Pestalotiopsis trachycarpicola, a new pathogen of Chinese prickly ash (Zanthoxylum bungeanum Maxim.) leaf spot disease in China

Chinese prickly ash (Zanthoxylum bungeanum Maxim.) is widely cultivated in tropical and subtropical regions for its significant economic and ecological values. However, with increasing acreage, diseases of this crop are becoming more frequent and severe, threatening yield and quality. Leaf spot is a common disease affecting this crop. In October 2022, leaf spots of Chinese prickly ash plants were found in many plantations in Zhenfeng County, Guizhou Province, China, with symptoms of suborbicular or oblong brownish-red lesions and black edges, occurring at an incidence of 17%. In the face of this problem, the aim of this study was to identify the causal agent associated with this symptom. The causal agent was identified as Pestalotiopsis trachycarpicola Y.M. Zhang & K.D. Hyde by morphological characteristics, molecular systematics of the internal transcribed spacer region (ITS), beta-tubulin (tub2), and translation elongation factor 1-alpha (tef1-alpha) genes sequences, and pathogenicity test. As far as we know, this is the first report of P. trachycarpicola causing leaf spot disease on Chinese prickly ash in China. This study provides valuable information for developing management strategies to control this disease on Chinese prickly ash.