Pollen morphology of &lt;i&gt;Teucrium&lt;/i&gt; L. (Lamiaceae, Ajugoideae) in Libya

Abdel Baset M. Askar,Ream I. Marzouk,Salama M. El-Darier

doi:10.3329/bjpt.v24i2.35118

Pollen morphology of <i>Teucrium</i> L. (Lamiaceae, Ajugoideae) in Libya

Abdel Baset M. Askar, Ream I. Marzouk + Show 1 more

Open Access

https://doi.org/10.3329/bjpt.v24i2.35118

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Abstract

Pollen grains of 11 taxa of Teucrium from Libya were examined using lightmicroscopy (LM) and scanning electron microscopy (SEM) in order to provide better insight on the evaluation of palynological attributes for species characterization of Teucrium with special emphasis on the five Libyan endemic. Two main pollen shapes were documented; subprolate and prolate or perprolate in T. fruticans. The exine sculpture inspected at surface, operculum and pole were mostly verrucate, perforate or scabrate. Teucrium fruticans attained the phenomenon of pollen dimorphism with two distinct shapes and specifics sculpture for each form. The results validated thetaxonomic significance of pollen grains for the discrimination among Teucrium species in Libya.Bangladesh J. Plant Taxon. 24(2): 219–226.

Highlights

Teucrium L. is the second-largest genus of subfamily Ajugoideae with cosmopolitan distribution over represented in the Mediterranean area (Navarro and EL Oualidi, 2000a; Radulović et al, 2012; Yasaman et al, 2016)
The taxonomic complexity of Teucrium is reflected in the changes in its classification using different characteristics as pollen morphology (Díez et al, 1993), karyology (Valdés-Bermejo and Sánchez-Crespo, 1978), indumentum characteristics (Manzanares et al, 1983; El Oualidi and Puech, 1993; Navarro and EL Oualidi, 2000b), phytochemistry (Harborne et al, 1986; VelascoNegueruela and Pérez-Alonso, 1990; Bukhari et al, 2014) and amino acid composition (Juani et al, 2004)
There is an imminent danger for genetic erosion of Libyan wild species due to the increment in drought and anthropogenic activities, that has resulted in habitat loss and fragmentation leading to the diminishing of the germplasm reservoir (Al-Idrissi et al, 1996)

Summary

Introduction

Teucrium L. is the second-largest genus of subfamily Ajugoideae with cosmopolitan distribution over represented in the Mediterranean area (Navarro and EL Oualidi, 2000a; Radulović et al, 2012; Yasaman et al, 2016). In Libya, Teucrium is represented by eleven taxa of which T. apollinis Maire & Weiller, T. barbeyanum Asch. Ex E.A. Durand & Barratte, T. davaeanum Coss., T. lini-vaccarii Pam. and T. zanonii Pam. are believed to be endemic to Libya (Marzouk et al, 2016). The present study was performed to assess the taxonomic value of pollen grains for species characterization of Teucrium.

Results

Conclusion