Grayer and Harborne
(1994) listed many flavonoids from higher plants with antifungal activity. Flavonoids (proanthocyanidins and small amounts of
dihydroquercetin) are involved in several defence mechanisms of
barley against Fusarium species (Skadhauge et al., 1997). In resistance against vascular pathogens causing wilt diseases, such as
F. oxysporum and Verticillium albo-atrum, flavonoids are stored in
specialised cells from where they can be infused into attacked tissue, such as xylem vessels. Such leaching is probably involved in
hypersensitive response and programmed cell death as common
mechanisms of plant defence (Beckman, 2000).