Analysis of volatile compounds of taperebá (Spondias mombin L.) and cajá (Spondias mombin L.) by simultaneous distillation and extraction (SDE) and solid phase microextraction (SPME)

Volatile compounds of cajá and taperebá fruits, both classified as Spondias mombin, but from different geographic origins, were extracted (and analyzed) using solid phase microextraction (SPME) and simultaneous distillation and extraction (SDE). Forty-eight compounds were identified in taperebá and 47 in cajá by SPME using a DVB/CAR/PMDS fiber. (E)-Caryophyllene (18.7%), ethyl butyrate (10.0%), and ethyl hexanoate (7.0%) were the most abundant components in taperebá volatiles extracted by SPME, whereas myrcene (41.1%) and beta-phellandrene (8.5%) were the major compounds in cajá. In the taperebá SDE extract, 46 substances were identified, and (Z)-caryophyllene (13.2%) and limonene (9.5%) were predominant. From the 42 substances found in the SDE extract of cajá, the major components were myrcene (38.0%) and p-cymene (6.2%). The two fruits showed similar chromatograms upon the use of SDE and SPME. These methods made it possible to determine 30 identical components in both fruits by using SDE and 32 by using SPME.     

Genetic erosion and in situ conservation of Lima bean (Phaseolus lunatus L.) landraces in its Mesoamerican diversity center

Lima bean (Phaseolus lunatus L.) is an important crop in traditional Mayan agriculture of the Yucatan Peninsula, Mexico, its Mesoamerican center of diversity. Genetic erosion in this species is currently a threat in this region out of 3 of 21 landraces dominate 71.24% of the cultivated area, and 12 are rare landraces grown only in 6.29%. Using 90 ISSR loci, we estimated the diversity and genetic relationships for 21 landraces to analyzing their risk of genetic erosion, and generate data for their in situ conservation. Total genetic diversity was high (h = 0.29), however it was lower than wild gene pool reported (h = 0.69). The abundant landraces had genetic diversity values lower (h = 0.13, I = 0.17) than the common (h = 0.26, I = 0.33) and rare landraces (h = 0.24, I = 0.27). However, the rare landraces are in a higher risk of genetic erosion due to local extinction. The cluster analysis showed no groups corresponding to morpho-phenological characteristics, geographic origin or traditional classification, which resulted from high inter-landraces gene flow levels. The molecular data confirmed that the domesticated Lima bean pool of the Yucatan Peninsula has a high risk of genetic erosion. If current tendencies in landrace cultivation continue, many will no longer be planted within two to three generations, with a consequent loss of their alleles. Programs urgently need to be established for in situ conservation of Lima bean landraces in this region.     

Influence of Soil Management and Crop Rotation on Physical Properties in a Long-Term Experiment in Paraná, Brazil

This work aims to evaluate the soil physical properties affected by cover crop rotation and soil management in a long-term experiment in southern Brazil. The experiment was established in 1986, with treatments combining six winter treatments and two tillage systems (conventional and no tillage). Bulk density, porosity, aggregate-size class distribution, and organic carbon content of the aggregates were determined at six depths. Bulk density was not affected by tillage systems and winter treatments. The soil disturbance by plowing enhanced the macroporosity, decreased the microporosity, and promoted the formation of smaller aggregate size, in comparison to no tillage. Apart from the soil management, all winter species increased the greater aggregate-size classes, mean weight diameter, geometric mean diameter, and aggregate stability index compared to the fallow treatments. At the no-till treatments, the greater part of sequestered carbon into the soil was stored into the lower and bigger soil aggregates.     

Effect of mulch rates and tillage systems on infiltrability and other soil physical properties of an Oxisol in Paraná, Brazil

