Magnetic Study of Weakly Contaminated Forest Soils

Water, Air, &; Soil Pollution - This paper reports on magnetic and magnetomineralogical studies of forest soils from Krkono?e (Giant Mountains) National Park in the Czech Republic....     

The effect of a mixture of two plant growth-promoting bacteria from Argentina on the yield of potato,and occurrence of primary potato diseases and pest – short communication

In 2017, we conducted a field experiment to test the influence of a mixture of two plant growth-promoting bacteria (Pseudomonas fluorescens and Azospirillum brasilense) on the yield of three potato varieties. In addition, the influence of the mixture on potato susceptibility to infection by the pseudofungus Phytophthora infestans and fungus Alternaria solani and to attacks by the Colorado potato beetle (Leptinotarsa decemlineata) was investigated. It was the first experiment of its kind in Europe. In the unusually hot and dry year, a positive influence on the yield (17%–31%) was found in all three varieties when the tubers were soaked in the bacterial mixture prior to sowing. We observed no significant differences in potato resilience/susceptibility to harmful organisms among the different treatments (soaked tubers, sprayed tubers, untreated tubers); however, there were significant differences in the productivity between the tuber varieties. The results of our research indicate the bacterial mixture used in this study has a high potential to support satisfactory potato yields under dry conditions and under low levels of infection by foliar fungal diseases and attacks by foliar insects.     

Pressurized liquid extraction and HPLC quantification of folic Acid in fortified wheat flours

A pressurized liquid extraction (PLE) method using phosphate buffer as solvent was applied for folic acid (FA) extraction from fortified wheat flours and was compared to a standard solid-liquid extraction (SLE) method. Extracted FA was quantified by reverse phase high-performance liquid chromatography (RP-HPLC) hyphenated with a phenyl column and an absorption photometric detector (λ = 280 nm). Detection and quantification limits were 0.12 and 0.4 ng, respectively, corresponding to 0.06 and 0.2 μg g(-1) of analyzed wheat flour. Equivalent FA contents were found by both extraction methods, but a single PLE allowed a total recovery of FA content, whereas at least three successive SLEs were needed to achieve a total recovery of FA. The obtained results indicated that PLE is a rapid and efficient technique for FA extraction from fortified wheat flour.     

Exploration of beer proteome using OFFGEL prefractionation in combination with two-dimensional gel electrophoresis with narrow pH range gradients

Two-dimensional gel electrophoresis in combination with mass spectrometry has already been applied successfully to study beer proteome. Due to the abundance of protein Z in beer samples, prefractionation techniques might help to improve beer proteome coverage. Proteins from four lager beers of different origins were separated by two-dimensional electrophoresis (2-DE) followed by tandem mass spectrometric analysis. Initially 52 proteins mostly from Hordeum vulgare (22 proteins) and Saccharomyces species (25 proteins) were identified. Preparative isoelectric focusing by OFFGEL Fractionator was applied prior to 2-DE to improve its resolution power. As a result of this combined approach, a total of 70 beer proteins from Hordeum vulgare (30 proteins), from Saccharomyces species (31 proteins), and from other sources (9 proteins) were identified. Of these, 37 proteins have not been previously reported in beer samples.     

Influence of drying on the flavor quality of spearmint (Mentha spicata L.)

Spearmint (Mentha spicata L.) was dried using three different drying methods: oven-drying at 45 degrees C, air-drying at ambient temperature, and freeze-drying. The effect of the drying method on the volatile compounds and on the structural integrity and sensory characteristics of the spice was evaluated. The volatile components from fresh and dried spearmint samples were isolated by simultaneous distillation-extraction (SDE) and analyzed by gas chromatography-mass spectrometry (GC-MS). A total of 28 compounds were identified, carvone, limonene, and 1,8-cineole, in that order, being the main components in all of the samples. Oven-drying at 45 degrees C and air-drying at ambient temperature were the methods that produced the best results. An increase in monoterpenes was observed in all of the dried samples, except in the freeze-dried samples that underwent freezing at -198 degrees C. Freeze-drying resulted in substantial losses in oxygenated terpenes and sesquiterpenes. The effect of each drying method on leaf structure was observed by scanning electron microscopy. From a sensory standpoint, drying the spearmint brought about a decrease in herbaceous and floral notes together with an increase in minty odor.     

