Winter wheat (Triticum aestivum L.) growth potential in the Slovak rural landscape

By the application of geographic information system (GIS) based on existing databases on soil characteristics, it is possible to quantify and assess categories of soil suitability important for crop cultivation. In this article we demonstrate such methods for winter wheat. The objective was to differentiate the Slovak rural landscape with respect to the possibility of effective winter wheat cultivation. The differentiation was based on soil climatic and production economic parameters. For soil categorization, correlation relationships between the site properties (soil and climatic conditions) and crop biological and agro-technical requirements were considered. The prediction was subsequently interpolated into four suitability categories: soils not suitable for wheat cultivation, less suitable soils, suitable soils, and very suitable soils. The database was developed and each area was added to it as well as the particular category of suitability for wheat cultivation. By using the GIS distribution in Slovakia, the maps of soil suitability categories for wheat cultivation were generated. In Slovakia, 29% of farmland was found to be very suitable for wheat cultivation, 25% suitable, 9% less suitable and 37% non-suitable by our calculations. These categories are characterized in detail and specified from the point of view of geographic, soil, climatic, production, economic and energetic parameters.     

Antisense expression of a caffeic acidO-methyltransferase ofStylosanthes humilis in transgenic poplar: Effect of expression onO-methyltransferase activity and lignin composition

Poplar (Populus tremula) was transformed with a construct carrying an antisense caffeic acidO-methyltransferase (COMT) cDNA (pOMT8) from a tropical pasture legume,Stylosanthes humilis. pOMT8 shows 83% overall homology to the corresponding COMT gene (pPCLA) of poplar. Of the 200 putatively-transformed plants regenerated on selective media after co-cultivation of poplar stem explants withAgrobacterium tumefaciens harbouring a CaMV 35S-antisensepOMT8 construct, a subset of 20 plants were randomly chosen for further analysis. PCR and Southern blot analysis demonstrated the stable integration of T-DNA into the genome of these plants. Antisense expression ofpOMT8 resulted in reductions in total COMT activity in the majority of the transgenic plants with the lowest total COMT activities (61–70% of untransformed control plants) being observed in four transgenic plants. The composition of lignin in transgenic plants was also changed, as detected by reductions in the content of syringyl units using infrared spectroscopy. However, no changes were found in the amount of insoluble lignin in transgenic plants as compared to untransformed control plants. These results indicate the potential of thepOMT8 gene to partially suppress COMT activity and modify the composition of lignin in transgenic poplar. This work was partly supported by General Management of Turkish Pulp and Paper Mills.     

A major gene for flowering time in almond

Almond (Prunus amygdalus Batsch) is the earliest temperate fruit species to bloom. This restricts the economic growing of almond to frost free regions. Most almond-breeding programmes aim to develop lateflowering cultivars in order to avoid frost damage and take advantage of higher temperatures which are favourable for pollination and fertilization. Flowering time is generally considered to be inherited quantitatively but a single gene conferring very late flowering in a qualitative way has been identified in several progenies tracing back to a single mutant, ‘Tardy Nonpareil’. The effect of this allele has been studied in three progenies, showing that the effect of this major gene is modified by minor genes, quantitatively inherited, and probably influenced by inbreeding.     

Effects of soil solarization on nematodes in Croatia

For the first time soil solarization was investigated in Croatia both in the field and in the greenhouse in 1991, 1992, 1993 and 1994. For two months (July and August), the soil was mulched with transparent polyethylene (PE) sheets of 0.015 or 0.050mm thickness. Soil temperatures at depths of 5, 10 and 20cm were recorded daily. In order to assess nematode population densities, soil samples were analysed before mulching and at the end of the mulching treatment. The results of these experiments showed that soil solarization drastically reduced the population of plant-parasitic nematodes (Meloidogyne, Pratylenchus, Paratylenchus, Tylenchus, Tylenchorhynchus spp.) by about 97–100% at a depth of 10cm and 92–97% at a depth of 20cm in the field, while in the greenhouse, the population of plant-parasitic nematodes was reduced by about 89–100% at a depth of 10cm and 98–100% at a depth of 20cm.In the same experiments, the population of saprophytic nematodes in the field was reduced by about 86–90% at a depth of 10cm and 72–89% at a depth of 20cm. In the greenhouse, the population of saprophytic nematodes was reduced by about 87–97% at a depth of 10cm and 87–93% at a depth of 20cm. This data shows that soil solarization was less effective in the control of saprophytic nematodes, which is considered to be an advantage.     

