れんこん表皮の褐変に関する研究

Effects of selenium on agronomical characters of winter wheat exposed to enhanced ultraviolet-B

Estudou-se o efeito do composto de lixo urbano na fertilidade e nos teores totais e extraídos com solução de DTPA 0,005 mol L-1 pH 7,3 dos elementos Fe, Mn, Zn e Ni em um Podzólico Vermelho-Amarelo textura arenosa, em casa de vegetação. Empregou-se sorgo como planta-teste, avaliando-se perfilhamento, produção de matéria seca e quantidade acumulada dos elementos P, K, Ca, Mg, Fe, Mn, Zn e Ni em função de doses de composto equivalentes a 0, 12,5, 25, 50 e 100 t ha-1, na ausência e na presença de adubação mineral. O composto aumentou a produção de matéria seca do sorgo na ausência de adubação mineral; esta, contudo, promoveu maior aumento de produção e perfilhamento das plantas. Na parte aérea de sorgo, não foi detectado Ni, enquanto as quantidades acumuladas de Fe, Mn e Zn relacionaram-se com os teores no solo extraídos com DTPA. A aplicação do composto de lixo promoveu aumento dos valores de pH, matéria orgânica, bases trocáveis, P resina e CTC do solo, reduzindo a acidez potencial (H + Al). Os teores totais de Fe, Mn e Zn no solo aumentaram com as doses do composto, enquanto o de Ni aumentou somente na ausência de adubação mineral. Os teores de Zn e Ni no solo, extraídos com DTPA, aumentaram com as doses do composto tanto na ausência como na presença de adubação mineral; já os de Mn e Fe diminuíram na presença de adubação mineral e não foram alterados na sua ausência. Apesar de não ter ocorrido acúmulo dos metais pesados no tecido vegetal, houve incremento no solo de alguns dos elementos; portanto, deve-se atentar para aplicações sucessivas de composto de lixo domiciliar.

Soil microorganisms play an important role in the mobilization of phosphorus (P), and these activities may be beneficial for plant P utilization. We investigated the effects on microbial P availability of different combinations of aluminum and iron (Al + Fe) concentrations and different P pools in humus soils from boreal forest ecosystems. We measured respiration rates in laboratory incubations before and after additions of glucose plus (NH4)2SO4 (Glu+N), with or without a small dose of KH2PO4. Glu+N was added in excess so that the availability of the inherent soil P would be growth-limiting for the microorganisms. The exponential increases observed in microbial growth after substrate additions (Glu+N) was slower for humus soils with high Al+Fe concentrations than for humus soils with low Al+Fe concentrations. Adding a small dose of KH2PO4 to humus soils with high Al+Fe concentrations did, however, increase the exponential growth, measured as the slope of the log-transformed respiration rates, by more than 200%. By contrast, the average increase in exponential growth was only 6% in humus soils with low Al+Fe concentrations. Almost eight times more carbon dioxide (CO2) was evolved between the substrate additions and the point at which the respiration rate reached 1 mg CO2 h−1 for soils with high Al+Fe concentrations compared to humus soils with low Al+Fe concentrations. The amount of CO2 evolved was positively related to the Al+Fe concentration of the humus soils (r 2 = 0.86, P < 0.001), whereas the slope was negatively related to Al+Fe concentration (r 2 = 0.70, P < 0.001). Easily available P forms were negatively related to the Al+Fe concentration, whereas organic P showed a strong positive relationship to Al+Fe (r 2 = 0.85, P < 0.001), suggesting that other forms of P, as well as inorganic P, are affected by the increased sorption capacity. The results indicate that P mobilization by microorganisms is affected by the presence of sorption sites in the humus layer, and that this capacity for sorption may relate not only to phosphate but also to organic P compounds.

The phenomenon of browning occurs gradually in the white sugar-coating layer (comprised of sucrose, talc, and powdered acacia) when the coating is applied on a large scale. We found that this phenomenon is negligible on sugar-coated tablets when they are prepared on a small scale. The smoothing layer prepared on a small scale is nearly as opaque as the subcoating layer. Conversely, the smoothing layer produced on a larger scale is semitransparent. In large-scale operations, the conditions required to make the smoothing layer opaque were established, and it was demonstrated that this method can restrict the browning phenomenon. It is considered that the nitrogen-containing contaminants in powdered acacia may react with heat-inverted sucrose (the Maillard reaction) to make brown substances in the smoothing layer and that the opaque appearance of the layer conceals the color accumulation of the brown substances in the smoothing layer and therefore restricts the browning phenomenon.

