Morfofisiologia vegetativa, reprodutiva, ação antifúngica e composição química do óleo essencial de jambu (Spilanthes oleracea L.)

Abstract

Jambu (Spilanthes oleracea L.) is an unconventional food plant native to the Amazon region. Its leaves and inflorescences are widely used in local cuisine, but recent studies have shown other potentials for the crop, such as in the cosmetics and pharmaceutical industries. However, little is known about its adaptation to other environments, as well as the properties and use of the essential oil, especially phytopathogens. The aim of this study was to evaluate Jambu accessions in the conditions of the Tocantinense Cerrado environment, their morphophysiological adaptation, plant and inflorescence phytomass production, essential oil yield and phytopathogen inhibitory potential. The field accessions were subjected to randomized block design in a 5 x 2 factorial scheme (accessions x period) and entirely randomized for mycelial inhibition analysis subjected to linear regression. The means were compared using the Tukey test and the characteristics assessed were: Plant height, number of leaves (NF), leaf area (AF), number of inflorescences (NI), total fresh mass (MFT), individual fresh mass (MFI), inflorescence diameter (DI), inflorescence length (CI), inflorescence dry weight (PSI), inflorescence area (AI), inflorescence volume (VI), water content of aerial part and inflorescence, form factor (FF), green mass productivity (PROD), physiological evaluations, essential oil yield, chromatographic analysis and phytopathogen inhibitory potential. The most suitable period for growing jambu plants was fall/winter. The accessions collected in Paragominas and Benevídes were superior for most of the morphological and physiological characteristics evaluated. For the inflorescence analyses, the period that showed the best performance for the S. oleracea inflorescences was the spring/summer period with the best morphophysiological indices for most of the variables analyzed. The phytochemical analysis of the essential oil revealed that the main compounds in its composition are Germacrene D, ß-Caryophyllene, β-Pinene, β-myrcene and Pentadecene,1. The oil from the leaves and stems of both varieties (yellow and purple inflorescence) effectively inhibited Curvularia eragrostidis. This demonstrates the crop's productive potential and its effectiveness in controlling phytopathogens, indicating that it is highly recommended for cultivation and further development in genetic improvement programs.