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81.
Pedro Talhinhas José Leitão João Neves-Martins 《Genetic Resources and Crop Evolution》2006,53(3):563-578
Lupinus angustifolius L. is a Mediterranean species, domesticated in the 20th century, representing an important grain legume crop in Australia
and other countries. This work is focused on the collection of wild germplasm and on the characterisation of morphological
and molecular diversity of germplasm accessions. It reports the collection of 81 wild L. angustifolius accessions from the South and Centre of Portugal, available at the ‘Instituto Superior de Agronomia Gene Bank’, with subsequent
morphological and molecular characterisation of a selection of these and other accessions. A multivariate analysis of morphological
traits on 88 L. angustifolius accessions (including 59 wild Portuguese accessions, 15 cultivars and 14 breeding lines) showed a cline of variation on wild
germplasm, with plants from Southern Portugal characterised by earlier flowering, higher vegetative development and larger
seeds. AFLP and ISSR molecular markers grouped modern cultivars as sub-clusters within the wider diversity of wild germplasm,
revealing the narrow pool of genetic diversity on which domesticated accessions are based. The importance of preserving, characterising
and using wild genetic resources for L. angustifolius crop improvement is outlined by the results obtained. 相似文献
82.
Sara Peres M. Clara F. Magalhães Maria Manuela Abreu Sara Leitão Ana Santos Maria José Cerejeira 《Journal of Soils and Sediments》2016,16(5):1612-1624
Purpose
Wastes from a former Portuguese steel plant were deposited between 1961 and 2001 on the riverbank of a tributary of the Tagus River creating a landfill connected to the river, posing a potential contamination risk to the Tagus estuary ecosystem. This study aims to assess the transfer of chemical elements from contaminated sediments to the estuarine water from cycles of sediment leaching so as to evaluate the ecotoxicity of the leachates, and to analyze the solid phases crystallized from those leachates.Materials and methods
Landfill sediment and estuarine water samples were collected during low tide. Sediment samples were analyzed for pH, electric conductivity (EC), Corg, NPK, and iron oxides. Leaching assays (four replicates) were done using estuarine water (200 cm3/replicate) and 1.5 kg of sediment per reactor. Each reactor was submitted to four leaching processes (0, 28, 49, and 77 days). The sediment was kept moist between leaching processes. Sediment (total (acid digestion) and available fraction (diluted organic acid extraction-Rhizo)) elemental concentrations were determined by inductively coupled plasma–instrumental neutron activation analysis (ICP/INAA). Leachates, and estuarine and sediment pore waters were analyzed for metals/metalloids by ICP/mass spectrometry (MS) and carbonates/sulfate/chloride by standard methodologies. Ecotoxicity assays were performed in leachates and estuarine and pore waters using Artemia franciscana and Brachionus plicatillis. Aliquots of the leachates were evaporated to complete dryness (23–25 °C) and crystals analyzed by X-ray powder diffraction (XRD).Results and discussion
Sediment with pH?=?8 and high EC and Corg was contaminated with As, Cd, Cr, Cu, Pb, and Zn. The element concentrations in the available fraction of the sediment were low compared to the sediment total concentrations (<1 % for Rhizo extraction). The concentrations of potentially hazardous elements in the estuarine water were relatively low, except for Cd. Concentrations of hazardous elements in the leachates were very low. Calcium, K, Mg, Na, and chloride concentrations were high but did not vary significantly among the four leaching experiments. Total concentrations of carbonate were much higher in leachates than in estuarine water. Both estuarine water and leachates showed negligible toxicity. Crystals identified in the solids obtained from the leachates by evaporation were halite, anhydrite, epsomite, dolomite, and polyhalite.Conclusions
The sediment showed the capacity to retain the majority of the potentially hazardous chemical elements. Remobilization of chemical elements from sediment by leaching was essentially negligible. The variation of total concentrations of Ca, carbonate, and sulfate in leachates indicates that the sediment contained reactive sulfides. Due to its composition, the sediment seems to be a dynamic system of pollution control, which should not be disturbed.83.
