Identification of the pathogens causing stem canker on Carya cathayensis

Species of the Botryosphaeriaceae family are important pathogens causing cankers and die-back on many woody plants. In previous studies Botryosphaeria dothidea has commonly been reported as a pathogen of Chinese hickory(Carya cathayensis) canker; however, it was unclear whether other species of Botryosphaeriaceae were also related to hickory canker. In one study, several species of Botryosphaeriaceae were isolated from Chinese hickory, and then they were identified based on anamorphic morphology and rDNA Internal Transcribed Spacer(ITS) sequences. A phylogentic analysis indicated that these isolates formed three clades and were identified as B. dothidea, B. fabicercianum, and B. obtusa with isolation rates of B. dothidea(71.42%) predominant and B. fabicercianum and B. obtusa being much lower(14.28%). In pathogenicity testing, all three pathogens caused stem cankers on Chinese hickory but had different degrees of pathogenicity. B. obtusa and B. fabicercianum were first reported as a pathogen of Carya cathayensis canker.