华中地区3种蔬菜对Zn的耐性和累积特性差异研究

Tolerance and Cumulative Effect of Zinc Pollution of Three Vegetables in Central China

[目的]比较华中地区3种常见蔬菜对Zn污染的耐性和累积特性的差异。[方法]在不同Zn浓度的胁迫下,对萝卜、小白菜和苋菜进行种子萌发试验和盆栽试验,研究不同处理对蔬菜种子发芽率、幼苗生长、生物量及Zn含量的影响。[结果]高浓度(2000mg/L)的Zn胁迫对小白菜和萝卜的种子发芽没有影响,但对苋菜有显著影响;较高浓度(500和2000mg/L)的Zn胁迫会影响3种蔬菜幼苗的生长;萝卜对过量Zn毒害的耐性强于小白菜和苋菜。各处理中,3种蔬菜的可食部位Zn含量均低于国家食品卫生标准。在Zn施加浓度为100、500和1000mg/kg土的处理中,萝卜的地上部和地下部Zn含量均低于小白菜和苋菜。[结论]萝卜抗土壤Zn污染的能力最强,比小白菜和苋菜更适合在Zn污染的农田中种植,以减少过量的Zn进入食物链。

[Objective] The aim was to study on differences in tolerance and cultivate effect of Zn pollution in three vegetables in central China.[Method] Seed germination tests and pot experiments of Raphanus Sativus L.,Brassica campestris ssp.Chinensis and Amaranthus mangostanus under Zn stress with different concentrations were carried out,to study the effects of different treatments on seed germination rates,seedling growth,biomass and Zn contents of vegetables.[Result] Zn stress with concentration of 2 000 mg/L had no significant influences on seed germination rates of pakchoi and radish,but had significant influences on seed germination rate of amaranth.Zn stress with concentrations of 500 and 2 000 mg/L had significant influence on seedling growth of the 3 vegetables.The tolerance of radish to excessive Zn toxicity was stronger than that of pakchoi and amaranth.In addition,Zn contents in edible part of the 3 vegetables in each treatment were lower than standard of food hygiene of China.When the added Zn was 100-1 000 mg/kg soil,the Zn contents in radish shoot and root parts were both lower than that in pakchoi and amaranth.[Conclusion] Radish had better tolerance on Zn pollution than pakchoi and amaranth,and was more suitable to be planted in Zn-contaminated soils than the other two vegetables in central China to reduce Zn contamination risk in food web.