Figure 5

Ultrastructure of the conidial wall as visualised by transmission electron microscopy. Conidia from reference strains CBS 113.26 (A) and IHEM 18963 (B and C) cultivated in the presence (C) or not (A and B) of pyroquilon 20 μg/mL, or of mutant isolates (D and E: pigmentless isolates IHEM 2508 and 9860; F: brownish isolate IHEM 15998) were processed for ultrastructural examination of their cell wall. Note the smooth surface of the conidia of reference strains cultivated in the presence (C) of pyroquilon and mutant isolates (D, E, F) and the lack of the outermost cell wall layer (arrowheads) which sometimes appears free in the surrounding medium (arrows). Bars correspond to 500 nm.