Effect of Growth Regulators and Ethanol on Termination of Dormancy in Potato Tubers

The main objective of this study was to find the best practice of inducing the sprouting of dormant potato tubers. We compared two protocols of breakage of dormancy, which are based on dipping excised potato eyes in an aqueous solution of gibberellic acid (GA₃) and kinetin (standard 1) or in the aqueous solution of GA₃, thiourea, and daminozide (standard 2), with a newly reported approach based on ethanol. We tested the effect of ethanol alone or in combination with GA₃ and/or kinetin on dormancy release and sprouting of the potato tubers. As a model, we used two potato genotypes (cultivars Pasat and Dorota), with long dormancy of 5 and 10 weeks respectively. We showed that the standard 2 was the most effective treatment both for dormancy breaking and in promoting sprout growth, especially for cv. Dorota, for which the treatment induced 82.3% of tuber eye-plugs to sprout 28 days after treatment and to produce 93.2% of emerged plants after subsequent 28 days of cultivation in the greenhouse. For this cultivar, similar efficacy was observed for the combination of 4% ethanol with GA₃ and kinetin. The same concentration of ethanol combined with GA₃ but without kinetin was the most efficient treatment for breaking dormancy of cultivar Pasat. However, the difference between the various treatment combinations was statistically insignificant. Ethanol alone or in combination with kinetin poorly induced breakage of dormancy, confirming the main role of GA₃ in artificial dormancy breaking. Thus our study showed that the standard 2 is the most effective approach for breakage of dormancy at least with long term-dormancy cultivars.     

Tulathromycin enhances humoral but not cellular immune response in pigs vaccinated against swine influenza

The effect of a standard, single dose therapy with tulathromycin was investigated on the postvaccinal humoral and cellular immune response in pigs vaccinated against swine influenza. Forty‐five pigs, divided into 3 groups, were used (control not vaccinated (C, n = 15), control vaccinated (CV, n = 15), and experimentally received tulathromycin (TUL, n = 15)). For vaccination of pigs, an inactivated, commercial vaccine was used. Pigs from TUL group received single dose of tulathromycin intramuscularly, at the recommended dose (2.5 mg/kg body weight). Pigs from TUL and CV groups were vaccinated at 8 and 10 weeks of age. The specific humoral and cellular immune response against swine influenza virus (SIV) was evaluated. The results of present study showed that humoral postvaccinal response after vaccination against SIV can be modulated by treatment with tulathromycin. In pigs from TUL group, the significantly higher titers of anti‐SIV‐specific antibodies were observed 4 and 6 weeks after booster dose of vaccine. Simultaneously, T‐cell‐mediated immune response against SIV was not affected by tulathromycin. Our recent study confirmed the importance of defining the modulatory activity of tulathromycin because of its influence on the immune response to vaccines. Since the antibodies against hemagglutinin are crucial for the protection against SIV, the present observations should prompt further studies on the practical significance of recent results in terms of clinical implications (postvaccinal protection) in the field conditions.     

Cover Image,Volume 75, Issue 3

The front cover image is based on the Research Article Does winter supplementary feeding affect deer damage in a forest ecosystem? A field test in areas with different levels of deer pressure by Zbigniew Borowski et al., DOI: 10.1002/ps.5131 . Image Credit: Karol Zub.

     

A novel extracellular peroxidase and nucleases from a milky sap of Chelidonium majus

Using affinity chromatography, SDS-PAGE, peroxidase activity assay and mass spectrometry data, a new extracellular peroxidase (CMP) from Chelidonium majus milky sap was isolated and characterized. The protein has a molecular weight of about 40 kDa and belongs to secretory class III plant peroxidases. The peroxidase activity is also accompanied by DN-ase activities. A novel CMP combined with other proteins is probably involved in development and differentiation of the plant and defence against different pathogens. It suggests that the biological activity of C. majus whole plants and extracts may depend not only on its alkaloidal content but also on the presence of biologically active proteins.     

Influence of selenium on oxidoreductive enzymes activity in soil and in plants

The aim of this greenhouse experiment was the assessment of the influence of H₂SeO₃ at soil concentrations of 0.05, 0.15 and 0.45 mmol kg⁻¹, on the activity of selected oxidoreductive enzymes in wheat (Triticum aestivum). The wheat plants were grown in 2 dm³ pots filled with dust-silt black soil of pH 7.7. Applied H₂SeO₃ caused activation of plant nitrate reductase at all concentrations, but activation of plant polyphenol oxidase at only two lower concentrations. The highest concentration caused inhibition of polyphenol oxidase and peroxidase. Plant catalase activity decreased under the influence of 0.15 and 0.45 mmol kg⁻¹ concentration. After the final analysis Se was quantified in plants and soil. The amounts in plants were: control (unamended soil) 1.95 mg kg⁻¹; I dose (0.05 mmol kg⁻¹) 18.27 mg kg⁻¹; II dose (0.15 mmol kg⁻¹) 33.20 mg kg⁻¹ and III dose (0.45 mmol kg⁻¹) 38.37 mg kg⁻¹, in soil: 0.265 mg kg⁻¹; 3.61 mg kg⁻¹; 10.53 mg kg⁻¹; 30.53 mg kg⁻¹; respectively. Simultaneously, a laboratory experiment was performed, where the activity of soil catalase and peroxidase were tested after 1, 3, 7, 14, 28, 56, and 112 days after Se treatment. Peroxidase activity in soil decreased with increasing Se content, over the whole experiment. The lowest dose of Se caused activation a significant 10% increase in catalase activity, but the influence of others doses was unclear.     