Renan Francisco Rimoldi Tavanti Grace David Queiroz Anne Caroline Da Rocha Silva Walmor Moya Peres Amanda Pereira Paixão Fernando Shintate Galindo 《Archives of Agronomy and Soil Science》2020,66(6):743-762
ABSTRACTThis study aimed to assess the physiological and biochemical responses of cotton plants to manganese (Mn2+) nutrition. Four cotton genotypes (G1 – TMG 47; G2 – FM 975 WS; G3 – TMG 11 WS and G4 – IMA 8405 GLT) were grown in nutrient solution under two Mn2+ concentrations (2 and 200 µmol L?1) for 10 days. No visible symptoms of Mn2+ toxicity were observed in the genotypes tested. All genotypes showed a marked increase in leaf chlorophylls, pheophytins, carotenoids, sucrose and total sugars concentration in response to high Mn2+ in a nutrient solution. However, the net photosynthetic rate, stomatal conductance, internal carbon dioxide concentration and transpiration decreased in genotypes G1 and G2 growing under 200 µmol L?1. Antioxidant enzymes such as superoxide dismutase (SOD), ascorbate peroxidase (APX) and glutathione reductase (GR) activities increased in genotypes G1, G3 and G4. Cotton genotypes showed an increased leaf antioxidant and sugar metabolism as a possible strategy to mitigate oxidative stress. The decrease in the net photosynthetic rate and stomatal conductance; the increased antioxidant enzymes activities (SOD, APX and GR); and the increase in leaf sucrose and total sugar concentration were the main physiological and biochemical responses in cotton plants to Mn2+ stress. 相似文献
84.
Fernández M Picó Y Girotti S Mañes J 《Journal of agricultural and food chemistry》2001,49(8):3540-3547
Pesticides applied in extended agricultural fields may be controlled by means of bioindicators, such as honeybees, in which are the pesticides bioaccumulate. Liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry (LC-APCI-MS) experiments with positive (PI) and negative (NI) ion modes were optimized for the analysis of 22 organophosphorus pesticides in honeybee samples. The extraction required 3 g of sample, which was extracted with acetone. The extract was purified with coagulating solution and reextracted with Cl(2)CH(2). Pesticides studied could be detected by both ionization modes except for parathion, parathion-methyl, and bromophos, which did not give signals in PI mode, and triazophos, which was not detected in NI mode. Fragmentation voltage and vaporizer temperature were optimized to achieve the highest sensitivity. The spectra profile of each pesticide in PI mode showed the [M + H](+) ion as the main signal, whereas in NI mode only fragment ions were shown. The detection limit obtained in selected ion monitoring mode ranged from 1 to 15 microg kg(-1). The average recoveries from spiked honeybees at various concentration levels (0.5-5 mg kg(-1)) exceeded 65% with relative standard deviations of 4-15%. The method was applied to real samples, in which residues of coumaphos and dimethoate were detected. 相似文献
85.
Carlos?Wildt Oriol?Gibert José?Luis?CortinaEmail author Giuliana?Coscera 《Journal of Soils and Sediments》2004,4(3):184-191
Goal, Scope and Background The remediation of heavy-metalcontaminated soils and sediments is of significant value to industrial areas around the world.
The spread of such pollutants can result in a potential risk of entering the groundwater system and being transported to potential
receptors. Leaching techniques can be an effective treatment option for the metal removal from soils and sediments. This approach
consists of washing or leaching the contaminated soil with an appropriate reagent and the subsequent treatment of the leaching
in an above-ground installation (on-site treatment) where metals can be removed and concentrated into a smaller volume. Among
the heavy metals, chromium is a commonly identified soil contaminant, particularly in sites with intensive economic activities
including agriculture, industrial, mining and mineral,processing.
Objective The objective of this work was the evaluation and development of a leaching process for the remediation of soils and sediments
polluted with chromium at laboratory scale. Chromium soil pollution was generated after the breakdown of a channel containing
chromium wastes from a tannery plant. The pollution extension has been estimated to be on the order of thousands of tonnes
of soil to be treated, with chromium contents ranging from 500 to 17,000 mg kg-1 soil.
