b'FEATURE ARTICLE Figure 3. The known and the unknown of the ISTA Reference Pest List (v14; Jan 2025). (A) Diversity of plant species (from top left to bottom right): apple, apricot, plum, pear, almond, rice, soybean, triticale, alfalfa, oat, sorghum, barley, araucaria, fir, Douglas fir, chickpea, potato, chestnut, oak, poplar, red cedar, cedar, nyger, ash gourd, amaranth, drumstick, sunflower, spruce, peach, cherry, wheat, rapeseed, cotton, pine, lentil, lupin, walnut, false cypress, millet, roselle, garlic. (B) Diversity of pest type, distinguishing the number of pests for which seed is a pathway among all seed-borne pests of a given type of pest. (C) Distribution of pests for which seed is or is not a pathway, or seed pathway is not proven for each pest category. (D) Regulated status of the pests inventoried in the ISTA-RPL v14, based on the EPPO Global Database information.covers 41 plant species, and the pests studied include the main types: fungi,can further be used as a starting point to perform other stages of a PRA oomycetes, bacteria, viruses, viroids and nematodes. Insects are almostwhich will challenge the stage 1 conclusions with other characteristics (e.g. completely absent from the lists (with only one representative) becauseavailability of seed treatment, resistant variety that does not multiply the their investigation started only recently, and they will be investigated morepathogen, field-representative epidemiological data, etc.).deeply in the near future. In total, the dataset lists 474 seed-borne pests, 179 of which have been proven to be transmitted by seed (37%), based onConnecting ISTA Tools on Seed Health for the an analysis of 714 scientific references (Fig. 3AC). Mining the EPPO GlobalBenefit of the Seed SectorDatabase, centralised information (consulted in June 2025) revealed thatThe ISTA Seed Health tool tryptic (ISTA-RPL, seed health methods and about half of the inventoried pests (Fig 3D; n=255/474) are regulated inSeed Health Test Image Database, ISTA-IDB) is designed to benefit a large at least one region/country on any matrix (e.g. seeds, fruits, plants, etc.).scope of users, including technical staff, researchers, students and teachers, In cases of pests for which the seed pathway is proven, the level reachespolicymakers, etc. All being freely available on the ISTA website, they 69% (n=124/179), while it is 44% when the seed pathway is not provenoffer valuable information on the identity of seed-borne pests for which (n=127/290), and 80% when seed is not a pathway (n=4/5). To improve theseed can be a pathway (ISTA-RPL), on the means to detect them (seed ISTA-RPL content, it would now be interesting to add information on howhealth methods), and on how to morphologically recognise them during the regulation involves the seed matrix for specific pesthost combinations. analyses (ISTA-IDB). The ISTA-IDB (seedhealthtestimagedb.info/about) was released in 2024 to bridge the gap in knowledge between experts and As defined in ISPM 2, each pest risk analysis (PRA) is a step-by-stepyoung scientists (Calliou, 2024). This tool aims to provide concise, clear framework. The PRA process involves three stages that drive the finaldescriptions of what seed-borne pests look like, based on the amalgamation decision on the possible regulation or not of a pest: (i) initiation; (ii) pestof high-quality images taken and reviewed by seed pathology experts. The risk assessment; and (iii) pest risk management. The first stage is definedISTA-IDB is a dynamic platform that not only allows any users to search for as the identification of organisms and pathways that may be consideredpictures of their favourite pests, but also to contribute by submitting their for pest risk assessment in relation to the identified PRA area (IPPC, 2019).own photographs. Notably, each image is contextualised with metadata (e.g. In that regard, the ISTA-RPL should be considered as part of a first step: itname of pest; agar medium on which it was grown; incubation conditions, inventories the biological features of pests for their ability to colonise seedsetc.), so that one can easily understand the morphological diversity of the (seed-borne pests) and of seeds to be a pathway of dissemination, basedsame pest tested under different environments. There is no doubt that this on a deep screening of the scientific literature. This bibliographic resourceonline tool will be valuable for training the next generation of analysts.12 SEED TESTING INTERNATIONAL www.seedtest.org'