铅胁迫对八仙花生理及主要根际特征的影响  

Effects of Pb stress on physiology and main rhizosphere characteristics of Hydrangea macrophylla

作　　者：宋云静 金净 赵冰 SONG Yunjing;JIN Jing;ZHAO Bing(College of Landscape Architecture and Arts,Northwest A&F University,Yangling 712100,Shaanxi,China)

机构地区：[1]西北农林科技大学风景园林艺术学院,陕西杨凌712100

出　　处：《浙江农林大学学报》2025年第1期133-142,共10页Journal of Zhejiang A&F University

基　　金：陕西省重点研发计划一般项目(2024NC-YBXM-236)。

摘　　要：【目的】探究铅胁迫对八仙花Hydrangea macrophylla根系生长生理、根系分泌物和根际土壤养分环境的影响,分析八仙花对铅胁迫的适应机制,为八仙花修复铅污染土壤提供科学依据。【方法】通过50 d的温室盆栽试验,研究0(对照)、500、1 500、2 500 mg·kg^(-1)铅胁迫对八仙花生长和铅吸收,根系氧化损伤、抗氧化系统、渗透调节物质和根系分泌物,及土壤理化性质、土壤酶和根际铅化学形态的影响。【结果】铅胁迫抑制了八仙花生长,尤其在2 500mg·kg^(-1)铅处理下,八仙花生物量较对照显著降低23.7%。但八仙花对高质量分数铅有一定耐受性,八仙花通过提高根系超氧化物歧化酶(SOD)和过氧化物酶(POD)活性,增加谷胱甘肽(GSH)质量分数,增强抗氧化能力,从而缓解铅胁迫对八仙花造成的氧化损伤;铅胁迫还提高了八仙花渗透调节物质的质量分数,其中可溶性糖质量分数在2 500 mg·kg^(-1)铅处理下达到最大,脯氨酸质量分数则相反;八仙花根系可以分泌脂肪酸、胺类,维持细胞结构、消除活性氧,乙醇酸分泌的增加促进了对铅的吸收;铅胁迫下土壤微生态环境得到改善,根际土壤蔗糖酶和过氧化氢酶活性在2 500 mg·kg^(-1)铅处理下达到最大,有效提高了土壤养分;随着铅质量分数的升高,根际pH降低、电导率增加,土壤铅可交换离子态、碳酸盐结合态占比最高分别达到2.03%、8.09%,提升了土壤铅的有效态成分,有利于八仙花对铅的吸收。【结论】八仙花对铅有良好的适应性,能够在含高质量分数铅的土壤中正常生长并改善土壤理化性质。[Objective]The objective is to explore the effects of different concentrations of lead(Pb)stress on the root growth physiology,root exudates and rhizosphere soil nutrient environment of Hydrangea macrophylla,and analyze its adaptation mechanism,provide a scientific basis to repair lead-contaminated soil.[Method]The effects of Pb[0(the control),500,1500,2500 mg·kg^(-1)]stress on the growth and uptake of Pb,root oxidative damage,root antioxidant system,root osmotic regulatory substances and root exudates,soil physical and chemical properties,soil enzymes and rhizosphere Pb chemical morphology were studied by a pot experiment.[Result]Pb stress inhibited the growth of H.macrophylla,especially under 2500 mg·kg^(-1) Pb treatment,the biomass decreased significantly by 23.7%compared with the control,but H.macrophylla had a certain tolerance to high concentrations of Pb.The oxidative damage caused by Pb stress on H.macrophylla was alleviated by increasing SOD and POD activities in the root,increasing GSH content and enhancing the antioxidant capacity.H.macrophylla also increased the content of osmotic regulatory substances.The soluble sugar content reached the maximum under 2500 mg·kg^(-1) Pb treatment,while the proline content was opposite.The root could secrete fatty acids and amines to maintain cell structure,eliminate reactive oxygen species,and the increase of glycolic acid secretion promoted Pb absorption.Soil microecological environment was improved under Pb stress.The activities of sucrase and catalase in rhizosphere soil reached the maximum under the treatment of 2500 mg·kg^(-1) Pb,which effectively improved soil nutrients.With the increase of Pb concentration,rhizosphere pH value decreased and EC value increased,and the exchangeable ionic state and carbonate binding state of soil Pb accounted for 2.03%and 8.09%respectively,which increased the available state composition of Pb and was conducive to the absorption of Pb by H.macrophylla.[Conclusion]H.macrophylla has good adaptability to Pb,and can grow normally

关 键 词：八仙花 铅污染土壤 生理响应 铅化学形态 土壤酶活性 

分 类 号：S606[农业科学—园艺学]