First report of branch blight disease caused by Aplosporella longipes on Physocarpus amurensis in China

From June through October 2020, symptoms of a branch blight disease were observed on Physocarpus amurensis plants in Harbin City, Heilongjiang Province, China. Leaves on infected branches were chlorotic, with many raised, grey spots forming on the epidermis of diseased branches. Diseased twigs formed semi-buried, small, spherical pycnidia, which were initially light brown and later turned dark. The pathogen was isolated and its pathogenicity was verified with Koch's postulates. Based on morphological characteristics and DNA sequence data the pathogen was identified as Aplosporella longipes. This is the first report of A. longipes in China and the first report of it causing branch blight disease of P. amurensis.