Common management practices, such as the application of green waste compost, soil moisture manipulation, and nitrogen fertilization, affect nitrous oxide (NO) emissions from agricultural soils. To expand our understanding of how soils interact with these controls, we studied their effects in 10 agricultural soils. Application of compost slightly increased NO emissions in soils with low initial levels of inorganic N and low background emission. For soils in which compost caused a decrease in emission, this decrease was larger than any of the observed increases in the other soils. The five most important factors driving emission across all soils, in order of increasing importance, were native dissolved organic carbon (DOC), treatment-induced change in DOC, native inorganic N, change in pH, and soil iron (Fe). Notable was the prominence of Fe as a regulator of NO emission. In general, compost is a viable amendment, considering the agronomic benefits it provides against the risk of producing a small increase in NO emissions. However, if soil properties and conditions are taken into account, management can recognize the potential effect of compost and thereby reduce NO emissions from susceptible soils, particularly by avoiding application of compost under wet conditions and together with ammonium fertilizer.

Assessment of Cd availability in rice cultivation (Oryza sativa): Effects of amendments and the spatiotemporal chemical changes in the rhizosphere and bulk soil.

Mississippi Valley-type (MVT) deposits contain about 20% of global zinc resources and host critical raw materials crucial to the development of green technologies. Despite their economic and strategic importance, there is a lack of consensus on the duration of mineralizing fluid flow events in MVT systems. This study couples in-situ U-Pb dating with Sr-isotope and trace element analysis of syn- and post-ore gangue carbonates to establish: (1) timing and duration, (2) redox evolution, and (3) flow rates of mineralizing fluids in the world-class San Vicente Zn-(Pb) deposit (Peru). New radiometric ages bracket the crystallization of syn-mineralization dolomite, characterized by high Fe and Mn contents and Sr isotopic values overlapping with that of host carbonates, between 103.2 ± 4.1 Ma and 70.6 ± 5.6 Ma. This age interval reveals a direct genetic relationship between flow of mineralizing fluids and late Cretaceous Andean compressional tectonics. Basinal fluid expulsion coeval with known tectonic events continues in the district until Pliocene times, driving episodic crystallization of post-ore hydrothermal carbonates between 61.6 ± 9.3 and 2.7 ± 0.2 Ma. The low Mn and Fe content and high 87Sr/86Sr values characteristic of these post-ore, bedding-parallel and cross-cutting carbonate veins indicate a colder, oxidized environment. Our findings highlight the contribution of paired carbonate geochemistry and U-Pb geochronology in drawing links between tectonic events, fluid expulsion and the waxing and waning of mineralization potential in foreland basins. The results of this study challenge our understanding of timescales in MVT systems and imply that anomalous metal enrichment in basinal fluids over a short temporal interval is not a necessary precondition to form economic-sized, sediment-hosted Zn-Pb deposits. Rather, it is the coexistence of a focused fluid flow in an interconnected aquifer with suitable metal depositional mechanisms over a prolonged period of time (106–107 yr) that allows precipitation of economic amount of base metals at a specific site in the upper crust.

The aim of the present study is to evaluate the status of plasma essential trace element selenium (Se), manganese (Mn), copper (Cu), zinc (Zn), and iron (Fe) concentrations and the effect of these elements on oxidative status in patients with childhood asthma. Plasma Se, Mn, Cu, and Zn concentrations were determined by atomic absorption spectrophotometry (AAS) and Fe concentrations, malondialdehyde (MDA), and total antioxidant capacity (TAC) were determined by the colorimetric method. The plasma MDA/TAC ratio was calculated as an index of oxidative status. Plasma albumin levels were measured to determine nutritional status. Plasma Fe concentrations, MDA levels and the MDA/TAC ratio were significantly higher (p<0.001, p<0.001, and p<0.01, respectively) and Se and Mn concentrations and TAC were lower (p<0.01, p<0.05, and p<0.01, respectively) in patients when compared to the healthy subjects. Plasma Zn, Cu, and albumin levels were not found to be significantly different in patients and controls (p>0.05). There were positive relationships between plasma MDA and Fe (r=0.545, p<0.001) and TAC and Se (r= 0.485, p<0.021), and a negative correlation between TAC and MDA values (r= -0.337, p<0.031) in patients with childhood asthma. However, there was no correlation between these trace elements and albumin content in patient groups. These observations suggest that increased Fe and decreased Se concentrations in patients with childhood asthma may be responsible for the oxidant/antioxidant imbalance.