Optimization of benzoxazinones as natural herbicide models by lipophilicity enhancement

Benzoxazinones are plant allelochemicals well-known for their phytotoxic activity and for taking part in the defense strategies of Gramineae, Ranunculaceae, and Scrophulariceae plants. These properties, in addition to the recently optimized methodologies for their large-scale isolation and synthesis, have made some derivatives of natural products, 2,4-dihydroxy-(2H)-1,4-benzoxazin-3-(4H)-one (DIBOA) and its 7-methoxy analogue (DIMBOA), successful templates in the search for natural herbicide models. These new chemicals should be part of integrated methodologies for weed control. In ongoing research about the structure-activity relationships of benzoxazinones and the structural requirements for their phytotoxicity enhancement and after characterization of the optimal structural features, a new generation of chemicals with enhanced lipophilicity was developed. They were tested on selected standard target species and weeds in the search for the optimal aqueous solubility-lipophilicity rate for phytotoxicity. This physical parameter is known to be crucial in modern drug and agrochemical design strategies. The new compounds obtained in this way had interesting phytotoxicity profiles, empowering the phytotoxic effect of the starting benzoxazinone template in some cases. Quantitative structure-activity relationships were obtained by bioactivity-molecular parameters correlations. Because optimal lipophilicity values for phytotoxicity vary with the tested plant, these new derivatives constitute a more selective way to take advantage of benzoxazinone phytotoxic capabilities.     

Genetic resources in apple,pear and vineyard peach populations in former Yugoslavia

Summary During the period 1988–90, several germplasm collecting trips were made to all republics of former Yugoslavia. A total of 56 old apple cultivars, many of which are represented in up to 5 types, 38 old pear cultivars and 367 genotypes of vineyard peaches were collected. The availability of so much genetic and genotypic wealth made it possible to start apple disease resistance breeding and peach cultivar and rootstock breeding programmes.     

Effects of some benzoxazinoids on in vitro growth of Cephalosporium gramineum and other fungi pathogenic to cereals and on Cephalosporium stripe of winter wheat

The benzoxazolinones benzoxazolin-2(3H)-one (BOA) and 6-methoxybenzoxazolin-2(3H)-one (MBOA) and selected degradation products of these compounds were examined for their in vitro antifungal activity against Cephalosporium gramineum, Gaeumannomyces graminis var. graminis, and Fusarium culmorum. BOA was also applied to the soil-incorporated inoculum of C. gramineum to test its capability of reducing Cephalosporium stripe disease in winter wheat. MBOA reduced the mycelial growth of G. graminis var. tritici, C. gramineum, and F. culmorum by 50% (EC50) at the concentrations of 77, 134, and 271 microg/mL of corn meal agar, respectively, and the corresponding BOA EC50 values for the fungi were 11, 189, and 456 microg/mL. BOA degradation products 2-amino-3H-phenoxazin-3-one (APO), 2-acetylamino-3H-phenoxazin-3-one (AAPO), and o-aminophenol (o-AP) were much more inhibitory to the growth of C. gramineum and G. graminis var. tritici than the parent compounds. APO, AAPO, and o-AP EC50 values were found to be as low as 0.58, 4.57, and 1.4 microg/mL, respectively, for C. gramineum and 0.78, 2.18, and 0.80 microg/mL for G. graminis var. tritici. These compounds applied at the corresponding concentrations did not significantly affect the mycelial growth of F. culmorum. The treatment of C. gramineum inoculum with a 1% water solution of BOA resulted in a significant reduction infection of winter wheat with C. gramineum as compared to the control with the untreated inoculum,but this treatment was not as effective as the application of a commercial fungicide.     

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.