五种木本园林植物叶片对镉污染胁迫的反应

文章探讨五种木本园林植物叶片对镉污染胁迫的反应。有关试验结果表明：在镉污染胁迫下,五种树木叶片的叶绿素总量、质膜透性、过氧化氢酶活性、游离脯氨酸含量及铅的富积量等生理生化特性均发生明显变化,但变幅不尽一致;其中海桐抗镉污染胁迫的能力优于女贞、银杏、香樟和鹅掌楸。     

NaCl胁迫对五叶地锦生长及某些生理特性的影响

用不同浓度的NaCl处理五叶地锦扦插苗 ,研究了盐胁迫对五叶地锦生长及生理特性的影响。结果表明 :小于 5 0mmol·L- 1 的NaCl处理 ,对五叶地锦生长及生理特性没有明显的影响 ;等于或大于 10 0mmol·L- 1 的NaCl处理 ,对五叶地锦的生长有明显的抑制作用 ,而且光合速率、蒸腾速率、气孔导度等生理指标值急剧降低 ,膜相对透性、MDA含量等指标明显增高。由此可以认为 ,10 0mmol·L- 1 NaCl是五叶地锦盐胁迫伤害的阈值。NaCl胁迫下光合作用的下降与膜的伤害、细胞内K 、Ca2 、Na 3种离子平衡关系破坏及糖的反馈性抑制有关 ,而与气孔导度和胞间CO2 浓度无关。盐胁迫下 ,叶片中可溶性糖、脯氨酸以及K、Ca、Na等 3种元素的含量增高。五叶地锦可能通过离子浓度和可溶性糖浓度的提高进行适度的渗透调节 ,以适应NaCl的胁迫。     

乌桕幼苗耐旱性研究

采用PEC,6000模拟干旱胁迫和自然干旱胁迫两种方法,通过测定土壤含水量、叶片电导率、叶片丙二醛含量等指标,分析比较不同品种乌桕幼苗在干旱胁迫下的生理生化变化及耐旱性。结果表明：鸟桕幼苗优13和优24耐旱性较强,优23子代幼苗耐旱性最弱。PEC6000模拟干旱胁迫与自然干旱胁迫试验结果基本一致,可以在一定程度上反映正常的干旱胁迫。     

高温胁迫对银叶树荧光参数的影响

为探讨高温对银叶树叶片的影响,本试验观测了高温胁迫下银叶树幼苗叶片荧光参数的变化.试验选取苗龄6个月、长势良好的银叶树苗开展研究,设置30℃、35℃、40℃、45℃、50℃五个温度梯度,讨论不同温度处理时银叶树幼苗叶片荧光参数的变化情况.结果显示:30℃、35℃胁迫处理中,OJIP曲线、初始荧光F0、PSII光能转化率...     

华南地区4种阔叶幼苗水分胁迫条件下的抗旱性初探

以火力楠、山杜英、木荷、黧蒴锥幼苗为试验材料,利用聚乙二醇6000(PEG-6000)人工模拟水分胁迫环境,研究了水分胁迫对这4种幼苗的影响。结果表明:随着水分胁迫强度的增加,火力楠和木荷叶片的相对含水量下降幅度较小, 山杜英次之,黧蒴锥下降幅度最大;火力楠和木荷叶片的相对电导率上升幅度较小, 山杜英次之,黧蒴锥叶片的相对电导率大幅增加;火力楠和木荷幼苗叶片脯氨酸含量变化不大,而山杜英和黧蒴锥比对照有明显的增加;4种幼苗叶片的可溶性糖含量随着水分胁迫强度的增加呈上升趋势;4种幼苗叶片的叶绿素含量一般呈小幅波动;重度胁迫36 h后,火力楠和木荷叶片的SOD活性显著提高,山杜英显著低于对照,黧蒴锥接近对照水平;火力楠叶片的MDA含量略有增加,木荷保持稳定,山杜英明显增加,黧蒴锥大幅增加。用主成分分析评价4种幼苗的抗旱性,结果表明:4种幼苗的抗旱性为木荷>火力楠>山杜英>黧蒴锥。     

低温对6种绿化树种幼苗生理过程的影响

在不同低温胁迫时间下,对大花五桠果Dillenia turbinata、双翼豆Peltophorum tonkinense、海南山竹子Garciniaoblongifolia、非洲桃花心木Khaya senegalensis、海南红豆Ormosia pinnata和盆架子Alstonia scholaris6种幼苗抗寒性进行了初步研究.结果表明:随着低温胁迫时间的延长,各树种相对电导率缓慢升高,脯氨酸含量波动较大,而叶绿素含量和超氧化物歧化酶(SOD)活性变化较小.大花五桠果叶片的丙二醛(MDA)含量增幅较大,其余树种出现波动最后接近对照水平.海南山竹子、海南红豆和大花五桠果叶片内蛋白质含量有所增加,其余树种波动后显著低于对照.采用主成分分析法进行抗寒性综合评价表明,6种幼苗的抗寒性大小依次为:海南红豆>非洲桃花心木>盆架子>海南山竹子>双翼豆>大花五桠果.     

