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Results 841 to 870 of 1498:

Mapping of QTLs involved in resistence to rice blast (Magnaporthe grisea) using Oryza minuta introgression linesOriginal Paper

Lutfor Rahman, Sakina Khanam, Jae-Hwan Roh, Hee-Jong Koh

Czech J. Genet. Plant Breed., 2011, 47(3):85-94 | DOI: 10.17221/19/2011-CJGPB

Introgression lines derived from Oryza minuta and O. sativa subsp. japonica var. Junambyeo were crossed for a mapping of the population composed of 112 recombinant lines to identify putative QTLs against rice blast disease using the percentage of diseased leaf area. By using 148 Sequence Tagged Site (STS) and Single Sequence Repeat (SSR) markers, five QTLs on chromosomes 6, 7, 9 and 11 and seven epistatic QTLs were identified against two blast isolates (KI307 and KI209). Of them two QTLs (qKI307-2 and qKI209-3) shared a similar position on chromosome 11. O. minuta introgression contributed the resistance allele for all of these QTLs. Combined phenotypic variations by QTL and (E-QTL) accounted for 56.9% against KI307, and 53.4% against KI209. Each QTL could account for the resistance variation between 11 and 24.6%. The resistance from wild introgressions was attributable to a combination of QTLs and epistatic effects between different loci, capable of inducing hypersensitive reactions. Our findings are in support of the strategy of pyramiding major QTLs to develop improved rice varieties with durable broad spectrum resistance against the blast fungus.

Laying pattern parameters in broiler breeder hens and intrasequence changes in egg composition

M. Gumulka, E. Kapkowska, D. Maj

Czech J. Anim. Sci., 2010, 55(10):428-435 | DOI: 10.17221/1698-CJAS

The aim of the study was to analyze the pattern of oviposition time in laying sequences in broiler breeder hens and to determine a relationship between egg position in the sequence and egg quality. The sequences were described using mean oviposition time (hour) within a sequence, mean lag of oviposition time between successive ovipositions, and mean and cumulative lag of oviposition for a sequence. Egg weight, percentage of egg components and shape index were determined for successive eggs in a sequence. The 2-, 3-, 4-, 5- to 6- and 7- to 9-egg sequences were considered. The light/dark regime was 16 h/8 h (05:00 a.m. to 09:00 p.m.). Hens laid the first egg in a sequence about 3.5 h after the beginning of the photoperiod. With increasing sequence length, the first egg was laid sooner after the beginning of the photoperiod and the intervals between successive ovipositions shortened. This suggests that when planning the frequency of egg collection in a flock of broiler breeder hens, one should account for changes in the egg sequence length during the production period. No significant relationship between egg position in the sequence and quality of egg components was observed.

Estimation of the baking quality of wheat flours based on rheological parameters of the mixolab curve

Iuliana Banu, Georgeta Stoenescu, Violeta Ionescu, Iuliana Aprodu

Czech J. Food Sci., 2011, 29(1):35-44 | DOI: 10.17221/40/2009-CJFS

The Mixolab device in view of the characterisation of the thermo-mechanical behaviour of ten different flours, and establishing the correlations between the rheological parameters of wheat flour supplemented with different additives such as fungal α-amylase, fungal hemicellulase, and fungal xylanase weres exploted. The rheological measurements were performed using the Mixolab, Alveograph, and Rheofermentometer. Our results indicated significant positive and negative correlations between the parameters investigated. The changes of the Mixolab curve trend depended on the amylase doses. Significant correlations were established also between the Mixolab parameters and the results of the baking tests; the β slope, C2, C3, and C4 were positively correlated with the specific volume of the bread. Taking into account the results obtained, we may conclude that Mixolab is a complex device that renders the evolution of the bread during the entire technological process, from the dough making to the starch retrogradation.

