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1.
研究了在重金属Pb、Cd污染土壤下,紫茎泽兰对氨氯吡啶酸的耐药性。结果表明,低剂量氨氯吡啶酸处理下,其鲜重防效随Pb浓度的升高显著增加,高剂量则呈先升后降的变化趋势;各处理IC50均小于对照,以500 mg/kg处理时为最低;低剂量氨氯吡啶酸处理时,紫茎泽兰鲜重防效随Cd浓度的增加显著增加,120 g/hm2氨氯吡啶酸处理时则随Cd浓度的增加呈下降趋势,各处理IC50均小于对照,以100 mg/kg处理组为最低;≤ 60 g/hm2氨氯吡啶酸处理时,Pb-Cd复合污染胁迫组的鲜重防效均小于单一Pb、Cd处理组,高于对照,120 g/hm2氨氯吡啶酸处理时,Pb-Cd复合污染胁迫组却高于单一Cd处理组和对照,接近单一Pb处理组,其IC50均高于单一Pb、Cd处理组。证实重金属Pb、Cd污染下,紫茎泽兰对氨氯吡啶酸的耐药性明显下降,鲜重防效显著提高,根系也受到一定程度的抑制,这对我国西南地区尤其是Pb、Cd污染严重地区紫茎泽兰的防治起到积极作用。 相似文献
2.
试验以紫茎泽兰(Eupatorium coelestinum L.)种子为材料,研究了重金属铅(Pb)、锌(Zn)、镉(Cd)单一及复合胁迫对种子萌发及幼苗根长的影响.结果表明,当Pb浓度在100～4 000 μmol/L时,紫茎泽兰种子的发芽率、发芽指数和发芽势都随着Pb浓度的增加而降低,但是当Pb浓度为100 ～200 μmol/L时,其发芽率、发芽指数及发芽势都比对照高,其中在100 μmol/L处理下其发芽率、发芽指数及发芽势都是最高的,分别为94.67％、42.25和89.67％;在Zn浓度为100 ～4 000 μmol/L范围内,紫茎泽兰种子的发芽率、发芽指数和发芽势随着Zn浓度的增加而降低;在Cd浓度为20～1 000 μmol/L范围内,紫茎泽兰种子的发芽率、发芽指数和发芽势都随着Cd浓度的增加而降低;在低浓度Pb(100 μmol/L)+Zn(100 μmol/L)复合胁迫下,其发芽率是最高的,为94.67％,之后随着复合浓度的增加,其发芽率、发芽指数和发芽势呈下降趋势;紫茎泽兰种子的发芽率、发芽指数和发芽势随着复合重金属Pb +Cd、Zn+ Cd、Pb+Zn+Cd浓度的增加而降低.无论是在单一还是复合重金属处理下,紫茎泽兰的幼苗根长与对照相比明显受到抑制. 相似文献
3.
绿洲油菜根际土壤中Cd,Pb赋存形态特征及其互作影响 总被引：1，自引：0，他引：1
采用盆栽试验,设计了Cd、Pb以及Cd/Pb复合胁迫三种污染情景模式种植油菜,利用Tessier连续提取法对绿洲油菜地土壤重金属元素的形态含量及比例特征进行了分析。结果表明:干旱区绿洲油菜地原状土壤中Cd和Pb分别主要以铁锰氧化物结合态及残渣态形式存在,而添加可溶性Cd和Pb后,两金属的主要赋存形态均为碳酸盐结合态。在任何浓度添加水平,可交换态Cd,Pb对外界浓度胁迫响应最大,残渣态响应最小。三种污染情景模式下油菜根际土壤中Cd,Pb形态拟合方程及生物活性系数的对比分析表明:两金属的互作对各元素活性的影响为:Pb的加入抑制Cd的土壤活性,而Cd的共存则促进Pb的土壤活性。 相似文献
4.
