Sporogenic germination of sclerotia in Aspergillus flavus and A. parasiticus

Abstract

Sclerotial germination in A. flavus and A. parasiticus is sporogenic, with conidial apparati produced directly from exposed sclerotium surfaces. Five of seven A. flavus strains formed conidial heads on individual surface-sterilized sclerotia within 48–72 h incubation on moist sand. Sclerotia incubated on nonsterile field soil also germinated to produce conidia and sclerotia buried for 10 days in nonsterile soil produced conidia within 72 h after being washed to the soil surface. Sporogenic germination may be important in enabling A. flavus and A. parasiticus to disseminate conidial inoculum. Eventual control of preharvest A. flavus infection in crops where aflatoxin is a problem may require agronomic practices designed to reduce the importance of sclerotia as a source of primary inoculum.