Figure 7

Fungal spot-inoculation of plants grown in a pouch. A. An overview of the root system of a 40-day old plant grown in a pouch. The plant was challenged when it was 5 day-old with fungal spores located in an agar plug. Inset: A close-up of the area indicated by a white square in A. The plug (delineated by arrows) was placed below the lateral roots. B. Close up on the roots which were pushed gently into the plug containing the fungal spores. Bar: 0.5 mm. C. An extra-radical hypha and some hyphopodia (asterisks) on the surface of a cleared root inoculated 21 days earlier. D. Arbuscules located within inner cortical cells of a cleared root inoculated 35 days earlier. E. Intraradical hyphae and a vesicle in the cortex of a root 35 DAI. F. An infection unit with extensive hyphal branches; note the hyphopodium (asterisk), the main intraradical hypha (arrowhead), an arbuscule (arrow), and a vesicle (V). C - F: Bar: 20 μm; ink-vinegar staining.