Effects of Pb and Zn stress on Trichosanthes kirilowii seedlings growth and stress-resistance physiological factors

The study with pot experiment showed that under Pb and Zn stress,the biomass of Trichosanthes kirilowii seedlings decreased,their plant dwarfed,and the number of leaves with yellow spots increased.Pb had greater effects on the seedlings growth than Zn.With increasing concentration of Pb,the contents of photosynthetic pigments increased first and decreased then,but increasing concentration of Zn had lesser effects on them.The contents of UV-B absorbing compounds and the activities of superoxide dismutase(SOD)and peroxidase(POD)increased while soluble protein and saccharide contents decreased with the increase of Pb and Zn concentrations.T.kirilowii seedlings had definite tolerance to Pb and Zn stress,but their growth and stress-resistance physiological factors were inhibited to a greater extent when the Pb and Zn concentrations were higher.