Effects of POD and Hg²⁺ on Seed Germination and Seedling Growth of Wheat

Experiments were carried out to study the effects of soaking wheat seeds with POD (peroxidase) and Hg²⁺ together on 10 morphological and physiological indexes during the seed germination and seedling growth. The results showed that exogenous POD could raise the seed germination rate, wake the increased average weight per day and the soluble protein centent of the leaves, and enhance the activities of SOD (superoxide dismutase) and POD of the leaves. The exogenous POD also resist and weaken the effects of the Hg²⁺ stress on the seeds germination rate, height of wheat, increased average weight per day and the soluble protein. Moreover, when Hg²⁺≥50 mg. L⁻¹, the resisting and weakening effects on the germination rate and the increased average fresh weight per day were more obvious. Besides, exogenous POD could further heighten the activities of SOD under the stress of Hg²⁺≤20 mg·L⁻¹, and POD under the stress Hg²⁺≤100 mg·L⁻¹ in the leaves. But exogenous POD should not obviously affect on the average length of the longest wheat roots, the number of lateral roots and the chlorophyll content of the leaves.