盐胁迫对碧桃生长发育的影响

以碧桃幼苗为试验材料,研究盐胁迫对其叶片电解质渗透率、丙二醛含量和叶片相对含水量的影响。结果表明：盐胁迫下,叶片的电解质渗透率有上升趋势,且胁迫时间越久,电解质渗透率上升的越高;叶片内丙二醛含量的变化趋势与电解质渗透率的变化趋势相似,胁迫时间越久、浓度越高,丙二醛含量越高;轻度盐胁迫对碧桃幼苗叶片相对含水量的影响不显著。     

秋旱对地被竹生理指标的影响

以铺地竹、黄条金刚竹、菲白竹、鹅毛竹4种地被观赏竹为试验材料,通过人为控水干旱胁迫及自然失水胁迫处理,测定了秋季干旱胁迫下4种地被观赏竹的质膜透性、叶绿素含量、光合作用等生理生化指标的变化,分析了4种地被竹对干旱胁迫的响应情况。结果表明:随着干旱胁迫时间的延长,叶片的细胞质膜透性呈上升趋势,但竹种间上升幅度不同,其中鹅毛竹的上升幅度最小。各竹种叶片中叶绿素含量随着干旱胁迫时间的延长逐渐下降,其中铺地竹下降幅度最大,为68.98%。     

5种屋顶绿化植物抗旱性研究

对应用于屋顶绿化的5种园林植物的抗旱性进行研究,分析了不同水分胁迫条件下,5种植物的叶片相对电导率、叶片相对含水量、叶绿素荧光、净光合速率、蒸腾速率和气孔导度等变化趋势。结果表明：随着水分胁迫强度的增大,5种植物的叶片相对电导率呈上升趋势,叶片相对含水量、叶绿素荧光、净光合速率、蒸腾速率和气孔导度呈下降趋势,但不同植物的抗旱生理指标变化幅度不尽相同。主成分分析结果表明,综合抗旱能力强弱为小蚌兰>铺地锦>假花生>马缨丹>南美蟛蜞菊;叶片相对含水量是评价水分胁迫最重要的指标,其次为相对电导率。     

镉对刺玫果和金银忍冬叶绿素荧光特性的影响

采用盆栽方法研究了土壤镉污染对刺玫果(Rosa davurica Pall.)和金银忍冬(Lonicera maackii Max.)叶绿素荧光参数的影响。设置4种镉污染浓度处理,即0(CK)、50、100和200 mg/kg风干土,让苗木在不同浓度的土壤中生长70d后,进行了叶绿素荧光参数测定。结果表明:随着土壤中镉处理浓度的增大,2树种的荧光参数Fv/Fm、ΦPSⅡ、qP均逐渐降低,qNP则逐渐上升;2树种荧光参数的变化幅度不同,刺玫果的变化幅度比金银忍冬小;以叶绿素荧光参数评价2树种抗镉污染胁迫能力,刺玫果较强,金银忍冬较弱。     

树叶中重金属含量及其指示大气污染的研究

通过对南京市区交通流量大的区域和相时清洁区(江苏省林科院)不同植物叶片重金属元素(Pb、Cd、Cu)含量的分析,研究了大气污染指数,初步探讨了植物重金属含量与城市大气污染之间的关系.研究表明.植物叶片中重金属Pb、Cd和Cu的累积量与大气中Pb、Cd和Cu的相对含量呈显著正相关;所调查绿化树种叶片的重金属含量因重金属种类、采样区和树种的不同具有明显差异,悬铃木叶片累积Pb的能力最强,而杨树叶片对Cd和Cu的累积能力最强.市区大气重金属质量状况为:交通枢纽区中央门、南京化工厂和沪宁高速属于重污染,生活区新庄属于中轻度污染,远郊林科院属于无污染区.     

