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Paste Extract (paste + extract)

Distribution by Scientific Domains

Life Sciences	50%
Earth and Environmental Science	50%

Selected Abstracts

Evaluation of the capacity of three halophytes to desalinize their rhizosphere as grown on saline soils under nonleaching conditions

AFRICAN JOURNAL OF ECOLOGY, Issue 4 2009
Mokded Rabhi
Abstract In the sabkha of Soliman (N-E Tunisia), soil samples of the upper 20 cm were taken during the driest period of the year (July,August) from inside and outside tufts of two perennial halophytes: Arthrocnemum indicum (Willd.) Moq. and Suaeda fruticosa Forssk., both from family Chenopodiaceae. Samples were analysed for electrical conductivity of the saturation paste extract (ECe) and soluble sodium (Na+) content. Then, tufts were divided into three size categories and their shoot biomass production and Na+ content were determined. Our results showed a considerable contribution of shoot Na+ accumulation to rhizosphere desalination. The capacity of the two native halophytes A. indicum. and S. fruticosa to desalinize saline soils was compared with that of an introduced halophyte, Sesuvium portulacastrum L. (Aizoaceae). Seedlings were grown under greenhouse conditions in pots containing 8 kg of saline soil each. Pots were irrigated with tap water during 170 days without leaching. Our results confirmed the contribution of shoot Na+ accumulation to soil desalination. They showed also that among the three studied species, Sesuvium portulacastrum L. seems to be the most convenient to be used for this purpose in arid and semi-arid regions where precipitation is too low to leach salts from rhizosphere. Résumé Dans la sebkha de Soliman (N-E de la Tunisie), des échantillons de sol ont été prélevés dans les 20 cm supérieurs pendant la période la plus sèche de l'année (juillet-août) à l'intérieur et à l'extérieur des touffes de deux halophytes pérennes, Arthrocnemum indicum (Willd) Moq. et Suaeda fructicosa Forsk., appartenant tous deux à la famille des Chenopodiaceae. L'analyse des échantillons s'est basée sur la conductivitéélectrique de la pâte saturée (ECe) et le contenu en sodium (Na+) soluble. Par ailleurs, les touffes d'halophytes ont été réparties en trois catégories selon leur taille, puis des touffes représentatives de chaque catégorie ont été récoltées pour la détermination de la biomasse et la charge en Na+ de leurs parties aériennes. Nos résultats ont montré que l'accumulation de ces ions au niveau des organes aériens contribue considérablement au dessalement de la rhizosphère. La capacité des deux halophytes locales A. indicum et S. fructicosa de dessaler des sols salins a été comparée à celle d'un halophyte introduite, Sesuvium portulacastrum L. (Aizoaceae). De jeunes plantules ont été cultivées sous serre dans des pots contenant chacun huit kilos de sol salin. Les pots ont été irrigués à l'eau de ville pendant 170 jours sans lessivage. Nos résultats ont confirmé la contribution de l'accumulation de Na+ par les organes photosynthétiques au dessalement du sol. Ils ont montré, également, que, parmi les trois espèces étudiées, S. portulacastrum semble être la plus prometteuse pour un tel programme dans les régions arides et semi-arides où les précipitations sont assez faibles pour lessiver les sels de la rhizosphère. [source]

Sodium removal from a calcareous saline,sodic soil through leaching and plant uptake during phytoremediation

