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

Four new molecular markers revealed 5 lineages, including a novel Inf4, within Alternaria sections Infectoriae and Pseudoalternaria infecting wheat and tomato.

• Why it matters: Understanding the diversity and classification of these fungi is crucial for managing their impact on crops and for studying their pathology and mycotoxin production, but current markers lack resolution.
• What they did: Researchers developed four highly informative markers (SIP-03, SIP-04, SIP-06, SIP-08) and evaluated them using 237 strains from wheat in Canada and tomatoes in the Baltic states, representing the largest dataset to date.
• The result: The markers showed high amplification success and phylogenetic signal, with 94.1% of strains consistently assigned across markers, enabling refined phylogenetic understanding and supporting future epidemiological and pathological studies.