硅对镉、锌、铅复合污染土壤中黑麦草生理生化性质的影响

Effects of silicon on physiological and biochemical properties of ryegrass under the compound pollution of Cd, Zn and Pb

采用正交试验设计L9(34)对黑麦草(Lolium perenne L.)进行温室盆栽试验,观测Cd、Zn、Pb复合污染条件下,硅(Si)对黑麦草生物量、叶绿素含量以及保护酶系统的影响。结果表明,Cd使黑麦草根系发育受阻导致生物量下降,中等水平的Zn和Pb有利于黑麦草生物量的积累;Cd、Zn、Pb复合污染造成黑麦草叶绿体结构的破坏,使叶绿素含量减少;低水平的Cd、Zn、Pb复合污染对黑麦草CAT和POD活性起到激发作用,但随着添加水平提高,两种酶活性受到抑制。Si可以促进黑麦草根系生物量的增加,有利于根系对水分和养分的吸收,保证地上部分的养分供给,使叶片生物量增加;硅化细胞的形成有利于黑麦草叶片对光能的吸收利用,Si也使叶绿素含量增加;Si对CAT和POD有显著激活作用,从而减轻重金属复合污染对黑麦草产生的伤害。

Pot experiments with an orthogonal experimental design L9（3^4） were conducted in the greenhouse to investigate the effects of silicon on the biomass, chlorophyll content and protective enzyme system of ryegrass（Lolium perenne L.）under the compound pollution of Cd, Zn and Pb. Results showed that the biomass of ryegrass decreased with increasing Cd application due to the inhibition of Cd to roots growth, but it increased at medium Zn and Pb application; the chlorophyll content of ryegrass decreased under Cd, Zn and Pb compound pollution which may destroy the structure of chloroplast; CAT and POD were activated at low Cd, Zn and Pb application, but were inhibited with the increasing application. Silicon increased the leaf biomass by increasing the root biomass of ryegrass which helped to uptake sufficient water and nutrients to keep it growing healthy; The formation of siliceous cells promoted the absorption and effective use of light energy by the leaves ofryegrass and also increased the chlorophyll content; Silicon significantly activated CAT and POD so as to alleviate the damage from Cd, Zn and Pb compound pollution.