First report of powdery mildew caused by Podosphaera xanthii on Kalanchoe blossfeldiana in China.
Kalanchoe blossfeldiana (Crassulaceae), native to Madagascar, is a herbaceous and commonly cultivated house plant. In March 2015, severe powdery mildew was observed on K. blossfeldiana in Jilin Agricultural University, Changchun, China. The disease incidence was approximately 40 to 80% on leaves of two potted plants. Whitish colonies covered both surfaces of leaves. Based on morphological characteristics, sequence analysis of the rDNA internal transcribed spacer region and pathogenicity tests, the causal agent was identified as P. xanthii. Powdery mildew on K. blossfeldiana has been reported as Golovinomyces orontii, Erysiphe sedi, Oidium sp., Pseudoidium kalanchoes and Sphaerotheca fuliginea. This is thought to be the first report of powdery mildew caused by P. xanthii on K. blossfeldiana in China. The results in this study extended the host range of P. xanthii.