Abstract: This paper studied the difference of three Fagopyrum esculentum cultivars in lead tolerance after treated their seedlings with different concentrations Pb²⁺ for seven days. The results showed that low concentration Pb²⁺ had definite stimulation effect on root growth, while high concentrations Pb²⁺ was in adverse.The inhibition of root growth under high concentrations Pb²⁺ was differed with cultivars,i.e., Xiqiao No.1 was most serious, followed by Jinqiao No.1, and Jiujiangkuqiao. Under 1 500 μmol Pb²⁺·L^-1, the relative cytoplasm membrane permeability of the three cultivars increased, but their chlorophyll and protein contents decreased to various degree. The increment or decrement was the largest in Xiqiao No.1 and the smallest in Jiujiangkuqiao. All of these suggested that among the three cultivars, Jiujiangkuqiao was the strongest in lead tolerance,while Xiqiao No.1 was the weakest.

Key words: Heavy metal ions, Itopenaeus vannamei, Hepatopancreas, Gill, Blood, SOD