The Structure of the Spores of Gigaspora Margarita

SUMMARY Light and electron microscopy have been used to study the changes that accompany germination in the spores of Gigaspora margarita. Regular germination is achieved following surface sterilization of the spores and the possible role played by sodium hypochlorite in spore activation is discussed. Following spore activation there is considerable redistribution of cytoplasm with a subsequent accumulation of cytoplasmic and wall material in the region of the bulbous‐shaped attachment. Germ‐tube development occurs in this region without the production of peripheral compartments that have been described for other spore types. The possible significance of this feature and the mode of germ‐tube wall development are discussed.