DIMORPHISM OF SPORES OF NOSEMA SPP IN CULTURED-CELL

A Nosema sp. from the lawn grass cutworm, Spodoptera depravata, produced two types of spores in cultured cells of Antheraea eucalypti. One was characterized by 3 to 5 coils of the polar tube, thin endospore (35 nm), early development (36 hr postinoculation), and the spontaneous discharge of a short polar tube. The other type characterized by 10 to 12 coils of the polar tube, thick endospore (91 nm), and late development (54 hr postinoculation) was the predominant spore in later culture and was similar to the purified spores harvested from diseased insects, which discharged a long polar tube. Nosema bombycis similarly produced two types of spores in cultured cell. © 1991.