Phytoextraction potential of Canna indica (L.) for Cd removal from a hydroponic system

The research explored Canna indica's ability to extract Cd in hydroponic conditions, determining its upper tolerance threshold and assessing Cd's impact on growth and biochemical properties. Plants were grown in 5L tanks containing nutrient solutions with varying Cd concentrations (0, 100, 200, 300, and 400 mg/L) for 18 days. Each treatment was performed in triplicate. Analysis of Cd content across roots, shoot, and leaves revealed high absorption rates of 89.5% to 96.8% efficiency for Cd treatments of 100-400 mg/L. Metrics like bioaccumulation coefficient (BAC), translocation factor (TF), and bio-concentration factor (BCF) were determined, indicating BAC > 1 across treatments, while TF was <1 for 100 mg/L and >1 for higher Cd treatments. Bio-concentration patterns varied with Cd concentration. Optimal Cd uptake occurred at 200-300 mg/L, declining notably at 400 mg/L. The study suggests C. indica's potential for phytoextraction up to 400 mg/L Cd contamination, but adverse effects emerged at >= 300 mg/L: reduced chlorophyll pigments, ascorbic acid, fresh/dry weights, and elevated leaf pH, indicating a Cd tolerance threshold of 300 mg/L for C. indica.