A 7-year-old tillage trial, comprising conventional tillage (CT), minimum tillage (MT) and no-tillage (NT), was chosen to study the relative importance of controlled mulch rates and soil physical properties such as bulk density, pore volume and hydraulic conductivity upon infiltrability. Infiltration measurements were carried out with a portable rainfall simulator. Mulch consisted of soya bean residues.Soil physical analysis showed higher bulk densities in the top 20 cm under NT, whereas CT, and to a lesser extent MT, led to the development of a plough pan in 20–30 cm depth. At the same time, compaction brought about a decrease in macropores and an increase in micropores. Total porosity ranged between 56.6% and 66.4%. Hydraulic conductivity did not differ significantly between tillage systems, and overall conductivity values were very high.The main factor influencing infiltrability was the formation of a surface seal depending on the degree of soil cover by mulch, irrespective of tillage system. For all 3 tillage systems, a 100% soil cover led to the complete infiltration of a 60-mm rainfall, whereas only 20% of the applied rain infiltrated when the soil was bare and the surface completely sealed. Plant residues of 4–6 t ha⁻¹ are proposed, as the minimum amount of mulch needed to reduce runoff and erosion effectively.     

Interactive effects of Si and NaCl on growth,yield, photosynthesis,and ions content in strawberry (Fragaria × ananassa var Camarosa)

The effects of silicon (Si) (0, 1, and 2 mM) and sodium chloride (NaCl) salinity (0, 20, and 40 mM) on the yield, photosynthesis, and ion content in strawberry grown in hydroponics were investigated. Salinity caused a reduction in leaf area and plant biomass, regardless of Si supplement. Leaf area in Si₁Na₂₀ treatment was 37% higher than that of Si₀Na₂₀ treatment. Salinity at 20 mM concentration had a 25% yield reduction in absence of Si, corresponding to no reduction in the yield in the presence of Si compared with the Si treatment without salinity. The highest reduction of photosynthetic rate (Pn) was observed in Si₁Na₄₀ treatment; however, in the presence of Si, there was no reduction in the Pn rate at 20 mM NaCl concentration. An obvious positive relationship was found between potassium/sodium (K/Na) and Pn rate. Within each Si concentration, the increased salinity increased Na concentration in the leaf tissue. However, when Si was supplied to the salinity treatments Na concentration was significantly lower than that of the similar treatments without Si. Supplement of Si to the nutrient solution increased the Si concentration in the roots, and old and young leaves. A clear negative relationship (r² = 0.71) was found between Si and Na concentration in the leaves. Salinity (NaCl₄₀) increased the proline level 2.5-fold in the absence of Si, corresponding to no changes the proline level in the presence of 1 mM Si concentration compared with the Si treatment without salinity. The salinity (40 mM) increased the electroleakage by 50% compared with 0 mM NaCl treatment in the absence of Si supplement. Findings from this study lead to the conclusion that Si supplement to the nutrient solution ameliorated the deleterious effect of salinity on the strawberry growth; these effects were attributed to an enhanced K/Na ratio and the reduction in Na content and electroleakage ability in the leaf tissue.     

Hydrogeochemistry of a Small Catchment in Northeastern Amazonia: a Comparison Between Natural with Deforested Parts of the Catchment (Serra do Navio,Amapá State,Brazil)

To undertake a comprehensive study of the disturbanceeffects due to mining activities (manganese oreexploitation) on the chemical composition of drainagewaters, a 164 ha catchment in North-eastern Amazoniatropical forest was sampled weekly for a year period(June 1993 to June 1994) to determine the contrasts inrainwater, throughfall and stream water chemistrybetween the upper undisturbed area and the lower partaffected by deforestation and mining works. During the3 dry months season only about 15% of the totalannual input-output of chemical species to and fromthe catchment occurs. In the three wettest months,about 30% of the flux occurs, except 60% of thepotassium and nitrate release from the catchmentoccurs in these three months. The rain waters areslightly acidic (pH ≈ 5.2) with lowalkalinity, while the stream water is nearly neutral(pH ≈ 6.9): alkalinity is generated within thesoil and soil water system. The rainfall-throughfallrelationship of the chemical species in the naturalareas exhibits strong internal recycling and littleexport from the catchment. In the area changed bydeforestation and mining works almost all chemicalspecies show a net export in surface waters: these aremainly derived from the deforested area of the basin,where most probably due to enhanced weatheringprocesses because the vegetation cover has tore-establish itself.     

