干旱及镉污染对巨菌草生理和镉富集特征的影响

巨菌草因具有生长迅速、生物量大等优点而成为重金属污染修复的良好材料,干旱是影响其生长和修复能力的主要原因。该研究采用盆栽实验方法,探讨了干旱处理(25%土壤田间持水量)、镉处理(3mg·kg~(-1))及其交互处理对巨菌草生长、光合、抗氧化酶活性、活性氧含量、镉积累与分配特征的影响。结果表明:(1)与对照相比,干旱处理、镉处理及其交互处理对巨菌草生物量积累和光合作用均有一定抑制作用,但各处理巨菌草的耐性系数均较高;叶片中丙二醛(MDA)含量及过氧化物酶(POD)和过氧化氢酶(CAT)活性在各处理下均不同程度升高,抗坏血酸过氧化物酶(APX)活性在交互处理下显著升高,而超氧化物歧化酶(SOD)活性在镉处理和交互处理下显著降低。(2)与单一处理相比,无论从生物量积累,还是叶片活性氧引起的细胞膜受损伤程度(用MDA表示)来看,交互处理并没有引起更严重的负面效应。(3)镉和交互处理下巨菌草各器官的镉含量均显著增加,且主要积累在根部;与镉处理相比,交互处理显著降低巨菌草的镉富集量,但未显著降低其地上部镉富集量。研究发现,巨菌草具有较强的耐旱性和抗镉污染的能力,干旱与镉交互处理并不会造成更严重的叠加负面影响,但会显著降低巨菌草地下部的镉富集量;在受到干旱及镉污染交互影响的区域种植巨菌草具有良好的修复前景。     

镉胁迫对紫花苜蓿幼苗生理特性和镉富集的影响

以\"甘农三号\"紫花苜蓿幼苗为材料,在水培条件下,探究了在10 d内不同浓度(0～2.0 mmol·L^-1)镉(Cd)胁迫对其根长、茎长、生物量、叶绿素和丙二醛(MDA)含量、超氧化物歧化酶(SOD)和过氧化物酶(POD)活性、Cd富集及其亚细胞分布的影响。结果表明:低浓度(0.125 mmol·L^-1) Cd能促进幼苗根和茎的生长,增加叶片叶绿素含量,较高浓度(0.5～2.0 mmol·L^-1) Cd显著抑制幼苗根和茎的生长,叶绿素及生物量显著降低; Cd胁迫使MDA含量显著增加,而SOD和POD活性显著增强,其中Cd胁迫浓度为0.5mmol·L^-1时,SOD和POD活性达到最大值,这可能是植物对环境胁迫的一种应激保护反应; Cd在各亚细胞组分中的含量依次为细胞壁>细胞质>线粒体>叶绿体,且均随Cd胁迫浓度的升高而增加。当Cd胁迫浓度为0.125 mmol·L^-1时,水培10 d的紫花苜蓿幼苗单株地上部对Cd的净化率最高可达0.214%,而整盆植株在单位体积内对Cd的净化率最高可达15.5%;当Cd胁迫浓度为2.0 mmol·L^-1时,紫花苜蓿幼苗地上部Cd含量达89.36μg·g-1。这些结果表明紫花苜蓿对Cd具有很强的富集能力,虽未达到Cd超富集植物的临界标准,但从植株生物量、耐Cd能力、富集Cd量及对Cd的净化率等方面综合考虑,紫花苜蓿在Cd污染土壤的植物修复中具备良好的应用价值。     

