镉和苯并[a]芘胁迫对小麦幼苗生理指标的影响

The Effect Cadmium and B[a]P on the Physiological Characteristic of Wheat Seedling

采用水培方法研究了镉(Cd)和苯并[a]芘(BaP)污染对小麦幼苗生理指标的影响。营养液中镉和苯并[a]芘的浓度分别为10mg.L-1和54mg.L-1。结果表明:与对照组相比,各胁迫组小麦生物量下降,株高降低,复合胁迫组地上及地下干重分别下降13.1%和49.8%,株高增长最低;各组超氧化物歧化酶(SOD)活性呈现升高-降低-升高趋势,且低于对照,过氧化物酶(POD)和过氧化氢酶(CAT)活性先升高再降低,复合胁迫组POD活性最高,CAT活性最低。镉、苯并[a]芘及其复合胁迫下,小麦幼苗的生长受到了一定抑制,且以复合胁迫最为显著。镉、苯并[a]芘联合作用的结果表现为协同促进作用。

The present study was designed to study the effects of Cd and B[a]P on growth parameters and some physiological characteristics of wheat seedling grown under hydroponic conditions during exposure to Cd（ 10 mg＂ L^-1） and B[a]P（54 rag＂ L^-1） for 1 - 11 d. The results showed that biomass and height of wheat seedling decreased under Cd and B[a]P stress, while the above ground and under ground dried weight declined 13.1% and 49.8% respectively under the combined effect of Cd and B[a]P. The activity of superoxide dismutase（SOD ） represented the trend of increase, then decrease, finally increase. All treatments showed lower SOD activity than the control. The activities of guaiacol peroxidase （POD） and catalase （CAT） increased, then decreased. The activities of POD was the highest, and the activities of CAT was lowest under the combined stress. Compared to individual treatment, the combined effect was more detrimental to the above parameters. The results indicated that the effect of Cd and B[a]P combined stress on wheat seedling was synergistic action.