Authors:V. Kovács, G. Vida, G. Szalai, T. Janda, and M. Pál
Large numbers of wheat genotypes were grown under field conditions and screened for biotic stress tolerance and certain protective compounds. It was found that both the salicylic acid and polyamine contents of the investigated genotypes varied over a wide range, while the antioxidant enzyme activities showed a similar pattern in the different genotypes. In order to investigate stress-induced changes in salicylic acid and polyamine contents, samples were collected from plants artificially inoculated with leaf rust (Puccinia triticina), on which natural powdery mildew [Blumeria graminis (DC.) Speer f. sp. tritici Em. Marchal] infection also appeared. Biotic stress mostly resulted in elevated levels of total salicylic acid and polyamines in all the genotypes. The activities of various antioxidant enzymes showed similar changes after infection regardless of the genotype. The investigation was aimed at detecting a relationship between the level of stress tolerance and the contents of protective compounds, in particular salicylic acid and polyamines.
Authors:B. Kovács, J. Horváth, O. Pálmai, T. Németh, and Z. Győri
Agricultural goods obtained and produced in Hungary have played an important role in the markets of Western Europe. By utilizing the ecological potentials of the Carpathian Basin, local inhabitants are in the position to produce considerable food surpluses in addition to meeting their own demands. With agricultural production becoming more and more intensive in Hungary, the application of mineral fertilizers also started to increase slowly from the 1960’s. From the mid-1970’s a uniform sampling, soil testing and fertilization extension system was created together with its own institutional and laboratory testing network. The intensive use of mineral fertilizers in Hungary lasted from the mid-1970’s to the last quarter of the 1980’s, during which an average amount of 230 kg·ha
NPK fertilizer was applied. In this period the so-called “build-up” fertilization was applied in conformity with the improvement of all other elements involved in the production technology, which was also clearly expressed in the agro-political objectives of those days aiming to obtain higher yields. At that time the nutrient supply and nutrient base of soils in Hungary increased clearly, so the production technology could no longer limit higher yields. In 1990 agriculture changed fundamentally and radically in Hungary, and the same was valid for nutrient supplies as well. At the beginning of the 1990’s there was a sudden decrease in the level of mineral fertilizer application (to below 40 kg NPK active ingredients·ha
), followed by a slow increase, which has reached the level of almost 70 kg·ha
by today. In the meantime the animal stock in Hungary has decreased and consequently the amount of manure has also fallen. All in all, the nutrient balance of Hungarian soils has always been negative since 1989. Due to the changes in its structure and ownership over the past twenty years or so, it has become very difficult to obtain reliable information about Hungarian agriculture. The Soil Resources Management General Partnership (in Hungarian: Talajerőgazdálkodás Kkt.) conducts extension work based on soil sampling and has a continuous flow of data on over thirty thousand hectares, beginning at the end of the 1970’s. Based on the analyses of these data it can be stated that the extra amount of nutrients over balance, applied during the period of replenishment (until the change in regimes) has been „removed” from the soil over the past fifteen years, consequently the Hungarian nutrient balance has become negative again. This kind of fertilization practice cannot be sustained in Hungary, as the maintenance of the production potential of Hungarian soils is far from being resolved at the moment; it poses risks to and questions sustainability, as well as it may cause a very serious competitive disadvantage to the country.
Authors:K. Mészáros Szécsényi, T. Wadsten, A. Kovács, and G. Liptay
Manganese(II) chloride complexes with 3,4- and 3,5-lutidine have been prepared. The crystal symmetry and cell dimensions have
been calculated on the basis of powder diffraction data. The compounds were characterised also by FT-IR spectrometry. The
thermal decomposition of the complexes has been studied by thermogravimetry and DSC. By plotting densities vs. molar mass,
the diagram obtained has correspondence to similar observations in other solid metal-lutidine complex systems.
Authors:A. Matkó, E. Szűcs, T. Takács, and S. Kovács
Today, companies have to face new challanges because of the globalization, new technologies, globalization of markets and increasing competition. In this accelerated world, it is essential that the companies adapt to the market, which is only available through the necessary information. The importance of market research is undoubted. In our study we would like to prove that in case of a beginner company — in this case a confectionery — it is important to perform a market research like for a company in any other segment. To perform it, the qualitative market research methods were used. Our questionnaire examines several aspects in order to provide an indication of the company’s founding.
Authors:T. Kaszab, Z. Kovács, D. Szöllősi, and A. Fekete
The objective of the work reported was to predict some sensory attributes of carrots stored under non-ideal conditions from the data obtained on taste measured by electronic tongue and on the physical properties (acoustic stiffness, cutting force, deformation work ratio and luminosity). There was a close correlation between the mechanical characteristics and the non-ideal storage time. Sensory evaluation showed significant ranking in “bite and chewing”, “sweet taste” and “global impression” attributes according to the Page test. Principal component analysis (PCA) plots were determined for the acoustic stiffness coefficient, cutting force and deformation work ratio and these showed that PC1 followed a tendency similar to that of the storage time. PCA plots were determined for the electronic tongue measurements and this PCA separated the sample groups along PC1 and PC2. We used partial least square (PLS) regression to predict “bite and chewing” from the acoustic stiffness coefficient, cutting force, and deformation work ratio with an acceptable correlation. The “sweet taste” was predicted from the electronic tongue measurement results with good correlation. The “global impression” was predicted by the acoustic stiffness coefficient, cutting force and deformation work ratio, and by the electronic tongue measurement results with close correlation.