Toxicity of three pesticides commonly used in Brazil to Pontoscolex corethrurus (Müller, 1857) and Eisenia andrei (Bouché, 1972)

The indiscriminate and excessive use of pesticides poses serious risks to humans and the environment, including soil biota. Ecotoxicological tests are useful to indicate the extent to which these chemicals are harmful and how and where their effects occur. Some of these tests were standardized by ISO (International Organization for Standartization) using the earthworm species Eisenia fetida and Eisenia andrei, both native to temperate climates. However, these species may be of lower relevance for soil ecotoxicological studies since they live in the litter and feed on fresh organic matter. The species Pontoscolex corethrurus, native to tropical regions, may be an alternative for more relevant ecotoxicological tests as it is an endogeic geophagous species. However, little is known of its sensitivity to pesticides. Therefore, avoidance and mortality tests were performed using E. andrei and P. corethrurus and three pesticides commonly used in Brazilian agriculture: carbendazim, carbofuran and glyphosate. The tests were conducted in tropical artificial soil (TAS). For carbendazim, the median avoidance concentration (AC₅₀) was 76.1 and 65.8 mg a.i. kg⁻¹ and the median lethal concentration (LC₅₀) 19.7 and 15.3 mg a.i. kg⁻¹ for E. andrei and P. corethrurus, respectively. For carbofuran, the AC₅₀ was 9.7 and 7.3 mg a.i. kg⁻¹ and LC₅₀ 13.5 and 9.3 mg a.i. kg⁻¹ for E. andrei and P. corethrurus, respectively. Concentrations applied in the field of these two pesticides have toxic effects on both species. Glyphosate showed no toxic effects for either species even at the highest concentration tested (47 mg a.i. kg⁻¹), although they displayed avoidance behavior at this concentration. The sensitivity of P. corethrurus appears to be similar to the standard species for the pesticides evaluated reinforcing the notion that E. andrei is a good test species. Nevertheless, further studies should be undertaken using other contaminants to confirm the similar sensitivity of both species and the relevance of E. andrei in ecotoxicological tests.     

Seasonal Variation of n-Alkanes and Polycyclic Aromatic Hydrocarbon Concentrations in PM10 Samples Collected at Urban Sites of São Paulo State, Brazil

Two campaigns were conducted in 2003 and 2004 at sites of different characteristics in São Paulo State. Atmospheric samples were collected twice a month during a 1-year campaign (an extensive campaign) from April 2003 to May 2004 at São Paulo City (SPA) site. The results showed that the pollutant concentrations were controlled not only by local source emissions but also through pollutant transport, both of which were dictated by the prevailing meteorological conditions. Chrysene, benzo(e)pyrene, and benzo(b)fluoranthene were the major compounds found, and diagnostic ratios indicated the multiplicity of sources: industrial, vehicular emission, and atmospheric transport. Intensive campaign (from July 15 to 30, 2003) samples showed higher cancer risk than those collected in the extensive campaign. Samples collected at the urban site (SPA) presented comparable values of PM₁₀ to the urban site influenced by sugarcane burning (Araraquara, ARQ). On the other hand, PAH average concentrations were higher at SPA than at other sites. In both campaigns, the highest value for dry atmospheric deposition flux was found in autumn and winter. Individually, BPe presented the highest deposition flux followed by BbF in the intensive campaign. It seems that during those periods, the dry deposition was the main airborne PAH removal mechanism. Diagnostic ratios suggested also vehicular emissions at the sites and photochemical reactions influencing in the atmospheric particulate matter composition. SPA and PRB samples presented higher cancer risk than ARQ in the intensive campaign.     

Spatial patterns of soil attributes and components in a mangrove system in Southeast Brazil (São Paulo)

Purpose

Among environmental factors governing innumerous processes that are active in estuarine environments, those of edaphic character have received special attention in recent studies. With the objectives of determining the spatial patterns of soil attributes and components across different mangrove forest landscapes and obtaining additional information on the cause–effect relationships between these variables and position within the estuary, we analyzed several soil attributes in 31 mangrove soil profiles from the state of São Paulo (Guarujá, Brazil).

Materials and methods

Soil samples were collected at low tide along two transects within the Crumahú mangrove forest. Samples were analyzed to determine pH, Eh, salinity, and the percentages of sand, silt, clay, total organic carbon (TOC), and total S. Mineralogy of the clay fraction (<2 mm) was also studied by X-ray diffraction analysis, and partitioning of solid-phase Fe was performed by sequential extraction.

