First Detection of Wilsonomyces carpophilus Causing Peach Fungal Shot Hole in Xizang Autonomous Region, China

Peach ( Prunus persica L.), a globally cultivated fruit crop belonging to the family Rosaceae, is severely affected by fungal shot hole in production areas worldwide. In this study, peach fruit ( P. persica ‘Xiahui 1’) exhibiting typical fungal shot-hole lesions was collected from Lhasa, Xizang Autonomous Region, China. The symptoms appeared as sunken lesions with reddish-brown margins, which often coalesced to form larger spots under severe disease conditions. Three fungal isolates were obtained from symptomatic fruit. Morphological characterization determined that conidia were spindle-shaped with ovate apical cells and truncated basal cells and ranged from hyaline to pale brown or dark brown, containing 0 to 7 transverse septa (predominantly 2 to 3) and occasionally 1 to 2 oblique septa. Phylogenetic analysis based on the internal transcribed spacer, the large subunit ribosomal RNA, and the translation elongation factor 1-α gene sequences confirmed the identity of the isolates as Wilsonomyces carpophilus. Pathogenicity tests demonstrated that inoculation of healthy peach fruit and leaves resulted in symptoms consistent with those observed in naturally infected samples. The pathogen was successfully reisolated from all inoculated plant tissues, fulfilling Koch's postulates. This study represents the first report of W. carpophilus isolation from symptomatic peach fruit in the Xizang Autonomous Region, China.