The effect of time of cutting on yield and the quality of the hop hybrid varieties Harmonie, Rubín and Agnus

K. Krofta, J. Ježek

Plant Soil Environ., 2010, 56(12):564-569 | DOI: 10.17221/187/2010-PSE

The influence of mechanized cutting time on the yield and quality of hops was studied for three years (2007, 2008 and 2009) in three Czech hybrid varieties Harmonie, Rubín and Agnus. The cutting term classified as 'early' was carried out at the turn of March and April. Further cutting dates were made at intervals of 7-10 days and they were classified as 'middle' and 'late' ones. Yield and contents of alpha acids were evaluated during the machine harvest. The measured data revealed no statistical relationship between term of cutting, alpha acid content and yield in any of the tested cultivars. However, during the experimental period considerable inter-annual differences were observed, especially in the yield. Average yield in the range of 2.0-2.5 t/ha in the period 2007-2008 decreased to 1.2-1.9 t/ha in 2009 due to downy mildew attack. On the basis of the obtained data it can be recommended to cut the hybrid varieties Harmonie, Rubín and Agnus in the first ten days of April, taking into account other factors such as age and the location of hop garden and current weather conditions.

The use of indirect methods for the prediction of lucerne quality in the first cut under the conditions of Central Europe

J. Hakl, J. Šantrůček, P. Fuksa, L. Krajíc

Czech J. Anim. Sci., 2010, 55(6):258-265 | DOI: 10.17221/86/2009-CJAS

The goal of this study was to compare the growing degree-days (GDD) and predictive equations for alfalfa quality (PEAQ) for the prediction of lucerne quality and to test their accuracy and suitability in the first cut period in Central Bohemia. Several additional stand parameters were verified in order to increase the accuracy of the quality estimate under these environmental conditions. In 2004-2007, the measurement and sampling were repeatedly realized from the late vegetative to the early bloom stage in six replications. For the GDD model across the years, the obtained R2 for NDF, ADF and CP were 0.40, 0.57 and 0.65, respectively. It seems that the forage quality response to accumulated GDD was related to the stand development and it could be the reason for low R2 across all the years. For the PEAQ model, R2 were 0.62, 0.92, and 0.85, respectively. Similarly like in the GDD model, the effect of stand development across the years on changes in the slopes of equations was observed. The accuracy of the model combination was not higher in comparison with the PEAQ model. The count of stems per plant, density of stems per m2, dry matter yield and average stem weight improved the NDF content prediction within a four-year period. In these models, variables which represent the stand development should be taken into account.

Comparison of the results of the ELISA, histochemical, and immunohistochemical detection of soya proteins in meat products

Matej Pospiech, Bohuslava Tremlová, Eva Renčová, Zdeňka Randulová, Zuzana Řezáčová Lukášková, Jana Pokorná

Czech J. Food Sci., 2011, 29(5):471-479 | DOI: 10.17221/209/2010-CJFS

This work compares the commonly used immunochemical methods for soya protein detection and alternative microscopic methods. Immunochemical methods were represented by the competitive ELISA method. Histochemical and immunohistochemical methods were used for microscopical examination. From a group of 252 meat products, each sample was examined for soya proteins by ELISA, histochemical, and immunohistochemical methods. The products came from the following categories: cooked sausages, ham, dry cooked sausages, and fermented sausages. The results showed that the highest accuracy was achieved by immunohistochemical examination. However, in the category of cooked sausages, this result was not statistically significant. Since the results in the individual categories differed, our results demonstrate that one single method does not always provide reliable and completely objective results. Immunohistochemical methods seem to be the most suitable for the verification of the reference immunochemical method results and prevention of false results.

Potential for pork production in the Czech Republic

Michal MALÝ, Zdeňka KROUPOVÁ, Dana ŽÍDKOVÁ, Jarmila PETEROVÁ, Lenka ŠOBROVÁ, Lukáš ČECHURA, Ludmila PÁNKOVÁ, Jiří MACH, Zuzana KŘÍSTKOVÁ, Tomáš MAIER, Jan HUČKO

