Characterization of Diaporthe species associated with peach constriction canker, with two novel species from China

Species of Diaporthe infect a wide range of plants and live in vivo as endophytes, saprobes or pathogens. However, those in peach plants are poorly characterized. In this study, 52 Diaporthe strains were isolated from peach branches with buds, showing constriction canker symptoms. Phylogenetic analyses were conducted using five gene regions: internal transcribed spacer of the ribosomal DNA (ITS), translation elongation factor 1-α (TEF), ß-tubulin (TUB), histone (HIS), and calmodulin (CAL). These results coupled with morphology revealed seven species of Diaporthe, including five known species (D. caryae, D. cercidis, D. eres, D. hongkongensis, and D. unshiuensis). In addition, two novel species D. jinxiu and D. zaofenghuang are introduced. Except for the previously reported D. eres, this study represents the first characterization of Diaporthe species associated with peach constriction canker in China, and contributes useful data for practicable disease management.