species (Glomerellales, Glomerellaceae) causing walnut anthracnose in China.

species can function as plant pathogens, saprobes or endophytes on a wide variety of plant hosts and are considered amongst the ten most significant genera of plant pathogens globally. China contributes almost half the walnut production in the world. However, species occurring on walnut remain largely unresolved in China. To explore the species found on walnut in China, 470 walnut fruit or leaf samples with anthracnose were collected from 14 main walnut-producing regions across seven provinces. A total of 165 strains were isolated from these samples. The isolates were identified, based on morphological characteristics and sequence analyses of , , , ITS and . Twelve species, including 11 known species (, , , , , , , , , and ) and a novel species ( ) were identified. The species distribution revealed regional prevalence as follows: was the most dominant species in Gansu, and in Shandong, in Beijing, in Shaanxi and in Yunnan. was the sole species isolated in Sichuan and Xinjiang Provinces. Koch's postulates were fulfilled, demonstrating that all 12 species cause anthracnose on walnut. This is the first report of , and as pathogens of walnut anthracnose worldwide.