Agric. Econ. - Czech, 2011, 57(11):545-554 | DOI: 10.17221/58/2010-AGRICECON

The main aim of the paper was a partial analysis of the production potential for pig fattening in the Czech Republic. This aim was achieved by econometric modelling of the production function, which was specified as a Cobb-Douglas function, with the level of average daily increase as the dependent variable, and feed compounds, mortality and weight of new stock as independent variables. The model was specified as a fixed effect model, and the parameters of the function were estimated by the method of least squares dummy variable, based on the ordinary least squares method. Verification of the estimated model was based on a t-test, coefficient of determination, Wald test, autoregressive test, and test of normality distribution of residuals. Subsequently, the estimated function was analysed and significant determinants of production were identified. The behaviour of the production functions was analysed for the average and marginal productions. The functions were also illustrated in graphs of production surfaces, from which the maps of isoproduction functions were derived. The isoproduction functions were used for the final analysis of the potential for pork production. The analysis was based on panel data from 32 farms focused on pig fattening, collected by our own survey. The research indicated significant differences between the surveyed farms. It also declared the most important factor of final production to be, with 99% probability, the new stock weight. The second most important determinant of final production is the feed compound A3, which is used in the final stage of fattening. For maximized production, the farmer should focus on the weight of pigs coming into fattening, choose the biggest one, and introduce the use of the feed compound A3. The results in the submitted paper should also be used by farmers to evaluate their production activity, and to compare their actual output with the theoretical value enumerated by the production function.

Use of the mobile nylon bag technique for determination of apparent ileal digestibilities of crude protein and amino acids in feedstuffs for pigs

T. Steiner, U. Bornholdt, W.C. Sauer, F. Ahrens, H. Jørgensen, R. Mosenthin

Czech J. Anim. Sci., 2011, 56(10):451-464 | DOI: 10.17221/3238-CJAS

Three digestibility experiments were conducted to evaluate the potential of determination of apparent ileal digestibilities (AID) of crude protein (CP) and amino acids (AA) by the mobile nylon bag technique (MNBT) using 21 feedstuffs and three mixed diets. In two conventional digestibility experiments (Exp. 1 and 2), AID were determined using in total 10 barrows (BW 35 kg) fitted with simple T-cannulas at the terminal ileum. For the MNBT studies, four pigs were fitted with a simple T-cannula at the proximal duodenum and a Post-Valve T-Caecum (PVTC) cannula at the terminal ileum. The MNBT studies included the feedstuffs (n = 10) from Exp. 1 and 2 as well as 14 further feedstuffs and mixed diets in which AID coefficients had been determined in previous trials. For each feedstuff 60 nylon bags were used. In vitro digestion of the bags was carried out in pepsin-HCl solution with 450 IU pepsin/l at pH 2.0 and 37°C for 4 h. In the 28-day in vivo experiment, 15 nylon bags per pig and day were inserted through the duodenal cannula and collected through the PVTC cannula after passage through the small intestine. Coefficients of AID were calculated based on the disappearance of CP and AA from the nylon bags during the in vitro and in vivo phase. In comparison with AID determined by the conventional method, AID of CP was on average 2.4% lower, whereas AID of lysine was on average 8.5% higher when determined by the MNBT. There was no significant (P > 0.05) correlation between AID coefficients of CP and AA determined by the conventional method and the MNBT, when all feedstuffs were taken into account. However, in cereals (n = 11), the correlation between AID coefficients determined by both methods was significant (P < 0.05) for CP (r = 0.61) and some AA (r ranging between 0.62 and 0.72). In conclusion, the potential of the MNBT to determine AID of CP and AA is rather limited. Differences in coefficients of AID of CP and AA were attributed to several factors such as diffusion of sample particles or endogenous protein through the nylon bags as well as to the presence of anti-nutritional factors (e.g. in legume seeds and oilseed meals).

Actual evapotranspiration from partially tile-drained fields as influenced by soil properties, terrain and cropOriginal Paper