《干旱区资源与环境》2017,(5):186-191
为了探讨生物炭添加对苏丹草吸收Cd、Pb的影响,在灰漠土中外源添加不同浓度的Cd和Pb,在此基础上添加5~20g/kg生物炭,通过盆栽试验研究生物炭对Cd、Pb在苏丹草中的分布及累积特征的影响。结果表明:添加生物炭和低浓度重金属能促进苏丹草的生长,使根、茎、叶生物量显著增加(P<0.05),但高浓度重金属的添加会抑制苏丹草的生长。在低中浓度重金属Cd-Pb的处理下,添加5~20g/kg生物炭,Cd在苏丹草根、茎、叶中质量分数、富集系数、转移系数及地上部分的累积量均呈降低趋势,Pb则相反。说明了生物炭的添加能抑制低中浓度Cd在苏丹草中的迁移。在高浓度重金属Cd-Pb的作用下添加生物炭对Cd和Pb在苏丹草中迁移均有抑制作用。 相似文献
5.
干旱区绿洲土壤中Cd、Pb、Zn、Ni复合污染对芹菜的影响及其富集迁移规律 总被引：4，自引：2，他引：2
通过盆栽试验和室内分析初步研究了干旱区绿洲土壤中Cd、Pb、Zn、Ni复合污染对芹菜生长的影响及重金属在芹菜体内的富集迁移规律。结果表明:随着外源重金属添加量的增加,芹菜的生长受到明显抑制。根据多元回归分析和偏相关分析,芹菜地上部和根部吸收Pb量分别与外源添加Pb、Zn、Ni量和Cd、Pb、Zn、Ni量达到极显著相关,其中土壤Zn含量的增加极显著的降低了芹菜地上部和根部对Pb的吸收。芹菜地上部及根部对Cd、Pb、Zn、Ni四种元素的富集系数大小顺序均为:Cd>Zn>Ni>Pb,且根部对四种重金属元素的富集能力显著大于地上部。Cd在芹菜中的平均迁移能力最强,Zn、Ni次之,Pb的迁移能力最弱。 相似文献
6.
用电感耦合等离子体分析了市郊排污河岸土壤重金属含量及“种杂草中重金属Cd、Cr、Cu、Mn、Pb和Zn的含量。结果表明,河岸土壤存在一定程度重金属污染,Cd含量较高,为3级,Cr为1级,Cu为2级,Pb为2级,Zn为2级。杂草对重金属的吸收、积累和运输能力因杂草种类、部位及重金属种类而不同。杂草对重金属的积累能力为：Cd〉Zn〉Cu〉Pb〉Mn〉Cr。杂草转移重金属系数为：Cr〉Pb〉Mn〉Cu〉Zn〉Cd。提出了适用于不同重金属Cd、Cr、Cu、Mn、Pb和Zn污染土壤的修复植物。 相似文献
7.
应用TAS-990原子吸收分光光度计测定乌鲁木齐市17种主要绿化树种的叶片Pb、Cd含量,运用ANOVA单因素方差的LSD多重比较不同植物叶片中重金属含量的差异,结合截距法和类平均法(聚类分析),并初步筛选出一批Pb、Cd积累能力强的树木。结果表明:绿化树种对Pb吸收量高的树木有桑树、桃树、黄金树,分别为12.35mg·kg-1、10.62mg·kg-1、10.31mg·kg-1,可作为Pb污染地区的绿化树种;对Cd吸收量高的树木有新疆杨、桑树和复叶槭,分别为0.76mg·kg-1、0.71mg·kg-1和0.51mg·kg-1,可作为Cd污染地区的绿化树种。同一树种Pb的积累比Cd的积累较高。推测乌鲁木齐市空气中Pb为主要空气污染物之一,而Cd不是该市主要的空气污染物。 相似文献
8.
