【作者】 孟国忠；

【导师】 季孔庶；

【作者基本信息】 南京林业大学 ， 园林植物与观赏园艺， 2013， 博士

【摘要】 本研究以金边虎尾兰、芦荟、金心吊兰、黄金葛、铁线蕨和鸟巢蕨等6种室内常见观叶植物为材料，采用室内人工熏气箱胁迫的方法，研究苯、甲醛单一和复合胁迫条件下，植物体内活性氧自由基（·O₂^-）的累积、叶绿素（Chl）含量、丙二醛（MDA）含量、脯氨酸（Pro）含量、超氧化物歧化酶（SOD）活性、过氧化氢酶（CAT）活性、过氧化物酶（POD）活性以及叶片微观结构的变化。通过研究不同植物对苯、甲醛污染的响应差异，揭示室内植物对苯、甲醛污染的响应机理、净化效果以及苯、甲醛对植物的毒害效应，为丰富室内植物逆境理论研究提供参考，主要研究结果如下：1.苯、甲醛单一胁迫对植物的毒害效应用浓度为0.1、1、3、5mg/m³的甲醛和浓度为0.11、0.55、1.1、3.3mg/m³的苯分别处理48h。在试验期间，随着苯、甲醛浓度的增加，与对照相比，6种植物的Chl含量呈现下降变化，活性氧自由基（·O₂^-）不断累积，膜脂过氧化程度增加（MDA增加），Pro含量逐渐增加，而SOD、POD、CAT三种保护酶活性因植物种类的不同出现持续增加、持续减少和先增加后减少三种不同的变化。当苯、甲醛胁迫浓度达最大值（苯3.3mg/m³，甲醛5mg/m³）时，6种植物的主要生理指标与对照相比差异达极显著，其中Chl含量下降幅度最大的植物是铁线蕨，降幅超过了30%，降幅较小的植物是黄金葛和金边虎尾兰，降幅在20%左右；·O₂^-含量增幅最高的植物是鸟巢蕨和铁线蕨，增幅超过了95%，增幅最小的植物是黄金葛，增幅小于72%；除鸟巢蕨、铁线蕨的SOD活性出现先增加后下降的变化外，其它植物的SOD随苯、甲醛浓度的增加而逐渐增加，说明此浓度的苯和甲醛对铁线蕨和鸟巢蕨毒害作用达到最大。运用主成分分析法对6种植物抗苯、甲醛能力进行评定，抗甲醛能力强弱排序为：金心吊兰>金边虎尾兰>黄金葛>芦荟>鸟巢蕨>铁线蕨；抗苯能力强弱排序为：金心吊兰>金边虎尾兰>芦荟>黄金葛>铁线蕨>鸟巢蕨。2.苯、甲醛单一胁迫对植物微观结构影响苯、甲醛胁迫对金心吊兰的气孔结构和叶片断面厚度都产生了影响。苯迫下，金心吊兰气孔长径与对照相比差异不显著，气孔短径在苯胁迫14d时比对照减少26.46%。甲醛胁迫下，气孔的长径、短径与对照差异不显著，但气孔形态由对照时的哑铃形变成不规则长方形，且大部分气孔处于闭合状态。金心吊兰叶片断面厚度和气孔密度呈现减少的变化趋势。在苯、甲醛各处理14d后，与对照相比，叶片厚度分别下降23.6%和35.53%，而气孔密度比对照下降21.95%3.苯、甲醛复合胁迫对植物的毒害效应苯、甲醛复合胁迫对植物的毒害效应与复合方式有关，但复合胁迫下的光合系统、抗氧化系统的变化并不是苯、甲醛单一胁迫下指标变化的简单叠加，而是一种较为复杂的交互作用。当甲醛浓度低于1mg/m³时，甲醛与苯的复合对植物生理指标的协同抑制作用并不明显；当甲醛浓度高于1mg/m³时，这种协同抑制作用明显增强。经主成分分析计算的综合值表明，当高浓度的甲醛（T3处理：3mg/m³，T4处理：5mg/m³）与苯复合时，金心吊兰、金边虎尾兰和铁线蕨对苯、甲醛复合胁迫的抗性从强到弱排序为：金心吊兰>金边虎尾兰>铁线蕨。4.室内植物对苯、甲醛复合胁迫的响应机制正常生长条件下，植物体内自由基的产生和清除处于一种动态的平衡。在较低浓度的苯、甲醛胁迫下，植物体活性氧自由基的累积还处于抗氧化酶的清除能力范围时，细胞膜不会被破坏，细胞可以维持正常的结构。随着胁迫浓度的增加，6种植物体内的活性氧自由基过度累积， SOD、POD和CAT的合成受到限制，活性下降，细胞质脂发生过氧化反应，导致丙二醛（MDA）含量增加，植物细胞结构被破坏生理功能出现紊乱，光合作用受阻，Chl含量下降，情况严重时会导致植物死亡。5.室内植物对苯、甲醛的净化效果用浓度为0.1、1、3mg/m³的苯和甲醛处理（单一和复合）24h，熏气箱及土壤吸附苯、甲醛的量随着时间的增加而增加，但吸附效果远低于植物的净化能力。相同胁迫条件下，空熏气箱的吸附能力低于土壤的吸附能力，而对苯的吸附能力又低于对甲醛的吸附能力。植物对苯、甲醛的净化效果与胁迫浓度和胁迫时间有关，浓度越高，净化效果越差。单一胁迫条件下，铁线蕨平均去除了37.61%的苯和41.64%的甲醛，而黄金葛和金边虎尾兰对苯和甲醛的去除率均超过49%；复合胁迫下，铁线蕨平均去除了41.06%的苯和41.28%的甲醛，而黄金葛平和金边虎尾兰对苯和甲醛的去除率均超过45%。更多还原

【Abstract】 In this dissertation, six different indoor plants including Sansevieria trifasciata var. laurentii,Aloe vera var. chinensis, Chlorophytum comosum var. mediopictum, Scindapsus aureum,Adiantum capillus-veneris and Asplenium antiquum had been tested in the experiment. Weanalyzed the accumulation of superoxide radicals（·O₂^-）, contents of chlorophyll （Chl）,malondialdehyde （MDA） and proline （Pro）, activities of superoxide dismutase （SOD）,peroxidase （POD）, catalase （CAT） and the variation of leaf microstructure in plants throughindoor artificial fumigation box, under the single and compound stress of benzene andformaldehyde. Studying the different responses to the pollution of benzene and formaldehydeamong the plants, the dissertation revealed that the response mechanism to the pollution ofbenzene and formaldehyde in indoor plants, as well as the toxicity mechanism of benzene andformaldehyde in the plants. By doing this, I hope that the results will provide a more scientificreference for enriching the theoretical research on plant responses to environmental stress. Themajor results were as follows:1. Toxicity mechanism in plants under the stress of benzene or formaldehydeTreated