Differentiation of Fusarium Species by Restriction Fragment Length Polymorphism Analysis of PCR-Amplified Ribosomal DNA

Fusarium species are ubiquitous soil-borne fungi, responsible for numerous plant diseases. They form an heterogeneous genus and their identification based on morphological characteristics remains difficult (Nelson, 1991). Our objective was to develop an additional and rapid procedure for the differentiation of Fusarium species, based on polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis of ribosomal DNA (rDNA). In this study, we estimated the variation in internal transcribed spacers (ITSs) and variable domains of the 28S rDNA among 18 Fusarium species. Moreover, for F. oxysporum and two closely related species, the results were compared with those obtained from PCR/RFLP analysis of ribosomal intergenic spacer (IGS) sequences.