Usninsäure aus jugoslawischen Flechten und ihre antibiotische Wirksamkeit

Zusammenfassung Es wurde L-Usninsäure aus jugoslawischen Flechten in reiner Form isoliert. Der Schmelzpunkt der Substanz (zwei Proben) ist bei . Die Elementarmikroanalyse sowie die qualitativen Reaktionen entsprechen auch der reinen L-Usninsäure. Ein drittes isoliertes Präparat hatte den Schmp. bei 196° und . Das Präparat mit dem Schmp. 204° wurde auf seine bakteriostatische Wirksamkeit verwendet, und zwar in fein pulverisierter Form in einer Blut-Agar-Nährlösung suspendiert (Rinnenmethode), sowie mit der Routinemethode der Diskuse. Ein Lösungsvermittler für die sehr schwer in Wasser lösliche Usninsäure wurde nicht angewendet.Die Methode der Suspendierung in dem Nährmedium ist etwas empfindlicher, aber weniger praktisch. L-Usninsäure wirkt in vitro bakteriostatisch auf Mikroorganismen der Kugelform und zeigt so eine Ähnlichkeit mit Penicillin. Sie entwickelt eine Wirksamkeit gegenüber Streptokokken, Staphylokokken und Pneumokokken. Auf grampositive Bacillen zeigt sie in Suspensions-Konzentrationen von 0,25, 0,5 und 1,0% keine Wirksamkeit, was mit der sehr schweren Löslichkeit der Substanz in Wasser im Zusammenhang stehen wird.Die Wirkungsweise der Usninsäure steht am nächsten dem Penicillin, obwohl dieselbe schwächer ist als beim letzteren.Gegen Penicillin resistente Stämme zeigten sich als empfindlich auf Usninsäure.Die Versuche werden fortgesetzt.

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Summary L-usninic acid was isolated in pure form from lichens of Jugoslavia. The melting point of the substance (two samples) lies at . The elementary microanalysis and the qualitative reactions are in accordance with the pure L-usninic acid. A third isolated preparation showed the melting point 196° C, and . The preparation (melting point 204°) was tested on the bacteriostatic effet, specifically pulverized suspended in a blood-agar-culture solution (Rinnen-method) (channel-method), as well as with the routine method of the discuse. A medium to rise the solubility in water of the very little soluble usninic acid was not used.The method of suspending this acid in the culture solution is somewhat more sensitive, but less usefull. L-usninic acid has in vitro a bacteriostatic effect on spherical microorganisms in resemblance with penicilline. It is effective against streptococci, staphylococci and pneumococci. On Gram-positive bacillae the usninic acid has no effect in concentrations of 0,25 0,5 and 1,0 % of the suspensions, probably in consequence of its very small solubility.The effectiveness of the usninic acid is analogous to that of the penicilline, but weaker than the last-named. Stocks resistant against penicilline showed sensible against usninic acid.The researches will be continued.

     

Peroral Application of Water-soluble Derivative of Propolis (WSDP) and Its Related Polyphenolic Compounds and Their Influence on Immunological and Antitumour Activity

Polyphenolic compounds are widely distributed in the plant kingdom and display a variety of biological activities, including chemoprevention and growth inhibition of tumours. Propolis contains a conglomerate of polyphenolic compounds. We investigated the effect of propolis and polyphenolic compounds, components of propolis, on the growth and metastatic potential of a transplantable mammary carcinoma (MCa) of the mouse. Metastases in the lung were generated by 2 x 10 tumour cells injected intravenously (i.v.). A water-soluble derivative of propolis (WSDP) and the polyphenolic compounds (caffeic acid (CA) and caffeic acid phenethyl ester (CAPE)) were given to mice perorally before or after tumour cell inoculation. WSDP, CA and CAPE reduced the number of metastases in the lung. This implies that the antitumour activities of the compounds used in these studies are mostly related to the immunomodulatory properties of the compounds, their cytotoxicity to tumour cells, and their ability to induce apoptosis and/or necrosis.     

