Effects of Heavy Metal Cadmium (Cd) Stress on Seed Germination and Seedling Growth of 4 Species of Forest Trees

In order to select suitable local plants for remediation of cadmium contaminated soil in Sichuan, seeds of 4 kinds of native woody plants (Pinus yunnanensis, Alnus cremastogyne, Toona ciliate and Acer pentaphyllum)were cultivated in cadmium(Cd) solutions with a series of concentrations to investigate the effects of heavy metals on seed germination and seedling growth. The results showed that Cd had no obvious effect on seed germination of P. yunnanensis, but inhibited that of A. cremastogyne and increased that of T. ciliate and A. pentaphyllum. Cd promoted the root and shoot growth of P. yunnanensis during seedling growth. For other species, Cd promoted shoot growth and inhibited root growth of A. cremastogyne and A. pentaphyllum, but inhibited the shoot growth and promoted root growth of T. ciliata. Tolerance evaluation results showed that the Cd tolerance of the 4 species in descending sequence were T. ciliata, P. yunnanensis, A. pentaphyllum and A. cremastogyne.