No abstract

No abstract

This article provides a summary of current knowledge about wheat metabolites that may affect resistance against Fusarium head blight (FHB). The mechanisms of resistance, the roles of secondary metabolites in wheat defense, and future directions for breeding are assessed. The soluble phenols play an important role in redox regulation in plant tissues and can act as antimicrobial compounds. The color of cereal hulls and grains is caused by such natural pigments as anthocyanins in the aleurone, endosperm, and pericarp layers of the grain. Phenolic acids, alkylresorcinols, and phytohormones actively participate in the defense system, whereas carotenoids show various effects against Fusarium species that are positively correlated with the levels of their mycotoxins. Pathogen infestation of vegetative tissues induces volatile organic compounds production, which can provide defensive functions to infested wheat. The efficient use of native resistance in the wheat gene pool, introgression of resistant alleles, and implementation of modern genotypic strategies to increase levels of native secondary metabolites with antifungal properties can enhance the FHB resistance of new varieties. Expanding the breeding interest in the use of forms with different grain color and plant organs can be a potential benefit for the creation of lines with increased resistance to various stresses.

Twenty-nine common oat (Avena sativa L.) cultivars were used for Fusarium head blight (FHB) resistance assessment during 2015-2017. The cultivars evaluated for FHB resistance were planted in hill plots (sowing into 15 cm circles 25 cm apart) in three replications and two variants (infected and uninfected). The plants were inoculated with a conidial suspension consisting of a mixture of Fusarium poae, F. graminearum and F. culmorum. The visual symptom score (VSS) was evaluated 14 days after inoculation. Yield tolerance to infection was determined by percentage reduction relative to non-inoculated control for the traits thousand grain weight (TGWR) and grain weight per panicle (GWPR). Seeds from infected spikes were analysed for deoxynivalenol (DON) as well as T-2 plus HT-2 toxin contents. It was found that determination of mycotoxin content in grain is necessary in order to fully describe the state of resistance against FHB in oats. Naked oat (A. nuda L.) cultivars were found to have higher resistance levels for all the tested traits and also lower concentrations of mycotoxins. Naked oat cultivars 'Kamil', 'Tibor', 'Izak', 'Otakar', 'Vjatskii', 'Saul', 'Avenuda', 'Gana' and 'Aldan' showed higher levels of resistance against FHB for of all the evaluated traits. The lowest concentration of DON was determined in the cultivar 'Vjatskii'. The weather conditions significantly influenced the development of infection in individual years and traits related to FHB resistance.