sp. nov.: A New Species Causing Canker and Dieback of Fruit Trees in China.

Canker and dieback are serious fungal diseases of woody plants that can cause huge economic losses to orchards. The purpose of this study was to classify and assess the pathogenicity of fungal species associated with canker and dieback on fruit trees growing in Henan Province, China. In total, 150 isolates of were obtained from six different fruit trees exhibiting typical symptoms of stem canker, branch dieback, and gummosis. Morphological examinations and phylogenetic analysis of ITS, , , and revealed two species, which are and a novel species, , respectively. Using Koch's postulates, we confirmed that the different isolates of can cause disease in their original hosts. The pathogenicity tests showed that can cause canker, dieback, and gummosis symptoms in four different hosts, indicating a relatively wider host range. Moreover, 10 isolates exhibited similar symptoms but different levels of virulence on shoots of peach trees under field conditions. This study demonstrated that was a new causal agent of canker and dieback of six fruit tree species, which could be a serious risk to the orchard industry in China. Furthermore, the findings provide a foundation for further epidemiological studies and the development of management strategies.