Results and discussion

The results obtained indicate important differences in soil composition at different depths and landscape positions, causing variations in physicochemical parameters, clay mineralogy, TOC contents, and iron geochemistry. The results also indicate that physicochemical conditions may vary in terms of different local microtopographies. Soil salinity was determined by relative position in relation to flood tide and transition areas with highlands. The proportions of TOC and total S are conditioned by the sedimentation of organic matter derived from vegetation and by the prevailing redox conditions, which clearly favored intense sulfate reduction in the soils (～80% of the total Fe is Fe-pyrite). Particle-size distribution is conditioned by erosive/deposition processes (present and past) and probably by the positioning of ancient and reworked sandy ridges. The existing physicochemical conditions appear to contribute to the synthesis (smectite) and transformation (kaolinite) of clay minerals.

Conclusions

The results demonstrate that the position of soils in the estuary greatly affects soil attributes. Differences occur even at small scales (meters), indicating that both edaphic (soil classification, soil mineralogy, and soil genesis) and environmental (contamination and carbon stock) studies should take such variability into account.

     

Remediation of heavy metal(loid)s contaminated sediments—in situ iron treatment and subsequent magnetic extraction

Purpose

Surface sediments contaminated with high levels of multiple heavy metal(loid) species are very common environmental problems. Especially, the labile and bioaccessible fractions of heavy metal(loid)s in the sediments are posing serious risks to the biota and the overlaying water quality. This study aimed at developing a potential method to manage the activity of the labile fractions of heavy metal(loid)s in surface sediments.

Materials and methods

This study assessed the feasibility of adding iron powder, a low-cost industrial by-product, to sediments containing high levels of Pb, As, and Cd to adsorb labile fractions of heavy metal(loid)s onto the sorbent surfaces and to retrieve the heavy metal(loid) laden powders by applying external magnetic field. In addition, the redistribution of Pb, Cd, and As in different sediment fractions, the dissolved fraction and the sorbent-adsorbed fraction, was also investigated and characterized.

Results and discussion

The results indicate that the bioactive labile fractions (exchangeable and carbonate-bound fractions) of heavy metal(loid)s are prone to concentrating onto iron powders and can be selectively removed from the sediments by magnetic retrieval. In addition, iron addition induces conversion of labile fractions of heavy metal(loid)s into more stabilized fractions.

Conclusions

Overall, the process can effectively minimize the activity of labile fractions of heavy metal(loid)s in surface sediments.

     

Triacylglycerols, glycerophospholipids, tocopherols, and tocotrienols in berries and seeds of two subspecies (ssp. sinensis and mongolica) of Sea Buckthorn (Hippophaë rhamnoides)

Berries and seeds of two subspecies (ssp. sinensis and mongolica) of sea buckthorn (Hippopha? rhamnoides L.) were compared in terms of triacylglycerols, glycerophospholipids, tocopherols, and tocotrienols. The berries of ssp. mongolica contained less oleic acid (4.6 vs 20.2%, p < 0.001) and more palmitic (33.9 vs 27.4%, p < 0.01) and palmitoleic (32.8 vs 21.9%, p < 0.05) acids in triacylglycerols than those of ssp. sinensis. The proportions of linoleic acid (32.1 vs 22.2%, p < 0.01, in berries; 47.7 vs 42.7%, p < 0.05, in seeds) and palmitic acid (21.1 vs 16.4%, p < 0.001, in berries; 17.0 vs 14.1%, p < 0.05, in seeds) in glycerolphospholipids were higher in ssp. mongolica than in ssp. sinensis, and vice versa with oleic acid (4.3 vs 18.5% in berries, 10.0 vs 22.2% in seeds, p < 0.001). A higher proportion of alpha-linolenic acid was also found in the glycerophospholipids of ssp. sinensis berries (16.2 vs 10.1%, p < 0.001). alpha-, beta-, gamma-, and delta-tocopherols constituted 93-98% of total tocopherols and tocotrienols in seeds, and alpha-tocopherol alone constituted 76-89% in berries. The total contents of tocopherols and tocotrienols varied within the ranges of 84-318 and 56-140 mg kg(-1) in seeds and whole berries, respectively. The seeds of ssp. mongolica were a better source of tocopherols and tocotrienols than those of ssp. sinensis (287 vs 122 mg kg(-1), p < 0.001). The compositional differences between the two subspecies should be considered when the berries are bred and exploited for nutritional purposes.     