Methods The whole process investigated in this study integrates three stages; a) chromium leaching from a sediment using a diluted
sulphuric acid solution, b) treatment of the leaching effluents with a magnesium oxide/limestone mixture for the precipitation
of chromium hydroxide after acidity neutralisation, and c) polishing step to remove the eventual remaining chromium by adsorption
onto natural zeolite. The amount of contaminated sediment treated ranged from 0.5 to 2 kg with chromium contents of between
2000 and 17,000 mg kg-1.
Results and Discussion The paper describes results on the performance of the process and the optimisation of steps including influence of acid sulphuric
concentration, chromium removal efficiency as well as alkaline reactive mixture proportions. Effluents from the leaching cells
showed a significant decay on the chromium concentration with the increase of leaching runs and a high content of acidity
(pH values close to 0.5). The treatment of these effluents in a second cell containing magnesium oxide/ limestone mixtures
resulted in a high efficiency in neutralisation of acidity (pH values around 7) and chromium removal (concentrations below
5 mg 1-1). The passage through a third compartment containing zeolite as an adsorbent decreased the chromium concentration below 0.5
mg 1-1,
Conclusions From the results obtained on the chromium leaching and immobilisation with magnesium oxide/limestone mixture at a laboratory
scale, it could be pointed out that: (a) diluted sulphuric acid solutions (3%) demonstrated a high efficiency on chromium
removal from sandy polluted soils on the kilogram scale, (b) mixtures of magnesium oxide/limestone demonstrated a high capacity
to neutralise the residual high acidity present on the effluents and to remove chromium by precipitation and (c) between the
limestone and caustic magnesia mixtures, those containing more than 60% of caustic magnesia provide the higher efficiency.
Recommendation and Outlook Future work would be directed to the evaluation of the integrated process of leaching and chromium precipitation on column
at a scale of 100 to 1000 kg. 相似文献
86.
Duarte RT Carvalho Simões MC Sgarbieri VC 《Journal of agricultural and food chemistry》1999,47(1):231-236
The objective of this research work was to fractionate bovine blood, collected hygienically in a slaughterhouse, into blood plasma protein concentrate, red blood cell concentrate, globin isolate, and a carboxymethylcellulose-heme iron (CMC-heme) complex. All four fractions were studied for proximate composition and amino acid and mineral contents. The nutritive value of plasma protein concentrate and globin isolate was comparatively studied using rat bioassays. The amino acid content in plasma protein concentrate is well balanced and produced net protein utilization and net protein ratio equivalent to 95% those of casein. Globin isolate ( approximately 91% protein) is deficient in isoleucine and S-containing amino acids and was unable to support rat growth at 10% concentration in the diet. Red blood cell concentrate and the isolated CMC-heme complex were good sources of bioavailable iron. Iron availabilities for CMC-heme and whole blood cell concentrate, related to ferrous sulfate as 100%, were 64 and 70%, respectively. 相似文献
87.
Jaciele Beserra de Lira Alberício Pereira de Andrade André Luiz Rodrigues Magalhães Fleming Sena Campos Gherman Garcia Leal de Araújo Diana Signor Deon 《Communications in Soil Science and Plant Analysis》2020,51(5):701-709
ABSTRACTThe objective is to determine the growth, yield and chemical characteristics of pearl millet irrigated with different levels of brackish water and organic matter in two cultivation cycles. The experimental design was randomized blocks in a 4 × 4 factorial arrangement, composed of 4 levels of brackish irrigation (25, 50, 75 and 100% evapotranspiration), 4 levels of organic matter (0, 15, 30 and 45 t ha?1) with 3 repetitions. Along two cultivation cycles, pearl millet crop was analyzed for: plant growth variables, fresh and dry mass production, water-use efficiency, and chemical composition. There was significant interaction between applied water levels and organic matter for lignin in the 2nd cut (P < .05). The number of leaves, number of dead leaves and fresh mass production were influenced by the isolated effect of brackish water levels in cut 1 (P < .05). In turn, fresh mass production, dry mass production, plant height, leaves length, panicle length, fresh mass production, crude protein and ether extract were influenced by the isolated effect of saline water levels in the 2nd cut (P < .05). Growth, biomass production and chemical composition variables in second cut are positively influenced by different brackish irrigation levels under low rainfall conditions. 相似文献
88.
