Crescimento, eficiência fotossintética e produção de metabólitos primários e secundários em Garcinia brasiliensis cultivada sob diferentes malhas fotoconversoras

Abstract

The Garcinia brasiliensis species is the subject of studies for the discovery of new bioactives with therapeutic potential, however, knowledge about its essential oils is still limited. Colored meshes change the quality and quantity of light incident on plants, which provides morphological and physiological changes in plants, and may even change secondary metabolism. Thus, growth, photosynthetic efficiency and the production of primary and secondary metabolites in Garcinia brasiliensis grown under colored nets were evaluated. For this, the seedlings were grown in 20 L pots and kept for 11 months in six different environments, which corresponded to the treatments: red mesh (50% shade), blue (50% shade), aluminet (silver; 50% shade). shade), black (50% shade), black (70% shade) and full sun (control). Bimonthly non-destructive analyzes of gas exchange, chlorophyll a fluorescence and shoot growth were performed. At the end of the experiment, the allocation of dry mass and the contents of carbohydrates, amino acids, proteins, phenolics and total flavonoids in leaves and roots were evaluated. The essential oil was extracted from the leaves and its biological activity was determined. The red and blue meshes altered the incident radiation spectrum, with two peaks of intensity being evidenced in the red one, one between 480 and 600 nm and another between 600 and 680 nm, while in the blue one it was slightly before 480 nm. The red net induced greater apical growth, while in the blue net the plants accumulated a higher chlorophyll content. The aluminet mesh was related to the maintenance of the net photosynthetic rate and the photochemical yield in the months of higher incidence of light and temperature. In the red net and in the aluminet, the plants had a greater accumulation of dry biomass. The highest EO yield was verified in plants grown under the blue net, however, the highest anti-inflammatory activities were detected in full sun, 50% black and aluminet. The content of phenolics and flavonoids in the leaves was higher in full sun. The intensity and quality of radiation interfere with the ecophysiology, growth and metabolism of plants, altering the therapeutic action of essential foliar oils of G. brasiliensis.