methods use single techniques or a combination of these (Table 1). Thediscussion session during the 34th ISTA Congress held in Christchurch, mycology methods consist of blotter tests, agar methods, embryo extractionNew Zealand (2025), should help define future directions for the challenge or immunoblot. The bacteriology methods combine microbiology,of detecting and identifying insects in seed samples.molecular biology and pathogenicity tests. The virology methods use serological techniques and indexing on plants. The nematology methodsThe current ISTA seed health methods cover 23 plant species, including allow identification by morphobiometry to be coupled with molecularvegetables (n=8), cereals (n=5), legumes (n=4), forest trees (n=4) and oilseed testing. Notably, most of the current methods have been validated for andcrops (n=2). There is also a need to broaden the diversity in terms of plant are applicable only to non-treated seeds, with treatment being definedspecies. For instance, forest trees remain under-represented, with only two as any process, physical, biological or chemical, to which a seed lot isseed health methods for fungal pathogens in Douglas fir, pine and/or two subjected, including seed coatings (ISTA Rules, section 7.2.3). While thespruce species. However, there is a growing concern that seed-borne pests interpretation of the definition may be subject to discussion in the seedare responsible for forest diseases (Denanc, 2024; Franic et al., 2024). There SEED TESTING INTERNATIONAL OCTOBER 2025 9'