Effects of egg mass and percentage mass loss during incubation on hatchability of eggs of the rock partridge (Alectoris graeca)

1. The effects of initial egg mass (IEM) and percentage mass loss during incubation (%ML) on hatchability of rock partridge eggs were investigated. 2. Eggs at the extremes of IEM had lower fertility and embryonic mortality. 3. Eggs at the extremes of %ML also had low fertility and hatchability was disproportionately reduced in eggs that had lost less mass during incubation. 4. Chick mass was a function of both IEM and mass lost during incubation. 5. In these respects rock partridge eggs are similar to that of other domesticated species of poultry.     

Acute and Subacute Metabolic and Endocrine Effects of Clenbuterol in Female Pigs

The aim of the study was to assess the relationship between acute and subacute metabolic and endocrine effects after intravenous administration of the ₂-adrenergic agonist clenbuterol in a growth-promoting dose to female pigs. Acute metabolic and endocrine effects were assessed by measuring the blood glucose, serum insulin and nonesterified fatty acid (NEFA) concentrations during 300 min after a single administration of clenbuterol. Significantly higher serum insulin and NEFA concentrations (19.90±2.50 U/ml, p<0.01, and 0.69±0.04 mmol/L, p<0.001, respectively) were measured 30 min after the preprandial administration of clenbuterol in female pigs. Over the same period, the levels of blood glucose (4.42±0.30 mmol/L) showed no difference from those of control pigs. The postprandial serum NEFA concentration decreased moderately during 210 min after feeding. Postprandial blood glucose and insulin concentrations increased and reached maximal levels 120 min after clenbuterol administration (10.91±0.60 mmol/L and 85.22±7.24 U/ml, respectively), and returned to basal levels at 300 min (4.20±0.21 mmol/L and 7.75±1.60 U/ml, respectively) after the administration of clenbuterol. Subacute metabolic and endocrine effects were assessed by measuring the blood glucose, serum insulin and NEFA concentrations for 21 days after the repeated doses of clenbuterol. In addition, the influence of clenbuterol administration on the endocrine regulation of the onset of the next expected oestrus in female pigs was assessed by measuring their serum 17-oestradiol and progesterone concentrations. Blood glucose, serum insulin and NEFA concentrations after the last administration of clenbuterol did not differ significantly from those in control animals. The onset of the next expected oestrus occurred regularly without any significant difference in serum 17-oestradiol or progesterone concentrations between the treated (9.83±2.60 pg/ml and 0.15±0.03 ng/ml) and control pigs (8.52±2.70 pg/ml and 0.25±0.06 ng/ml). The study results suggest the duration of intravenous administration of clenbuterol in a growth-promoting dose necessary to influence the metabolic and endocrine activities in female pigs.     

Aeromonas hydrophila Isolated from Wild Freshwater Fish in Croatia

Aeromonas hydrophila was recovered from fish living in lake Vrana on the Croatian island of Cres. The occurrence of the bacterium in the fish was assessed and related to gross signs of disease and findings at necropsy as a potential health hazard for fish. Isolated bacteria were subjected to morphological, physiological, biochemical and antibiotic susceptibility tests. A total of 26 A. hydrophila isolates were obtained. There was a clear seasonality, as no isolates were recovered in the summer months. Most of the isolates were sensitive to all the antimicrobials used in the study except novobiocin and penicillin G. Affected fish manifested haemorrhages over the skin, in the liver, kidney and swim bladder, spleen infarcts, fatty liver, ascitic fluid and swollen haemopoietic tissues. A. hydrophila does not appear to pose a major threat for the fish in the lake at present but under unfavourable and stressful conditions it could seriously compromise fish health.     

Defence Responses Against TNV Infection Induced by Galactoglucomannan-derived Oligosaccharides in Cucumber Cells

Galactoglucomannan-derived oligosaccharides (GGMOs) showing biological activity in growth, morphogenesis and cell viability were tested in a host pathogen interaction. As a model system, cucumber (Cucumis sativus L. cv. Laura) reacting hypersensitively to tobacco necrosis virus (TNV) was used. The defence reactions were dependent on the degree of polymerisation and concentration of oligosaccharides, as well as on the time of application of virus to plant cotyledons. Disease symptoms were inhibited by 60–75%. The average number of lesions per cotyledon was significantly decreased when oligosaccharides were used simultaneously or 24h prior to virus inoculation. Significant changes in peroxidase, beta-glucanase and chitinase activities accompanied the defence reaction. It can be concluded that oligosaccharides derived from spruce galactoglucomannan induce non-specific resistance to local viral infection in plants. GGMOs probably act as inhibitors of the virus infection, rather than inhibitors of direct virus multiplication.