Influência da idade da planta na composição química do óleo essencial de Lippia alba e de um ciclo de seleção recorrente na atividade formicida

• Autor(a) principal: Pinto, Vanderson dos Santos
• Data de Publicação: 2017
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFS
• Texto Completo: https://ri.ufs.br/handle/riufs/6766
• topic: Erva-cidreira; Essências e óleos essenciais; Plantas; Composição das plantas; Melhoramento genético; Erva-cidreira-brasileira; Metabolismo secundário; Melhoramento vegetal; Atividade inseticida; Brazilian lemon balm; Secondary metabolism; Plant breeding; Insecticidal activity.; CIENCIAS AGRARIAS

Brazilian lemon balm (Lippiaalba (Mill.) N. E. Brown) is a medicinal and aromatic species widely used to fight diseases. Its essential oil, rich in carvone, has insecticidal activity on pests of agricultural interest. Cutting ants cause severe economic damage to forest and horticultural species and hinder cultivation worldwide. Plant aging is one of the main factors that alter the biological activity of essential oils. The objective of this work was to evaluate the influence of plant age on the essential oil of L. alba accessionsand of a recurrent selection cycle onformicidal activity. The experiments were carried out at the Experimental Farm - Campus Rural UFS.The experiment consisted of a randomized blocks design with three replications. For the first experiment, 18 L. albaaccessions were used at two plant ages: one-year-old plants (February2006), and ten-year-old plants (February 2016). In the second experiment, a recurrent selection cycle was carried out with three accessions of the limonene/carvonechemotype. For the progeny competition experiment, three parent genotypes and 11 progenies were taken to the field. In the first experiment, plant age influenced the essential oil production and the chemical composition.The highest essential oil content increase was observed for accessions LA-41 (0.69-2.48%) and LA-53 (0.76-2.84%). The compounds with the greatest variation in the second harvest were p-cymene (0.00-5.12%), limonene (0.00-11.08%), and elemol (0.00-10.54%), because of plant aging. In the second experiment, the highest dry weight of aerial part was observed for parental LA-56 (57.54 g plant-1). The essential oil content was higher in the progeny LA-57-10 (2.844%) and the parental LA-57 (2.664%). Carvone concentration was higher for LA-57 (59.02%), with a significant difference when compared with the evaluated progenies. Among the progenies, the highest carvone concentration was observed for LA-56-04 (57.78%) and the lowest for LA-57-01 (17.71%) and LA-57-02 (17.27%).One recurrent selection cycle resulted in increased formicidal activity of some progenies. Higher mortility of Acromyrmex balsani was caused by the essential oils of the progenies LA-56-04 and LA-70-03.