with0.1,1,3,5mg/m³formaldehyde or0.11,0.55,1.1,3.3mg/m³benzene for48hours, the contents of Chl in six plants decreased as the concentration of benzene andformaldehyde increased, the·O₂^-was accumulating, the MDA and Pro content were increasing,therefore, the activities of SOD, POD and CAT in different species showed three differentpatterns such as increasing continuously, decreasing continuously and firstly increasing and thendecreasing.When the concentration of benzene and formaldehyde reached the maximum （benzene3.3mg/m³and formaldehyde5mg/m³）, the major physiological indexes of six plants had greatdifferences compared with the contrast. Adiantum capillus-veneris was the plant with the largestdecline in Chl content, reduced more than30%. The plants with the smallest decline wereScindapsus aureum and Sansevieria trifasciata var. laurentii, decreased about20%. Adiantumcapillus-veneris and Asplenium antiquum were the plants with the largest increase in super oxideanion content, increasing over95%. The plant with the smallest increase was Scindapsus aureum,increasing less than72%. Except of the activities of SOD in Adiantum capillus-veneris andAsplenium antiquum first increased and then decreased, they increased continuously as theconcentration of benzene and formaldehyde increasing. It indicated the present concentration offormaldehyde or benzene had the greatest toxic effects on Adiantum capillus-veneris andAsplenium antiquum. This dissertation measured the anti ability to benzene and formaldehyde of six plantsthrough the principle component analysis. The anti ability to formaldehyde from the strongest toweakest was Chlorophytum comosum var. mediopictum, Sansevieria trifasciata var. laurentii,Scindapsus aureum, Aloe vera var. chinensis, Asplenium antiquum and Adiantum capillus-veneris.The anti ability to benzene from the strongest to weakest was Chlorophytum comosum var.mediopictum, Sansevieria trifasciata var. laurentii, Aloe vera var. chinensis, Scindapsus aureum,Adiantum capillus-veneris and Asplenium antiquum.2. Effects on microstructure of spider plant under the stress of benzene or formaldehydeBenzene and formaldehyde had some different effects on the pore structure and thethickness of leaf cross-section of Chlorophytum comosum var. mediopictum. Under the stress ofbenzene, the stomatal length-diameter of Chlorophytum comosum var. mediopictum had notsignificant difference by contrast, and the stomatal short-diameter reduced26.46%in14days bycontrast. Under the stress of formaldehyde, the length-diameter and short-diameter had notobvious differences by contrast, but the shape had changed from dumbbell shape to rectangle.Most stomas gradually entered the closed state as the stress time increasing.The leaf cross-section thickness and stomatal density of Chlorophytum comosum var.mediopictum decreased under the stress of benzene and formaldehyde. Under the treatment ofbenzene and formaldehyde, the thickness decreased23.6%and35.53%14days later, as well as,the stomatal density was21.95%lower than that of control.3. Toxicity mechanism in plants under the compound stress of benzene and formaldehydeThe toxicity