Abstract: To study the response of Zizania latifolia to Pb2+ stress in different cultural medium, a single-harvested cultivar Jiangshu and a double-harvested cultivar Fenghongzao of Zizania latifolia were cultured in reed sediment substrate and soil with different Pb²⁺ concentrations. The changes of some morphological, physiological and biochemical indexes of the Zizania plant and the Pb²⁺ residues in Zizania galls were investigated. The results showed that contents of soluble protein, protective enzyme activities, area and chlorophyll content of functional leaves and net photosynthetic rate ascended under low concentration of Pb²⁺ treatment and descended along with the increase of Pb²⁺ concentrations, while the content of proline ascended all along. Contents of soluble protein and proline were lower but the functional leaf area was higher observably in leaves of plants grown in reed sediment substrate than those in soil in the same concentration of Pb²⁺ stress. The Pb²⁺ residues in Zizania galls were lower than in products of other vegetable. Reed sediment substrate treatments reduced the Pb2+ residues in Zizania galls significantly, comparing with soil treatments. It is implied that the Zizania galls were more secure when cultured in reed sediment substrate.

Key words: Zizania latifolia, lead, residue, cultural medium