Wall fibrils ingerminating sporangiospores of Gilbertella persicaria (Mucorales)

Summary In germinated sporangiospores of Gilbertella persicaria, negatively contrasted fibrils, 20–70 Å diam, are seen in thin sections of the inner vegetative wall that is continuous with the germ tube wall. The fibrils are randomly oriented in a loose network in this wall and in the germ tube wall. Germ tubes have an additional surface layer of fine, positively contrasted fibrils which appear as a nap-like coating on the hyphae. Patterns of wall fibril orientation are not revealed by transverse sections of spore and germ tube walls, whereas oblique and tangential sections are favorable for examining cell wall architecture in situ. Staining patterns show textural and compositional differences among various wall layers.