LAND DEGRADATION AND DEVELOPMENT, Issue 3 2003
M. Qadir
Abstract Saline,sodic and sodic soils are characterized by the occurrence of sodium (Na+) to levels that can adversely affect several soil properties and growth of most crops. As a potential substitute of cost-intensive chemical amelioration, phytoremediation of such soils has emerged as an efficient and low-cost strategy. This plant-assisted amelioration involves cultivation of certain plant species that can withstand ambient soil salinity and sodicity levels. It relies on enhanced dissolution of native calcite within the root zone to provide adequate Ca2+ for the Na+Ca2+ exchange at the cation exchange sites. There is a lack of information for the Na+ balance in terms of removal from saline,sodic soils through plant uptake and leaching during the phytoremediation process. We carried out a lysimeter experiment on a calcareous saline,sodic soil [pH of saturated soil paste (pHs),=,7.2, electrical conductivity of the saturated paste extract (ECe),=,4.9,dS,m,1, sodium adsorption ratio (SAR),=,15.9, CaCO3,=,50,g,kg,1]. There were three treatments: (1) control (without application of a chemical amendment or crop cultivation), (2) soil application of gypsum according to the gypsum requirement of the soil and (3) planting of alfalfa (Medicago sativa L.) as a phytoremediation crop. The efficiency of treatments for soluble salt and Na+ removal from the soil was in the order: gypsum,,,alfalfa,>,control. In the phytoremediation treatment, the amount of Na+ removed from the soil through leaching was found to be the principal cause of reduction in salinity and sodicity. Copyright © 2003 John Wiley & Sons, Ltd. [source]

Reducing salinity and organic contaminants in the Pearl Harbor dredged material using soil amendments and plants

REMEDIATION, Issue 4 2002
N. V. Hue
Phytoremediation is an emerging technique that can be used to economically remediate sites contaminated with trace elements and/or man-made organic contaminants. This technique was used on Pearl Harbor (Oahu, Hawaii) dredged material (PHDM) containing polycyclic aromatic hydrocarbons (PAHs) and some heavy metals. The dredged material was first amended with a high-calcium soil (Waialua Mollisol) and a biosolids-based compost at different proportions to yield varying salinity levels. A mixture that yielded an electrical conductivity (EC, a measure of salinity) of the saturated paste extract of 15 to 20 dS/m was identified and used to evaluate the salt tolerance of five plant species. Relative germination and one-month-old biomass indicated that common bermuda grass (Cynodon dactylon), seashore paspalum (Paspalum vaginatum), beach pea (Vigna marina), and cow pea (Vigna unguiculata) can produce at least 40 percent of biomass of the control at an EC of approximately 18 dS/m, suggesting the four plants are relatively salt tolerant. In contrast, Desmodium intortum either did not germinate or died within two weeks after germination at the same salinity level. A subsequent greenhouse experiment, using mixtures of the PHDM (0 or 25 percent dry weight), organic amendments (10 percent leucaena green manure or biosolids-based compost), and a Mollisol (65 or 90 percent dry weight) in 6-liter pots containing 4 kilograms of material yielded the following results: (1) A combination of transplanted seashore paspalum, seeded bermuda grass, and seeded beach pea was effective in taking up sodium (Na), thereby reducing salinity and making the medium more amenable to diversified microbes and plants, which may be effective PAH degraders; (2) total PAH concentration was reduced by about 30 percent after three months of active plant growth, but degradation of individual PAH members varied significantly, however; (3) leguminous green manure, as a soil amendment, was more effective than compost for use in bio- and/or phytoremediations; and (4) soil amendments, when applicable, could supplement living plants in reducing organic contaminants, such as PAHs. © 200 Wiley Periodicals, Inc. [source]

Effects of tomato paste extracts on cell proliferation, cell-cycle arrest and apoptosis in LNCaP human prostate cancer cells

BIOFACTORS, Issue 2 2005
Eun-Sun Hwang
Abstract Since tomato consumption is associated with decreased risk of prostate cancer, cell proliferation, cell cycle progression and apoptosis by LNCaP human prostate cancer cells might elucidate action of tomatoes. To discover possible bioactive fractions of tomatoes, whole tomato paste and its water and hexane extract were used and biomarkers of carcinogenesis were measured. After 6, 24 and 48 hr of incubation, cells were harvested and determined cell growth. Tomato paste hexane extract inhibited cell proliferation by 33% compared to the control after 48 hr incubation. Whole tomato paste and its water extract showed only modest growth inhibition. Tomato paste hexane extract at 5 ,M lycopene increased G2/M-phase of the cell cycle from 13 to 28% and decreased S-phase cells from 45 to 29%. Apoptosis was observed at the 5 ,M hexane extract at the late stages during 24 and 48 hr treatment. Tomato, therefore, deserves study as a potential chemopreventive/chemotherapeutic agent. [source]