Lestes dryas kirby—a declining species of dragonfly (odonata) in need of conservation: Notes on its status and habitat in England and Ireland

A study of Lestes dryas was made in 1978. None was found in ten localities in south east England, which had held populations in the period 1940–1947. Major changes had occurred in eight of the localities, and these could readily account for the disappearance of the insect from them. A search for L. dryas was made in apparently suitable habitat in the Cambridgeshire Fens but none was found. L. dryas was found on three out of eighty waterbodies visited in the west and south of Ireland. Neutral or slightly acid waters with extensive emergent vegetation, notably Equisetum fluviatile, Scirpus lacustris and Typha sp., and supporting the dragonflies Sympertrum sanguineum and/or Coenagrion pulchellum, appear to indicate a suitable habitat for the species. The decline of L. dryas appears to have been caused by a combination of factors: loss of habitat, periods of drought and small population numbers.     

The influence of lithology on hillslope development in the area of the Jacupiranga Alkaline Complex and its surroundings (São Paulo,Brazil)

The area of the Jacupiranga Alkaline Complex and its surroundings is characterized by a variety of slope forms. Their spatial differentiation and the differences in relative relief and hilltop heights are a function of lithology. Significant contrasts exist, particularly between the ultramafic rocks of the Alkaline Complex and the quartz-rich rocks of the surrounding Precambrian basement. Although climatic conditions are uniform, the physical and chemical properties of the weathering products formed on the various rock types are very different. Through their properties, they affect the hillslope processes and thereby influence the hillslope development. Slope-forming processes on deeply weathered ultramafic rocks are slow mass movements and chemical denudation. On the more resistant ultramafic rocks, wash processes appear to be more important. Wash and rapid mass movements predominate on gneisses, granites and mica schists.The geomorphological development of the Jacupiranga Alkaline Complex can be explained in terms of a long, continuous downwearing. The large differences in elevation within the Alkaline Complex suggest that the development towards a more differentiated relief may extend well back into the Tertiary. The mutual adjustment of slope forms, processes and lithological controls favoured the development of rock-dependent summit heights, where heights are determined by the steepness of the slopes and the spacing of the drainage lines. Climatic fluctuations in the Pleistocene failed to produce any fundamental change in the long-term development of the hillslopes as their duration was too short with respect to the relaxation time of the hillslopes or their influence was not great enough to alter the overall trend of slope development.     

Amendment of soils with fresh and post-extraction lavender (Lavandula angustifolia) and lavandin (Lavandula × intermedia) reduce inoculum of Verticillium dahliae and inhibit wilt in strawberry

Soils that were naturally infested with high levels of Verticillium dahliae, the causal agent of wilt disease in strawberry, were amended with fresh and waste lavender, fresh and waste lavandin, hydrosols generated during essential oil production, BioFence™ (a mustard-based defatted seedmeal pellet), or water in microcosms to estimate their efficacy against microslecrotia of the pathogen. Single chemicals and mixtures of the chemicals detected from the substrata were also effective in microcosms. The mixtures were more effective than were the individual chemicals. Microplot evaluation of fresh and waste lavender and lavandin was also made in comparison to BioFence™ and water controls. Lavandin waste was compared to BioFence™ and untreated controls at three sites in field plots that were subsequently planted to strawberry. Disease incidence and severity were measured over time in the field. All of the Lavandula-based materials could be associated with large reductions in the numbers of viable of microsclerotia recovered in all but one experiment with greatest effect in microcosms and smaller effects in microplots and field plots, as could BioFence™ pellets. Due to the high levels of inoculum found at all field sites the reduction in pathogen inoculum density was not necessarily associated with a corresponding reduction in disease incidence, nor with severity as determined by yield. The monoterpenoids associated with the Lavandula spp. are of lower volatility than the isothiocyanates associated with crucifer decomposition and were detected for more than one week after materials were incorporated in soil. This suggests both differences in mode of action and the possibility of combining either the chemicals or the materials that produce them in order to further enhance efficacy. Several non-target effects were considered: numerosity and diversity of bacterial and fungal populations; infection by arbuscular mycorrhizal fungi; and functional diversity of soil microflora. No persistent non-salient effects were detected.     

