The Glomerella Leaf Spot (GLS), caused by Colletotrichum gloeosporioides is an emerging and destructive plant disease, of which little is known about the relationship pathogen/host. The objective of this study was to quantify the number of appressoria per conidium and verify the presence of Conidial Anastomosis Tubes (CAT) formed on apple resistant and susceptible leaves to GLS, inoculated with two isolates of C. gloeosporioides (MANE55 and MANE147). The early penetration events of C. gloeosporioides were similar in both genotypes, but the isolated MANE55 showed a greater number of germinated conidia with multiple appressoria. CAT on lesions of GLS were observed for both the isolates at all time intervals.
glomerella leaf spot; Malus domestica; resistance
