African Journal of
Plant Science

  • Abbreviation: Afr. J. Plant Sci.
  • Language: English
  • ISSN: 1996-0824
  • DOI: 10.5897/AJPS
  • Start Year: 2007
  • Published Articles: 677

Full Length Research Paper

Anatomical adaptations in species of Poaceae growing in Al-Ha'ir region of Riyadh, Saudi Arabia

Shamah A. Banan
  • Shamah A. Banan
  • Department of Botany and Microbiology, College of Science, King Saud University P. O. Box 2455, Riyadh 11451, Saudi Arabia.
  • Google Scholar
Ahlam A. Al-Watban
  • Ahlam A. Al-Watban
  • Department of Botany and Microbiology, College of Science, King Saud University P. O. Box 2455, Riyadh 11451, Saudi Arabia.
  • Google Scholar
Abdullah R. Doaigey
  • Abdullah R. Doaigey
  • Department of Botany and Microbiology, College of Science, King Saud University P. O. Box 2455, Riyadh 11451, Saudi Arabia.
  • Google Scholar
Abdulaziz A. Alsahli
  • Abdulaziz A. Alsahli
  • Department of Botany and Microbiology, College of Science, King Saud University P. O. Box 2455, Riyadh 11451, Saudi Arabia.
  • Google Scholar
Mohamed El-Zaidy
  • Mohamed El-Zaidy
  • Department of Botany and Microbiology, College of Science, King Saud University P. O. Box 2455, Riyadh 11451, Saudi Arabia.
  • Google Scholar


  •  Received: 28 March 2019
  •  Accepted: 23 April 2019
  •  Published: 31 July 2019

Abstract

The aim of this work was to determine the anatomical adaptations of leaves and stems of four species of Poaceae (Cynodon dactylon L. Pers., Chloris barbata SW. (Chloridoideae), Setaria verticillata L. P. Beauv., and Panicum coloratum L. (Panicoideae)) growing naturally at Al-Ha'ir region near Riyadh, Saudi Arabia. Cross-sections of the leaves revealed that the epidermis cells were spherical to oval and formed one layer with a thick cuticle as well as numerous bulliform cells in a fan shape and prickles. Ground tissue (mesophyll) consists mostly of chlorenchyma cells. A large vascular bundle surrounded by two bundle sheaths, outer sheath parenchyma and inner sheath sclerenchyma were observed in C. barbata and C. dactylon, while one bundle sheath of sclerenchyma surrounds the vascular bundle in S. verticillata and P. coloratum, while one bundle sheath with chlorenchymatous cells surrounded the small vascular bundles. Our results showed that all species contained a Kranz anatomy indicative of a C4 photosynthetic pathway despite belonging to two different subfamilies, Panicoideae and Chloridoideae. Oil droplets appeared in the mesophyll tissue of P. coloratum and S. verticillata. Cross-sections of stems revealed an epidermis which consists of one layer of cells with spherical to oval shape and had a thick cuticle. Ground tissue contains strands of chlorenchyma cells followed by sclerenchyma tissue surrounding vascular bundles, thereby making a continuous cylinder. The vascular bundles were scattered in the ground tissue, with each vascular bundle surrounded by a single sclerenchymatous bundle sheath. Our results indicate that these plants were characterized by anatomical adaptations that enhance drought-tolerance capabilities, facilitating survival in arid and semi-arid regions such as Al-Ha'ir and thus these plants can be used to increase vegetation cover and pasture area in dry environments.

 

Key words: Anatomy, adaptations, Poaceae, Cynodon dactylon, Chloris barbata, Setaria verticillata, Panicum coloratum.