The chemical characterization of the aroma of dessert and sparkling white wines (Pedro Ximénez, Fino, Sauternes, and Cava) by gas chromatography-olfactometry and chemical quantitative analysis

Wines from Pedro Ximénez (PX), Fino, botrytized Sauternes, and Cava were screened by gas chromatography-olfactometry (GC-O), and the most relevant aroma compounds were further quantified in six different wines of each group. The comparison of GC-O and quantitative data with similar data from white young wines has made it possible to identify the aroma compounds potentially responsible for the specific sensory characteristics of these wines. Results have shown that all these wines are relatively rich in 3-methylbutanal, phenylacetaldehyde, methional, sotolon, and the ethyl esters of 2-, 3-, and 4-methylpentanoic acids. While Cava has a less specific aroma profile halfway between these special wines and young white wines, PX is richest in 3-methylbutanal, furfural, beta-damascenone, ethyl cyclohexanoate, and sotolon; Fino in acetaldehyde, diacetyl, ethyl esters of branched aliphatic acids with four, five, or six carbon atoms, and 4-ethylguaiacol; and Sauternes in phenylacetaldehyde, 3-mercaptohexanol, and 4-methyl-4-mercaptopentanone.     

(Methyl)Mercury,Arsenic, and Lead Contamination of the World’s Largest Wastewater Irrigation System: the Mezquital Valley (Hidalgo State—Mexico)

We investigate the potential of near-infrared (NIR) spectroscopy to predict some heavy metals content (Zn, Cu, Pb, Cr and Ni) in several soil types in Stara Zagora Region, South Bulgaria, as affected by the size of calibration set using partial least squares (PLS) regression models. A total of 124 soil samples from the 0–20 and 20–40 cm layers were collected from fields with different cropping systems. Total Zn, Cu, Pb, Cr and Ni concentrations were determined by Atomic Absorption Spectrometry. Spectra of air dried soil samples were obtained using an FT-NIR Spectrometer (spectral range 700–2,500 nm). PLS calibration models were developed with full-cross-validation using calibration sets of 90 %, 80 %, 70 % and 60 % of the 124 samples. These models were validated with the same prediction set of 12 samples. The validation of the NIR models showed Cu to be best predicted with NIR spectroscopy. Less accurate prediction was observed for Zn, Pb and Ni, which was classified as possible to distinguish between high and low concentrations and as approximate quantitative. The worst model performance in cross-validation and prediction was for Cr. Results also showed that values of root mean square error in cross-validation (RMSE_cv) increased with decreasing number of samples in calibration sets, which was particularly clear for Cu, Pb, Ni and Cr content. A similar tendency was observed in the prediction sets, where RMSEP values increased with a decrease in the number of samples, particularly for Pb, Ni and Cr content. This tendency was not clear for Zn, while even an increase in RMSEP for Cu with the sample size was observed. It can be concluded that NIR spectroscopy can be used to measure heavy metals in a sample set with different soil type, when sufficient number of soil samples (depending on variability) is used in the calibration set.     

Simultaneous determination of furanocoumarins in infusions and decoctions from "Carapiá" (dorstenia species) by high-performance liquid chromatography

The use of furanocoumarins, which are photosensitizing compounds, combined with exposure to UV-A radiation is a common treatment for vitiligo, psoriasis, and a number of other skin diseases. Although furanocoumarins plus UV-A treatment is highly effective, several studies have shown that exposure to high doses increases the risk to development of cutaneus carcinoma. Several Dorstenia species are used in folk medicine, mainly against skin diseases, because of the presence of biologically active compounds. We present here analysis of the chemical composition of furanocoumarins from infusion and decoction of "Carapiá" (Dorstenia species), which is used in Brazil against several diseases. We have employed high-performance liquid chromatography (HPLC) procedures for the quantitative determination of psoralen, bergapten, and isopimpinellin. The contents of furanocoumarins revealed an insignificant difference between infusion and decoction. Dorstenia tubicina and D. asaroides contained psoralen and bergapten only in the rhizomes, whereas D. vitifolia shows solely isopimpinellin in both rhizomes and aerial parts.