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991.
992.
Association of Copper and Zinc Levels in Oil Palm (Elaeis guineensis) to the Spatial Distribution of Ganoderma Species in the Plantations on Peat
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Mohd Rashid Mohd Rakib Choon‐Fah Joseph Bong Ahmad Khairulmazmi Abu Seman Idris Mohamadu Boyie Jalloh Osumanu Haruna Ahmed 《Journal of Phytopathology》2017,165(4):276-282
Nutrients are essential for normal physiological processes in plants, and they play important roles in defence mechanisms against pathogens. Oil palms cultivated on peat are more prone to nutrient deficiency, especially micronutrients, and this may affect their susceptibility to Ganoderma species, the major threat to the sustainability of oil palm throughout South‐East Asia. This study was conducted to investigate the association of copper (Cu) and zinc (Zn) in mature oil palm to the spatial distribution of Ganoderma species in the plantations on peat. Foliar samples (frond 17) of oil palm from two plantations (Betong and Miri) on peat in Sarawak, Malaysia, were collected based on the spatial distribution pattern of Ganoderma, and total Cu and Zn were quantified spectrometrically. The experiment was conducted twice at a 1‐year interval. The concentrations of Cu and Zn were significantly lower in oil palms from infected areas in contrast to those from uninfected areas. In addition, oil palms in infected areas in Miri suffered Cu and Zn deficiencies. Furthermore, Cu and Zn were significantly lower in the oil palms in Miri that had higher Ganoderma occurrence, as compared to those in Betong, which had significantly higher Cu and Zn but lower Ganoderma occurrence. 相似文献
993.
Ajitha J. Priya Sankara R. Gajulapalli Krishnaiah Abburi Veera M. Boddu 《Bioremediation Journal》2008,12(3):145-155
Biosorption of chromium, copper, and nickel from aqueous solution by Tamarindus indica fruit nut testa (TFNT) in its pristine and acid-treated forms was studied under equilibrium and column-flow conditions. TFNT, a tannin-containing material, was characterized by energy dispersion x-ray fluorescence (EDXRF) and Fourier transform infrared (FTIR) spectral techniques and surface analysis. The effect of experimental variable parameters such as pH, concentration of metal ions, amount of adsorbent, and contact time on adsorption was investigated. Batch isothermal equilibrium data were analyzed on the basis of Langmuir and Freundlich adsorption isotherms. The kinetics of the adsorption process were studied in terms of Lagergren first-order kinetic model. The monolayer adsorption capacities of pristine and acid-treated forms of tamarind seed coat were found to be 44.8 and 77.5 mg/g for Cr(VI), 55.8 and 99.0 mg/g for Ni(II), and 84.7 and 85.4 mg/g for Cu(II) ions, respectively. The column-flow adsorption data were used to obtain breakthrough curves. The biosorbent loaded with the metal ions was regenerated using 1.0 M HCl and the regenerated bed was used for subsequent adsorption-desorption cycle. 相似文献
994.
Aims: Copper is a critical metal of modern industry, and is the most widespread heavy metal contaminant in wastewater. Therefore, isolation of copper‐tolerant microbes having the potential as biosorbent is fascinating not only from an environmental microbiology, but also from a biotechnology view point. In this study, we attempted to isolate highly copper‐tolerant microbes from soil samples of the Nabanobori copper mine, the oldest mine in Japan. Methods and Results: As a result of an enrichment culture, two fungal strains were isolated from soil of the smelter remains. The isolates could grow in a maximum of 200 mmol l?l Cu2+, and grew under a wide pH range. The Cu2+‐binding capacity of nontreated biomass of the isolates was around 35 mg Cu2+ g?1‐biomass. Analysis of 18S rDNA suggested that the isolates belong to the Aspergillus/Penicillium clade, but they represented a distinct lineage against known neighbours. Conclusion: The isolates were highly copper‐tolerant, and their Cu2+‐binding capacity was comparable to well‐studied fungal sorbents. The isolates were implied as novel species. Soil of the historic old mine under weather‐beaten conditions might be a suitable source for metal‐tolerant microbes. Significance and Impact of the Study: The present results advance our understanding of metal‐tolerant microbes, and offer a new tool for both environmental control and metal recovery operations. 相似文献
995.
