Micromorphological Foliar Screening for Identification of Moraceae Taxa using Light Microscopy (LM) and Scanning Electron Microscopy (SEM) Techniques

A study on foliar epidermis was conducted on nine species belonging to the Moraceae family to investigate diverse micromorphological characteristics that hold taxonomic importance in leaf epidermis. Based on LM (light microscopy) and SEM (scanning electron microscopy), it was found that the shape of epidermal cells in the studied members is rectangular, irregular, polygonal, and pentagonal on both leaf epidermal surfaces. The common shape of the epidermal cells is polygonal in most species. The size of the epidermal cell in length and width varies from species to species. The wall of the epidermal cells is thick in most species, except in Broussonetia papyrifera (L.) L’Hér. ex Vent. and Morus alba L., and Morus laevigata Wall. ex Brandis, where the epidermal cells are thin on both leaf surfaces. It was found that the majority of the plants are hypostomatic, i.e., the adaxial surface of the leaves has no stomata. Most species have anomocytic stomata on the abaxial surface of the leaf. The cyclocytic stomata were found only in Ficus elastica Roxb. ex Hornem. and Ficus benjamina L. The stomata type, which is rare in the studied species, is cyclocytic, laterocytic, and paracytic. We found variations in the shape and size of leaf epidermal cells and stomata on both leaf surfaces in all selected species. The most important element of the leaf is the stomatal index, which serves as a geographic indicator and shows the transpiration rate of the leaf. The stomatal index ranges from (76.7%) in B. papyrifera to (2.13%) in F. benjamina on the adaxial surface, while on the abaxial surface it is highest (61.8%) in Ficus religiosa L. and lowest (3.06%) in Ficus virens Aiton. The identification of the plants at both genus and specific-levels was found to be taxonomically appropriate based on the epidermal architecture of the leaves. Thus, the current study aims to clarify the qualitative and quantitative properties of the leaf epidermis in order to give information for Moraceae family species identification and categorization.