Tolyposporium penicillariae, the causal agent of pearl millet smut

Abstract

Sporeballs of the pathogen of Pennisetum americanum varied from circular to near-polyhedral (42-325 × 50-175 µm) and contained 200-1400 teliospores. Teliospores were mostly circular, 7-12 µm diam. Max. germination of aggregated teliospores occurred at 30°C and different germination patterns were observed. Cultural characters on different media varied. The fungus grew well within 3-5 days on potato or carrot agar at 35°. Growth remained purely sporidial even after repeated subculturing. Sporidia were borne on promycelia, laterally and/or terminally and reproduced by budding. Sporidia were spindle-shaped, 8-25 µm long. Individual separated teliospores seldom germinated. The use of sporidial inoculum in screening for smut resistance in P. americanum is discussed