不同浓度铅、锌对玉米生长的生态毒理学效应研究

Study of the different concentrations of lead,zinc to eco-toxic effects of maize growth

利用盆栽试验,研究不同浓度铅、锌处理对玉米生长的生态毒效应。结果表明:铅浓度在250mg/kg内促进玉米发芽,高于此浓度则抑制发芽,所有锌处理均提高了玉米的发芽率,低浓度锌可提高种子的发芽势,高浓度则有抑制作用;铅浓度为125mg/kg时就对叶面叶绿素、芽、根、株高、干鲜重产生影响,随着铅用量的加大抑制性越大;锌处理对叶绿素含量、芽、根、株高、干鲜重的作用表现为随着用量的加大,促进作用先逐渐增大然后逐步减弱直至产生抑制;各个器官中铅富集量高低顺序为:根系>秸秆>叶>籽实,各个器官中锌富集量高低顺序为:叶>籽实>根系>秸秆;土壤不同形态铅含量随铅用量的加大而增大,同时也改变了土壤中铅形态分配的比例,使非残渣态含量增加;随着外源锌的投入量的加大,改变了锌在土壤中形态分配的比例,矿物态、碳酸盐结合态锌比例逐渐下降,晶体氧化铁结合态、无定型氧化铁结合态、氧化锰结合态比例逐步增大,但无论是原状土还是外源污染土其交换态锌和有机结合态锌含量所占比例很低,不足0.1%。

Pot experiment was conducted to study the effects of different concentrations of lead, zinc to eco-toxlc effects of maize growth. The results show that： the concentration of lead lower than 250mg/kg promoted the corn germination, higher than this concentration inhibited germination, all the zinc processing heighten corn germination rate, low concentrations of zinc can improve seed germination potential, high concentrations inhibited; when lead concentration at 125 mg / kg ,it impacts for follar chlorophyll, bud, root, plant height, fresh and dry weight ,the lead dosage the more, the inhibition the increaser; chlorophyll content, bud, root, plant height, fresh and dry weight of the zinc processing ,the role of promoting gradually increases with the amount of the increase, then gradually weakened until inhibition; the order of the accumulation of lead in various organs： root 〉 straw〉 leaf〉 seed, the order of the accumulation of zinc in various organs： leaf〉 seed〉 root〉 straw; with the increased usage of lead, the soil different forms of lead content trend significantly increases, but also changed the morphological distribution of lead in the soil, the proportion of non-residual fraction content increased. With the increasing amount of exogenous zinc inputs,change the proportion of morphological distribution of zinc in the soil, Mineral-Zn, CAB-zn in the proportion of crystalline iron ox- ide bound, COFe-Zn, AOFe-Zn, Omn-Zn gradually increase the proportion, EX-Zn and OM-Zn of content proportion undisturbed soil or outside source contaminated soil is very low, less than 0.1%.