Caracterização morfoanatômica e química de quatro variedades de Hancornia speciosa Gomes (Apocynaceae)

Abstract

Hancornia speciosa Gomes, known as mangabeira, is a native species of the Brazilian Cerrado with significant ecological and economic importance, being utilized in the food and pharmaceutical industries. However, the taxonomic differentiation of its botanical varieties remains challenging due to overlapping morphological characteristics and the lack of detailed comparative studies. Therefore, this study aimed to characterize the morphology, anatomy, and foliar chemical composition of four botanical varieties (H. speciosa var. speciosa, H. speciosa var. cuyabensis, H. speciosa var. gardneri, and H. speciosa var. pubescens), cultivated in an ex situ germplasm bank at the Federal University of Goiás (UFG). This work intends to contribute to the taxonomic clarification of the species and includes the development of a digital booklet (e-book) for scientific popularization. To this end, morphological and anatomical analyses were conducted using light microscopy and scanning electron microscopy (SEM). The results demonstrated differences among the varieties, particularly concerning phyllotaxis, leaf shape and size, stomatal arrangement, and trichome presence. H. speciosa var. pubescens exhibited pilose leaves with abundant tector trichomes, as well as stomata located in depressions on the abaxial epidermis, which may represent a xeromorphic adaptation. H. speciosa var. cuyabensis was distinguished by its whorled phyllotaxis, a unique feature within the studied group. Histological analyses revealed that all varieties possessed a dorsiventral mesophyll, bicollateral vascular bundles, and abundant laticifers. The comparative analysis established a set of anatomical characters that can aid in the taxonomic identification of the varieties and in the quality control of mangabeira-derived products. The chemical composition of the leaves was analyzed by High-Performance Liquid Chromatography (HPLC), focusing on the quantification of the flavonoid rutin, which has antioxidant and anti-inflammatory properties. The results showed significant differences in rutin content among the varieties, indicating intraspecific variation. H. speciosa var. speciosa presented the highest levels of rutin, suggesting greater pharmacological and antioxidant potential. H. speciosa var. gardneri and H. speciosa var. pubescens also showed notable levels of these compounds, suggesting their applicability in the pharmaceutical industry. However, seasonal analyses are required to verify if rutin concentrations are stable throughout the year. The data obtained support the hypothesis that different botanical varieties of the species may have distinct potentials for biotechnological applications, making them relevant for future research on quality control and the sustainable use of the plant. Finally, an e-book was created using the results from the preceding chapters. The e-book provides general information about the Cerrado, characteristics of the mangaba fruit, recipes, and related activities. The findings of this dissertation contribute to the taxonomic differentiation of Hancornia speciosa. The morpho-anatomical and chemical characterization of these varieties not only advances the knowledge of Cerrado biodiversity but also opens avenues for the sustainable utilization of the species in the production of bioproducts.