Document Type : Original Article
Author
Biology Department, College of Science, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia.
Abstract
To study the micromorphology of leaf surfaces and nutlets, this investigation was conducted on a few Lamiaceae taxa from Upper Egypt. The taxa studied included Mentha longifolia, M. spicata, Plectranthus scutellarioides, Ocimum basilicum, and O. basilicum var. purpurascens, in addition to P. amboinicus, which was not included in the investigation of nutlets. The following microscopy techniques were used in this work: scanning electron microscopy (SEM), light microscopy (LM), and stereomicroscopy (SM). The results of foliar micromorphology proved that it has a high taxonomic impact, especially on leaf surface texture. The results also demonstrated two shapes of glandular hairs: linear, with two subforms: flattened and articulated, as well as slender. Glandular trichomes differed in shape depending on the number of head cells and the shapes of the stalk and base cells. Glandular hairs are characterized by two shapes: firstly, mushroom-shaped multicellular heads. Multicellular heads are distinct as large glands, “umbrella heads,” or small glands. The second was simple, unicellular-head glandular hair. The nutlet micromorphology of the five taxa showed a significant taxonomic diagnosis in terms of shape, dimensions, coloration, areole position, and coat surface characteristics, especially the texture pattern and hairiness of the nutlet surface. Three different artificial keys based on foliar and nutlet micromorphology and trichome types were introduced to identify the taxa under study. Additionally, principal component analysis (PCA) was employed to determine the degree of genetic variation and ascertain the axes' and their corresponding characteristics' respective discriminative powers, as well as the categorization using a bi-plot diagram
Keywords
Main Subjects
)
View on SCiNiTO