Diversity of Species Associated with Trunk Diseases of (Peach) in Northern China.

Peach () is widely cultivated in China, but fungal diseases, particularly Cytospora canker, significantly impact tree health, reducing fruit yield and economic value. This disease mainly weakens tree branches and trunks, sometimes leading to tree death. There are no updated studies on the diversity of species associated with peach Cytospora canker in northern China. To determine the species associated with this disease, we surveyed five provinces from 2022 to 2023, collecting 72 disease samples with symptoms including branches with black fruiting bodies, cankers, cracking, dieback, and gummosis. Through morphology and multi-loci phylogeny, 127 isolates were identified into four known (, , , and ) and two previously undescribed species ( sp. nov. and sp. nov.). (73.60%) was the most abundant. Pathogenicity tests indicated that except for , all other species were pathogenic to peach, with . being the most aggressive. This study is the first to report the novel host association of on peaches globally and represents the first comprehensive investigation of species associated with canker diseases in the main peach production area in northern China, offering a foundation for developing effective disease management strategies.