ALLELOPATHIC ACTIVITY OF Amburana cearensis SEED EXTRACTS ON MELON EMERGENCE

Abstract

Amburana cearensis is a species rich in coumarin, a phenolic compound that is a natural inhibitor of the germination process. In Caatinga, this species occurs in areas where melons are cultivated, and even after deforestation, they may be present in the soil seed bank. The aim of this study was to investigate the allelopathic activity of A. cearensis aqueous seed extract fractions on the emergence of melons and to carry out photochemical analyses of the extracts. Four experiments were carried out based on the fractionation of the seed extract: E1 - hexane fraction, E2 - dichloromethane fraction, E3 - ethyl acetate fraction, and E4 - aqueous fraction. The statistical design was completely randomized, with four replicates, each having 20 seeds. The treatments were composed of different extract concentrations (1, 0.5, 0.25, 0.125, and 0%) and phytochemical prospecting of the extracts obtained during fractionation was performed. The extracts obtained from the hexane fraction affected the emergence and initial development of melon seedlings. The dichloromethane, ethyl acetate, and aqueous extracts had negative effects on the formation of dry matter, shoots, and roots, with the highest concentrations prompting the most negative effects. Coumarin was present in all extracts, but its concentration was highest in the hexane fraction, which was consequently characterized as highly phytotoxic during the bioassays.

Alelopatia de espécies da Caatinga

“…A presença de fitotoxidade para alguns vegetais de importância econômica como feijão caupi e melão, foi verificada em bioensaios envolvendo extratos de Libidibia ferrea (Alves et al, 2019) e A. cearenses (Oliveira et al, 2020) respectivamente; tais resultados ratificam a importância de que por instalação de sistemas agroflorestais haja um correto dimensionamento populacional das plantas.…”

Morfoanatomia da raiz de Arabidopsis thaliana submetida à cumarina (1,2- benzopirona)

“…Cumarinas são lactonas do ácido hidroxicinâmico originárias da rota dos fenilpropanóides. São sintetizadas pela maioria das plantas superiores (MURRAY et al, 1982;OLIVEIRA et al, 2020) em tecidos foliares, sementes e frutos (ZOBEL e BROWN, 1995).…”