Figure 2

Aspects of hyphal organization before fruiting of M. perniciosa. A-D: Scanning electron micrograph shows aerial hyphae. E-F. Section of mycelial mat of the "dark reddish pink" stage on dead cocoa branch, stained with Lugol and Safranine. A: Hyphae of mycelial mat in the white phase (Griffith medium). Note branched hyphae (yellow arrow), hyphal fusion (white arrow), thin layer apparently composed by cell wall materials (red arrow) and hyphae with irregular aspect (pink arrow; bar = 10 μm). B. Details of external hyphae after some days of exposure of mycelial mat to frequent irrigation. Note impregnated material in superficial hyphae (bar = 10 μm). C. Dark reddish pink mycelia with protuberance on the hyphae surface were they over layer the impregnated material, fanning out in ring shape (bar = 20 μm). D. Amorphous material recovering hyphae in differentiated primordium (bar = 10 μm). E. An outer layer (arrow) and aggregate aerial hyphae can be seen on the surface (bar = 0.12 mm). F. Hyphal nodule observed in reddish-pink mycelium (bar = 0.04 mm).