Identification of phytotoxic metabolites of a new Fusarium sp. inhibiting germination of Shiga hermonthica seeds.

An undescribed species of Fusarium was isolated from the parasitic plant Striga hermonthica in Sudan. When grown both on liquid and solid media this strain produced toxic compounds causing the total suppression of germination of Striga seeds. Purification of the liquid culture led to the isolation and identification of fusaric and dehydrofusaric acid, at 263 and 382 mg l-1 respectively. The organic extract of solid culture did not contain those acids nor some other powerful known Fusarium toxins, but showed the presence of three main toxic metabolites, having a strong inhibitory activity, whose identification is in progress.