Renata DUFFKOVÁ, Antonín ZAJÍČEK, Eva NOVÁKOVÁ

Soil & Water Res., 2011, 6(3):131-146 | DOI: 10.17221/20/2010-SWR

Physical properties of soils have a significant influence on their water regime and should be considered when selecting suitable agricultural crops for particular sites, taking into account the crop productivity and its water requirements. Mean daily rates of actual evapotranspiration (ETa) were obtained by collation of measured or otherwise estimated 10-min values for the years 2004, 2006 and 2009 for a partially tile-drained agricultural experimental catchment in the Bohemo-Moravian Highland (Czech Republic). ETa was measured using the Bowen ratio (β) and energy balance (BREB) method at four weather stations located on different soil types (Stagnosols, Cambisols) and terrain relief positions (defined with respect to the groundwater recharge and discharge zones) over different crops (cereals, oil rape and permanent grassland). A systematic influence of soil properties on the evapotranspiration rate was more pronounced during the periods of limited transpiration (soil drought, crop maturity), when the average daily ETa was significantly lower and the corresponding β significantly higher over coarser-textured soils (shallow Haplic Cambisols), namely (year-ETa (mm/day)/β): 2004 - 1.75/1.66; 2006 - 2.44/0.93; 2009 - 2.60/0.81), than over finer-textured soils (Stagnic Cambisols and Haplic Stagnosols), namely: 2004 - 2.92/0.97; 2006 - 3.06/0.44; 2009 - 3.42/0.39). When the transpiration was not limited by soil water deficit, it acted as an equalizing factor smoothing down evapotranspiration from heterogeneous soil areas, whereby the effect of the soil physical properties was masked. With regard to soil water regime and evapotranspiration, the tile-drained Stagnic Cambisol lands behaved similarly as non-drained Haplic Cambisols. The effects of land use and of the terrain relief position could not be tracked independently, because the permanent grassland was situated in the wetter and texturally heavier parts of the catchment and the positions of the recharge/discharge zone coincided with the positions of texturally lighter/heavier soils, respectively.

To the issue of economic efficiency of public projects in agriculture

Edita ŠILEROVÁ, Lucie SEVEROVÁ, Stanislav BENDL

Agric. Econ. - Czech, 2011, 57(5):232-239 | DOI: 10.17221/133/2010-AGRICECON

It is the task of the economists to assess - under the conditions of the public budgets restrictions - whether the return rate of investments into public projects is sufficient enough in order to justify these projects in comparison to an alternative utilization of the expended resources. Complex e-learning systems, which include both the educational part and the subsequent verification of the students' knowledge, have lately been gaining on popularity in agriculture, in the public ICT projects from the field of education. The objective of the article is to explain the means of expressing economic efficiency of public projects on the example of establishing the Moodle e-learning system.

Evaluation of economic efficiency of orchards investment project with respect to the risk

Zlata SOJKOVÁ, Izabela ADAMIČKOVÁ

Agric. Econ. - Czech, 2011, 57(12):600-608 | DOI: 10.17221/104/2011-AGRICECON

Continuous elimination of the acreage of orchards in Slovakia has a negative impact on the overall fruit production. Improvement of the conditions could be achieved by introducing new technological systems into orchards and supporting the measures motivating farmers. Three investment strategies for planting apple orchards are presented in the paper: slim spindle, high density and extended orchards. Economic efficiency of the systems is evaluated through the return of investment, net current value and inner profit percentage. Within the assumption of the objective evaluation of input parameters, we can expect an acceptable economic efficiency of the investment only in the "slim spindle" technological system. The simplified deterministic evaluation of economic efficiency is further deepened with the identification of the relevant risk factors, followed by its quantification by the simulation processes. Taking the risk into account leads to a significant decrease of the economic attractiveness of investments.

The arsenic speciation transformation in artificially arsenic-contaminated fluvo-aquic soil (Beijing, China)

X. Zeng, Q. He, L. Bai, L. Li, S. Su

Plant Soil Environ., 2011, 57(3):108-114 | DOI: 10.17221/198/2010-PSE

Arsenic (As) speciation transformation often accompanies adsorption-desorption when exogenous arsenide is poured into soil. Disregarding the speciation transformation when evaluating adsorption-desorption of As can greatly influence the experimental results. In this study, batch experiments were conducted, and the results indicated that exogenous monomethylarsonic acid (MMA) or dimethylarsinic acid (DMA) added to fluvo-aquic soil collected from agricultural area in Beijing of China, was completely converted into As(V) after cultivated for60 or 90 days. However, when exogenous As(V) was added to the soil, no speciation transformation of As(V) was observed. Furthermore, although the total As concentration, which was 6.55 or 11.55 mg/kg in aqueous extracts of the soil to which MMA or DMA had been added, respectively, remained stable after cultivated for 30 or 60 days, the As speciation transformation of MMA or DMA into As(V) in soil still occurred. Differences in As speciation can result in different fates and behaviors of As in soil, and As speciation transformation should be taken into account when evaluating the adsorption-desorption of As.

