Anatomical variability of the trunk wood and root tissues of Rhizophora racemosa (G. Mey) and Avicennia nitida (Jacq.) and bio-accumulation of heavy metals in mangrove trees

Abstract

The aim of this study was to investigate the anatomical structure of the trunk wood and the roots of A. nitida and R. racemosa, two mangrove trees from Gabon. The anatomical differences between the trunks and the roots were used to understand their bio-remediating differences through heavy metals. It was found that the roots of A. nitida were less abundant in cells number/mm² than its trunk which exhibited the largest cells diameter. The roots and the trunk of R. racemosa didn’t exhibit significant difference between their cells number. Nevertheless, the trunk of that mangrove tree displayed the largest cells diameter and somewhat traumatic channels. Any interspecies variability was found between their trunk vessels diameter. However, a significant difference was found regarding their vessels number/mm², the trunk of A. nitida was richer in vessels compared to R. racemosa one. The roots of the latter were more abundant in vessels and they displayed the largest cells diameter than A. nitida. Broad parenchyma bands and sclerous cells lacked within R. racemosa while they were richer in A. nitida roots and trunk. The occurrence of those anatomical structures which storage substances was thought to act in the highest heavy metals bio-remediation of Avicenniaceae than Rhizophoraceae.

© 2016 International Formulae Group. All rights reserved.

Keywords: Mangrove, parenchyma bands, sclerous cells, bioremediation, heavy metals