Anatomical Response of Amaranthus hybridus Linn. as Influenced by Pharmaceutical Effluents

Abstract

Anatomical studies were carried out on the leaves, stems and roots of Amaranthus hybridus subjected to irrigation of 10%, 20%, 30% and 40% concentrations of pharmaceutical effluents to identify the responses of this plant to the treatment. Leaf structures of A. hybridus showed no significant change due to the effect of the effluents. Significant reduction was observed in the trichome density and number of epidermal cells at the adaxial surface as from the 20% effluent concentration upward (p<0.05). Stomatal size significantly reduced on both leaf surfaces as from 20% effluent concentration upward while stomatal density increased significantly at the adaxial surface from the 20% effluent concentration (p<0.05). Tetracytic and anisocytic stomatal complex-types were observed in A. hybridus with varied modifications from 20% effluent concentration upward at both leaf surfaces. Vessels and phloem cells in the stems and roots of A. hybridus were seriously affected by the effluent. Vessel walls were thickened and their width reduced significantly as from 20% effluent concentration upward while phloem cells experienced progressive loss of structural integrity from the same concentration (20%) upward in both the stems and roots. This study showed that the pharmaceutical effluents have toxic effect on A. hybridus and the effects were more pronounced as from 20% concentration.