&lt;p style="text-align: justify;"&gt;A study has been carried out during the 2001 ripening period with Tempranillo variety grafted onto 110R, in order to know the productive and qualitative differences provoked by different geographic locations in the region of Castilla y León (Spain), through experimental plots located on the West side of the Duero river valley, in the Apellation of Origin (A.O.C.) Ribera del duero, and on the East side, in the Cigales A.O.C.&lt;/p&gt;&lt;p style="text-align: justify;"&gt;The vines were head trained and 2-bud spur pruned, with a radial distribution of the spurs and 10 buds per vine. The Ribera del Duero vineyard was planted in 1987. The annual rainfall along the last 10 years has been 421 mm 3 layers can be distinguished on the soil of the trial with the following kind of textures: the first one is a loamclay- sandy soil, the second is clayey and the third one, deepest, is clayey-loam. The Cigales vineyard was planted in 1993. The annual rainfall along the last 10 years has been 399 mm 3 layers can be distinguished on the soil of the trial with the following kind of textures: the first and second layers are sandy-loam soil and the third one, deepest, is sandy-clay.&lt;/p&gt;&lt;p style="text-align: justify;"&gt;The average temperature during the vegetative cycle in Cigales A.O.C. is higher than in Ribera del Duero A.O.C. On the other hand, at the beginning of the ripening period the temperatures are lower in Cigales, which together with the soil conditions have provoked a lower vegetative development and the variations on the vegetative-reproductive balance. The soil and climate conditions in the Ribera del Duero experimental plot have provoked a higher vegetative development of the vines and different characteristics of the berries with respect to the Cigales plot, probably due to a lower water stress along the vegetative cycle. The berry weight in the Cigales A.O.C. has been 25% lower than in Ribera del Duero A.O.C. The differences in berry weight were maintained along the ripening period. The vineyard conditions of the Ribera del Duero A.O.C. have allowed to obtain, for a similar yield per vine to the Cigales A.O.C., berries with higher sugar concentration and lower pH. However, the total acidity has shown statistical differences only in the first sample, becoming the results similar over the ripening period. The differences in pH are not correlated with the total acidity evolution, which could be due to the higher potassium concentration in the Cigales A.O.C, being in this case lower the total acidity of the berries.&lt;/p&gt;&lt;p style="text-align: justify;"&gt;The phenolic maturity has also been affected by the soil and climate conditions, so the Ribera del Duero plot has shown a higher total polyphenols index along the ripening period than the Cigales plot. The total anthocyanins concentration maintained similar values in both plots, although the final concentration at harvest was lower in the Cigales A.O.C. The extractable anthocyanins concentration, measured by Glories method, has followed a similar evolution than the total anthocyanins in both areas of study.&lt;/p&gt;

Direct application of sewage sludge to soil is controversial due to, among others, its highly variable composition, odour, and risks for health. The obtained composts with the addition of sewage sludge were tested for the contents and availability of manganese and iron. Once composts were applied to the soil, their effect on the content and availability of Mn and Fe in soil and bioaccumulation in the plant were determined. The addition of sewage sludge enriched composts with manganese and iron, but did not increase the content of water-extracted forms of Mn and Fe. The compost with addition of biochar had more organic matter-bound forms of Mn and Fe. Composts amended with sewage sludge had lower effect on the amount of Poa pratensis L. biomass than maize straw compost. The content of Mn and Fe in Poa pratensis L. was in the range permissible for biomass used as fodder. Smaller addition of all composts to the soil significantly increased the content of mobile manganese forms; however, neither the type nor the dose had effect on the content of iron mobile forms. There was no significant differences in the content of organic matter-bound forms of Mn and Fe in soil after the application of composts.

Trace element zoning in dolomite: Proton microprobe data and thermodynamic constraints on fluid compositions

