Abstract:To explore the remediation of Liquidambar formosana Hance to lead-contaminated soil and provide scientific reference for the promotion of planting maple in contaminated heavy metals, annual L. formosana Hance seedlings were used as test materials, the physiological characteristics and accumulation characteristics of L. formosana Hance seedlings under 6 Pb2+ concentrations (0, 100, 300, 500, 800, and 1 000 mg/kg) were studied. The principal component analysis method was used to screen the 12 physiological indexes of L. formosana Hance and evaluate the tolerance. The results showed that with the increase of Pb2+ concentration, the biomass, soluble sugar content, soluble protein content, free proline content, superoxide dismutase (SOD), and peroxidase (POD) of L. formosana seedling leaves showed a upward-downward trend, which indicate a "low promotes high suppression" effect. The content of malondialdehyde (MAD) showed an upward trend. Both chlorophyll a and chlorophyll b showed a downward trend, but the downward trend of chlorophyll a was not significant. Net photosynthetic rate (Pn), stomatal conductance (Gs), CO2 concentration (Ci), and transpiration rate (Tr) all showed an upward-downward trend. The lead content in the underground part of L. formosana>the lead content in the above-ground part, the transfer coefficient was the largest at T2 and T3, and the enrichment coefficient was negatively correlated with the stress concentration. The results of principal component analysis showed that the cumulative contribution rate of the two principal components extracted was as high as 92.462%, indicating that these two principal components can reflect most of the information. Free proline, net photosynthetic rate, stoma conductance, intercellular CO2 concentration, transpiration speed, and SOD activity were the simplified 6 indexes. The principal component scores showed that the lead tolerance of L. formosana seedlings is ranked as T3>T4>T2>T1>T5>T6. Comprehensively, the L. formosana Hance seedlings have certain tolerance, enrichment, and transfer ability to heavy metal lead, and this study provide theoretical basis for introducing L. formosana Hance to areas with heavy metal pollution and alleviating soil heavy metal pollution.