QUANTITATIVE VARIABILITY OF SUGAR RESIDUES AT THE SURFACE OF FUSARIUM-OXYSPORUM CONIDIA AS DETECTED BY LECTIN TYPING

Helix pomatia lectin, Concanavalin A, Wheat germ agglutinin and Tetrag onolobus purpureas lectin were used to identify- N-acetylgalactosamine , D-mannose, N-acetylglucosamine and L-fucose sugar residues, respecti vely, on the surface of microconidia of Fusarium oxysporum strains. On the basis of the use of FITC-labelled lectins, N-acetylglucosamine, N -acetylgalactosamine and D-mannose sugar residues were identified and did not vary qualitatively between the strains tested. L-fucose residu es were not detected, whatever the strain tested. Agglutination experi ments showed a quantitative variability in the carbohydrate residues d etected with ConA and WGA within the F. oxysporum species. The aggluti nation responses of the isolates tested did not reflect either their p athogenicity or their host specificity.