Abstract: The physiological responses of forage sorghum to cadmium (Cd), lead (Pb), and combined pollution were studied by pot experiment. Results showed that the chlorophyll content of forage sorghum decreased with the increase of Pb, Cd concentration, whereas leaf cell membrane permeability, MDA content and proline content increased. The toxicity of Cd was higher than Pb when treated with either Cd or Pb and there was no significant difference between compound treatment and single treatment when Cd concentration was 5 or 10 mg·kg^-1. Compound treatments with the Cd concentration of 50 mg·kg^-1and Cd₁₀Pb₅₀₀ treatment had higher toxicity than either Pb or Cd treatment. Pb enhanced the Cd toxicity of high concentration. The mechanisms of Cd-Pb interaction needed to be further studied.

Key words: Pb, Cd, Compound stress, Forage sorghum, Physiological indices

摘要： 采用盆栽试验研究了土壤外源重金属铅、镉及其复合污染对饲用高粱（Sorghum vulgare Pers.）部分生理指标的影响。旨在为植物生长代谢过程中适应和抵御重金属污染的损伤机制提供一定的理论依据。结果表明：随着Pb和Cd单一及复合胁迫浓度的增加，饲用高粱的叶绿素含量降低，丙二醛含量、叶片细胞膜透性、脯氨酸含量均呈上升趋势。Pb和Cd单一处理组中Cd胁迫的毒害作用强于Pb。Cd浓度为5和10 mg·kg^-1的复合处理组与单一处理组间无显著差异，Cd浓度为50 mg·kg^-1的复合处理组以及Cd₁₀Pb₅₀₀复合处理组对饲用高粱幼苗的毒害作用高于单一胁迫，表明Pb加强了高浓度Cd对植物的毒害作用。

关键词: 铅, 镉, 复合胁迫, 饲用高粱, 生理指标