No abstract

This study aimed to evaluate the morphological and anatomical changes of Salvinia auriculata exposed to different concentrations 0, 2.5, 5, 7.5 and 10 µM of cadmium (Cd) and its effect on plant growth. The experiment was conducted in the laboratory of Plant Anatomy of the IF Goiano/Rio Verde Campus, Goiás. Cd free samples of S. auriculata, was obtained from the Aquários Plantados company, located in Belo Horizonte. The material was grown hydroponically for 20 days and after the experimental period, the leaf samples were fixed, including in historesin, cut to 5 μm thick thick, stained with toluidine blue and the images were obtained in an optical microscope. The toxic effects of Cd on S. auriculata was observed at lowest concentration with the appearance of chlorotic and necrotic spots. Microscopic analysis showed increased height and width of the aerenchyma gaps, mesophyll and a reduction in abaxial surface epidermal cells, due to increased doses of this metal. It was observed that S. auriculata is a plant sensitive to Cd, and thus indicated for environmental monitoring.

Vernonia ferruginea Less. is a perennial shrub species, present in several regions of Brazil, especially in the savanna. It is popularly used as a phytotherapic. This fact justifies the need to anatomically characterize the plant for its accurate identification and to conduct histochemical studies with the aim of identifying the chemical nature of its cellular constituents. The species-specific data will contribute significantly to pharmaceutical quality control and also provide information about the sites of specific chemical compounds. Samples of V. ferruginea vegetative organs were collected and submitted to the usual plant anatomy and histochemical techniques. The leaves are anfihipoestomática with anomocytic stomata; have tector and glandular trichomes that store essential oils. The stem has collateral-type vascular bundles arranged in a eustele structure; it also has glandular and tector trichomes. The root has brachysclereids, endoderm with various chemical compounds and vascular bundles having axial elements and rays. Few differences were found in the structure of vegetative organs in relation to other species of the genus, confirming the importance of the details shown.

Quina (Strychnos pseudoquina A. St. Hil.). Loganiaceae, a native tree from the Brazilian savannah, is widely used in npopular medicine. In the present study, quina leaves of plants grown in glasshouse or at field conditions were anatomically and histochemically characterized. For the anatomical studies transverse sections taken from the middle third of leaves were stained with 0.05% toluidine blue, pH 4.0. Leaf samples were diaphanized and stained with 1% safranine to study the leaf surface. Phenolic compounds, lipids, starch, and alkaloids were analyzed by several histochemical methods. It was found in the quina leaves the stomata are present only in the abaxial surface and are paracytic. The typical epidermal cells are slightly sinuous and have few trycomas. Cuticle is thin in leaves of plants grown in greenhouse but thick in leaves of plants at field condition. The mesophyll is typically dorsiventral containing collateral vascular bundles. Phenolic compounds were found in the epidermal cells however no lipids, starch or alkaloids were found in any leaf tissue.