Authentication, Micromorphology and Ultrastructure of Pollen Grains and Seeds of Endemic Taxa in Saint Katherine Protectorate, South Sinai, Egypt

The endemic taxa were restricted to a specific geographic region and they are essential for setting conservation priorities. This study aimed to update the endemic taxa list in Saint Katherine Protectorate (SKP) depending on literature reviews, field trips and herbaria consultation. Other characters also recorded viz, sex forms, dispersal types and flowering time. Also, the morphological characters of the pollen grains and seeds were examined and photographed using light microscope (LM) and scanning electron microscope (SEM). In addition, the mineral composition of pollens and seeds was detected using energy dispersive X-ray (EDX). The updated list included 13 taxa belonging to 11 genera and 8 families. All the recorded taxa were bisexual; ballochores were the most represented dispersal type. There was a gradual increase in the endemic taxa from March to August while decreasing from October to February. Pollens were isopolar and medium in size. They possessed colpate, colporate, or porate aperatus, as well as reticulate exine sculpture. Furthermore, operculum and margo were absent in most of the pollens. The seed colour ranged from light brown to black; elliptic; basal hilum; polygonal and irregular-shaped seeds were the most represented. All previous characters were diagnosed at generic and specific levels, which helped in the construction of artificial keys to facilitate the differentiation between the studied taxa. The present study has the priority in describing pollens and seeds of Astragalus fresenii and Micromeria serbaliana, in addition to the description of the seeds of Ballota kaiseri. The presence and percentage of twelve elements detected by EDX differed significantly within the investigated pollen grains and seeds. The present data indicated that pollen grains and seeds of studied taxa had high percentages of carbon, oxygen, phosphorous, magnesium, nitrogen and calcium. This study is the first attempt using EDX technique with these taxa. © 2021 Friends Science Publishers