This study aims to identify races of V. inaequalis present in the apple-growing regions of Southern Brazil. Apple plants and detached leaves were inoculated by spraying and also by using four drops of inoculum (2.5 x 10(5) conidia.mL-1) on the surface of each leaf. Four fungal isolates from Rio Grande do Sul and five from Santa Catarina State, 2005 season, were used. Following inoculation, the plants were incubated in a controlled environment (RH 90-100%, 16-20 ºC, darkness) for 48 h and then moved to the greenhouse. Sprayed leaves were maintained in agarized water medium and incubated for 48 h in the dark at 17ºC. Afterwards, leaves were dried off and incubated together with the single-drop-inoculated detached leaves, under conditions of 19ºC and 18 h of light. Evaluations were made 20 days after inoculation. The pattern of symptoms led to a conclusion that the nine isolates were of race 1. The same was observed on the spray-inoculated detached leaves but not with the single-drop inoculation method. This is the first report of the presence of race 1 of V. inaequalis in South America.
Malus sp.; apple scab; host-pathogen interactions; virulence; detached leaves