铅胁迫对金银花生长、生理及积累特性的影响

Effects of Lead Stress on Growth and Physiological Metabolism and Accumulation Characteristics of Lonicera Japonica

摘要:

为探讨不同浓度铅(Pb)胁迫对金银花生长、生理及积累特性的影响,利用盆栽法研究了不同Pb处理浓度(0、400、600、800、1 000 mg/kg)对封丘金银花生长、生理代谢及吸收积累的影响,检测其株高增量、单株产量、渗透调节物质、抗氧化酶活性等指标,并用隶属函数法对其耐铅性进行综合评价。结果表明:金银花对铅的积累主要在根部,富集能力大小表现为根>叶>花,隶属函数法分析表明,封丘金银花对铅胁迫具有中度耐性。低浓度铅胁迫对金银花的生长影响不显著,当铅浓度≥800 mg/kg时,株高增量、生物量等与对照相比下降明显(P<0.05);铅浓度为1 000 mg/kg时,金银花单株产量与对照相比下降了54.90%,达到最大值。金银花叶片中叶绿素含量随铅浓度升高呈下降趋势,游离脯氨酸、可溶性糖、可溶性蛋白含量有所增加,尤以高浓度时(≥800 mg/kg)差异最为显著;铅胁迫造成金银花叶片丙二醛(MDA)和抗氧化酶活性升高,当Pb浓度为600 mg/kg时,MDA含量与对照没有明显差异;SOD活性比对照提高了41.65%;Pb浓度为1 000 mg/kg时,MDA含量达到最大值,与对照差异显著,POD、CAT活性分别比对照提高78.92%、45.60%。

Abstract:

The aim of this study was to investigate the effects of different concentrations of lead（Pb） stress on the growth, physiology and accumulation characteristics of Lonicera japonica, the effects of different concentrations of lead（0 mg/kg, 400 mg/kg, 600 mg/kg, 800 mg/kg, 1 000 mg/kg） on the growth, physiological metabolism and absorption and accumulation of Lonicera japonica were studied by pot culture. The plant height increment, yield per plant,osmotic regulators and antioxidant enzyme activities were measured. The membership function method was used to evaluate its lead resistance comprehensively. The results showed that the accumulation of lead in Lonicera japonica was mainly in the root, and the accumulation capacity was root ＞ leaf ＞ flower. Subordinate function analysis showed that Lonicera japonica had moderate tolerance to lead stress. The growth of Lonicera japonica was not significantly affected by low concentration of lead. When the concentration of lead was more than 800 mg/kg, plant height increment and biomass decreased significantly compared with the control（P＜ 0.05）; when the concentration of lead was1 000 mg/kg, the yield of Lonicera japonica decreased by 54.90% compared with the control, reaching the maximum value. The content of chlorophyll in Lonicera japonica leaves decreased with the increase of lead concentration,but the content of free proline, soluble sugar and soluble protein increased, especially at high concentration（＞ 800 mg/kg）; the activity of MDA and antioxidant enzymes in Lonicera japonica leaves increased under lead stress, and there was no significant difference between the content of MDA and the control when the concentration of lead was600 mg/kg. The activity of POD and CAT increased by 41.65% and 78.92% and 45.60% respectively when the concentration of Pb was 1 000 mg/kg.