Micromorphological characteristics of leaf epidermis for the identification of certain Solanoideae (Solanaceae)

Ragab, Osama G.; Gabr, Dalia G.; Khafagi, Azza Ahmed

doi:10.21608/ijtar.2022.139481.1002

Micromorphological characteristics of leaf epidermis for the identification of certain Solanoideae (Solanaceae)

Document Type : Original Article

Authors

¹ Botany and Microbiology Department, Faculty of Science (Boys Branch), Al-Azhar University, Cairo, Egypt

² Botany and Microbiology Department, Faculty of Science (Girls Branch), Al-Azhar University, Cairo, Egypt

10.21608/ijtar.2022.139481.1002

Abstract

The foliar epidermis has great value in plant taxonomy studies. Light microscopy and scanning electron microscopy were conducted on the leaf surface micromorphological features, such as types of trichome (glandular and non-glandular) and epidermal cells and stomatal characteristics, of 21 species from Solanoideae belonging to the family Solanaceae. The studied species showed diversity in cuticle ornamentation, epidermal cell shape, and surface sculpture. Trichomes have four types: glandular, non-glandular, stellate, and dendritic. The studied Hyoscyamus species were characterized by the absence of non-glandular trichomes. The anticlinal walls are undulate in most species but some species have sinuous and straight wall. The cuticular layer on leaves was detected in four patterns: smooth, finely warty, warty-crustose, and finely striate wax. The stomatal size, shape, and aperture also varied among species. Nearly all the investigated species had anisocytic and anomocytic types of stomata. Hyoscyamus species had anomocytic stomata. Clustering analysis revealed the separation of the studied species into two major clusters. Cluster I consisted of three species (the studied species of Lycium. Cluster II was divided into two groups. The first group comprised Withania species, whereas the second group included the studied taxa of Solanum, Hyoscyamus, Physalis and Datura. An identification key using micromorphological characters are provided to distinguish studied genera and species of Solanoideae. This study revealed that the types of trichome and epidermal cells, stomata, and cuticle ornamentation within the species show significant variation and can be helpful for taxonomic purposes.

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