First report of powdery mildew caused by Podosphaera macularis on Potentilla indica in Henan Province, China

Powdery mildew was observed on Potentilla indica (mock strawberry) in Xinyang, Henan Province, China, during April and May from 2024 to 2026. The pathogen was identified as Podosphaera macularis based on morphological characteristics combined with phylogenetic analyses. Microscopic examination revealed typical features of Podosphaera, including subcylindrical to barrel-shaped conidia with distinct fibrosin bodies. The internal transcribed spacer (ITS), large subunit (LSU) rDNA, and beta-tubulin (TUB2) sequences of specimen SMZML (GenBank accessions PZ463255, PZ463257, PZ467648) showed 100% identity to Po. macularis reference sequences. Phylogenetic analysis of the concatenated ITS LSU-TUB2 dataset placed the specimen within a highly supported Po. macularis clade. Pathogenicity was confirmed by fulfilling modified Koch’s postulates, with symptoms developing 9–12 days after inoculation. This is the first report of powdery mildew caused by Po. macularis on P. indica in Henan Province, China. These results expand the known host range of Po. macularis and indicate that P. indica may serve as a reservoir for powdery mildew inoculum, potentially affecting other rosaceous crops.