Introductory biology of Fusarium moniliforme.

Fusarium moniliforme is a name that has been applied to any of six biological species (or mating populations) that share the teleomorph (sexual stage) Gibberella fujikuroi. Two of these six biological species, termed "A" and "D", are known to produce fumonisin mycotoxins. Strains from the "A" biological species grow as endophytes on maize and often comprise 90+% of the Fusarium isolates recovered from healthy maize seed. It is possible to distinguish all six biological species using sexual fertility and isozymes. Other attributes, such as morphological characters and sequences from the ribosomal DNA internally transcribed spacer (rDNA-ITS) region, can be used to identify some, but not all, of the biological species. Within a biological species, genetic variability and population structure can be assessed with anonymous RFLPs and tests of vegetative compatibility. The "A" biological species is genetically diverse, and the sexual cycle appears to be important in the life cycle of field populations of this organism in the United States.