Abstract: Taking watermelon variety Jingxin NO． 1 as the test material and spraying water as the control，0.5，1.0，2.0，4.0，8.0 mg/L Na₂SeO₃were sprayed on the watermelon leaves respectively，and Se，Cd and Pb content in leaves and fruits of watermelon were dynamically monitored so as to study the effect of foliar application of Se on Cd and Pb accumulation and theirs' metabolism in plants，as well Se's role in alleviating Cd and Pb toxcity． The results showed that: foliar application of Na2SeO3 could mostly promote watermelon's Se absorption at fruit-set period，and 4.0 mg/L and 2.0 mg/L Na₂SeO₃could obviously inhibit Cd's and Pb's accumulation in watermelon respectively;2.0 - 4.0 mg /L Na₂SeO₃ could effectively inhibit MDA's accumulation and 1.0 - 8.0 mg /L could promote Se's accumulation( P ＜ 0.01) ; the concentration order of Na₂SeO₃'s effect on inhibiting Cd's accumulation in watermelon was: 4.0 mg/L ＞2.0 mg/L ＞1.0 mg/L ＞0.5 mg/L ＞ 8.0 mg/L ＞ the control， and Pb's accumulation: 2.0 mg /L ＞1.0 mg/L ＞0.5 m /L ＞4.0 mg/L ＞8.0 mg/L ＞ the control． Therefore， foliar application of Se was an effective way to supplement watermelon's Se content，and 2.0 - 4.0 mg/L Na₂SeO₃ could increase watermelon's Se content and inhibit the accumulation of Cd and Pb as well．

Key words: Watermelon, Leaf, Fruit, Se, Heavy metals, Antagonism

CLC Number: 

• S134.7