Phytotoxicité de huit mycotoxines associées à la fusariose de l'épi chez le blé

Abstract

The study of eight mycotoxins from Fusarium spp. at concentrations ranging from 0 to 4.3 mg/L for deoxynivalenol, 3-acetyldeoxynivalenol, nivalnol, and a culture filtrate, and from 0 to 14.3 mg/L for T2 toxin, HT2 toxin, diacetoxyscirpenol, and zearalenone, demonstrate that trichothecenes are phytotoxic. The inhibition of coleoptile elongation by each trichothecene is well described by a linear equation and these compounds show differences in phytotoxicity. Deoxynivalenol and 3-acetyldeoxynivalenol are 2.5 times more toxic than T2 toxin, 8 times more toxic than HT2 toxin, and 13 times more toxic than diacetoxyscirpénol. The culture filtrate, which contains deoxynivalenol and 3-acetyldeoxynivalenol, is the most toxic to the coleoptile. A mixture of four purified trichothecenes, deoxynivalenol, 3-acetyldeoxynivalenol, T2 toxin, and nivalénol, revealed differences in trichothecene susceptibility among 11 wheat cultivars. Moreover, reduction of coleoptile elongation of these cultivars was correlated with scabsusceptibility (r = 0.74; P = 0.0068).