Authors:Míra Mándoki, M. Dobos-Kovács, T. Bakonyi, and M. Rusvai
Kidney samples from chickens diagnosed with acute nephritis and gout were subjected to histological and electron microscopic examination. The investigations revealed cytoplasmic inclusion bodies in the tubular epithelial cells containing round virions of about 30 nm in diameter. Since avian nephritis virus (ANV) is known as a potential causative agent of the so-called baby chick nephropathy, an RT-PCR assay was developed for the molecular detection of ANV-specific nucleic acid in the specimen. The specificity of the assay was confirmed by direct sequencing of the amplicon obtained in the reaction. The nucleotide sequence of the PCR product showed 92% identity with the reference ANV sequence deposited in the GenBank database. After having been validated on some other suspicious cases of avian nephritis, the PCR method described in this study can be a potential tool for routine diagnostic examination of samples submitted from cases of gout and nephropathy in chickens.
Authors:T. Szili-Kovács, G. Máthé-Gáspár, P. Máthé, and A. Anton
of the chloroform fumigation extraction method was tested for detecting soil
microbial biomass and p-nitrophenyl phosphate (pNP) for acid phosphatase
activity to study their response to heavy metal pollution in the rhizosphere
soil of planted willow
The experimental site was located in the Toka River Valley (North-East
Hungary) along the riverbank that had been severely polluted by flooding. The
river had transported heavy metal and arsenic ions from several heaps deposited
imprudently near a historic lead and zinc mining site. A phytoremediation
experiment was set up by planting willow trees with the aim of extracting toxic
elements from the soil. A strong significant difference between the control and
the metal-contaminated rhizosphere soils resulted much lower microbial biomass
values in the polluted soils, which suggests disturbance in the organic matter
transformation dynamics. A significant increase in acid phosphomonoesterase
activity was determined in the soil due to the pollution. The phosphatase
enzyme production of living organisms may be stimulated by the measured higher
moisture content and significantly lower LE-soluble phosphorus content of the
polluted soil samples. The correlation established between soil water content
and phosphatase activity was positive (r = +0.85), while that between LE-P
content and phosphatase activity was negative (r = -0.69). The most important
stimulating effect was attributable to the lower available phosphorus content,
resulting from the heavy metal (Pb, Zn) content of polluted soil.
Both measured biological parameters therefore were
suitable for indicating soil pollution, but the change was adverse, the biomass
decreased, while phosphatase activity increased. Microbial biomass and phosphatase
activity were not correlated, indicating the different account
of ecological factors that alter the biological properties of a soil.
Isoperla nagyi sp. n. is described on the basis of morphology of male and female adults and eggs. The new species is classified as an isolated species within the West Palaearctic Isoperla. It was found in the lower elevations of the Ţarcu Mts that is forming a high range of the westernmost Southern Carpathians. Further contributions are given on the stonefly fauna of the Ţarcu Mts, including notes on the Romanian distribution of Brachyptera bulgarica Raušer, and the taxonomy and distribution of Isoperla pusilla (Klapálek).
Authors:T. Kovács, Z. Bihari, A. Hargitai, I. Mécs, and K. L. Kovács
The changes of cell surface hydrophilicity in Bacillus subtilis were analyzed in response to oxygen-limitation, heat shock, salt stress, pH-shock, phosphate- and carbon-limitation. Although cell surface hydrophilicity varied during growth phases, an increase of surface hydrophilicity was observed under several of these stress conditions. An observed drop in intracellular GTP and/or ATP may be an element of the signal transduction pathway leading to an increase in surface hydrophilicity in response to environmental stresses. Attachment of cells to soil particles under salt stress conditions is strongly influenced by the degS/degU two-component system, which thereby provides a mechanism for the bacteria to escape from the hostile environment.
Authors:E. Lellei-Kovács, E. Kovács-Láng, T. Kalapos, Z. Botta-Dukát, S. Barabás, and C. Beier
The influence of simulated climate change on soil respiration was studied in a field experiment on 4 m × 5 m plots in the semiarid temperate Pannonian sand forest-steppe. This ecosystem type has low productivity and soil organic matter content, and covers large areas, yet data on soil carbon fluxes are still limited. Soil respiration rate — measured monthly between April and November from 2003 to 2006 — remained very low (0.09 — 1.53 μmol CO
) in accordance with the moderate biological activity and low humus content of the nutrient poor, coarse sandy soil. Specific soil respiration rate (calculated for unit soil organic matter content), however, was relatively high (0.36–7.92 μmol CO
) suggesting substrate limitation for soil biological activity. During the day, soil respiration rate was significantly lower at dawn than at midday, while seasonally clear temperature limitation in winter and water limitation in summer were detected. Between years, annual precipitation appeared to be important in determining soil carbon efflux intensity. Nocturnal warming increased soil temperature in 1 cm depth at dawn by 1.6°C on the average, and decreased topsoil (0–11 cm) moisture content by 0.45 vol%. Drought treatment decreased soil moisture content by an average of 0.81 vol%. Soil respiration rate tended to decrease by 7–15% and 13–15% in response to heat and drought treatment, respectively, although the changes were not statistically significant. Nocturnal warming usually prevented dew formation, and that probably also influenced soil respiration. Based on these results, we expect a reduction in the volume and rate of organic matter turnover in this ecosystem in response to the anticipated climate change in the region.