Mycotoxin profiles and plumpness of Tritordeum grain after artificial spike inoculation with Fusarium culmorum W.G. Smith

Abstract

The responses to artificial spike inoculation with Fusarium culmorum were compared in 11 Tritordeum lines, two durum wheat cultivars and one naked barley cultivar. Inoculation of Tritordeum spikes led to a significant decrease in spike weight, kernel weight per spike, and kernel weight (by 18, 28, and 16 %, respectively). Durum wheat responded most strongly to inoculation, particularly with regard to spike weight and kernel weight per spike (decrease of 42 % and 53 %, respectively). Inoculation induced a significant increase in the total concentration of trichothecenes (9902 vs 558 μg/kg in non-inoculated control) and other Fusarium toxins (40,207 vs 3250 μg/kg in non-inoculated control) in Tritordeum grain. The content of three Alternaria toxins was not significantly modified by inoculation. The principal component analysis (PCA) of all fungal metabolites supported the discrimination of control and inoculated grain, and the results were used to divide the examined Tritordeum lines into two groups with different mycotoxin profiles. The first group (five lines) was more similar to naked barley, whereas the second group (six lines) showed greater similarity to durum wheat. The analyzed Tritordeum lines responded differently to inoculation, which suggests that lines with a low propensity to accumulate Fusarium toxins in grain can be selected from the existing gene pool. The study also demonstrated that Tritordeum grain accumulates significantly smaller amounts of mycotoxins than durum wheat grain.