Abstract
Infection process by Mycovellosiella nattrassi, the causal agent of leaf mold of eggplant, was histologically observed on host and nonhost plants using scanning electron and bright field microscopy. The fungus penetrated the leaf tissues through stomata. After penetration, the hyphae ramified and grew in the intercellular spaces of the spongy mesophyll cells. After vigorous growth in the spongy cells, aerial hyphae grew through stomata onto the leaf surface. In a comparison of the infection process between the adaxial and abaxial sides of the leaf after artificial inoculation, infection was more frequent on the abaxial side than adaxial. Aerial hyphae also developed more rapidly through stomata on the abaxial side. As one of the host responses, cytoplasm became granulated in the palisade and epidermal cells. On a nonhost, such as tomato and sweet pepper, the fungus also penetrated in the same mode as in eggplants; however, the growth of hyphae on nonhost plants was poorer than that on eggplants.
