Details of the protocols for inoculum preparation and inoculation are given in Chen et al. (2008). Briefly, 35-day-old seedlings were spray-inoculated with zoospore/sporangia suspensions of× 104/mL of selected pathogen isolates. Inoculated seedlings were incubated in a growth room at 100% relative humidity and 20 ± 2C without light for the first 24 h. Afterwards, growth room conditions were maintained at 60–95% RH, a daily 14-h light period (70 E m2s-1) and 20 ± 2 C. Each plant was visually scored 10 days after inoculation according to the following scale, where 0 = nosymptoms; 1 = 1–5% leaf area affected, small lesions