Anatomy and histochiemistry of the leaf blade of Minquartia guianensis Aubl. (Coulaceae)

Abstract

The study of leaf anatomy is essential for understanding the mechanisms of plant adaptation to environmental conditions. The species Acariquara (Minquartia guianensis Aubl.) is widely distributed, has high durability and timber importance, and is used for medicinal purposes by traditional populations. Therefore, this study aimed to describe the anatomical structures and histochemistry of M. guianensis leaves, with a view to contributing essential information that is lacking in the literature. The research was conducted in the municipality of Itacoatiara, in Amazonas. Adult leaves in good phytosanitary condition were collected from adult trees located in a forest management area. Histological techniques of epidermal dissociation were applied, stained with safranin, in addition to leaf sections stained with safrablau, which were subsequently observed and photographed under an optical microscope. For histochemical testing, fragments of the leaf sections were subjected to reagents and photographed to record the original coloration of the tissues. In the frontal view, the epidermis has a more rectilinear and elongated periclinal wall compared to the anticlinal wall. The stomata, classified as paracytic, are distributed on both leaf surfaces, characterizing the leaf as amphistomatic. In cross section, the epidermis is uniseriate, with branched multicellular trichomes and a thick cuticle. The midrib consists of an amphivasal vascular bundle. Histochemical tests indicated the presence of starch, phenolic compounds, tannins, lipids, proteins, and alkaloids. The results contribute to the identification of the species in studies of adaptation and acclimatization to biotic and abiotic factors and prospects for possible metabolites with medicinal properties.

Keywords: Plant histology; Trichomes; Amphioestomatic