Evaluation of phytoremediation potential and resistance of Gladiolus grandiflora L. against cadmium stress

Abstract

Although irrigation water is a fundamental need for plant growth, it is also a source of pollutants if contaminated with harmful materials like cadmium (Cd). Irrigation water possessing abundant Cd causes damage to soil, plants, animals and ultimately human beings through the food chain. A pot experiment was conducted to evaluate the gladiolus (Gladiolus grandiflora L.) potential of Cd accumulation and the capability of the plant to be an economically beneficial choice in presence of high Cd irrigation water supply. Artificially prepared four levels of Cd irrigation water were applied to the plants viz., 30, 60, 90 and 120 mg L^-1. The results revealed that 30 mg L^-1 Cd had no difference in all growth-related parameters when compared to the control. Photosynthesis rate, stomatal conductance and transpiration rate along with plant height and spike length were reduced with high accumulation levels of Cd in plants. The main plant portion for Cd storage found in Gladiolus grandiflora L was corm where the amount of Cd was 10-12 times higher than the amount found in leaves, and 2-4 times more than the stem. This deportment was further established by the translocation factor (TF). In corm to shoot TF and corm to stem TF, the factor reduced with increasing Cd levels, while, in corm to leaves TF, Cd levels were statistically non-significant. From corm to shoot TF value of 0.68 and 0.43 in case of 30 and 60 mg L^-1, Cd treatments indicates good phytoremediation potential of Gladiolus in low and moderate Cd-polluted environments. Conclusively, the study reveals the good capability of Gladiolus grandiflora L. to harvest Cd from the soil and water in reasonably good amount with sufficient potential to grow under irrigation-based Cd stress. Under revelations of the study, Gladiolus grandiflora L appeared as a Cd accumulator which could potentially be used as a sustainable approach for phytoremediation of Cd.

Keywords: Cadmium; Gladiolus; Phytoremediation; Stress tolerance.