Two experiments were conducted to assess nutrient partitioning in coffee (Coffea arabica cv. Typica land race Guatemala) infected with Meloidogyne konaensis. Nutrient levels were quantified from soil, roots, and leaves. In the first experiment, 500-cm3 aliquants of a Kealakekua Andisol were infested with four initial population densities of M. konaensis ranging from 0 to 1,500 freshly hatched second-stage juveniles. Coffee plants (~3 months old) were transplanted into the soil and grown for 25 weeks. Plants responded to nematode infection with decreases (P < 0.05) in concentrations of Ca, Mg, P, and B and increases (P < 0.05) in concentrations of Mn, Cu, Zn, and Ca/B in the roots. Mn and Cu uptake by roots was decreased (P < 0.05) by nematode infection even though concentrations of Mn and Cu increased (P < 0.05) in the roots. Concentrations of Ca and Mg also decreased (P < 0.05) in the leaves, whereas the concentration of Zn increased (P < 0.05). In the second experiment, the soil was amended with Zn at 0 or 5 mg/kg soil and infested with M. konaensis at 0, 100, 1,000 or 10,000 eggs/1,200 cm3 soil. Three-month-old coffee seedlings of similar height were weighed and transplanted into pots and then placed in a greenhouse and grown under 50% shade for 23 weeks. Concentrations of P, K, Ca, Mg, Mn, B, and Zn increased in roots of nematode-free plants growing in Zn-amended soil. The beneficial effects due to the Zn amendment were not apparent in nematode-infected plants. Mn, B, and Zn uptake by coffee roots and P and B concentrations in coffee leaves responded similarly. Management of M. konaensis is necessary to achieve optimal nutrient management in coffee. 相似文献
996.
Donald S. Cherry John H. Van Hassel Jerry L. Farris David J. Soucek Richard J. Neves 《人类与生态风险评估》2002,8(3):591-601
Previous studies indicated that inputs from the Clinch River Plant (CRP), a coal-burning, power-generating facility in Carbo, Virginia, caused impairment to transplanted freshwater mussels. These findings necessitated the examination of instream biological responses to CRP effluents. Therefore, our objective was to derive a site-specific Criterion Maximum Concentration (CMC) for copper (Cu), the toxic constituent of the effluent. This was accomplished by conducting acute toxicity tests with Cu using 17 different genera native to or currently residing in the Clinch River watershed. Four native unionids and a mayfly (Isonychia bicolor) had genus mean acute values of 60?µJ.g/L or lower (ranging from 37 to 60?µJ,g/L). With a GMAV of 88?µJ,g/L, Ceriodaphnia dubia ranked sixth among the 17 genera tested, and the fathead minnow, Pimephales promelas, ranked fourteenth with a GMAV of 310?µJ.g/L. Despite the sensitivity of the indigenous mussels tested, the site-specific CMC of 18?µJg/L was not substantially lower than the national CMC for Cu (20?µJ,g/L, hardness = 150?mg/L as CaCO3). While we conducted acute exposure tests, future investigations should incorporate both biomarker and population or community-level studies to determine low-level contaminant impacts on freshwater mussels. 相似文献
997.