Measurement of coupled nitrification-denitrification in paddy fields affected by Terrazole,a nitrification inhibitor 总被引:2,自引:0,他引:2
David?CarrascoEmail author Eduardo?Fernández-Valiente Yoanna?Ariosa Antonio?Quesada 《Biology and Fertility of Soils》2004,39(3):186-192
Coupled nitrification-denitrification and potential denitrification were measured as 15N2O and 15N2 evolution rates in ammonium sulphate-treated rice soils with or without Terrazole [5-ethoxy-3 (trichloromethyl) 1,2,3 Thiadizole] under laboratory and field conditions. The greatest coupled nitrification-denitrification activity was found after drying and rewetting the soil, with maximum values of 322 ng N cm–2 h–1 in the laboratory and 90.8 ng N cm–2 h–1 in the field. These 15N2O + 15N2 evolution rates were about 10 times lower than potential denitrification in these soils. These results and the observed decrease in 15N2O + 15N2 evolution rate in soils treated with Terrazole (60% under laboratory conditions and 52% under field conditions) indicate that denitrification was limited by coupled nitrification-denitrification activity. Oxygen and previous addition of ammonium sulphate appear to control the rate of 15N2O + 15N2 evolution in ammonium sulphate-fertilised soils. 相似文献
89.
M.?Gutiérrez López M.?Ramajo Matesanz J.?B.?Jesús Lidón D.?J.?Díaz CosínEmail author 《Biology and Fertility of Soils》2003,37(4):231-236
This microcosm study investigated the effect of Hormogaster elisae on the abundance of soil Collembola and Acari in laboratory cultures. Two types of microcosm were prepared: type I consisted of plastic boxes with a 2-mm mesh cage containing two H. elisae, and type II consisted of plastic boxes without a cage. The respective controls contained no earthworms. All of them were kept at 18°C and 20% moisture for 21 days. After this period of time the microcosms were tested and microarthropods were extracted, identified and counted. In general, more microarthropods were recovered from the soils without earthworms. There were significant differences between the soils with respect to the abundance of Collembola (Isotomidae and Sminthuridae), and Acari (Gamasida and Oribatida). The results suggest that, under the experimental conditions employed, H. elisae reduces the abundance of these groups of microarthropods. This may be due to several reasons. A change in environmental heterogeneity produced by H. elisae is suggested. A possible interspecific relationship between these two groups due to competition or depredation is also discussed. 相似文献
90.
Comparison between phenetic characterisation using RAPD and ISSR markers and phenotypic data of cultivated chestnut (Castanea sativa Mill.) 总被引:2,自引:0,他引:2
Luís Goulão Teresa Valdiviesso Carlos Santana Cristina Moniz Oliveira 《Genetic Resources and Crop Evolution》2001,48(4):329-338
Patterns of phenotypic and phenetic variability in sixPortuguese cultivars of chestnut (Castanea sativa Mill.) are evaluated. Morphological characterisationwas based on the quantification of seventeen traits. Varianceanalysis showed significant differences among cultivars, and cultivar× year for all the traits studied, and trees within cultivarsshowed also some significant differences for some of themorphological variables. A significant correlation was obtainedbetween length of the leaf blade and the percentage of unisexual andandrogynic inflorescence with the effective thermal index,accumulated rainfall from April to October and from July to October,or the accumulated temperature below seven during the dormant period.Principal Component and cluster analysis were performed to group thecultivars, according to their similarity coefficients. For molecularcharacterisation, 125 RAPD and 157 ISSR polymorphic markers wereamplified using 28 and 7 primers respectively. High level ofcongruence among the two marker systems (r =90.5%) was obtained from comparison of pheneticsimilarities based on the percentage of shared fragments. ISSRmarkers revealed important advantages over RAPDs, due to a higheffective multiplex ratio (12.5 for ISSR compared with 2.2 forRAPD analysis) and reproducibility. Although morphological andmolecular results are comparable, slight differences are showed incluster analysis UPGMA dendrograms. Molecular analysis explainedhomonym situations among 'Martainha' and'Longal' cultivars in Portugal. 相似文献