Pathogenicity and mycotoxin profile of Fusarium spp. inducing wheat head blight in Algeria

Abstract

Fusarium is one of the world's most harmful wheat pathogens, causing severe crop diseases like Fusarium head blight (FHB). They constitute a serious threat to the production of wheat by considerably reducing crop yield, quality, and safety due to grain contamination with mycotoxin. The focus of the current study emphasizes aspects related to the pathogenicity and toxigenicity of some FHB isolates recovered from symptomatic Algerian wheat samples. Three genotypes of durum wheat were subjected to two pathogenicity tests (in vitro and in vivo), and the results showed a significant difference in aggressiveness on different phenotypic parameters, indicating intrinsic genetic variation in the host-pathogen interaction. All of the Fusarium isolates tested for mycotoxinogenicity produced Deoxynivalenol, zearalenone, and T-2 toxin. With DON, the most common mycotoxin type, producing 7.128µ/kg in the ELISA test and 373196.19µg/kg by LC-MS/MS, exceeding the European limits (1750µg/kg), the FusBo59 isolate of F. culmorum stands out as the most toxic. Following DON (18.2%) and 3-ADON (9.1%), 15-ADON (63.6%) emerged as the most prevalent toxin in wheat grains, according to a toxin analysis. T-2 and zearalenone (ZEN) were present, but at concentrations below the permissible limits (100µg/kg). On the other hand, F. avenaceum FusBi7 stood out as being the most aggressive, and the Cirta variety was the most tolerant to attacks from the Fusarium isolates studied. Thus, our data demonstrate that disease induction and toxin generation evolve independently of each other.