Canes from diseased vines located in Geneva, NY, were collected during the spring of 2013 and incubated in a clean, sealed plastic box with wet paper towels to provide humidity. Diaporthe ampelina conidia were collected from oozing lesions and plated on potato dextrose agar (PDA, Difco Laboratories, Detroit, MI, USA), and emerging colonies were subcultured onto fresh PDA plates. Cultures were maintained at room temperature under fluorescent light and transferred to fresh PDA every 3–4 weeks. For RNA-Seq experiments, controlled inoculations were made using a solution of conidia obtained by flooding pycnidia-bearing colonies on PDA plates with sterile distilled water; after approximately 5 min, the resulting spore suspension was decanted and diluted in sterile water plus Tween 20 (10 µl/l) to a final concentration of 107 conidia/ml.