羽衣甘蓝对镉的耐性和富集特征研究

以观赏绿化植物羽衣甘蓝(Brassica oleracea L.var.acephala DC.)为试验材料,采用盆栽试验,研究其对镉的耐性和富集特征,探讨羽衣甘蓝对镉污染土壤生物修复的可行性。结果显示:(1)随着镉处理浓度的增加,羽衣甘蓝干重呈先升高后降低的趋势,20~80mg·kg-1镉处理能促进植株的生长,100~120mg·kg-1镉处理虽然显著抑制了根系的生长,但是促进了地上部的生长,整体而言对全株生长无明显影响,表明羽衣甘蓝对镉有较强的耐性,且地上部的耐性高于根系。(2)所有镉处理下,羽衣甘蓝叶片的SOD、POD和APX活性较高,MDA含量和电解质渗漏率与对照无差异;而镉处理浓度高于80mg·kg-1时,根系的SOD、CAT和APX活性显著降低,MDA含量和电解质渗漏率显著升高,引起严重的膜脂过氧化伤害,这可能是羽衣甘蓝地上部的镉耐性高于根系的原因之一。(3)羽衣甘蓝地上部的镉含量高于根系,且随着镉处理浓度的增加均逐渐增加,在镉处理浓度为120mg·kg-1时达到最大值,分别为50.15mg·kg-1(根系)和52.01mg·kg-1(地上部);植株对镉的转运系数大于1,地上部镉富集量高于根系,地上部最大富集量为每株343.19μg。研究表明,羽衣甘蓝对镉有很强的耐性和富集、转运能力,是一种良好的修复镉污染土壤的观赏绿化植物资源。     

镉胁迫下4种宿根花卉的生理生长响应及其抗性差异

以百合科宿根花卉大花萱草、“金娃娃”萱草、“甜心”玉簪、东北玉簪为研究材料,研究其在Cd质量浓度为40 mg/kg处理下,随着植物体内镉的积累,不同时期4种花卉生理生长的响应,并根据各项指标的测定结果对4种花卉的抗镉胁迫能力进行综合评定。结果表明,镉胁迫下,植株受害情况不仅受时间主效应的影响,还受时间×树种、时间×树种×质量浓度交互效应的影响。经方差分析和多重对比,并用隶属函数法进行综合评定,[JP3]得出4种花卉的抗镉胁迫能力强弱顺序依次为“甜心”玉簪、“金娃娃”萱草、大花萱草和东北玉簪。[JP]     

辣椒对镉胁迫的生理响应

以福湘5号、兴蔬215和川腾1号这3个辣椒品种为材料,用含有0mg/L、100mg/L、200mg/L、300mg/L重金属镉的1/2霍格兰培养液对具10片真叶的辣椒苗进行处理,7d后测定各项生理指标。结果表明,镉对辣椒的生长有很强的毒害作用,随着镉胁迫浓度的升高,3个辣椒品种的生物量、叶片叶绿素含量、电导率、丙二醛含量和活性氧清除系统酶活性都受到了不同程度的影响。在镉胁迫下,辣椒植株的株高、根长、鲜重受到明显抑制,根系发育畸形,叶片黄化。镉胁迫的毒害作用在3个辣椒品种间有差异。其中川腾1号耐镉胁迫能力较强,福湘5号次之,兴蔬215最差。     

中国沙棘幼苗对土壤镉生理耐性和富集转运特征的性别差异

为探究中国沙棘对土壤镉(Cd)胁迫的性别响应差异,该研究以中国沙棘2年生幼苗为材料,利用盆栽试验研究在不同浓度Cd处理下(0(CK)、25、50、100和200 mg·kg^-1)雌、雄株幼苗的生长、叶片生理特性以及Cd富集特征的差异。结果表明：(1)Cd处理下中国沙棘幼苗雌、雄株的株高和基径生长以及各器官生物量均表现出低浓度(<50 mg·kg^-1)促进,高浓度(> 100 mg·kg^-1)抑制的现象;低浓度Cd处理下雌株的株高、基径增长率和生物量的增幅均高于雄株;高浓度Cd处理下(200 mg·kg^-1)雄株株高增长率、叶生物量和总生物量分别较CK显著降低,而雌株均未显著下降。(2)随着Cd浓度升高,雌、雄株叶片光合色素含量和抗氧化酶活性呈先升后降的变化趋势,丙二醛(MDA)和渗透调节物质含量呈上升趋势;Cd浓度为50～200 mg·kg^-1时,雌株叶片的光合色素含量、抗氧化酶活性和渗透调节物质含量均高于雄株,而MDA含量始终低于雄株。(3)随着Cd浓度升高,雌、...     