Improved method to obtain pure alpha-galactosides from lupin seeds

Improvement of a previously described method of purification of alpha-galactosides, members of the raffinose family of oligosaccharides (RFOs), has been developed for lupins. The considerable amount of sucrose present in the RFO preparations obtained by the previous method has been removed by modifying the purification stage on diatomaceous earth and charcoal. The present method allows for the preparation of high-purity RFOs containing approximately 99.4% of RFOs in the form of a white fine powder, which provides new perspectives for the production of pure alpha-galactoside preparations for their use as prebiotics in functional foods.     

Role of ghrelin in regulating rabbit ovarian function and the response to LH and IGF-I

The aim of these in vivo and in vitro studies was to examine the role of ghrelin in the control of plasma hormone concentrations, the proliferation, apoptosis and secretory activity of ovarian granulosa cells and the response of these cells to hormonal treatments. Female rabbits were injected with ghrelin (10 μg/animal/day for one week before ovulation induced by 25 IU PMSG and 0.25 IU LHRH). On the day of ovulation, blood samples were collected and analyzed for concentrations of progesterone (P₄), testosterone (T), estradiol (E₂), estrone-sulphate (ES), insulin-like growth factor I (IGF-I) and leptin (L) by RIA. Some control and ghrelin-treated animals were killed in the periovulatory period, their ovaries were weighed and granulosa cells were isolated and cultured for 2 d. Cell proliferation (expression of PCNA) and apoptosis (expression of TdT) were evaluated by immunocytochemistry and TUNEL respectively. Secretion of P₄, T, E₂, IGF-I, and prostaglandin F (PGF) by granulosa cells cultured with and without LH or IGF-I (1, 10 or 100 ng/ml medium) was assessed by RIA. The remaining control and treated animals were kept until parturition, while the number, viability and body weight of pups were recorded.     

Speciation of Cadmium in the Bottom Sediment of Rybnik Reservoir

Forms of cadmium occurrence in the bottom sediment of a heated water reservoir, polluted substantially with this metal was analysed in the paper. Apart from the analysis mentioned above, a total cadmium content in the bottom sediment and a content of cadmium dissolved in the water of the reservoir was also determined. Dependences between particular forms of cadmium occurrence and its total content in the bottom sediment were analysed. An influence of cadmium content in water on the level of particular cadmium forms in the bottom sediment and an influence of other parameters of the reservoir's water on the content of cadmium in the bottom sediment were also examined.     

Mercury content and its bioconcentration factors in wild mushrooms at Łukta and Morag,northeastern Poland

Total concentrations of mercury were determined using cold-vapor atomic absorption spectroscopy (CV-AAS) in the fruiting bodies of 16 species of wild mushrooms and underlying soil (0-10 cm) substrates collected in the areas of the Communes of Morag and ?ukta in the county of Ostróda in northeastern Poland in 1997-1998. A total of 174 composite samples of caps, 174 stalks, 80 whole fruiting bodies (collectively 1254 specimens), and 252 soils were examined. Among several species of mushrooms analyzed, the greatest concentrations were between 1300 and 71000 ng.g(-1) of dry matter. These levels were found in the caps of Sweating mushroom (Clitocybe rivulosa), King Bolete (Boletus edulis), and Common Puffball (Lycoperdon perlatum) and also were characterized by the highest bioconcentration factors (BCF) for Hg, which ranged between 160 +/- 82 and 110 +/- 34. The cap to stalk quotient for mercury concentrations was approximately 2 for most of the species except Poison Pax (Paxilus involutus), which had a greater concentration in caps than in stalks and a quotient of 4.4 +/- 7.2. Hg concentrations in the underlying soil substrates (0-10 cm layer) ranged between 21 +/- 21 and 390 +/- 130 ng.g(-1) of dry matter. The results showed that the consumption of mushrooms, considered to be the sole dietary source of mercury at the highest or mean element concentrations found, is not hazardous at daily ingestion rates of less than 70 and 210 g of fresh product, which would result in a hazard index value of less than unity.     

Influence of a shrub corridor on movements of passerine birds to a lake littoral zone

A pine forest was separated from a lake littoral zone by a meadow on one area (discontinuous) while these habitats were separated by a shrub strip in another area (continuous). This shrub strip acted as an ecological corridor enhancing the movements of birds between the forest and the littoral reed zone. The number of individuals of non-littoral species that visited the reed zone was higher (p < .001) on the area with the connecting shrub strip in autumn but the number of species visiting the littoral zone was not significantly higher. Significantly more (p < .001) autumn movements by birds in the continuous area were oriented along paths between the forest and the littoral zone whereas movements in the discontinuous area paralleled the littoral and forest zones (p < .001). Movements of birds were concentrated along the edge of the shrub strip. The spatial configuration of the landscape facilitated access by some forest birds to the littoral habitat.