Structural homology and expression tendency of the natural immune response of the terminal complement components to inoculations in pigs: a reviewReview

D.V.A. Khoa

Vet Med - Czech, 2013, 58(1):1-9 | DOI: 10.17221/6650-VETMED

The transmission of infectious agents from domestic animals to humans is a matter of particular concern at present. Inoculation can enhance the defences of each individual animal but only in the short term. Certainly, it will be of immense benefit if biotechnology and genetic techniques are applied to farm animal breeding and selection programs to improve productivity, performance and health status as well as for the construction of sustainable animal production systems and promotion of animal welfare. In recent years, efforts to drive candidate genes like cytokines, haptoglobin, complement system, C-reactive protein, a 2-macroglobulin, retinol binding protein, transcortin, and etc. associated with immune traits have successfully been studied in human and different animal species. Here, we compared the molecular structure and evaluated the expression tendency of the haemolytic complement activity (HCA) of porcine candidate genes encoding the terminal complement components (TCC) C6-9. The results suggested that (1) high homology of complement genes among mammalian species may open new ways in cure/ treatment of disease; (2) Muong Khuong animals (Vietnamese potbelly pig) have a great genetic potential to improve the health status of pigs; and (3) HCA in the classical pathway can be developed further by different activation modes, with the potential improvement of animal health.

Short overview of food consumption databasesReview

Viktória SZŰCS, Erzsébet SZABÓ, Diána BÁNÁTI

Czech J. Food Sci., 2013, 31(6):541-546 | DOI: 10.17221/160/2013-CJFS

The utilisation of food consumption databases is widespread and involves for example, the risk assessment, understanding of consumers' food consumption trends, health education, and planning of prevention projects. Harmonisation of national consumption data for international comparison is an important and challenging work. First attempts started in the 70's and have been continuing up to now. The present study gives an overview of the collection methods, types and utilisation of food consumption data, as well of the most important phases of the international harmonisation work. As this study shows, it is crucial to harmonise the surveys parameters like the time of the data collection, method, number of participants, and number of the analysed days for an internationally comparable consumption database. From this point of view, the efforts of the EU menu project are promising.

List of field crop varieties registered in the Czech Republic in 2012New Varieties

R. Šafaříková

Czech J. Genet. Plant Breed., 2013, 49(1):48-49 | DOI: 10.17221/19/2013-CJGPB

Determination of silicon in Czech beer and its balance during the brewing processOriginal Paper

Rudolf Cejnar, Oto Mestek, Pavel Dostálek

Czech J. Food Sci., 2013, 31(2):166-171 | DOI: 10.17221/65/2012-CJFS

Inductively coupled plasma mass spectrometry was used for the determination of silicon in beer samples from the Czech market and in brewing raw materials and semiproducts. The content of silicon in barley malt depended on the barley variety and growing region. The goal was to establish silicon concentration in Czech beer and to find out which processes are the most significant in terms of silicon concentration in beer. The silicon concentration in Czech beer ranged from 16 mg/l to 113 mg/l depending especially on two factors. Firstly, the silicon content in beer increased as the original wort concentration and increased secondly, during decoction mashing, silicon from malt was leached to a much greater extent than in the case of infusion mashing.

Fertility enhancing effects of methanolic leaf extract of Dracaena arborea in albino rats (Rattus norvegicus)Original Paper

S.O. Ekere, C.N. Okoye, A.F. Udoumoh

Czech J. Anim. Sci., 2013, 58(11):520-524 | DOI: 10.17221/7047-CJAS

The effects of methanolic extract of Dracaena arborea on mean testicular weight, mean cauda epididymal sperm reserve, and testicular morphology were evaluated. A total of sixty mature male Sprague Dawley rats were divided into three equal groups. The first group (A) received distilled water while the other two groups (B and C) received orally the methanolic leaf extracts of Dracaena arborea in two doses (100 and 500 mg/kg, respectively) daily for 84 days. Following oral administration of the extract, mean testicular weight, mean cauda epididymal sperm reserve, and testicular morphology were determined on days 28, 42, 56, 70, and 84. The extract produced a significant and dose-dependent increase (P < 0.05) in the sperm number. There was also a significant increase (P < 0.05) in the mean testicular weights on days 70 and 84 of the extract administration. The testicular morphology remained unchanged while further testicular histology examination revealed increased spermatogenesis. It was concluded that the methanolic leaf extract of D. arborea has fertility enhancing properties.

