First report of Botryosphaeria dothidea causing leaf blight on Yulania denudata in China

Yulania denudata are widely cultivated in China and worldwide for their versatile uses. Thus, sustainable disease management requires critical knowledge of Y. denudata pathogens. In August 2022, a leaf blight disease was observed on Y. denudata mature tree in the campus of Nanjing Forestry University, located in Xuanwu district, Nanjing City, Jiangsu Province, China. Isolations from the symptomatic leaves yielded Botryosphaeria-like fungal isolates. Phylogenetic analysis utilizing internal transcribed spacer (ITS), translation elongation factor 1-α (EF1-α), and β-tubulin (TUB) of isolate YL 2–1, YL 4–2, YL 5–3, YL 6–1 confirmed the species as Botryosphaeria dothidea. Leaf inoculations with the representative isolate YL 6–1 produced disease symptoms on Y. denudata. Finally, Koch's postulates were established by re-isolation and re-identification of B. dothidea isolates from the inoculated leaves. To the best of our knowledge, this is the first report of B. dothidea causing foliar disease symptoms on Y. denudata in China. These findings will contribute to developing disease management strategies for Y. denudata leaf blight.