The potential of repetitive-sequence-based polymcrase chain reaction (rep-PCR) fingerprinting of fungal genomic DNA as a rapid and simple alternative to random amplified polymorphic DNA (RAF'D) analysis in the study of phylogenetic relationships, and also as a diagnostic method, was investigated with species of Tilletia. DNA primers (BOX, ERIC and REP) corresponding to conserved repetitive element motifs, originally described in prokaryotes, were used to generate genomic fingerprints of T. indica, T. walkeri, T. controversa, T. laevis, T. tritici, T. goloskokovii, T. barclayana and members of the T. fusca complex. Computer-assisted analysis of the database of combined fingerprints clearly distinguished each taxon and indicated phylogenetic relationships consistent with previously reported RAPD analyses. There were three main cluster groupings where isolates showed 35-40% similarity. Group 1 included T. indica and T. walkeri, group 2 included members of the T. fusca complex, as well as T. controversa, T. laevis, T. tritici and T. goloskokovii, and group 3 included only T. barclayana. If, as is likely, the conserved repetitive element motifs on which this technique is based are widespread or universal in fungal species, rep-PCR shows strong potential, not only as a simple generic taxonomic tool, but also as a diagnostic method.

The potential of repetitive-sequence-based polymerase chain reaction (rep-PCR) fingerprinting of fungal genomic DNA as a rapid and simple alternative to random amplified polymorphic DNA (RAPD) analysis in the study of phylogenetic relationships, and also as a diagnostic method, was investigated with species of Tilletia. DNA primers (BOX, ERIC, and REP) corresponding to conserved repetitive element motifs, originally described in prokaryotes, were used to generate genomic fingerprints of T. indica, T. walkeri, T. controversa, T. laevis, T. tritici, T. goloskokovii, T. barclayana, and members of the T. fusca complex. Computer-assisted analysis of the database of combined fingerprints clearly distinguished each taxon and indicated phylo-genetic relationships consistent with previously reported RAPD analyses. There were three main clusters with isolates showing 35 to 40% similarity. Group 1 included T. indica and T. walkeri; group 2 included members of the T. fusca complex, as well as T. controversa, T. laevis, T. tritici, and T. goloskokovii; and group 3 included only T. barclayana. If, as is likely, the conserved repetitive element motifs on which this technique is based are widespread or universal in fungal species, rep-PCR shows strong potential, not only as a simple generic taxonomic tool, but also as a diagnostic method.

The diversity found in culture collection strains of Curtobacterium flaccumfaciens pv. flaccumfaciens was characterized by serology and repetitive-sequence-based polymerase chain reaction (rep-PCR). Using strain NCPPB 559 as the reference antigen, immunofluorescence tests with polyclonal and monoclonal antibodies confirmed that no epitope appeared to be common to all strains of this pathovar. Screening of hybridoma cell lines againsl strains of this pathovar, as well as against other members of this genus and species, identified two distinct epitopes. Phylogenetic analysis of the rep-PCR genomic fingerprints of Curtobactei; Clavibacter, and Rathayibacter species, grouped all the C. flaccumfaciens strains and pathovars together, but the C. flaccumfaciens pv. flaccumfaciens strains did not form a single cluster. Rather, they dispersed into two clusters, along with strains of other pathovars of this species. Members of one cluster reacted with one of the monoclonal antibodies, while members of the other did not.Résumé : La diversité constatée dans des collections de souches de Curtobacterium flaccumfaciens pv. flaccumfaciens a été caractérisée par sérologie et par la methode rep-PCR (reaction en chaTne de la polymérase basée sur des sequences répétitives). La souche NCPPB 559 servant d'antigène de reference, des épreuves d'immunofluorescence a l'aide d 1 anticorps polyclonaux et monoclonaux ont confirmé qu'aucun épitope ne semblait commun a toutes les souches de ce pathovar. La comparaison des lignées d'hybridomes avec ce pathovar, ainsi qu'avec d'autres membres de ce genre et de cette espèce, a mis en evidence deux épitopes distincts. L'analyse phylogénétique des empreintes génomiques obtenues par rep-PCR d'espèces de Curtobactei; de Clavibacter et de Rathayibacter a eu pour résultat de regrouper tous les pathovars et souches de C. flaccumfaciens, mais les souches de C. flaccumfaciens pv. flaccumfaciens ne formaient pas un groupe unique. Elles se répartissaient plutot en deux groupes, a l'instar des souches d'autres pathovars de cette espèce. Les membres d'un groupe ont réagi avec l'un des anticorps monoclonaux, mais pas ceux de l'autre groupe.Mots clés : Curtobacterium, sérologie, reaction en chaine de la polymérase basée sur des sequences répétitives.

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