Iron (Fe) toxicity is recognized as a widely observed nutritional disorder that lowers rice crop productivity worldwide. The high concentration of Fe in soil may also alter the uptake and accumulation of other mineral elements. However, the relative change in the accumulation of other mineral elements affected by Fe toxicity is largely unknown. Therefore, this experiment studied the mineral nutrition of two Fe-tolerant (Bw372 and Bw267-3) and Fe-susceptible (Bw272-6B and Bg359) rice varieties to variable Fe concentration in the growing medium. Four Fe concentrations were used; 7 mgL− 1(1.25 × 10− 4molL− 1), 100 mgL− 1 (1.79 × 10− 3molL− 1), 300 mgL− 1 (5.37 × 10− 3 molL− 1), and 500 mgL− 1 (8.95 × 10− 3 molL− 1). The experiment was conducted as a hydroponic system with 15 plants as replicates for each treatment combination. Results revealed that, when increasing Fe concentration in the growing medium, tissue Fe, Na, and Co concentrations increased while tissue Mn, Mg, Mo, Cu, Zn, and Cd concentrations decreased for all the varieties. When comparing varieties, the concentration of Fe in Bw372 was the lowest, and that in Bw272-6B was the highest. As a result, the reduction in shoot dry weight (SDW) and root length (RL) to increased Fe concentration was the lowest in Bw372 (33% for SDW and 40% for RL) and highest in Bw272-6B (64% for SDW and 52% for RL). Moreover, Bw372 and Bw267-3 did not show bronzing symptoms when grown in any of the tested Fe concentrations. These traits have contributed to Bw272-6B being susceptible and Bw372 being tolerant to Fe toxicity.

Compost contributes plant-available nutrients for crop production and adds partially decomposed carbon (C) to the soil organic carbon (SOC) pool. The effect of compost applications and other agricultural practices on SOC and total nitrogen (N) pools was determined in a sandy-loam Humic Gleysol at the Research Farm of McGill University, Ste-Anne-de-Bellevue, Quebec. Experimental plots with continuous silage corn (Zea mays L.) and silage corn-soybean (Glycine max L. Merr.) production were under conventional tillage (CT) or no-tillage (NT) management. Composted cattle manure was applied each spring at rates of 0, 5, 10 and 15 Mg (dry weight) ha-1 and supplemental NPK fertilizers were added to meet crop requirements. The C input from crop residues was affected by tillage, crop rotations and compost application, but differences in the SOC and total N pools were due to compost applications. After 5 yr, compost-amended plots gained 1.35 to 2.02 Mg C ha-1 yr-1 in the SOC pool and 0.18 to 0.24 Mg N ha-1 yr-1 in the total N pool, as compared with initial pool sizes when the experiment was initiated. These gains in SOC and total N were achieved with agronomic rates of compost and supplemental NPK fertilizers, selected to match the phosphorus requirements of silage corn. Such judicious use of compost has the potential to increase the SOC and total N pools in agroecosystems under annual crop production. Key words: Composted cattle manure, corn silage, mineral fertilizer, plant-available nitrogen, soil organic carbon

Mature specimens of Parasol Mushroom were collected annually in the outskirts of the Siemiany (2000–2003) and Rafa (2001–2003) sites in the northern part of Poland to examine temporal variations and similarities in the composition of 20 chemical elements. Analysis was done under the same condition and using well-validated analytical methods. Elements were determined by inductively coupled plasma–atomic emission spectroscopy and cold vapour–atomic absorption spectroscopy (Hg). The ranges of Ag, Al, Ba, Ca, Cd, Co, Cu, Cr, Fe, Hg, K, Mg, Mn, Na, Ni, P, Pb, Rb, Sr and Zn concentrations in the caps of fruiting bodies were similar (p > 0.05; Mann-Whitney U test) for both geographically distant sites, and these specimens from Rafa were more contaminated with Pb (p < 0.05; Mann-Whitney U test). The annual collections of caps in the Siemiany site varied in Ag, Al, Ba, Ca, Cd, Co, Cu, Fe, Hg, Na, Rb and Sr and contents (0.05 < p < 0.001), while they were similar in Cr, K, Mg, Mn, Ni, P, Pb and Zn (p > 0.05; Mann-Whitney U test). The annual collections of specimens from the Rafa site varied in contents of Ag, Al, Ba, Ca, Fe, Hg, K, Mg, Mn, P, Rb and Zn (p > 0.05), while they were similar in Cd, Co, Cr, Cu, Na, Ni, Pb and Sr (p < 0.05). The results of this study imply that metallic elements content of Parasol Mushroom collected at the same undisrupted sites, and hence keeping the same geochemical condition for mushroom development and fructification (the same stands and probably the same mycelia), can fluctuate over the years or the life-span of mycelium. Hence, when assessing the nutritional value of essential metallic elements and status of non-essential or toxic metallic elements in Parasol's Mushroom caps (and probably also of other mushrooms species) to man, the possible fluctuation in contents over time have to be taken into account.

Characterisation of urban catchment suspended particulate matter (Auckland region, New Zealand); a comparison with non-urban SPM