锰胁迫下盐肤木锰富集及生理响应特征

为揭示盐肤木(Rhus chinensis)锰积累特征与耐受机制,该研究通过盆栽试验方法,分析0(CK)、1、5、10和20 mmol·L^-1Mn²⁺胁迫对半年生盐肤木幼苗生长、生理生化特征及其锰富集特征的影响。结果表明：(1)盐肤木在Mn²⁺浓度为0～10 mmol·L^-1条件下生长发育状况良好,且在5 mmol·L^-1Mn²⁺处理下叶片舒展,叶片颜色较深,生长最佳,而在20 mmol·L^-1Mn²⁺条件下部分叶片出现褐色斑点、萎蔫卷边的现象;随着Mn²⁺浓度的升高,盐肤木幼苗的生物量呈先升高后下降的趋势,并在5 mmol·L^-1Mn²⁺胁迫时最高。(2)随着Mn²⁺浓度的升高,盐肤木叶片中光合色素含量呈先升后降的趋势,且在Mn²⁺浓度为5 mmol·L^-1时达到峰值。(3)随着M...     

结缕草对重金属镉的生理响应

采用水培的方法研究了不同浓度的Cd²⁺对结缕草叶片枯黄程度的影响,结果表明5mg/L、10mg/L和30mg/L Cd²⁺处理对结缕草叶片的枯黄比例无显著影响;以10mg/L 的Cd²⁺处理结缕草植株,研究了结缕草对镉的生理响应。与对照相比,Cd²⁺处理30d时结缕草叶片的超氧阴离子自由基(O^-₂·)含量、丙二醛(MDA)含量和相对电导率(RC)显著升高,升高幅度分别为58.69%、38.52%和68.69%,表明Cd²⁺对结缕草叶片产生了氧化胁迫。与对照相比,Cd²⁺处理30d时最大量子产量(F_v/F_m)和实际量子产量(F_v'/F_m')分别显著下降3.90%和11.36%;处理20d时实际光化学效率(ΦPSⅡ)和相对电子传递速率(rETR)分别显著下降22.22%、22.66%,处理30d时分别显著上升12.5%、18.12%;处理20d时光化学猝灭系数(q^p)显著下降14.29%,非光化学猝灭系数(NPQ)则显著上升38.54%,表明结缕草叶片的光反应机构受到了伤害,而光保护能力得到了提高。与对照相比,Cd²⁺处理下超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性先升高后降低,而过氧化物酶(POD)活性先降低后升高;脯氨酸、可溶性糖含量升高,处理30d时可溶性糖含量显著上升63.35%;处理前20d时可溶性蛋白的含量高于对照,处理30d时却低于对照。随着Cd²⁺处理时间的增加,结缕草地下部Cd含量逐渐升高;地上部Cd含量先升高后降低,差异显著;处理20d时地上部镉含量最高,转运系数最高,达到45.84%;处理10d时镉在结缕草地上部的分布比例小于地下部,而处理20d、30d时地上部镉的分布比例占优势,表明结缕草具备修复植物的潜质。镉在结缕草地下部水溶态所占比例最大,其次是氯化钠和醋酸提取态;与地下部不同,结缕草地上部醋酸提取态镉的含量要高于氯化钠提取态。综上,结缕草对Cd²⁺具有一定的耐受性。     

木槿品种对镉胁迫的生理响应及耐镉能力评价

研究镉胁迫对木槿的生理影响,比较木槿品种的镉耐受能力,为镉污染地区的植物材料选择提供依据.以3个木槿品种为材料,采取盆栽控制试验,测定其生长、生理指标,通过隶属函数分析综合比较品种耐镉能力.木槿的株高与地径增长量、叶绿素A+B与可溶性蛋白含量随胁迫浓度增加呈先上升后降低或逐渐降低趋势,而且随时间延长,降低程度不断加强;...     

