铅、镉和铬在叶类蔬菜中的累积及对其生长的影响

 研究结果表明: 重金属元素铅(Pb) 、镉(Cd) 、铬(Cr) 对几种叶类蔬菜生长和产量都有明显的影响, 且其影响因蔬菜种类、元素种类和浓度的不同而有很大差异, 叶用莴苣> 苋菜> 芥菜> 菜薹>蕹菜, Cr > Cd > Pb ; 不同蔬菜类型可食部位积累重金属元素的顺序为苋菜> 叶用莴苣> 菜薹> 蕹菜> 芥菜;各元素从营养液向蔬菜体内转移的迁移累积率顺序为Cd > Cr > Pb。随着各元素浓度的增大, 对蔬菜生长的影响和其可食部分的富集量随之加大。

Effects of Heavy Metals of Pb, Cd and Cr on the Growth of Vegetables and Their Uptake

Five main leaf vegetable cultivars of Guangdong province were grown in nutrient solution with several levels of Pb, Cd and Cr to evaluate the effect of heavy metals of Pb, Cd and Cr on the vegetable growth and their uptake. The obtained results showed that heavy metals of Pb, Cd and Cr affected greatly on the growth of vegetables. The effect varied significantly with different cultivars, the sorts and levels of heavy metal. The heavy metals decreased the yield of five vegetables in following order: lettuce > edible amaranth > leaf mustard > water spinach (swamp cabbage)> flowering Chinese cabbage. The inhibiting effect of three heavy metals on five vegetables cultivars had a toxicity order: Cr > Cd> Pb. The amounts of residual heavy metals in eatable organs of vegetables were found to be in following order: edible amaranth >lettuce > flowering Chinese cabbage > water spinach (swamp cabbage) >leaf mustard. The cumulated rate of heavy metals: Cd > Cr >Pb. The vegetable yield decreased and the contentration of heavy metals increased when the levels of three heavy metals increased.