ABSTRACT
Immature ascostromata of Eupenicillium ochrosalmoneum, a citreoviridin-producing fungus, that were recovered from dried corn ears at harvest ripened to form ascospores when incubated (25 C) on moist nonsterile soil. Percentages of ascostromata containing ascospores were recorded for the following incubation intervals: 2 wk = 0%; 4 wk = 72%; 6 wk = 82%; 8 wk = 87%. Immature ascostromata harvested from 2-, 3-, 4-, and 5-wk-old cultures grown on autoclaved corn kernels were also capable of ripening on soil, their rates of ripening being similar and independent of the time of harvest. Burial of immature ascostromata in soil prevented ripening. The temperature range favorable to ascospore formation (20–30 C) was narrower than that for ascostroma production (20–37 C) or vegetative growth (15–37 C). The dispersal of immature ascostromata onto field soils during corn harvest, with their subsequent ability to form ascospores on soil, suggests that the ascostroma may be an important source of inoculum in the disease cycle of E. ochrosalmoneum.