Cleistothecia of Eupenicillium ochrosalmoneum form naturally within corn kernels

Abstract

Eupenicillium ochrosalmoneum Scott & Stolk formed cleistothecia in insect-damaged and fungus-infested preharvest corn from fields near Tifton, GA. When fungus-infested ears were incubated in moist chambers (21 days dark incubation; 25 °C), large numbers of immature sclerotioid cleistothecia (50–150) developed within individual kernels, often filling them. The cleistothecia were exposed by removing sections of the kernel pericarp. Isolates of E. ochrosalmoneum that were obtained from individual surface sterilized cleistothecia proved to be prolific cleistothecial producers. Cleistothecia also formed within kernels inoculated after autoclaving. Production of the teleomorphic state typical of E. ochrosalmoneum was observed when these kernels were incubated up to 10 weeks. This represents the first time that any species assigned to the Trichocomaceae has been shown to form cleistothecia within the seeds of vascular plants. Citreoviridin, a potent neurotoxin, was produced in culture media inoculated with one of the isolates (NRRL 6568).