VIEW ARTICLE

Penetration of Maize Leaves by Helminthosporium turcicum. P. S. Knox-Davies, Department of Plant Pathology, University of Stellenbosch, Stellenbosch 7600, Republic of South Africa; Phytopathology 64:1468-1470. DOI: 10.1094/Phyto-64-1468.

Penetration of maize leaves by Helminthosporium turcicum was studied in trypan blue-stained whole leaf mounts. Penetration was direct and a fine infection hypha developed from the appressorium. The outer epidermal cell wall became thickened and the plasma membrane invaginated at the site of penetration. An intracellular vesicle was formed at the end of the infection hypha and stout colonization hyphae extended to adjacent cells. Initial subcuticular growth of the fungus and the development of more than one infection hypha from an appressorium were occasionally observed.