菖蒲幼苗对Cd胁迫的响应及其Cd富集能力分析

研究了菖蒲（Acorus calamus L．）幼苗对不同浓度Cd胁迫的响应及其Cd富集能力。结果表明,随Cd浓度的提高（0～25mg·L^-1）,菖蒲幼苗的株高、根长、干质量、叶绿素含量和对Cd的耐性指数均逐渐下降,脯氨酸含量逐渐升高;各处理组的SOD和POD活性均高于对照,且以15mg·L^-1Cd处理组最高。随胁迫时间延长（1—10d）,叶绿素含量持续下降,而SOD和POD活性及脯氨酸含量则先升高后下降。菖蒲幼苗体内Cd含量随Cd浓度的提高而增加,根系对Cd的富集能力高于地上部分。在Cd胁迫条件下,菖蒲幼苗对Cd的转移系数小于1,根系对Cd的滞留率为89．5％-93．9％,表明菖蒲幼苗根系对Cd有较强的滞留作用和富集能力。     

四种北方阔叶树种苗木对土壤镉胁迫的生长反应与抗性比较

采用盆栽方法,研究了4种北方阔叶树种茶条槭、山梨、五角槭和山荆子一年生苗木对土壤镉胁迫的生长反应和抗性.采用土壤和风化砂混合物作为栽培基质,设计5种土壤镉浓度梯度处理(对照、10、50、100、200mg·kg^-1).结果表明,低浓度处理(≤50mg·kg^-1)刺激各树种苗木的地径、树高生长,其中茶条槭在10mg·kg^-1处理下地径和苗高增加幅度最大,分别为对照的135.8%和146.0%;随着镉处理浓度的增加,地上部生长量下降,茶条槭在最高浓度处理下,生长量降低最大,地径和苗高仅分别为对照的241%和280%.叶片和新枝生物量变化存在较大种间差异,茶条槭和山梨在低浓度处理时总体上表现增加;山荆子新枝生物量增加,叶生物量减少;五角槭表现一致减少.最高浓度处理时,叶和新枝生物量受影响最大的是茶条槭,分别为对照的4.6%和7.3%;其次为五角槭,分别为对照的5.7%和7.9%;山梨和山荆子受影响的幅度相对较小.新根生物量除山梨外,其它3个树种苗木的生物量表现一致下降,其中下降幅度以茶条槭最大,最高浓度处理仅为对照的2.3%.山梨在低浓度处理下,新根生物量有所增加,分别为对照的125.5%和117.1%.     

Physiological responses and tolerance threshold to cadmium contamination in Eremochloa ophiuroides

Plant tolerance is one of the preconditions in soil phytoremediation. The physiological responses and tolerance threshold of centipedegrass (Eremochloa ophiuroides) were investigated under eight different Cd concentrations (0, 60, 120, 180, 240, 300, 360, and 420 mg Cd kg(-1)) in a sand culture system. The results showed that turf quality, leaf relative water content (RWC), leaf electrolyte leakage (EL), leaf osmotic potential did not show significant changes under 180 mg Cd kg(-1) compared with the control, and relative growth rate (RGR), turf density, leaf chlorophyll content, photochemical efficiency (Fv/Fm) did not show significant changes under 240 mg Cd kg(-1) compared with the control throughout the whole experiment. Regression analysis was used to determine the threshold Cd concentrations for each physiological parameter and the most sensitive parameter occurred by RWC of 197 mg Cd kg(-1) which was chose as Cd tolerance threshold in centipedegrass because under this concentration the plant did not show any significant difference with the control in all growth and physiological parameters measured in this experiment. The phytoextration rate of centipedegrass reached 0.87% in 36 d under 180 mg Cd kg(-10 treatment.     