采用克里金插值法对宝鸡某冶炼厂周边农田土壤中铅镉含量及形态空间分布特征进行了研究,并分析了土壤中铅镉总量及各形态含量与小麦中铅镉含量的相关性,目的在于为冶炼厂周边土壤重金属污染的表征提供依据。结果表明,土壤中Pb形态的高低顺序为：残渣态>有机硫结合态>铁锰氧化态>可交换态,Cd形态为：可交换态>残渣态>有机硫结合态>铁锰氧化态。土壤中Pb总量及Pb、Cd铁锰氧化态在距离冶炼厂500 m处含量均显著高于1 500 m和2 500
m处,后两者之间无差异;而Cd总量及Pb、Cd可交换态、有机硫结合态和残渣态在三个采样距离并没有表现出显著性差异。克里金插值分析表明,除Pb可交换态外,Pb和Cd其余形态在一定程度上均显示出与风向的一致性。相关分析表明,土壤中Pb、Cd可交换态、铁锰氧化态与小麦Pb和Cd含量均有显著的相关性,表明冶炼厂周边旱地土壤中,Pb、Cd可交换态和铁锰氧化态都可能作为土壤重金属污染空间分布和有效性表征的指标。 相似文献
9.
以干旱区绿洲土壤和油菜为供试对象,通过Cd-Zn和Cd-Pb-Zn胁迫下的盆栽试验研究了Cd-Zn污染绿洲土壤条件下Pb的介入对油菜生长及吸收和迁移Cd、Zn的影响。结果表明,Pb的介入促进了油菜茎叶的生长,在较低水平(Cd≤1.8mg·kg-1、Zn≤300mg·kg-1)时促进了根系的生长,而在较高水平(Cd>1.98mg·kg-1、Zn>300mg·kg-1)时则抑制了根系的生长;Pb的介入促进了油菜对Cd、Zn的吸收,但并未影响油菜对Cd、Zn吸收的变化趋势;Pb的介入促进了油菜对Cd、Zn的富集,却抑制了对Cd、Zn的迁移。 相似文献
10.
泾河流域农业土壤重金属污染调查与评价 总被引：7，自引：0，他引：7
通过对泾河流域主要农业区土壤样品的采集、监测,依据泾河流域土壤重金属元素背景值和国家<土壤环境质量标准>(GB15618-1995)二级标准作为评价标准,分析了对土壤环境及人体危害较大的Cd,As,Cr,Pb等重金属元素的累积和污染程度.结果表明:以泾河流域土壤重金属元素背景值为评价标准,泾河流域农业土壤重金属累积污染程度具有Pb＞As＞Cd＞Cr的特征;泾河流域农业土壤重金属Pb,As,Cd累积污染程度较高,主要是由于人类长期不合理使用化肥所致.以国家土壤环境质量二级标准为评价指标,泾河流域农业土壤重金属污染程度具有As＞Cd＞Cr＞Pb的特征;泾河流域农业土壤样品重金属单项污染指数Pi和综合污染指数P均小于0.7,土壤环境中的重金属含量现状适宜于无公害农产品和果品基地建设的要求. 相似文献
11.
Yih-Shen Hwang Mir S. Mulla Mary Mistrot Pope Cesar Rodriguez 《Pest management science》1982,13(5):517-522
N,N-Diethyl-, N,N-dipropyl-, N,N-di-isopropyl, and N,N-di-isobutylalkanamides in which the acyl moiety ranged from C8 to C21 were synthesised, and their larvicidal activity was determined against the first-instar larvae of the southern house mosquito Culex quinquefasciatus Say. The four homologous series of amides generally showed an increase in their larvicidal activity as the carbon number in the acyl moiety of the amides increased, until the activity reached a maximum. Subsequently, an increment of carbon number resulted in declining activity in the higher homologues, until the activity disappeared. N,N-Diethyltetradecanamide, N,N-dipropylundecanamide, N,N-di-isopropylundecanamide, and N,N-di-isobutlynonanamide or -dodecanamide were the most active compounds in their respective homologous series of amides; however, they were less active than their analogous N,N-dimethylalkanamides previously studied. 相似文献
12.
