Detached Twig Assay for Bacterial Canker Response Evaluation on Peach v2

A detached dormant twig assay, previously applied in cherry, was adapted to evaluate peach germplasm response to Pseudomonas syringae pv. syringae (Pss). Dormant shoots were cut into 10 cm segments, surface-sterilized, and inoculated with either a Pss suspension resuspended in 10mM MgCl2 buffer or with the buffer alone. Following six weeks of incubation, including one week at low temperature to induce ice nucleation, inner bark lesion length was quantified visually and using ImageJ. This assay effectively differentiates genotypes based on lesion development, providing a method to assess tolerance to bacterial canker in peach.