Airborne laser scanning data as a source of field topographical characteristicsOriginal Paper

J. Kumhálová, F. Kumhála, P. Novák, Š. Matějková

Plant Soil Environ., 2013, 59(9):423-431 | DOI: 10.17221/188/2013-PSE

One of the factors frequently affecting yields is topography. Topographic data can be obtained from various sources with different precision. This work evaluates suitability of airborne laser scanning data for use as another source of topographical characteristics creation in a smaller scale in regards to precision agriculture needs. Simple models of elevation, slope and flow accumulation were created and the correlation between yield and topography was determined over a seven-year period in relation to precipitations and temperature. The suitability of airborne laser scanning data was proved with certain limitations. Flow accumulation model derived from original airborne laser scanning data indicated the right trend of flow accumulation but not as clearly compared to other models. In drier years the correlation coefficients between flow accumulation and yield reached up to 60-70%.

Immunohistochemical detection of soya protein - optimisation and verification of the method

Matej POSPIECH, Bohuslava TREMLOVÁ, Eva RENČOVÁ, Zdeňka RANDULOVÁ

Czech J. Food Sci., 2009, 27(1):11-19 | DOI: 10.17221/2848-CJFS

A functional immunohistochemical method for soya proteins detection was developed. The procedure is based on the avidin-biotin complex (ABC) method that attains sufficient sensitivity. The method was verified by the analysis of the model samples of different forms of soya additives containing various concentrations of soya isolate. The detection limit of soya present in the model samples was 0.5%. Different possibilities of the background staining were tested. The best results were obtained with the background staining according to Calleja. The results were confirmed by the accredited indirect ELISA method. The method allows the identification of various forms of soya proteins such as isolates, texturates, concentrates, and flour.

Evaluation of the Prunus interspecific progenies for resistance to Plum pox virusOriginal Paper

Jaroslav SALAVA, Jaroslav POLÁK, Ivan OUKROPEC

Czech J. Genet. Plant Breed., 2013, 49(2):65-69 | DOI: 10.17221/252/2012-CJGPB

Sharka disease caused by the infection with the Plum pox virus (PPV) in stone fruit trees is worldwide the most devastating for stone fruit production. Until now, good sources of resistance to PPV within the peach group have not been available. There are no commercial cultivars of peach that are resistant to PPV. Other Prunus species are known to show varying levels of resistance. Interspecific hybrids GF 677 (Prunus amygdalus × P. persica) and Cadaman (P. davidiana × P. persica) were revealed to be resistant to PPV. The resistance to a Dideron isolate of the descendants of Cresthaven × GF 677 and Cresthaven × Cadaman and their progenitors was evaluated after inoculation by chip-budding in a sealed screenhouse. Results demonstrate a certain level of resistance in both progenies of interspecific hybrids and indicate a potential for PPV resistance transfer to commercial peach cultivars but it will be necessary to perform backcrosses with peach cultivars of agricultural interest in order to return pomological and agronomic traits. For the definitive confirmation of resistance/susceptibility it will be necessary to wait until the adult stage of hybrids.

How much birch (Betula papyrifera) is too much for maximizing spruce (Picea glauca) growth: a case study in boreal spruce plantation forests

Ch.D.B. Hawkins, A. Dhar, B.J. Rogers

J. For. Sci., 2012, 58(7):314-327 | DOI: 10.17221/8/2012-JFS

Interest in conifer-broadleaf mixedwood forests has greatly increased due to continuous demand for hardwood products and a shift towards more biological or ecosystem-based management. In British Columbia, more than 30% of the productive forest land is a conifer-broadleaf mixture and current forest regulations are more conifer biased rather than maintaining a mixed-species condition. The aim of this study was to examine the impact of paper birch on white spruce growth. Spruce growth data from 10 to 18 years old complex stands indicate that radial, height, and stem volume was not impacted by retaining up to 3,000 stems.ha-1 of birch. Similarly, growth and yield model projections suggest spruce-birch stands would be more productive up to a threshold birch density (3,000 stems.ha-1) than pure spruce stands. At a 4% real interest rate, the removal of birch from these stands does not appear to be warranted as an investment. The results suggest that instead of encouraging uniform broadleaf removal across conifer plantations, mixed species management strategies could enhance the forest productivity, stand diversity and resilience.

