Abstract: Effects of Cd,Pb and their combined pollution on physiological indexes in leaf of the Hordeum vulgare seedling were studied by the indoor cultivation experiments. The results showed that with the increase of Cd,Pb and Cd+Pb concentrations, content of soluble sugar increased first and decreased afterwards. In Cd,Pb single treatment condition, different concentrations Cd,Pb can make cellular membrane penetration(CMP) in leaf increase, relative conductance of leaf exosmosis liquids and content of proline ascended. Damnification of Cd+Pb combined treatment on CMP was higher than those of Cd,Pb single treatment, effect of low concentrations(5+50 mg·L^-1) combined treatment on content of soluble sugar was higher than those of Cd,Pb single treatment. In different treatment time(3,5 d), Effects of all Cd+Pb combined treatment on content of proline in leaf were higher than those of Cd,Pb single treatment, toxicity of Cd in H. vulgare seedling was higher than that of Pb. However, toxicity of Cd+Pb combined treatment in H. vulgare seedling was higher than that of Cd,Pb single treatment, interaction mechanism of Cd,Pb was deserved further study.

Key words: heavy metal, Hordeum vulgare, soluble sugar, cellular membrane penetration(CMP), proline