长武旱塬不同麦玉轮作系统产量效应模拟研究 总被引：1，自引：0，他引：1
利用EPIC模型对不同麦玉轮作系统进行模拟,通过对其输出结果的分析,综合考虑产量、经济效益、干旱胁迫和氮肥生产率等因素,对不同麦玉轮作系统进行综合评价,从而比较不同麦玉轮作系统的优劣。结果表明:(1)在模拟研究期间,8种麦玉轮作系统的产量均呈波动性下降趋势,其平均值分别为4.61、4.40、4.16、4.48、4.28、4.29、4.714、.55 t/hm2。所有的麦玉轮作系统中,麦玉轮作系统"春玉米→冬小麦"的经济效益最好。(2)在模拟研究期间,麦玉轮作系统"春玉米→冬小麦→冬小麦"的冬小麦和春玉米所遭受的年均干旱胁迫日数最少(29.51d)。在干旱年份麦玉轮作系统中的冬小麦较春玉米更容易遭受干旱威胁。综合产量、经济效益、作物所遭受的干旱胁迫天数和麦玉轮作系统的氮肥生产率等因素,在长武地区适宜采用的麦玉轮作系统为春玉米→冬小麦。 相似文献
13.
运用温室葡萄水热平衡观测资料,分析了东北日光温室葡萄的能量平衡和能量分量日变化、生育期变化以及分配规律,同时也分析了潜热通量（λET）对环境因子的响应。结果表明：水热通量各分量在整个生育期日变化总体上呈现为单峰趋势,净辐射（Rn）的峰值最大为618.75 W·m-2,λET峰值最大为242.73 W·m-2,感热通量（H）峰值最大为327.93 W·m-2;在新梢生长期,白天λET较小,为34.55 W·m-2,随着生育期推进,λET逐渐增大,在果实着色成熟期达到最大值（78.49 W·m-2）之后减小;H在各生育期能量中均占了绝大部分;白天潜热通量占净辐射的比例（λET/Rn）在新梢生长期最小,为25.28%,在果实着色成熟期最大,为44.17%;感热通量占净辐射比例（H/Rn）整个生育期几乎都达50%以上,土壤热通量占净辐射比例（G/Rn）相对较小,变化范围为4.46~12.32 W·m-2;在整个生育期能量比率大小依次为H/Rn>λET/Rn>G/Rn。在不同生育阶段瞬时尺度上,Rn是影响潜热变化最主要的气象因子,R2高达0.88。在日尺度上,各气象因子对潜热通量的影响在逐渐变弱,相对湿度（RH）与λET相关系数仅为0.28。但无论从瞬时尺度还是日尺度,Rn都是影响潜热通量最主要的气象因子。各气象因子对潜热通量的影响大小依次为：Rn>VPD>Ta>RH。 相似文献
14.
施肥对小麦、玉米和大豆连作土壤微生物群落功能多样性的影响 总被引：2，自引：0，他引：2
为了明确长期施肥和不施肥条件下作物连作对土壤微生物群落功能多样性的影响,以典型黑土为研究对象,选取长期定位实验站长期施肥和不施肥条件下的小麦、玉米和大豆连作处理,通过稀释平板法和Biolog Eco微平板法,测定土壤细菌、真菌、放线菌数量、碳源代谢活性等指标,为建立合理的农田管理措施提供数据支撑和理论依据。结果表明:长期施肥条件下大豆、小麦和玉米连作土壤细菌、真菌和放线菌数量均高于不施肥处理,且均以大豆连作处理细菌和真菌数量最高。不施肥条件下小麦和玉米连作土壤细菌总数较大豆连作处理分别下降了24.8%和31.0%,真菌总数分别下降了64.0%和51.2%;施肥条件下小麦和玉米连作土壤细菌总数则较大豆连作处理分别下降了29.0%和45.5%,真菌总数分别下降了26.7%和31.5%。Biolog结果表明,不施肥条件下小麦连作处理的平均颜色变化率(AWCD)高于玉米和大豆连作处理,施肥条件下则是大豆连作处理的AWCD值高于小麦和玉米连作处理。不施肥条件下大豆、玉米和小麦连作处理利用最多的碳源是碳水化合物类,施肥后不同连作处理利用最多的是碳水化合物类和多聚物类。大豆和小麦连作不施肥条件下土壤微生物利用率最高的碳源均是α-D-乳糖,施肥条件下利用率最高的碳源均是D,L-α-甘油,而不论施肥与否,玉米连作条件下土壤微生物利用率最高的碳源均是D-半乳糖醛酸;葡萄糖-1-磷酸盐和γ-羟基丁酸是农田黑土微生物群落特异利用的关键碳源。主成分分析得出,施肥对土壤微生物碳源代谢能力的影响大于作物的影响。 相似文献
15.
