A novel Cryphonectria species (Cryphonectriaceae, Diaporthales) discovered on Eucalyptus, including insights into the mating biology of the genus.

A new Cryphonectria species, Cry. eucalypticola, was discovered on Eucalyptus in North Sumatra and is only mildly pathogenic.

• Why it matters: Understanding the diversity and biology of Cryphonectria species is important due to their ecological and economic impacts as pathogens, exemplified by the chestnut blight.
• What they did: Researchers used DNA sequencing of six loci, phylogenomic analyses, and morphological observations to identify the fungus, and conducted inoculation trials on four eucalypt genotypes, revealing its mild pathogenicity and homothallic mating system.
• The result: The findings show that Cry. eucalypticola is likely an endophyte with low aggressiveness, and its presence on trees infected by Ceratocystis manginecans suggests it sporulates on dying bark, expanding knowledge of Cryphonectria diversity and reproductive biology.