Eighty-seven strains belonging to 18 species of
Fusarium were characterized by restriction fragment length
polymorphism (RFLP) analysis of ribosomal DNA (rDNA). The polymerase
chain reaction (PCR) was used to amplify a fragment including internal
transcribed spacers and variable domains of the 28S rDNA. Data from
RFLP analysis of amplified rDNA using eight frequent-cutting
restriction enzymes permitted the definition of 23 rDNA haplotypes.
The combination of only four restriction enzymes was sufficient to
resolve the 23 haplotypes. Each haplotype could be assigned to a
single Fusarium species, except for two haplotypes which were
common to two or three closely related species. Polymorphism was found
within some Fusarium species. Grouping among
Fusarium strains derived from restriction analysis was, on
the whole, in agreement with other molecular and morphological
classification criteria. Therefore, the PCR/RFLP method described
in this paper provides a simple and rapid procedure for the
differentiation of Fusarium strains at the species
level.