Ecotype Lag2‐2 is susceptible to Oidium heveae HN1106. Leaves from 4‐week‐old plants were inoculated with O. heveae HN1106. (A) The symptoms of Arabidopsis accessions Lag2‐2, HKT‐2, Shigu‐2 and Col‐0 infected with O. heveae HN1106 at 10 days post‐inoculation (dpi). (B) Light micrographs of O. heveae growth in the Lag2‐2, HKT‐2, Shigu‐2 and Col‐0 ecotypes at 10 dpi. Light microscopy images were taken after visualization of the fungal structures using Coomassie brilliant blue at 10 dpi. Bar, 50 μm. These experiments were repeated twice with similar results.