Deoxynivalenol-producing ability of Fusarium culmorum strains and their impact on infecting barley in Algeria
Résumé
The cereal-pathogenic Fusarium culmorum (W.G. Smith), causal agent of various blights and rot diseases, is considered as a chronic fungus of economic concern worldwide including North African countries such as Algeria. This pathogen produces a wide range of mycotoxins, amongst which the type B-trichothecene deoxynivalenol (DON). In addition to its acute and chronic side effects in livestock and humans, DON is believed to play a determinant role in the pathogenesis toward Triticeae. However, regardless its significant occurrence and impact, little is known about trichothecenes-producing ability of F. culmorum infecting cereals in Algeria. The PCR assay based on Tri genes of 12 F. culmorum strains (designated Fc1-Fc12), which were recovered from several cropping areas of North Algeria, revealed their trichothecenes-producing ability with 3-AcDON genotype. The molecular prediction was confirmed by HPLC analysis. All strains were able to produce the toxin at detectable levels. Strains Fc1 and Fc12 were the highest producers of this mycotoxin with 220 and 230 µg g(-1), respectively. The evaluation of pathogenic ability of strains through a barley infesting experiment exhibited the significant disease impact of most strains. Significant correlation between the DON-producing ability of strains and the increase in both disease severity (r = 0.88, P = 0.05) and disease occurrence (r = 0.70, P = 0.05) was observed. Chemotyping of F. culmorum isolates and evaluation of their pathogenic ability are reported for the first time for isolates from Algeria, and highlights the important potential of F. culmorum to contaminate cultivated cereal with DON trichothecenes.
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