几种城市绿化树种叶片中铅砷铬镉汞元素的含量特征

2003年对昆明、思茅、丽江3个城市的16个绿化树种叶片中的铅、砷、铬、镉、汞5种重金属元素的含量进行了测定，并结合采集地的空气污染指数进行了相关分析。结果表明：麻栗坡含笑、山玉兰和杜英叶片中Pb的含量与空气污染指数间的相关性显著；石楠、云南拟单性木兰、山玉兰、冬樱花叶片中As的含量与空气污染指数间的相关性达显著或极显著水平；杜英、山玉兰、石楠、天竺桂、云南拟单性木兰叶片中Cr的含量与空气污染指数间的相关性均为显著和极显著；石楠、杜英、冬樱花叶片中Cd的含量与空气污染指数间有显著或极显著的正相关性；8个树种叶片中Hg的含量与污染指数间均没有显著的正相关性。而16个树种中，冬樱花叶片中5种重金属元素的总含量最大，为15．563mg／kg；总含量最低的树种是竹柏（0．692mg／kg）等，两者总含量的差异达14．871mg／kg。不同树种对环境中Pb、As、Cr、Cd、Hg等5种元素的吸收富集能力有较大的差异。16个树种叶片中Cd和Cr含量的相关系数为r0.05=0．582^＊，说明Cr与Cd之间有显著的互相促进作用；Cd与Hg元素含量的相关系数为r0.01=0．807^＊＊，也表明Cd与Hg间有十分显著的互相促进的作用。     

Cd胁迫对灰木莲幼苗生长及某些生理特性的影响

通过对灰木莲幼苗在重金属镉(Cd)胁迫下生长与生理特征的分析,研究在镉胁迫下生长和生理特征的变化情况.结果表明,灰木莲幼苗的苗高和地径的增长率随着Cd2+浓度的增加而减少,Cd2+对苗高增长的影响较为显著;叶片的保护酶活性在低浓度下升高,在高浓度下保护酶的活性受到抑制;丙二醛浓度、游离脯氨酸含量随着镉胁迫的增加而缓慢上...     

Effects of two iron sources on iron and cadmium allocation in poplar (Populus alba) plants exposed to cadmium

Effects of 10 microM cadmium (supplied as Cd nitrate) on the utilization and allocation of iron (Fe) were investigated in poplar (Populus alba L.) plants grown in nutrient solution with Fe(III)-EDTA or Fe(III)-citrate as the Fe source. The effects of Cd were also compared with those of Fe deprivation. The accumulation of Fe in roots was 10-fold higher in plants grown with Fe-citrate than with Fe-EDTA. Cadmium decreased leaf chlorophyll concentrations and photosynthetic rates, and these decreases were more marked in plants grown with Fe-citrate than with Fe-EDTA. In both Fe treatments, addition of Cd caused large increases in root and shoot apoplasmic and non-apoplasmic Cd contents and increases in root Fe content; however, Cd decreased shoot Fe content, especially in plants grown with Fe-citrate. New leaves of plants grown with Fe-citrate had small cellular (non-apoplasmic) Fe pools, whereas these pools were large in new leaves of plants grown with Fe-EDTA. Non-apoplasmic Cd pools in new leaves were smaller in plants grown with Fe-citrate than with Fe-EDTA, indicating that inactivation of non-apoplasmic Cd pools is facilitated more by Fe-EDTA than by Fe-citrate. In the presence of Cd, Fe-EDTA was also superior to Fe-citrate in maintaining an adequate Fe supply to poplar shoots. Differences in plant responses to Fe-EDTA and Fe-citrate may reflect differences in long-distance transport of Fe rather than in acquisition of Fe by roots.     

Absorption and Accumulation of Heavy Metal from Soil by Leaves of Populus x euramericana cv.‘Neva’Plantation

The absorption and enrichment of heavy metal elements by leaves of Populus×euramericana cv.’Neva’ were analyzed through content assessing of heavy metal elements in soils of three forest lands at Fangshan District in the southern suburb of Beijing. These forest lands with P.×euramericana cv. ’Neva’plantation were around with the various sources of pollution such as cement mill,stone mill, sewage and garbage.Some of heavy metal elements such as Cd,Pb,Cu,and Zn were found in the soil samples and leaves of P.×euramericana cv.’Neva’ grown on the three forest lands which were investigated.The results of investigation showed that the soils of three forest lands were polluted with Pb, Cd,Cu and Zn in varying degrees.The contents of Pb,Cu and Zn in soils were significantly different among the three forest lands,whereas the average content of Cd(0.077 6 mg·kg^-1) was less but that of Pb,Cu,and Zn(37.61,26.25 and 90.3 mg·kg^-1 ) were more than the average background value of Beijing.The contents of Pb,Cd,Cu and Zn in leaves of P.×euramericana cv.’Neva’ were different among three forestlands.With the changes of heavy metal contents in soil samples,there was no regularity on the changes of different heavy metal contents in leaves of P.×euramericana cv.’Neva’ grown on different forest land.P.×euramericana cv.’Neva’ can absorb and accumulate Pb,Cd,Cu and Zn in soil but showed different capacities of absorption and accumulation with the order of Cd>Zn>Cu>Pb.Especially,its absorption and accumulation capacity for Cd was strong with maximum enrichment factor higher than 16 and showed high accumulation on low background,whereas its enrichment capacities for Pb and Cu were relatively poorer with average enrichment factor of less than 1.At different forest lands,there existed great difference on absorption capacity of P.×euramericana cv.’Neva’ with the same heavy metal.     

