Plasticidade foliar e produção de biomassa seca em Copaifera langsdorffii Desf. cultivada sob diferentes espectros de luz

Abstract

Changes in the internal tissues of the leaf, particularly the dimensions of oil storage cavities, are subject to genetic factors, but the quality and intensity of radiation can interfere with the ontogeny and density of secretory elements. In this sense, the aim of this work was to evaluate the effect of light quality and intensity on the anatomical characteristics of the leaf, analyzing the oil secretory cavities and the production of dry biomass in seedlings of Copaifera langsdorffii Desf.. Plants were grown for six months in environments covered with polypropylene mesh of red, blue, and black colors, with 50% and 70% shading, and under direct sunlight. Plants grown under the colored meshes, when compared to those under direct sunlight, showed no statistical differences regarding leaf thickness: red mesh (344.08 μm), blue mesh (349.48 μm), 50% black shading (325.22 μm), and 70% black shading (336.48 μm); the same occurred with respect to the diameter of the vascular bundles of the midrib: direct sunlight (14.60 μm), red mesh (16.12 μm), blue mesh (14.76 μm) 50% black shading (14.76 μm), and 70% black shading (15.48 μm); but differences were found concerning stomatal density, diameters of secretory cavities, and dry biomass. Adequate formation of Copaifera langsdorffii Desf. seedlings was verified with the use of blue mesh with 50% shading.