Fig. 2

Schematic diagrams of in vitro stem segments inoculation methods used in this study. A Selected 1-year-old branches from 3-year-old poplar hybrid clones, washed, sterilized and cutted into 25–30 cm segments. B Soaked the segments in water. C inoculated the segments using the mycelium plugs of canker pathogen, and covered the inoculated sites. D Pricked the inoculated sited using a needle. E Observed the formation of the necrotic lesion on the segments after inoculation