First report of Alternaria black spot of rose caused by Alternaria alternata in China.
During 2017 autumn season, leaf black spot symptoms were observed on rose (Rosa hybrida) plants in the campus of the China Agricultural University in Beijing, China. Subcircular black spots evolved in leaf discoloration and necrosis, seriously reducing the aesthetic value of the plant. The causal pathogen was isolated and identified as Alternaria alternata based on morphological, molecular and pathogenicity analyses. This is thought to be the first report of A. alternata causing black leaf spot on the Rosa genus in temperate regions (East Asia).