Application of Scanning Electron Microscopy to Study Morphological and Anatomical Features of Sea Buckthorn Leaves

Abstract

Introduction. Scanning electron microscopy is a modern method that allows us to study not only the morphological features of objects, but also to conduct micro-X-ray structural analysis. Currently, the method is being actively introduced into the study of biological objects (including plant ones). Sea buckthorn ( Hippophaë rhamnoides L.) leaves are a non-pharmacopoeial type of medicinal plant raw materials. Further study of the morphology, anatomy and phytochemical composition of leaves can contribute to the production of new, including combined, medicines, which will require the development of a pharmacopoeia article for this medicinal plant raw material. Aim. The aim of the study was to study the morphological and anatomical features of sea buckthorn leaves by scanning electron microscopy. Materials and methods. The object of the study was dried whole leaves of sea buckthorn ( Hippophaë rhamnoides L.), collected in the Voronezh region in 2021 during the period of mass fruit maturity. To carry out the study by scanning electron microscopy, pieces of leaves were previously sprayed with gold on an automatic spraying unit Q150R ES (Quorum Technologies Ltd., United Kingdom) to increase conductivity. Micrographs were obtained using an electron microscope JSM-6510LV (JEOL Ltd., Japan). Results and their discussion. The morphology and some features of the anatomical structure of sea buckthorn leaves were studied and the main microdiagnostic signs (surface character, types of trichomes, the presence of stomata) were clarified. The content of elements (silicon, potassium, aluminum, carbon and calcium) was determined during the microrentgenostructural analysis. Micrographs of pollen grains of the plant were obtained, the presence of the element iron in them was established. Conclusion. For the first time, the method of scanning electron microscopy was used to study the morphological and anatomical features of sea buckthorn leaves. The main diagnostic signs of leaves and their location have been clarified. It has been established that carbon predominates in the composition of the raw material elements, and calcium also accumulates. The accumulation of aluminum, silicon and potassium in numerous hairs densely covering the upper, and especially the lower, surfaces of the leaf blade is assumed. The morphology of the surface of pollen grains of sea buckthorn, having a spherical shape with a spiny shell, has been established. Pollen grains, in addition to carbon, are characterized by the accumulation of iron and silicon.