ULTRASTRUCTURE OF TERMITE-ASSOCIATED FUNGUS LABOULBENIOPSIS-TERMITARIUS

Ultrastructural features of L. termitarius suggest that this termite-associated fungus may belong to the ascomycetes. Spores are formed without cleavage vesicles typical of sporangial fungi, abundant epiplasm remains, and septal walls between cells of the simple thallus bear a single pore. A single ascus forms from the base of the terminal sporogeneous cell, but deliquesces by the time of spore maturation. Haustoria are not present, although secretory vesicles were noted in 2 areas of the foot cell suggesting the mode of attachment. Although many aspects of this fungus suggest relationships with the Laboulbeniales, the uniascal thallus, one-celled spores, and lack of haustoria exclude Laboulbeniopsis from this taxon.