Oomycete Pythium spp. and fungi Fusarium spp. and Gaeumannomyces spp. were isolated from discolored tissues of wheat root. Pathogenicity tests revealed that Pythium and Fusarium populations contain strains of different level of pathogenicity. There were also several nonpathogenic Fusarium isolates. Gaeumannomyces population consist of the only high pathogenic isolates.nbsp; Pathogenicity of Fusarium isolates depends on the species. F. graminearum and F. culmorum showed the highest level of pathogenicity. Nonpathogenic isolates of F. oxysporum and F. solani are, probably, the secondary invaders of diseased roots. The pathogenicity of Pythium isolates doesnrsquo;t depend on species. nbsp;