Summary Acquired resistance is a threat to antifungal efficacy in medicine and agriculture. The diversity of possible resistance mechanisms and highly adaptive traits of pathogens make it difficult to predict evolutionary outcomes of treatments. We used directed evolution as an approach to assess the resistance risk to the new fungicide fenpicoxamid in the wheat pathogenic fungus Zymoseptoria tritici . Fenpicoxamid inhibits co...

Summary S eptoria leaf blotch is mainly controlled by fungicides. Z ymoseptoria tritici , which is responsible for this disease, displays strong adaptive capacity to fungicide challenge. It developed resistance to most fungicides due to target site modifications. Recently, isolated strains showed cross‐resistance to fungicides with unrelated modes of action, suggesting a resistance mechanism known as multidrug resistance ( MDR...

Summary Carboxamide fungicides target succinate dehydrogenase ( SDH ). Recent field monitoring studies have identified B otrytis cinerea isolates resistant to one or several SDH inhibitors ( SDHIs ) with amino acid substitutions in the SDH B subunit. We confirmed, by site‐directed mutagenesis of the sdhB gene, that each of the mutations identified in field strains conferred resistance to boscalid in B . cinerea , and in some c...