Biochemical changes in ears of wheat genotypes subjected to Fusarium spp. attack.

In wheat, Fusarium fungus promotes the appearance of destructive disease named as Fusarium head blight (FHB) that can cause grain yield reduction and mycotoxin accumulation. The focus of this research was to verify the influence of Fusarium graminearum and F. culmorum on wheat genotypes with different susceptibility to FHB: "Super Žitarka" (susceptible), "Lucija" (moderately resistant) and "Apache" (resistant). The experiment was performed under field conditions by artificial spore inoculation of ears at the flowering stage. The effectiveness of antioxidative enzymes, hydrogen peroxide (HO) content and malondialdehyde (MDA) content were observed at several sampling points after Fusarium inoculation (3, 15 and 24 hours). "Lucija" responded to pathogen by increase of guaiacol peroxidase (POD) activity, high HO and MDA content in the early post-inoculation times (3 and 15 hours), compared to control. "Super Žitarka" displayed inhibition of catalase (CAT) activity throughout the whole time course of the experiment. Infected plants of "Apache" showed notable decline in MDA content over time. Moreover, in "Apache" increased HO accumulation was observed immediately after Fusarium exposure (3 and 15 hours), compared to 24 hours. Rapid overproduction of HO under Fusarium stress marked "Apache" as FHB-resistant.