Fixation of dormant Tilletia teliospores for thin sectioning.

Dormant Tilletia caries teliospores in fixative solution or distilled water were frozen onto specimen chucks of an FTS Sorvall-Christensen frozen thin sectioner and cut or fractured at various temperatures (-20 C to -75 C) and thickness settings (10, 15, 20 and 25 mum). Cytoplasm of dormant spores was well preserved and organelles were found to differ from those of germinated spores in morphology. This procedure makes it possible to fix adequately dormant spores and thus compare the ultrastructure and histochemistry of dormant spores with those of germinated spores.