铅胁迫对乌桕(Sapium sebiferum)叶片光合特性的影响  

Effects of Lead Stress on the Photosynthetic Characteristics of Sapium sebiferum Leaves

作　　者：蒲光兰[1] 彭艳菲 易海燕 王婷 袁大刚 PU Guanglan;PENG Yanfei;YI Haiyan;WANG Ting;YUAN Dagang(College of Forestry,Sichuan Agricultural University/National Forestry and Grassland Administration Key Laborary of Forest Rescources Concervation and Ecological Safety on the Upper Reaches of the Yangtze River/Forestry Ecological Engineering in the Upper Reaches of the Yangtze River Key Laborary of Sichuan Province,Chengdu 611130,China;College of Resources,Sichuan Agricultural University,Chengdu 611130,China)

机构地区：[1]四川农业大学林学院/长江上游森林资源保育与生态安全国家林业和草原局重点实验室/长江上游林业生态工程四川省重点实验室,成都611130 [2]四川农业大学资源学院,成都611130

出　　处：《四川农业大学学报》2025年第2期375-382,396,共9页Journal of Sichuan Agricultural University

基　　金：国家科技基础资源调查专项(2022FY100202)。

摘　　要：【目的】明确Pb胁迫对乌桕叶片光合特性的影响,进一步探讨乌桕对土壤重金属Pb污染的修复潜力,为Pb污染区修复树种的选择提供参考。【方法】以4 a生乌桕苗木为试验材料,通过盆栽控制试验,以不添加Pb为对照,研究不同Pb浓度处理(500、1000、1500、2000、3000 mg/kg)对乌桕叶片光合特性和苗木生长的影响。【结果】①Pb胁迫抑制了乌桕苗木生长,Pb浓度越高,抑制效果越明显;Pb处理浓度为3000 mg/kg时地径最低,显著低于其余各Pb胁迫处理和对照,地径较CK减少了1.94 mm,根系大面积变黄且呈团块状。②Pb对乌桕光合色素含量和叶片颜色的影响随胁迫程度不同而有异。Pb处理浓度≤1000 mg/kg时,Pb对乌桕叶片叶绿素含量(chla、chlb、chll)影响较小,当处理浓度为3000 mg/kg时,Pb胁迫显著降低了乌桕叶片叶绿素含量(chla、chlb、chll)。叶片颜色随Pb处理浓度的增加逐渐变黄,当Pb处理浓度超过1500 mg/kg时,叶片大面积黄化后逐渐变紫,Pb处理浓度为3000 mg/kg时,叶片呈较深的紫红色。③Pb胁迫对乌桕光合特性有显著影响。随Pb胁迫程度的加剧,乌桕叶片P_(n)、L_(s)、G_(s)、F_(v)/F_(0)、F_(v)/F_(m)、ETR和qP等总体呈下降趋势;C_(i)、C_(i)/G_(s)、NPQ和Ex呈上升趋势。光合参数不同,Pb胁迫对其影响程度有异。其中,P_(n)、F_(v)/F_(m)和ETR等对Pb胁迫较为敏感,轻度胁迫下(500 mg/kg)呈显著下降趋势,胁迫至3000 mg/kg时降至最低;而F_(v)/F_(0)、E_(x)等参数相对稳定,仅胁迫至3000 mg/kg时,其值发生显著变化。【结论】乌桕耐受性较好,低浓度Pb胁迫下乌桕苗木可正常生长;胁迫至3000 mg/kg时,乌桕叶片光系统受到严重损伤,苗木生长受到抑制。此结果可为Pb污染区修复树种的选择提供参考。【Objective】The effects on photosynthetic characteristics of Sapium sebiferum leaves were clarified to investigate the plant's potential for remediating soil contaminated with the heavy metal Pb,providing a theoretical reference for selecting tree species suitable for lead-contaminated areas.【Method】This study examined the impact of different Pb concentration(500,1000,1500,2000,3000 mg/kg)on the photosynthetic parameters and seedling growth of four-year-old Sapium sebiferum in controlled pot experiments,with no Pb treatments as the control.【Result】①Pb stress inhibited the growth of Sapium sebiferum seedlings,with more pronounced inhibition at higher Pb concentration;the smallest ground diameter was observed at 3000 mg/kg,significantly lower than that other Pb stress treatments and the control,decreasing by 1.94 mm compared to the control.The root turned yellow over large areas and became clumped.②The effects of lead stress on leaf color and chlorophyll content varied with stress level.Pb treatments concentration of 500 mg/kg and 1000 mg/kg had little effect on Chla,Chlb and Chll contents,while 3000 mg/kg significantly reduced chlorophyll content.Leaf color gradually turned yellow with increasing Pb concentration,becoming a deeper purple-red at 3000 mg/kg after extensive yellowing.③Pb stress significantly affected photosynthetic characteristics.The value of P_(n),L_(s),G_(s),F_(v)/F_(0),F_(v)/F_(m),ETR,and qP decreased with increasing Pb stress,while C_(i),C_(i)/G_(s),NPQ,and Ex increased.Pb stress had varying effects on different photosynthetic parameters.For example,Pn,F_(v)/F_(m)and ETR were more sensitive,decreasing significantly under light stess(500 mg/kg)and reaching their lowest levels at 3000 mg/kg.In contrast,F_(v)/F_(0)and E_(x) were relatively stable,changing significantly only at 3000 mg/kg.【Conclusion】Sapium sebiferum seedlings demonstrated greater tolerant and grew normally under light Pb stress.However,the photosynthetic light system of Sapium sebiferum leaves was severely dama

关 键 词：乌桕 铅胁迫 生长 光合生理 植物修复 

分 类 号：S727.3[农业科学—林木遗传育种]