模拟酸雨和Pb复合胁迫对2种草坪草生长及抗氧化生理的影响

摘要

[目的]探讨模拟酸雨和Pb复合胁迫对高羊茅(Festuca arundinacea Schreb.)和多年生黑麦草(Lolium perenne)生长及抗氧化生理的影响.[方法]通过盆栽试验研究了模拟酸雨(pH分别为3.5、4 5、5.6)和Pb(0、500、1 000、1 500 mg/kg)复合胁迫对高羊茅和黑麦草的生物量、叶绿素含量、丙二醛(MDA)含量以及超氧化物歧化酶(SOD)活性、过氧化物酶(POD)活性、可溶性糖含量和电导率的影响.[结果]高羊茅和黑麦草生物量和叶绿素含量均随酸雨强度和Pb浓度的增加而下降,且在pH为3.5、Pb浓度为1 500 mg/kg时出现最低值；叶中SOD和POD活性均随Pb浓度和酸雨强度的增加而先升高后降低；MDA含量和可溶性糖含量以及电导率均随Pb浓度和酸雨强度的增加而逐渐升高,且在pH 为3.5、Pb浓度为1 500 mg/kg时出现最大值.[结论]高羊茅和黑麦草通过调节抗氧化酶系统和提高可溶性糖含量来应对酸雨和Pb胁迫,但在高酸度酸雨和高浓度Pb复合胁迫下2种草坪草生长均受到明显抑制,在低酸度酸雨和低浓度Pb复合胁迫下高羊茅表现出相对较好的抗性.%[Objective] The aim was to explore the effects of simulated acid rain and Pb combined stress on growth and antioxidative physiology of Festuca arundinacea Schreb. and Lolium perenne. [Method] Effects of simulated acid rain (plI 3. 5, 4. 5 and 5.6) and Pb (0, 500, 1 000 and 1 500 mg/kg) combined stress on the biomass, chlorophyll content, malondialdehyde (MDA) content, superoxide dismutase (SOD) activity, peroxidase (POD) activity, soluble sugar content and electric conductivity of F. arundinacea and L. perenne were studied by pot experiment. [Result] The biomass and chlorophyll content of F, arundinacea and L. perenne both decreased with the increase of simulated acid rain and Pb concentration, and the lowest values appeared when pH was 3. 5 and Pb concentration was 1 500 mg/kg. The activities of SOD and POD in leaves increased and then decreased with the increase of simulated acid rain and Pb concentration. The contents of MDA and solublc sugar and the electric, conductivity gradually increased with the increase of simulated acid rain and Pb concentration, and the maximum value appeared when pH was 3.5 and Pb concentration was 1 500 mg/kg. [Conclusion] Both F. arundinacea and L. perenne deal with the combined stress of simulated acid rain and Pb through adjusting antioxidant enzymes system and increasing soluble sugar content. However, the growth of F. arundinacea and L. perenne are obviously inhibited under the combined stress of high-acidity simulated acid rain and high-concentration Pb, and F. arundinacea shows good resistance to the combined stress of low-acidity acid rain and low-concentration Pb.