The Stress Of Cd,Cu And Pb Compound Pollution On Mustard And Their Absorption And Enrichment Characteristics In Mustard

Cd, Cu and Pb are the main heavy metal contaminant in soil environment which posed the threat to agricultural safety by the majority presenting in surface soil. In present study, cruciferous mustard was selected as houseplants and the pot experiments were carried out under the application of Uniform Design. In order to understand the effects of Cd-Pb-Cu compound pollution on the mustard and it's respond to the stress of compound pollution, the growth status, changing characteristics of some physiological and biochemical indexes, the Cd-Pb-Cu uptake and accumulation, and the absorption of the some mineral elements of mustard were investigated and analyzed. The results showed as following:(1). There were interactions of Cu x Pb, Cd x Pb and Cu x Cd for mustard by all potted mustard houseplant experiments (P<0.05) which significantly inhibited on growth of mustard's underground parts, and in which, the interactions of Cd x Pb,Cu x Pb inhibited the growth of its upground parts (P<0.05). There were also interactions of Cu x Cd which reduced the chlorophyll concentrations of leaves, while Cu-Pb increased chlorophyll concentrations. Cd was the main factor which reduced chlorophyll concentrations of leaves. All the treatment concentrations could significantly increase the content of praline and MDA but inhibit the activity of SOD (p<0.01), however, there was opposite result only when the Cu concentration was below 200mg/kg (P<0.05).(2). The order of ability for heavy metal absorption and accumulation in mustard was Cd> Cu>Pb. Mustard showed more accumulation of Cd and higher tolerance to the stress of Cu and Pb. Cd-Cu compound effect could promote the enrichment of Cd and Cu in various parts of the mustard and increase transportation of Cu to the upground part. Cu-Pb compound effect increased the enrichment of Cd but inhibited the accumulation of Cu in mustard. Cu significantly inhibited the absorption of Pb.(3). Similar characteristics of mustrad's absorption and transportation of Mg, Fe and K presented among all treatments, namely the Mg content in shoot was much higher than that in root, while Fe and K mainly accumulated in the root. Cd greatly increased the absorption of K and inhibited the absorption of Fe; Cu has inhibited the absorption of K in underground part of mustard, meanwhile, Cu and Cd-Pb coupled effects decreased K transport from root to shoot.