The rust fungus Maravalia cryptostegiae , from south-west Madagascar, was introduced into Australia in 1995 as a classical biological control agent against the highly invasive rubber-vine weed Cryptostegia grandiflora , a woody climber endemic to Madagascar. The rust was released at 69 sites between 1995 and 1997 and is now established throughout the plant's exotic range in Queensland, estimated at over 40 000 km2 . Dispersal was low in the first 3–4 months but was virtually linear thereafter, and the rust spread over 100 km within the first year; after 3 years it was recorded 550 km away from the nearest release site. Spraying both dry and aqueous inoculum of uredinioid teliospores from the ground using mist-blowers, as well as from the air by atomizing spore suspensions, resulted in rust-induced defoliation, producing an overall reduction in fecundity and biomass of the weed. In sites with low water tables, weed growth decreased markedly, with a reduction in plant volume from 9 m−3 to 1 m−3 over a 4-year period. Both rust- and drought-induced stress combined to cause up to 75% plant mortality at some sites, and at all monitored sites, seedling recruitment was virtually nil. Improved growth of indigenous grasses amongst rubber-vine thickets has increased fuel loads and created opportunities to use fire as a component of an integrated approach to the management of this economically and ecologically damaging weed. 相似文献
16.
Mercury, arsenic, and cadmium in fish, water, and sediment of American Falls Reservoir, Idaho, 1974.
Mercury and cadmium were found in fish, water, and sediment of American Falls Reservoir (AFR), Idaho. Mercury and cadmium levels in some fish exceeded human health standards set by the Food and Drug Administration, U.S. Department of Health, Education and Welfare, and the World Health Organization. Analyses performed on the flesh of rainbow trout showed mercury residues of up to 1.20 mg/kg, which were higher than residues previously reported in trout collected in 1970 and 1971 from AFR. Cadmium residue levels were as high as 0.80 mg/kg. Although arsenic was found in reservoir sediment at levels of 1.36-2.40 mg/kg, it was not detected in fish. 相似文献
17.
Jean-Pierre Blein 《Pesticide biochemistry and physiology》1982,17(2):156-161
The activity of 15 herbicides from different families was assayed on nonphotosynthetic Acer pseudoplatanus cells, in batch suspension culture. They inhibited growth, stimulated the oxygen consumption by cells, and changed the pH evolution of the culture medium. Amides did not seem to disturb the membrane properties. Some diphenyl ethers and phenols directly modified the proton compartmentation of cells whereas some other diphenyl ethers, nitriles, triazines, and uracils altered permeabilities to potassium and leucine. Changes in membrane permeabilities to protons and medium constituents were discussed. 相似文献
18.