Control of Conyza spp. with glyphosate - a review of the situation in EuropeReview

Manda SANSOM, Antonio A. SABORIDO, Marielle DUBOIS

Plant Protect. Sci., 2013, 49(1):44-53 | DOI: 10.17221/67/2011-PPS

In Europe, glyphosate resistant populations have developed in some weed species in perennial crops, including three species of the genus Conyza documented by the International Survey of Herbicide Resistant Weeds. Conyza spp. biology is reviewed in this paper and related to population dynamics and the development of resistant populations. Suboptimal growth stage at application, improper agricultural practices such as overreliance on glyphosate and long-term use of sublethal doses are identified as the most important factors of resistance development. Current control methods in perennial crops including mixtures of glyphosate with other active ingredients are discussed and effective weed management strategies are described to manage the development and spread of glyphosate resistant Conyza spp. in Europe.

Corpus luteum development and its morphology after aspiration of a preovulatory follicle is related to size and steroid content of the follicle in dairy cowsOriginal Paper

A. Vernunft, J.M. Weitzel, T. Viergutz

Vet Med - Czech, 2013, 58(4):221-229 | DOI: 10.17221/6760-VETMED

Secretion of adequate levels of progesterone from a proper corpus luteum (CL), which develops out of the cells of a healthy preovulatory follicle, is a key-factor for establishment of a pregnancy. The aim of this study was to investigate the relationship between morphological and secretory characteristics of preovulatory follicles and their corresponding corpus luteum with regard to the post-partum period in high-yielding dairy cows. Therefore, ultrasound-guided aspirations of preovulatory follicles were performed repeatedly, using 20 first lactating cows between 26 and 121 days after parturition. Heat was induced with a PGF analogon followed by administration of a GnRH analogon. The dominant follicle was aspirated 21 h after administration of the GnRH analogon. The diameters of the follicles were estimated at aspiration and the morphology of the resulting luteal tissue was examined on day 14 after follicle aspiration using ultrasonographic examinations. Concentrations of progesterone (P4) and 17-beta-oestradiol (E2) were determined in the follicular fluids (FF) and P4 concentration was estimated at the time of CL examination in plasma. A CL development occurred in 82% after dominant follicle aspiration. The interval of time between parturition and follicle aspiration did not affect the investigated variables. The diameter of the aspirated preovulatory follicle was positively correlated to the cross-section area of the developed luteal tissue (R = 0.60; P < 0.01) as well as to the plasma P4 concentration on day 14 after follicle aspiration (R = 0.47; P < 0.05). Also, E2 concentrations in FF were positively correlated to cross-section area of the luteal tissue (R = 0.54; P < 0.05). Comparing the FF of the follicles that gave rise to a CL after aspiration to follicles that did not, both types had comparable P4, but the former type harboured higher E2 concentrations. In conclusion, preovulatory follicle diameter as well as steroid concentrations in the follicular fluid could be used prospectively to identify cows which will have well-developed CLs and high plasma P4 levels later. On the other hand, CL development after follicle aspiration can be used as a retrospective quality parameter of dominant follicles. These results will help to identify suitable animals for breeding or recipients for embryo transfer.

EMS induced intercellular chromatin transmigration in Papaver somniferum L.Short Communication

Girjesh KUMAR, Sana NASEEM

Czech J. Genet. Plant Breed., 2013, 49(2):86-89 | DOI: 10.17221/85/2012-CJGPB

The phenomenon of chromatin migration was observed during microsporogenesis in an ethyl methane sulphonate (EMS) treated population of poppy, which is an important medicinal plant. Cytomixis occurred through a cytoplasmic channel or by direct fusion of pollen mother cells (PMCs); the former was more recurring than the latter. The process was associated with irregular meiosis. PMCs with differing chromosome numbers from the normal diploid number (2n = 22) through cytomixis may lead to the production of aneuploid and polyploid gametes. An increase in the concentration of EMS had a positive effect on the percentage of PMCs showing cytomixis. In addition to cytomixis, other chromosomal abnormalities were also found. Cytomixis along with the related chromosomal abnormalities largely affected the post-meiotic products resulting in some pollen sterility.