107 杨对土壤重金属的吸收和富集

对北京市南郊房山区107杨绿化林地进行了土壤重金属吸收富集研究,林地周围有水泥厂、石材厂、污水和垃圾等不同污染源,结果表明:林地土壤受到了Pb、Cd、Cu和Zn不同程度的污染,Pb、Cu、Zn含量差异显著,Cd平均含量(0.077 6 mg·kg^-1)低于北京市背景值,但Pb、Cu、Zn平均含量分别为37.61、26.25和90.3 mg·kg^-1,均超过了背景值,3块林地107杨叶片的Pb、Cd、Cu和Zn含量不同,与土壤重金属含量的变化无明显规律性,107杨叶片对土壤Pb、Cd、Cu和Zn重金属元素均能吸收富集,但对不同重金属的吸收富集能力不同,呈现出Cd>Zn>Cu>Pb的变化趋势,尤其对Cd具有很强的富集能力,富集系数最高值大于16,表现出了低背景高富集,而对Pb、Cu的富集能力相对较小,富集系数均小于1;不同林地107杨叶片对同种重金属元素的吸收存在较大的差异。     

模拟酸雨对3种盆栽灌木幼苗叶矿质元素含量的影响

采用盆栽方法，以3种不同pH值（3．0、4．0、5．0）的模拟酸雨溶液对红檵木、杜鹃、夏鹃幼苗进行浇灌处理，研究不同pH值的酸雨对幼苗叶矿质元素含量的影响．结果表明：模拟酸雨对3种灌木幼苗叶矿质元素含量均有一定影响，3种幼苗叶中的大多数矿质元素含量变化不一致，表明不同植物的不同元素对酸雨的反应不同；各酸雨处理红檵木幼苗叶K、Mg、Mn、Ni、S、Al的含量较对照增加，其中Al、Ni含量是随着酸雨pH值的降低而逐渐增加．Zn含量比对照含量有所减少，N、P、Ca、Fe、Cu、Cd、Pb含量不随酸雨pH值的变化而变化．红檵木幼苗叶Al含量与模拟酸雨的pH值达到显著负相关；3种酸雨处理后的杜鹃幼苗叶P、Cu、Mn、Pb含量均比对照增加．其中P、Cu含量是随酸度的增大而逐渐增加，Ca、Zn含量比对照有所减少，N、K、Mg、S、Al、Fe、Ni、CA含量没有随着酸度变化而随之变化的趋势，P含量与模拟酸雨的pH值达到显著负相关；3种酸雨处理后的夏鹃幼苗叶P、K、Mg、Al、Fe、Cu、Mn、Ni、Pb含量比对照增加．其中P、Ni是随酸度增加逐渐增加，Zn含量比对照减少，N、Ca、S、Cd含量则表现为有的酸雨处理增加，有的下降，Ni含量与模拟酸雨的pH值达到显著负相关．该项研究可为南方绿化植物的选择提供理论依据．     

Accumulation of heavy metal in Platanus orientalis, Robinia pseudoacacia and Fraxinus rotundifolia

Plants are capable of reducing environmental pollutions through uptaking contaminants in their tissues. In the study site, twenty one-year-old leaves and shoots as well as twenty soil samples were sampled and analyzed by Inductively Coupled Plasma (ICP). We investigated the uptaking ability of lead (Pb) and cadmium (Cd) by the leaves and shoots of Platanus orientalis, Robinia pseudoacacia and Fraxinus rotundifolia in Karaj city, the western Tehran, Iran. We also evaluated the total metal accumulation capacity by using metal accumulation index (MAI). Results indicated that there was no significant difference in uptaking contents of Cd and Pb in the leaves among the trees. However accumulation of Cd in shoots of F. rotundifolia and R. pseudoacacia was significantly higher than that of P. orientalis. The accumulation of Pb in shoots of R. pseudoacacia was significantly higher than the other species. The amount of Pb in the soil of the study area was significantly higher than Cd. Concentrations of Cd and Pb in leaves of the three species are in the ranges of 2.4 2.7 mg Kg-1 and 7.1 14.4 mg Kg-1 , respectively. R. pseudoacacia had the highest MAI value for leaves (2.21) and F. rotundifolia had the highest MAI value for shoots (2.4).