Effect of arbuscular mycorrhizal fungi on the cadmium phytoremediation potential of Eichhornia crassipes (Mart.) Solms

Abstract

Contamination of water with heavy metals is a rising concern for human health and the environment. Removal of heavy metal contaminants in soil- water environment is challenging. Therefore, feasible and effective methods are needed to remove those contaminants from soil and water. Arbuscular mycorrhizal fungi (AMF) are specific rhizospheric microorganisms that have beneficial effects on plant growth. Arbuscular mycorrhizae share a mutualistic symbiosis with the roots of Eichhornia crassipes (Mart.) Solms (water hyacinth), which is capable of absorbing cadmium (Cd) from contaminated water, making it an effective phytoremediating aquatic plant. The aim of this study was to evaluate the effect of AMF on the phytoremediation potential of water hyacinth in cadmium uptake and to examine the growth of water hyacinth plants in different cadmium concentrations. A pot experiment was carried out using water hyacinth inoculated with and without AMF, with the addition of different Cd levels (0, 5, 10, 20, 50 ppm) for a period of 52 days. Water, soil, root and shoot were analyzed for Cd using an atomic absorption spectrophotometry. The highest AMF colonization (74.98%), Cd concentration in shoot (0.22 ppm) and root (0.25 ppm), relative growth rate of plants (0.52 g/day), dry biomass of roots (0.56 g) and shoots (0.62 g) were displayed by AMF inoculated plants. Further, the treatments that comprised of AMF inoculated plants were shown the reduced Cd concentration in both soil and water for each Cd addition. A positive correlation was observed AMF colonization and relative growth rates of plants and AMF colonization and Cd concentrations of plant roots and shoots. The research findings have proved that AMF was capable to augment the phytoremediation potential of Eichhornia crassipes from cadmium contaminated soil-water environment. Thus, it was concluded that AMF can be used as inoculums alongside water hyacinth to phytoremediate contaminated soil and water.