Phytotoxic substances with allelopathic activity of Norantea guianensis on cultivated species and weeds

Resumo

Allelopathy is a type of chemical interference, which occurs when plant species produce compounds that affect the growth of other species and a promising area for the herbicides formulation. In this context, it was aimed to study the species Norantea guianensis (Marcgraviaceae) and evaluate the allelopathic activity of its leaves on the seeds and initial growth of lettuce, tomato and coffee senna seedlings. The experimental design was completely randomized, evaluating the chemical composition of the leaves and the germination and growth in the germination chamber and vegetation house. With the chemical profile (aqueous and ethanolic), 10 classes of constituents were detected in the extracts. The major components were phenolic compounds and derivatives, differing only in the intensity of reducing sugars, saponins, steroids, triterpenes and coumarins. Among the phenolic derivatives it was possible to detect gallic acid, rutin, 1-2 benzoquinone and a quinone. The process of seed germination and seedling formation was affected negatively, indicating that the presence of secondary compounds have inhibitory action, demonstrating that the species has potential in the search for herbicidal compounds.