Arsenic tolerance and phytoremediation potential of Conocarpus erectus L. and Populus deltoides L.

ABSTRACT

The present study was conducted to explore arsenic (As) tolerance and phytostabilization potential of the two tree species, buttonwood (Conocarpus erectus) and eastern cottonwood (Populus deltoides). Both plant species were grown in pots and were exposed to various soil As levels (control, 5, 10, 15, and 20 mg kg⁻¹). The plants were harvested after 9 months for the evaluation of growth parameters as well as root and shoot As concentrations. With increasing soil As levels, plant height stress tolerance index (PHSTI) was significantly decreased in both tree species, whereas root length stress tolerance index (RLSTI) and dry matter stress tolerance index (DMSTI) were not affected. Root and shoot As concentrations significantly increased in both tree species with increasing soil As levels. Translocation factor and bioconcentration factor were less than 1.0 for both plant species. This study revealed that both tree species are non-hyperaccumulators of As, but they could be used for phytostabilization of As-contaminated soils.

KEYWORDS:

• arsenic
• phytostabilization
• Conocarpus erectus
• Populus deltoides

Acknowledgments

The authors are thankful to COMSATS Institute of Information Technology, Islamabad, Pakistan, for providing financial support to conduct this study under CRGP. They gratefully acknowledge the helpful comments from anonymous reviewers who made excellent suggestions that helped to improve this manuscript.