Physiological responses of four herbaceous plants to aluminum stress in South China

Different plants have physiological responses under A1 stress,but there is no systematic study to examine physiological responses of herbaceous plants under Al stress.The aim of this study is to investigate the effect of Al on physiological characteristics of four herbaceous plants,which distributed in red soil area in South China,and to analyze the differences in physiological responses to Al stress between the four herbaceous plants.Four herbaceous plants(Pharbitis nil,Cassia occidentlis,Echinochloa colonum and Aeschynomene indica)were used,and the seed germination percentage,the contents of chlorophyll,proline,and malondialdehyde(MDA),membrane permeability(MP),soluble sugar,and activities of peroxides(POD)and cata lase(CAT)in leaves under five Al3+ treatments(0,80,400,2000,and 10000 mg/L)were assayed with the sand culture method.The results showed remarkable effects of Al3+ on physiological characteristics of these four herbaceous plants.The seeds of all the four species could not germinate at 10000 mg/L.and the growth of all plants were retarded under the 2000 mg/LAr3+ treatment.Compared with the control,2000 mg/L Al3+ significantly(P＜0.05)reduced the contents of chlorophyll a and chlorophyll a+b,and increased the contents of MDA and MP.The content of proline in creased very significantly(P＜0.01)and activities of POD and CAT were depressed.The contents of MDA and MP in leaves of P.nil and A.indica decreased,and the activities of POD and CAT in leaves of the two plants increased under 80mg/L and 400 mg/L.However,the changes in C.occidentlis leaves were opposite to those of the above two plants.The changes in leaves of E.colonum were similar to those of P.nil and A.indica at 80 mg/L.but were opposite to those at 400mg/LAr3+.It is suggested that plants with higher activities of POD and CAT,more contents of chlorophyll and proline,and lower contents of MDA and MP consequently improve the tolerance to Al stress under low and middle Al treatments.     

Physiological responses of four herbaceous plants to aluminum stress in South China

Different plants have physiological responses under Al stress, but there is no systematic study to examine physiological responses of herbaceous plants under Al stress. The aim of this study is to investigate the effect of Al on physiological characteristics of four herbaceous plants, which distributed in red soil area in South China, and to analyze the differences in physiological responses to Al stress between the four herbaceous plants. Four herbaceous plants (Pharbitis nil, Cassia occidentlis, Echinochloa colonum and Aeschynomene indica) were used, and the seed germination percentage, the contents of chlorophyll, proline, and malondialdehyde (MDA), membrane permeability (MP), soluble sugar, and activities of peroxides (POD) and catalase (CAT) in leaves under five Al³⁺ treatments (0, 80, 400, 2 000, and 10 000 mg/L) were assayed with the sand culture method. The results showed remarkable effects of Al³⁺ on physiological characteristics of these four herbaceous plants. The seeds of all the four species could not germinate at 10 000 mg/L, and the growth of all plants were retarded under the 2 000 mg/L Al³⁺ treatment. Compared with the control, 2 000 mg/L Al³⁺ significantly (P < 0.05) reduced the contents of chlorophyll a and chlorophyll a + b, and increased the contents of MDA and MP. The content of proline increased very significantly (P < 0.01) and activities of POD and CAT were depressed. The contents of MDA and MP in leaves of P. nil and A. indica decreased, and the activities of POD and CAT in leaves of the two plants increased under 80 mg/L and 400 mg/L. However, the changes in C. occidentlis leaves were opposite to those of the above two plants. The changes in leaves of E. colonum were similar to those of P. nil and A. indica at 80 mg/L, but were opposite to those at 400 mg/L Al³⁺. It is suggested that plants with higher activities of POD and CAT, more contents of chlorophyll and proline, and lower contents of MDA and MP consequently improve the tolerance to Al stress under low and middle Al treatments. __________ Translated from Acta Phytoecologica Sinica, 2005, 29(4): 644–651 [译自: 植物生态学报, 2005, 29(4): 644–651]     

Physiological responses and accumulation of pollutants in woody species under in situ polluted condition in Southern China

