野生圆锥八仙花对Pb(NO3)2重金属胁迫的生长及生理响应

Wild Hydrangea paniculata Sieb.Growth and Physiological Response to Lead Stress

以圆锥八仙花(Hydrangea paniculata Sieb)为试材,采用水培法研究了圆锥八仙花对Pb重金属胁迫的响应,设置0、50、100、150、200 mg·L-1不同浓度Pb(NO3)2处理,分别在处理后5、10、15、20、25 d测定了生长和生理生化指标。结果表明:50 mg·L-1 Pb(NO3)2处理的叶片数、相对生物量、株高、根长、相对生长率(RGR)、净同化率(NAR)和生物量(DB)以及叶绿素总量含量和类胡萝卜素含量均高于CK。丙二醛(MDA)、脯氨酸(Pro)、过氧化物酶(POD)和超氧化物歧化酶(SOD)活性与CK差异不明显。Pb胁迫伤害症状调查表明150 mg·L-1 Pb(NO3)2为圆锥八仙花的耐性阈值,超过该阈值后,Pb浓度增加,相对生长率、净同化率生物量降低。叶绿素含量和类胡萝卜素含量降低,并随处理时间延长而降低,丙二醛和脯氨酸大量累积,过氧化物酶和超氧化物歧化酶活性增加。圆锥八仙花具有较强的抗铅能力,可以用于铅尾矿区土壤修复和铅污染土地区的植物修复。

Hydrangea paniculata Sieb. was cultivated in hydroponics,in which Pb(NO3)2 was in different concentrations that were 0 mg·L-1,50 mg·L-1,100 mg·L-1,150 mg·L-1,200 mg·L-1,respectively,and the growth and physiological index were measured in 5 days,10 days,15 days,20 days,25 days.The results showed that the treatment of 50 mg·L-1 Pb(NO3)2 had higher value in leaf number,relative biomass,plant height,root length,relative growth rate(RGR),net assimilation rate(NAR),biomass(DB) as well as the content of chlorophyll and carotenoid than those of CK,respectively.The content of malondialdehyde(MDA),proline(Pro),as well as the activity of peroxidase(POD) and superoxide enzyme(SOD) were no significance of CK.Lead stress injury symptom survey indicated that the lead patience threshold was application of Pb(NO3)2 up to concentrations of 150 mg·L-1,more than which the relative growth rate(RGR),net assimilation rate(NAR) and biomass(DB) were reduced significantly over 25 days post period when lead concentration increased,and the chlorophyll and carotenoid content decreased with the extension of processing time and had more reduce,but malondialdehyde(MDA),proline(Pro) concentration accumulating increased,peroxidase(POD) and superoxide disproportionation enzyme(SOD) activity increased,respectively.Hydrangea paniculata Sieb.had strongly resistance to lead,for which could be used for soil remediation in lead tailings and phytoremediation in lead-contaminated soil areas.