Growth Physiology and Absorption Characteristics of Ficus Virens and Ligustrum Lucidum Under Combined Stress of Pb and Cd

Taking Ficus virens and Ligustrum lucidum as experimental materials, the growth physiological changes and absorption and accumulation characteristics of Pb and Cd of F. virens and L. lucidum under different Pb and Cd concentration were studied by pot experiment. The adaptability of the 2 tree species to Pb and Cd contaminated soil was comprehensively evaluated by principal component analysis and membership function method, aiming at exploring the remediation potential of the 2 tree species to Pb and Cd contaminated soil. The results showed that under the combined stress of Pb and Cd, the growth of plant height and ground diameter of the 2 tree species was inhibited, biomass decreased, total chlorophyll decreased and MDA content increased. The comprehensive score of lead and cadmium tolerance showed that F. virens was more tolerant. Pb accumulation in root of F. virens was more than L. lucidum. Cd accumulation in root and shoot of L. lucidum was more than F. virens. Cd promoted the absorption of Pb by L. lucidum and inhibited the accumulation of Pb by F. virens in the compound pollution. Pb promoted the accumulation of Cd by 2 tree species under heavy Cd level. The results show that F. virens is more tolerant to Pb and Cd combined stress than L. lucidum, and has a certain potential for remediation of Pb and Cd combined contaminated soil, while L. lucidum is not suitable for areas with high Cd concentration in combined contaminated soil.