Physiological leaf traits and accumulation of pollutants of ten woody species in response to air pollution at seriously polluted site Sanguigang (SGG) and control site Maofengshan (MFS) in Southern China were studied. Net photosynthetic rates of most species at SGG were lower than those at MFS, but stomatal conductance (g_s) showed opposite trend. The specific leaf area of Aporusa dioica, Sapium discolor, Schefflera octophylla and Toxicodendron succedaneum were significantly, 46.77, 13.09, 55.11 and 23.51 %, higher in SGG than in MFS, while chlorophyll content being the opposite. A. dioica had the highest sulphur (S) content at both sites (11.74 mg g^?1 at SGG and 11.07 mg g^?1 at MFS). Heavy metals concentrations were generally higher in species at SGG than at MFS. S. octophylla showed significantly higher concentrations of Zn, Cd and Mn (341.81, 2.41 and 2,287.29 μg g^?1) than other species at SGG. Moreover, A. dioica had the highest Pb concentration (9.19 μg g^?1), and L. glutinosa showed the highest Cr concentration (3.40 μg g^?1). According to the integrated results, we infer that A. dioica, S. octophylla and L. glutinosa are the promising species for phytoremediation in the ceramic industry polluted environment.     

Physiological responses to Cd and Zn in two Cd/Zn hyperaccumulating Thlaspi species

In a model hyperaccumulation study a Cd/Zn hyperaccumulator Thlaspi caerulescens accession Ganges and a recently reported Cd/Zn hyperaccumulator Thlaspi praecox grown in increasing Cd and Zn concentrations in the substrate and in field collected polluted soil were compared. Plant biomass, concentrations of Cd and Zn, total chlorophylls and anthocyanins, antioxidative stress parameters and activities of selected antioxidative enzymes were compared. Increasing Cd, but not Zn in the substrate resulted in the increase of biomass of roots and shoots of T. praecox and T. caerulescens. The two species hyperaccumulated Cd in the shoots to a similar extent, whereas T. caerulescens accumulated more Zn in the shoots than T. praecox. Cadmium amendment decreased total chlorophyll concentration and glutathione reductase activity, and increased non-protein thiols concentration only in T. praecox, suggesting that it is less tolerant to Cd than T. caerulescens. In the field-contaminated soil, T. caerulescens accumulated higher Cd concentrations; but as T. praecox produced higher biomass, both species have similar ability to extract Cd.     

土壤水分变化对玉米苗期吸收积累镉的影响

采用土壤盆栽试验研究不同土壤水分含量对玉米苗期吸收积累 Cd的影响。试验结果表明 ,玉米生物量及其吸收 Cd量在玉米不同的生长时期差异较大。2 2 d收获时 ,玉米地上部和地下部生物量均随着田间持水量 (35 %～ 85 % )的增加而提高 ;而 16 d收获时 ,玉米生物量在田间持水量为 35 %和 85 %时比在其它水分时低许多。 16 d和 2 2 d收获时 ,玉米地上部 Cd含量在田间持水量 5 5 %时分别达到最大值 ,5 5 .4 1mg/ kg和 39.33mg/ kg;而在田间持水量 85 %时分别达最小值 ,2 7.97mg/ kg和 2 3.5 2 m g/kg。在玉米根系的影响下 ,土壤溶液 Cd含量基本上随着玉米的不断生长而降低。田间持水量为 6 5 %时的土壤溶液 Cd含量比田间持水量为 75 %和 85 %时大。玉米总吸 Cd量与水分蒸腾量之间呈极显著的线性正相关关系     

硒对镉胁迫下水稻幼苗生长及生理特性的影响

采用溶液培养 ,研究不同浓度的硒和镉处理对稻苗的株高、叶片干重、叶绿素、还原糖、叶片丙二醛含量以及保护酶 SOD、POD、CAT活性的影响。结果表明 ,镉胁迫下稻苗矮化 ,镉毒害使叶片失绿 ,干重降低 ,还原糖含量下降 ,叶片 MDA含量增加 ,POD活性增强 ,而 SOD、CAT活性降低 ;硒可减轻镉对水稻的毒害 ,表现为 :减轻镉胁迫对株高增加的抑制 ,提高叶绿素含量 ,增加叶片干物质积累 ,提高叶片还原糖含量 (Cd0 .5 mg/ L加 Se 0 .1 0～ 0 .5 0 mg/ L例外 ) ,降低 MDA含量与 POD活性 ,提高 SOD、CAT活性