摘要： 以京欣一号西瓜为试材,用0(清水对照),0.5,1.0,2.0,4.0,8.0 mg/L Na₂SeO₃喷施叶面,定期采样监测西瓜叶片和果实中硒、镉和铅等生理指标动态变化,研究叶面喷施硒肥后重金属镉和铅在西瓜生物体内的积累和代谢机制,以及硒对重金属镉和铅的拮抗作用。结果表明,西瓜坐果期叶片喷施Na₂SeO₃,叶片有机硒含量最高,对硒吸收能力最强。4.0 mg/L Na₂SeO₃处理叶片镉含量最低,对镉抑制效果最好,2.0 mg/L处理对铅抑制效果最好,2.0～4.0mg/L处理对丙二醛(MDA)积累抑制效果最好。1.0～8.0 mg/L Na2SeO3处理西瓜果实中硒的积累量均与对照差异显著(P<0.01),不同质量浓度Na2SeO3处理对镉积累抑制效果大小为4.0 mg/L>2.0 mg/L>1.0 mg/L>0.5>8.0 mg/L>清水对照,对铅积累抑制效果大小为2.0 mg/L>1.0 mg/L>0.5 mg/L>4.0 mg/L>8.0 mg/L>清水对照。因此,叶片喷施硒肥是西瓜补硒的一种有效措施,质量浓度为2.0～4.0 mg/L的Na₂SeO₃,既能提高西瓜硒含量,又能降低果实内镉和铅的积累。

关键词: 西瓜, 叶片, 果实, 硒, 重金属, 拮抗

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

中图分类号: 

• S134.7