Structural variation of leaves of medicinal species associated with “erva-mate”, under different light intensities

Abstract

The objective of this study was to analyze the leaf morphology of four medicinal species (Bauhinia forficata; Maytenus ilicifolia; Mikania glomerata, and Vitex megapotamica) associated with Ilex paraguariensis (“erva-mate”), at three light conditions and to indicate the best light regime for the cultivation of these species. The experiment was set up in the Fazenda Capão Bonito (25 50’ 64’’ S and 49 43’ 69’’ W) in Castro, PR, Brazil, and was composed by three light treatments: 100% (full sunlight), 26,23% (half-shade) and 13,83% (shade). Comparing the morphological characteristics among treatments and species, M. ilicifolia, V. megapotamica, and B. forficata presented the same variation pattern, except for the leaf area in B. forficate, the thickness of the palisade parenchyma in M. ilicifolia, and the chlorophyll concentration which was different among the three species. M. glomerata had the highest foliar plasticity, except for the chlorophyll concentration. The mean values of AEF indicate that the shade treatment produces the highest biomass, by unity of area, for all species. However, additional studies on the quantification of active principles, growth rates, seasonal responses, and distinct nutritional conditions among the light treatments can provide additional information for the implementation of more efficient methods of cultivation for these medicinal species.