FIG. 1.

Plant colonization by P. indica. Maize plants were inoculated with P. indica. Roots were harvested 4 (A), 7 (B), and 16 (C and D) days after inoculation, stained, and observed by light microscopy. Bars, 10 μm. (A) A fungal appressorium attached to the root surface. Arrow 1 indicates a hypha leading to the appressorium; arrow 2 indicates a hypha leading away from the appressorium into the plant. (B) A root segment showing intercellular hyphae. Arrows indicate plant cell walls. (C) Cortical cells with coiled and branched intracellular hyphae. (D) Cortical cells showing round bodies.