ABSTRACT

Agave americana was evaluated for its phytoremediation potential of the soils contaminated with Cd. This plant was selected because of its drought tolerance and high biomass. The pot culture experiment was carried with five levels of cadmium (0, 25, 50,100, and 200 mg Cd kg soil⁻¹). Parameters, viz. uptake, translocation factor (TF), translocation efficiency (TE), bioconcentration factor (BCF), etc., were calculated to study the phytoremediation potential. The study indicated that the plant was highly tolerant to Cd at lower levels, i.e., up to 50 mg Cd kg soil⁻¹, but there was a significant reduction in dry weight of root, leaf, and total at higher levels of, i.e.,, 100 and 200 mg Cd kg soil⁻¹. Cd mainly accumulated in the roots, and exclusion was found to be the principal physiological tolerance mechanism. Based on the tissue concentration of Cd (<100 μg g⁻¹ in the leaves; and TF and BCF <1), A. americana was classified as an excluder of Cd. However, since, the plant could establish an evergreen cover over the contaminated/polluted land surface because of its exponential reproductive capacity, it could be suitable for the phytostabilization of soils contaminated with Cd.

摘要

对龙舌兰进行了Cd污染土壤的植物修复潜力评估。选择该植物是因为其耐旱和高生物量。用五种水平的镉（0、25、50,100和200 mg Cd kg土壤^-1）进行盆栽试验。参数，即。计算吸收，易位因子（TF），易位效率（TE），生物浓缩因子（BCF）等，以研究植物修复潜力。研究表明，该植物在较低水平（即高达50 mg Cd kg土壤^-1）下对镉的耐受性很高，但在较高水平（即， ，100和200 mg Cd kg土壤^-1。镉主要积累在根中，排他是主要的生理耐受机制。根据镉的组织浓度（叶片中<100μgg ^-1； TF和BCF <1），将美洲曲霉归为镉的排除物。然而，由于该植物由于其指数繁殖能力而可以在受污染/污染的土地表面上建立常绿覆盖物，因此它可能适合于被Cd污染的土壤的植物稳定化。