Nxumalo, Nokukhanya Nokuphila2023-02-162023-02-162022https://hdl.handle.net/10539/34568A dissertation submitted in fulfilment of the requirements for the degree of Master of Science by Coursework and Research Report to the Faculty of Science, School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, 2022The main aim of this study was to investigate and compare the metal uptake efficiency between the indigenous T. usneoides and the exotic T. chinensis in South Africa and to assess the effect of mycorrhizal fungi in enhancing cadmium uptake and alleviating the plant metallotoxicity. A pot experiment was conducted with treatments of cadmium and cadmium with mycorrhizal fungi and controls with no cadmium treatments for each of the two Tamarix species (Tamarix usneoides and T. chinensis) for a 21-days period. The control plants however, were split as control (plants with no Cd or mycorrhizal fungi) and control with mycorrhizae (plants with mycorrhizal fungi but no Cd). Mycorrhizae was applied to the soil one week prior to the treatment of the soil with cadmium at a concentration of 100mg/kg of soil. At the end of the experiment dry plant biomass and chlorophyll content were recorded and the soil as well as the plant tissues (roots and shoots) were analysed for Cd content using the ICP-OES and ICP–MS methods. The bioconcentration factor (BFC) and translocation factor (TF) were calculated. The results showed decreased plant biomass and chlorophyll content in the presence of cadmium in both species. The plant biomass and chlorophyll content of T. chinensis was significantly greater than T. usneoides in all treatments. The shoot cadmium concentration of T. chinensis in the cadmium only treatment was 47% higher than in the T. usneoides, while in the roots this trend reversed with T. usneoides having 53% higher Cd content than the T. chinensis. The same trend was observed for the cadmium with mycorrhizal fungi treatments. Both Tamarix species showed BCF results of >1 and TF of < 1. The BCF of T. usneoides was, however, significantly 53% higher than that of the T. chinensis. The mycorrhizal fungi did not have an impact on increasing the uptake of cadmium or in improving the plant cadmium toxicity effect on both species. This study indicates that the Tamarix species are good candidates for phytoremediation, but the T. usneoides had a greater ability of Cd uptake from the contaminated soil than the exotic T. chinensis. Thus, considering that it is an indigenous species, the T. usneoides remains the preferred plant of choice for phytoremediation in mining sites of South Africa.enDissertation