Caracterização química e avaliação do efeito alelopático do óleo essencial de Mansoa alliacea na germinação e crescimento inicial de alface e tomate.

Abstract

Essential oils (EOs) are present in approximately 5% of all plants on the planet. We present in its chemical composition monoterpenes, sesquiterpenes, phenylpropanoids, esters and other low molecular weight chemical substances. The substances that make up these oils are related to the particular characteristics of each oil and its application. The Bignoniaceae family is represented by around 100 genera and 840 species and is distributed mainly in tropical and subtropical regions of the planet, being especially diverse in the tropical forests of Brazil. Mansoa alliacea is one of the most important members of the family thanks to its significant biological activities. It can be stated that no results were found from allelopathic tests using M.alliacea essential oil. In this way, the importance of studying the allelopathic potential of standard seeds such as lettuce and tomato is assumed, as a huge contribution to the studies of natural products.Therefore, this work aims to evaluate the yield, chemical profile and allelopathic activity of the essential oil from Mansoa alliacea leaves. To this end, Mansoa alliacea leaves were collected in the Itacoatiara region and the essential oil was obtained by hydrodistillation of the fresh material in a Clevenger apparatus. Next, the chemical components of the essential oil were identified through GC-MS analysis, which showed 17 constituents, with the main compounds being Diallyl Trisulfide (50.3%) and Diallyl Disulfide (39.9%). The allelopathic effect test of Mansoa alliacea EO was carried out against the germination and initial growth of lettuce (Lactuca sativa) and tomato (Solanum lycopersicum); Treatments with essential oil reduced the vigor of Lactuca sativa seeds at concentrations of 1% and 0.1%, showing better allelopathic activity. And for tomatoes, the inhibitory activity was at concentrations of 0.01% and 0.001%. Therefore, the results of allelopathic tests are promising; however, tests can be carried out in comparison with seeds with herbicidal potential, using M.alliacea essential oil, with the aim of studying seeds of agronomic and economic interest.