Taxonomic significance of stamens and pollen morphology of some selected taxa of Primulaceae in Egypt

Abstract

The circumscription study of Primulaceae is still uncertain and remains controversial. Stamens and pollen grains morphological characters of five species and one variety representing five genera viz., Anagallis, Lysimachia, Coris, Primula and Samolus of Primulaceae in Egypt have been studied using LM and SEM. The specific target of the present study is to evaluate the taxonomic value of the macro and micromorphological characters of stamens and pollen grains in order to distinguish between the studied species. The obtained results showed remarkable variations in anther shape, anther dehiscence, filament attachment and presence of trichomes on the anther filament. Pollen grains are radially symmetrical, isopolar, spheroidal-subprolate to prolate, with amb angulaperturate or fossaperturate and tricolpate or tricolporate. Tectum is microreticulate, reticulate with perforated lumine and clavate exine ornamentation. Out of the studied taxa Coris monspeliensis is distinguished by the presence of prominent margo, reticulate exine ornamentation, minute luminal perforations decreasing towards the colpi, orbicular anther shape, latrorse dehiscence of anthers with short longitudinal slit and presence of glandular diseriate trichomes at the base of the filaments. Clavate exine ornamentation as well as lanceolate anther shape, extrorse dehiscence and short filament can distinguished Samolus valerandi from the remaining studied taxa. An artificial key for the studied species was constructed based on stamens and pollen morphological criteria is provided.

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

“…Four taxa belonging to Caryophyllaceae are characterized by the presence of annulus which is absent in the rest of the studied taxa. These findings corroborate with Yildiz (2005); Krachai et al (2009); Pinar et al (2009); Osman (2012); Mostafavi and Mehregan (2014);El-Ghamery et al (2018) and Shiha (2020).…”

“…The research studies on the morphology of pollen grains and seeds of endemic taxa in Saint Katherine are few. There is no previous complete data available, despite that we can refer to some studies dealt with these taxa either in the context of the endemic flora of Egypt or as separate taxa within special groups (Shehata and Kamel 2007;Rabei et al 2016;El-Ghamery et al 2018;Shiha 2020).…”