Identification of Caragana arborescens shoot blight disease caused by Phaeobotryon caraganae sp. nov. (Botryosphaeriales) in China

In Harbin, Heilongjiang, China, a shoot blight of Caragana arborescens exhibiting light brown-to-brown sunken lesions with immersed fruiting bodies was observed during May through October of 2017. A survey was conducted to determine the extent and severity of the disease. In May 2017, a total of 12 diseased C. arborescens trees were found among 80 samples, with a field infection rate of 15%. Twelve random branches showing symptoms were collected and examined for symptoms and signs. Phylogenetic analysis, morphology, and isolate pathogenicity towards C. arborescens after inoculation of 20 healthy branches with spore suspensions revealed a new pathogenic species causing the shoot disease, which is described here as Phaeobotryon caraganae. P. caraganae is a new species and causes C. arborescens shoot disease. Future research on Phaeobotryon is important to improve our understanding of shoot diseases.