S.M. Burton S.D. Rundle M.B. Jones 《Journal of Aquatic Ecosystem Stress and Recovery (Formerly Journal of Aquatic Ecosystem Health)》2002,9(3):185-191
Despite proven utility as ecotoxicological testorganisms in marine systems, harpacticoidcopepods have not been used in freshwaterbiomonitoring. Here we assess the value ofBryocamptus zschokkei, a common member ofmeiofaunal stream communities, as a testorganism for lotic systems by measuring theeffects of copper on acute (survival ofovigerous females) and sub-lethal (offspringproduction, juvenile [i.e. naupliar andcopepodite] development times) end points. Allovigerous females survived exposure atconcentrations <180 µg Cu l–1, butat >180 µg Cu l–1, mortalityincreased with exposure times up to 72 h;seventy-two and ninety-six hour LC50s wereidentical (290 µg Cu l–1). After sixtydays, total offspring production per femaledeclined with increasing copperconcentration; no offspring were producedat 150 µg Cu l–1 and significantlyfewer offspring were produced at 100 µg Cul–1 compared with the control. In thejuvenile development tests, nauplii andcopepodites did not survive at 150 µg Cul–1, but there was no significant effecton development times at lower Cu concentrations(0–100 µg Cu l–1). Comparison oflaboratory-derived, toxicity end points withdata for B. zschokkei populations incopper-contaminated streams in south-westEngland, demonstrated that significant declinesin the number of surviving offspring closelymatched concentrations of copper across whichdeclines in field populations occurred. Theseresults indicate that B. zschokkei haspotential as an ecologically-relevant testorganism for lotic systems. 相似文献
998.
Rolf A. Løvstad 《Biometals》2004,17(2):111-113
Serum albumin (human, bovine) has a specific Cu(II)-ion binding site, and is proposed to act as a copper transport protein in blood plasma. Human transferrin, normally about 30% saturated with iron in vivo, has two sites/molecule capable of complexing Cu(II); one more strongly than the other (Hirose et al. 1996). The present study shows that this binding site has a slightly stronger affinity for Cu(II) than that on the albumins. However, both human- and bovine albumin could take up part of the transferrin bound Cu(II), the second order rate constant for the reaction estimated to 12 mM(-1) min(-1) for both species. In vivo the albumin concentration is considerably higher than that of iron-free transferrin, and it seems unlikely that the latter can compete with albumin for non-ceruloplasmin cupric ions. 相似文献
999.
有机螯合剂在芦苇富集转运铅中的作用 总被引:2,自引:0,他引:2
近年来,随着人口的激增和工农业生产的迅猛发展,土壤和水体的重金属污染日益加重。植物提取技术作为一种新兴的修复重金属污染的治理方法,以其潜在的高效、经济及其生态协调性等优势被广泛关注。其研究主要是利用对某些重金属具有超富集能力的超积累植物或耐性植物,配合添加一定量的鳌合剂来进行修复。由于超富集植物一般生长缓慢且生物量小,因此利用对重金属有一定耐性的生长快速、生物量大的植物来进行修复更具有广阔的应用前景。芦苇作为一种多年生禾本科植物,具有生物量大、耐受性强和分布广泛的特点,已经被研究和应用到环境治理的多个领域。本文通过户外盆栽沙培试验,研究了铅胁迫下,分别在 2-10 mmol·L-1共 5 个浓度梯度的 EDTA 和柠檬酸两种鳌合剂处理下,芦苇生长对铅的响应以及对铅在植物体内的富集转运的影响。初试结果表明∶在 4mmol·L-1 Pb(NO3)2胁迫下,施加 EDTA 对芦苇的生长具有一定的抑制作用。当 EDTA 浓度为 10 mmol·L-1 时,透灌 7 d 后,其芦苇根和地上部(茎和叶)干重分别是空白试验(未加螯合剂)的 68.0% 和 72.3%,而柠檬酸对植物生物量的影响较小。同时,EDTA 和柠檬酸对铅在芦苇体内的富集和转运,都起到了促进作用。分别施加 10 mmol·L-1的 EDTA 和柠檬酸,其植物根部和地上部的铅浓度分别为空白试验的 7.4 倍、10.7 倍、2.5 倍、3.5 倍。EDTA 在促进植物体内铅的吸收和从根部到地上部的转运效率方面要比柠檬酸更为有效。尽管像 EDTA 和柠檬酸这样的鳌合剂能够在一定程度上提高植物的富集效率,但考虑到螯合剂自身对植物的毒害性、对环境的潜在威胁以及运行成本等方面因素,目前,寻找高效、廉价、可生物降解的鳌合剂以及大生物量的耐性植物成为植物提取技术的研究重点。 相似文献
1000.