Glomeromycota comprises the arbuscular mycorrhizal (AM) fungi, which occur in all agricultural soils worldwide with varying abundance and richness depending largely on climate, soil, crop/vegetation and land use intensity They are of major significance for ecosystems, as they improve plant growth, suppress pathogens and enhance soil fertility & stability and water infiltration. AM fungi comprise > 350 species divided into 3 classes, 9 orders, 26 families and >60 genera. They are at risk due to excessive soil cultivation or application of plant protection products. We ask, which taxa are appropriate to be tested in dose-response ecotoxicological laboratory experiments with plant protection products (PPP) and their active substances (AS). Different AM fungal taxa are clearly seasonal or not, have specific life cycles, hyphal networks and spore formation characteristics. Spores, or ‘fruit-bodies’, are differentiated within weeks, only after months or years, and sometimes not at all. They are formed singly, in clusters or huge agglomerations, in soils or preferably in plant roots, either perfectly mature, or as early aborted spores without any germination capacity and function. Estimations can be made about the beneficial performance of well-studied AM fungal taxa or about their sensitivity in different soil management or cropping sytems and agricultural land use intensities. Glomeromycetes species have increased beneficial potentials, with respect to plant growth promotion, plant health, soil structure formation or soil health. Some species are commercially available, for bio-remediation, as bio-pesticides or bio-fertilizers. Genera with most positive ecological value, or highest benefits for plants or soils either belong to Glomerales, Entrophosporales, Diversisporales, Acaulosporales or Gigasporales. In contrast, Archaeosporales or Paraglomerales spp. were rarely shown to have positive effects on plants or soils, while Pacisporales and Sacculosporales spp. have rarely been cultured. It is however a black box, which of all these taxa might be more or less sensitive to herbicides, insecticides or even fungicides. Here, we aim to identify those AM fungi with different traits, properties and ecological benefits, but also most suited for ecotoxicological tests with AS or PPP. Our criteria are based on the knowledge on fungal structures, culturability, significance as non-target organisms and especially as ‘improvers’ of plant growth & health and soil fertility.