Resumen El minador sudamericano de la hoja del tomate (TLM), Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), es una plaga importante del tomate, la papa y otras especies solanáceas de relevancia económica. El manejo de plagas de TLM basado en el uso de insecticidas convencionales puede ser problemático debido a diversas causas, entre ellas, la reducción de los beneficios económicos por los altos costos de los insecticidas, la destrucción de las poblaciones de enemigos naturales, la presencia de residuos de insecticidas en los frutos del tomate y el rápido desarrollo de resistencia a los insecticidas, especialmente cuando se alcanzan niveles elevados de infestación. La búsqueda de compuestos activos menos persistentes beneficiaría a la producción hortícola, así como al medio ambiente y a los consumidores. En el presente estudio, evaluamos la toxicidad de un extracto de hexano en diferentes concentraciones obtenido de frutos frescos del árbol del paraíso Melia azedarach L. (MA), sobre huevos de TLM, larvas de segundo estadio y pupas mediante pruebas de contacto en el laboratorio. Los resultados indicaron que, al aumentar las concentraciones, también aumentaba la mortalidad de huevos, larvas y pupas. El análisis de los datos probit mostró que la CL50 para el extracto de MA en huevos de TLM, larvas del segundo estadio y pupas fueron 948,93, 346,72 y 1,75 μl/ml, respectivamente. Concluimos que este extracto tiene potencial para controlar T. absoluta, pero se deben realizar más estudios ecotoxicológicos para concluir sobre su seguridad en otros organismos y el medio ambiente.

Abstract The South American tomato leaf miner (TLM), Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), is an important pest of tomato, potato and other solanaceous species of economic relevance. Pest management of TLM based on the use of conventional insecticides can be problematic due to various causes, among them, the reduced economical profits from high insecticide costs, the destruction of natural enemies’ populations, the presence of insecticide residues on tomato fruits and the rapid development of insecticide resistance, especially when high levels of infestation are reached. The search for less-persistent active compounds would benefit horticultural production, as well as the environment and consumers. In the current study, we evaluated the toxicity of a hexane extract at different concentrations obtained from the chinaberry tree Melia azedarach L. (MA) fresh fruits, on TLM eggs, 2nd instar larvae and pupae by means of contact tests in the laboratory. Results indicated that with increasing concentrations, mortality of eggs, larvae and pupae also increased. Analysis of probit data showed that LC50 for MA extract in TLM eggs, 2nd instar larvae and pupae were 948.93, 346.72 and 1.75 μl/ml, respectively. We conclude that this extract has potential for controlling T. absoluta but further ecotoxicological studies should be carried out to conclude on its safety in other organisms and the environment.

ABSTRACT The early stages of quinoa germination are sensitive to drought stress. For this purpose, a study entitled the effect of selenium in different concentrations on germination characteristics and some antioxidant enzymes of quinoa under drought stress conditions with polyethylene glycol (PEG 6000) was investigated. The first experimental factor was seed priming with selenium (from two sources: sodium selenate and selenium nanoparticles: SeNPs ? 33.4 nm) at 0.5, 1.5, 3, 4.5, 6 mg·L?1 concentrations, besides, no priming treatment was used as control. The second factor was drought stress with PEG 6000 in concentrations 0, –0.4, –0.8, and –1.2 MPa. Drought stress with accumulation of reactive oxygen species (ROS) had a negative effect on most of the measured traits. In seeds that were primed with appropriate selenium concentrations, germination parameters and antioxidant enzyme activity as well as proline and protein content increased compared to the control treatment. Under conditions of severe stress (–1.2 MPa), the highest activity of catalase (CAT), superoxide dismutase (SOD), and ascorbate peroxidase (APX) enzymes was observed in prime with selenium nanoparticles at concentrations of 4.5, 6.0 and 4.5 mg·L?1, respectively. Concentrations higher than 3 mg·L?1 of selenium nanoparticles and concentrations of 3 mg·L?1 sodium selenate had the highest accumulation of photosynthetic pigments under control (stress-free) conditions. The present study shows that selenium priming can reduce the harmful effects of drought stress on quinoa by altering germination properties and biochemical properties.

Hiperlipidemia é um fator de risco bem conhecido para diversas doenças inclusive aterosclerose, doenças cardíacas e derrame cerebral. Na procura de potenciais agentes antihiperlipidêmicos a partir de plantas para prevenir essas doenças, a polpa e as sementes de Citrullus colocynthis foram testadas para verificar seus efeitos no perfil lipídico de coelhos Nova Zelândia hiperlipidêmicos. Nos grupos experimentais que receberam a polpa de C. colocynthis ou 100 mg/kg das sementes, os perfis lipídicos foram significantemente reduzidos quando comparados ao grupo de controle (P<0,05).

Hyperlipidemia is a well-known risk factor for several illnesses including atherosclerosis, heart and vascular diseases and stroke. In the search for potential anti-hyperlipidemic agents from plants to prevent these conditions, the pulp and the seeds of Citrullus colocynthis were assessed for their effects on the lipid profile of hyperlipidemic New Zealand rabbits. In the experimental groups that received the pulp of C. colocynthis or 100 mg/kg of seeds, the lipid profiles were significantly reduced when compared to the control group (P<0.05).