Infection and Fungal Development of Tubakia dryina on Sweet Gum (Liquidambar styraciflua)

Infection and fungal development of Tubakia dryina were investigated on leaves of sweet gum using a combination of microscopic techniques. Conidia of T. dryina adhered to the leaf surface and formed septate germ tubes. Germ tubes terminated in small appressoria that formed directly over epidermal cells. Intra- and intercellular hyphae ramified extensively throughout the leaf tissue. Host cells associated with the infection site became necrotic and collapsed, resulting in macroscopic disease symptoms.