Antifungal activity of methanol extracts from spikes of Triticum spelta and Triticum aestivum genotypes differing in their response to Fusarium culmorum inoculation

Abstract

Abstract:The total concentrations of free phenolic compounds and peroxidase were determined in spikes (collected at the flowering stage) of some spelt and common wheat cultivars differing in their response to F. culmorum infection. The antifungal activity of methanol extracts obtained from spikes was also evaluated. The tested genotypes differed significantly in their response to inoculation. The most resistant were Torka and Zebra among common wheat cultivars, and Weisser Grannenspelz among spelt cultivars. The average content of free phenolic compounds in spikes of spelt and common wheat was 1246.56 µg g −1 and 1236.58 µg g −1 , respectively. The cultivars whose spikes contained the largest amounts of phenols showed the weakest response to F. culmorum infection. No significant differences were observed with regard to peroxidase content, which was 5.22 U g −1 in common wheat spikes and 5.14 U g −1 in spelt spikes. Methanol extracts from spikes of all wheat cultivars contained antifungal substances. The extracts from spelt spikes inhibited the growth of F. culmorum on PDA to a lesser degree than the extracts from common wheat spikes. This corresponds to the results of field trials, in which T. spelta generally exhibited a stronger response to F. culmorum infection than common wheat. The high correlation (r = 0.816) between mycelium growth inhibition on the medium and F. culmorum infection indicates that an evaluation of the antifungal activity of extracts from spikes may be used for the selection of breeding materials directed towards increased resistance to Fusarium head blight.

Effect of 5-n-Alkylresorcinol Extracts from Durum Wheat Whole Grain on the Growth of Fusarium Head Blight (FHB) Causal Agents

“…In consideration of the environmental and economical implications associated with the use of chemical fungicides, there has been an increased interest in discovering biologically active natural compounds and extracts from higher plants as new classes of pesticides. Plant secondary metabolites, once not considered important compounds, are now thought to mediate chemical defense mechanisms by providing chemical barriers against animal and microbial predators and have enormous potential to inspire and influence modern agrochemical research. − Among the secondary plant constituents, alkylresorcinols (ARs) and their derivatives are considered to serve as phytoanticipins and allelochemicals, although direct evidence is still lacking . ARs belong to an extensive family of bioactive compounds, referred to as nonisoprenoid phenolic lipids, which occur primarily in plants, fungi, and bacteria .…”