The mode of action of trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine), oryzalin (3,5-dinitro-N4,N4-dipropylsulfanilamide), pronamide(N-(1,1-dimethylpropynyl) 3,5-dichlorobenzamide), and propham (isopropyl carbanilate) on purified microtubules from pig brains and on the ultrastructure of wheat (Triticum aestivum L. “Mediterranean,” C. I. 5303) and corn (Zea mays L. “yellow dent, U. S. 13”) roots was compared with that known for colchicine. Colchicine disrupts the in vivo cortical and spindle microtubules of root cells. Like colchicine, the herbicides trifluralin, oryzalin, and pronamide caused the loss of both cortical and spindle microtubules of root cells. The rate of microtubule disappearance depended on the type of herbicide and length of exposure of roots to the herbicide. Unlike colchicine, cortical microtubules were present in propham-treated roots but they were disoriented within the cell.In vitro polymerization studies with pig brain microtubules (Sus scrofa) showed that the herbicides failed to inhibit the assembly of purified microtubular protein into microtubules and that radioactively labeled herbicides did not bind to the microtubular protein. Colchicine inhibited the polymerization of microtubular protein and readily bound to the microtubular subunits. These results indicate that the mode of action of the herbicides is not similar to that of colchicine and that the loss of microtubules from root tip cells treated with trifluralin, oryzalin, and pronamide may be caused by these herbicides interfering with synthesis of microtubular protein or metabolism of endoplasmic reticulum membranes involved in microtubule assembly. The mode of action of propham appears to be on the microtubular organizing centers rather than on microtubules per se. 相似文献
19.
ABSTRACT Modeling techniques were developed to quantify the probability of Tilletia indica entering and establishing in Western Australia (WA), and to simulate spread, containment, and the economic impact of the pathogen. Entry of T. indica is most likely to occur through imports of bulk grain or fertilizer (0.023 +/- 0.017 entries per year and approximately 0.009 +/- 0.009 establishments per year). Entry may also occur through straw goods, new or second-hand agricultural machinery, and on personal effects of travelers who have visited regions with infected plants. The combined probability of entry and establishment of T. indica, for all pathways of entry, is about one entry every 25 years and one establishment every 67 years. Alternatively, sensitivity analysis does show that increases in quarantine funding can reduce the probability of entry to about one entry every 50 years and less than one establishment every 100 years. T. indica is spread efficiently through contaminated farm machinery, seed and soil, rain, air currents, and animals. Depending on the rate of spread of the pathogen and the amount of resources allocated for detection, the time until first detection could range from 4 to 11 years and the economic impact could range from 8 to 24% of the total value of wheat production in WA. 相似文献
20.
PETER H. SIKKEMA SHARAREH HEKMAT CHRISTY SHROPSHIRE NADER SOLTANI 《Weed Biology and Management》2009,9(2):173-178
Dry bean producers in Ontario, Canada, have few herbicide options available for annual broad-leaved weed management and there is little information on the tolerance of dry bean to linuron. The tolerance of black, cranberry, kidney, and white bean to the pre-emergence (PRE) application of linuron at the rates of 0, 500, 1000, 1500, 2000, and 2500 g ai ha−1 was evaluated in field studies conducted in 2005 and 2006 at Exeter and in 2006 at Ridgetown, Ontario. The four market classes differed in their response to linuron. Cranberry and kidney bean were more tolerant to the PRE application of linuron than black and white bean. Linuron applied PRE caused as much as 12% injury in cranberry and kidney bean, 47% injury in black bean, and 56% injury in white bean. Linuron applied PRE at 500–2500 g ai ha−1 had no effect on the height of cranberry and kidney bean but decreased the height by 7, 8, and 15% in black bean and by 10, 13, and 23% in white bean at 1500, 2000, and 2500 g ai ha−1 , respectively. Linuron applied PRE at the rates evaluated did not cause any adverse affect on the yield of cranberry, kidney, and white bean but black bean yield was reduced by 16% at 2500 g ai ha−1 . Based on these results, there is not an adequate margin of crop safety for the PRE application of linuron in black and white bean at rates >1000 g ai ha−1 . However, there is a potential for the use of linuron PRE for weed management in cranberry and kidney bean at the rates evaluated. 相似文献