mechanism in plants under the compound stress of benzene and formaldehydewas related to the compound pattern. The changes of photosynthetic system and antioxidantsystem under the compound stress were not the simple addictive effects as that under the singlestress, while they were a complex interaction. When the concentration of formaldehyde was lessthan1mg/m³, the physiological indexes of plants would be relieved, and such effects woulddecrease while the concentration of benzene and formaldehyde increases. When theconcentration of formaldehyde was more than1mg/m³, the physiological indexes of plants wouldbe synergistic inhibited under the compound stress of benzene and formaldehyde.Through the principle component analysis, the ordered resistance to the compound stress ofbenzene and formaldehyde from the strongest to weakest was Chlorophytum comosum var.mediopictum, Sansevieria trifasciata var. laurentii and Adiantum capillus-veneris, when underthe compound stress of formaldehyde in high concentration （Treatment3:3mg/m³, Treatment4:5mg/m³） and benzene.4. Response mechanism to the stress of benzene and formaldehyde in indoor plantsThe production and elimination of reactive oxygen types in plants were in dynamic balanceunder the normal growth conditions. The membrane could not be destroyed and kept the normalstructure when it was under the stress of benzene and formaldehyde in low concentration, and theaccumulation of free radical was in the scope that the antioxidant enzyme was normal. As theconcentration increasing, the reactive oxygen types of the six plants would be over accumulated. Once they were out of the elimination ability of antioxidant enzyme （SOD, POD and CAT）, theirsynthesis would be limited and the activities would decrease, and lipid peroxidation of cellswould lead to the content of MDA increase, then the cell structure and physiological functionwould be destroyed, the photosynthesis would be limited and the content of Chl would decrease,or even the plant would die if the situation was serious.5. Purification effect of indoor plants under the compound stress of benzene and formaldehydeWhen treated with0.1,1,3mg/m³formaldehyde and benzene （single or compoundtreatment） for24hours, the fumigation box and soil absorbed benzene and formaldehydeincreasingly as the time prolonging. In the same condition, the adsorption capacity of fumigationbox was weaker than that of soil, and the adsorption capacity to benzene was weaker than toformaldehyde.The purifying effects of plants were highly related to the stress concentration, and the higherconcentration, the worse purifying effects. Under stress of benzene or formaldehyde,37.61%benzene and41.64%formaldehyde were removed by Adiantum capillus-veneris. The averageremoval rates of benzene and formaldehyde byScindapsus aureum and Sansevieria trifasciatavar. laurentii were more than49%. Under compound stress of benzene and formaldehyde,41.06%formaldehyde and41.28%benzene were removed by Adiantum capillus-veneris, in themeantime, average more than45%formaldehyde and benzene were removed by Scindapsusaureum and Sansevieria trifasciata var. laurentii.更多还原