Phytotoxicity of indole alkaloids from cereals

a test with the microalga chlorella vulgaris was used to evaluate the allelopathic potential activity of indole alkaloids present in cereals. gramine, the main indole alkaloid present in barley shows the highest toxicity. a model mechanism of action for auxin was used to analyze the structural effect on the observed toxicity. germination inhibition on seeds and shoot length inhibition activities of gramine on barley, rye, oat, wheat, lettuce cultivars and the weed lollium rigidum were measured. results are discussed in relation to the phytotoxic selectivity of gramine on the seeds germination. in addition, the toxicity of barley aqueous extracts on the germination of oat seed was also determined. phytotoxicity of the extracts is in agreement with the phytotoxicity of pure gramine.