ULTRASTRUCTURAL STUDIES OF THE SPORE WALL OF GIGASPORA-ALBIDA (GLOMALES)

Morphological and ultrastructural studies were carried out to describe spore wall structure in Gigaspora albida. Spores at different stages of development were observed, with different wall patterns being ident ified during the process of spore maturation. The spore wall has the f ollowing zones: an outer amorphous electron-dense zone, two inner zone s, each with a different thickness and electron density and an innermo st, electron-dense zone that produces invaginations into the sporoplas m. The third zone becomes laminated during spore development. In more mature spores these laminae are prominent and easily distinguishable w ith the light microscope. These wall laminations are structurally diff erent from those observed in spore walls of other Glomales species.