New informative molecular markers for Alternaria sections Infectoriae and Pseudoalternaria reveal the diversity of lineages infecting wheat and tomato.

Four new molecular markers enabled precise identification of Alternaria lineages, revealing six distinct groups including a novel lineage infecting wheat in western Canada.

• Why it matters: Accurate classification of Alternaria fungi is crucial for understanding their role in crop diseases and mycotoxin production, but existing markers lack resolution. Addressing this gap improves disease management and risk assessment in agriculture.
• What they did: Researchers developed four highly informative molecular markers from phylogenomic data and tested them on 237 strains from wheat and tomato crops across Canada and Europe, analyzing phylogenetic relationships.
• The result: The markers successfully distinguished all known lineages and identified a new one, Inf4, with high consistency, enabling better tracking of fungal diversity, host associations, and geographic distribution for crop protection.