Approximation of subsurface drainage discharge by De Zeeuw-Hellinga theory and its verification in heavy soils of fluvial landscape of the Cerhovice brookOriginal Paper

Jakub Štibinger

Soil & Water Res., 2009, 4(1):28-38 | DOI: 10.17221/37/2008-SWR

The subsurface drainage discharge is one of the most important indicators of the impact of the drainage systems on the water management. The procedure adopted in this study is based on the application of the De Zeeuw-Hellinga theory to derive the final expression for the estimation of the value of the subsurface drainage discharge. A simple analytical approximation of the Bussinesq's Equation was used to verify theoretically the validity of the De Zeeuw-Hellinga assumptions and to confirm the correctness of other corresponding processes. The formulas describing the subsurface drainage discharge were derived in the conditions of the unsteady state subsurface flow to drains. These conditions included the approximately horizontal impervious layer and the Dupuit's assumptions and Darcy's law. No recharge to the groundwater table was realised during the drainage testing. The applicability of the De Zeeuw-Hellinga formula and the accuracy of the analytical approximation of the subsurface drainage discharge by the Bussinesq's Equation were verified by the real field measurements on the heavy soils of the experimental watershed area of the Research Institute for Soil and Water Conservation (RISWC) Prague-Zbraslav, Czech Republic. The same data were successfully used also for the confirmation of the accuracy of the method for the derivation of a simple analytical approximation of the subsurface total drainage quantity. It was demonstrated that this approximation of the subsurface drainage discharge by De Zeeuw-Hellinga theory could satisfactorily serve in the area of water engineering practice as an elementary tool for the immediate estimation of the values of the subsurface drainage discharges from the pipe drainage systems in the saturated porous environment. The advantage of this approximation is particularly the minimum amount of the input data, e.g. the basic soil hydrology data and drainage system basic design parameters. The sphere of the use of the De Zeeuw-Hellinga equations is certainly very wide. The verifications of the field test results and measurements demonstrated that the possibilities of applications and their perceived benefits to the user can be fulfilled.

Cox-2 expression after chemotherapy in a canine nasal transitional cell carcinoma: a case reportCase Report

J.E. Ojeda, M. Moroni, M. Mieres, E. Paredes

Vet Med - Czech, 2013, 58(11):599-604 | DOI: 10.17221/7144-VETMED

An eight year-old mixed breed dog was referred for evaluation with chronic sneezing, epistaxis and nasal bone deformation. A clinical exam revealed a deformity of the left nasal bone. Cytological evaluation of the nasal cavity showed round and cuboid cells in different stages of maturation. Computed tomography images identified a diffuse soft tissue mass in the nasal cavity. The histopathological diagnosis was transitional cell carcinoma. Chemotherapy with cisplatin and piroxicam was initiated. Computed tomography was used to follow the chemotherapy outcome. As many nasal carcinomas express COX-2, its expression was evaluated before and after chemotherapy. Computed tomography revealed a significant reduction of the tumour mass. Inmunohistochemistry showed a marked decrease in COX-2 expression and after 1120 days, the dog remained without clinical signs. Thus, the use of piroxicam and cisplatin is revealed to be effective in the treatment of a nasal transitional carcinoma in a dog. Also, it is possible to postulate that a decrease in COX-2 expression after chemotherapy may be regarded as an indication for a good response to the treatment and favourable outcome. To the authors' knowledge this is the first report that evaluates COX-2 expression after chemotherapy.

Trade practices of retail chains as far as the transaction cost analysis in relationships manufacturer - retailer are concerned in the milk industry

Jaroslav KITA, Katarína MÁZIKOVÁ, Marta GROSSMANOVÁ, Pavol KITA

Agric. Econ. - Czech, 2012, 58(6):264-274 | DOI: 10.17221/61/2011-AGRICECON

The primary purpose of this article is to discuss the trade practices used by retail chains from the point of view of the possible solutions of conflicts between the members of the distribution channel, which have an influence on selling prices for the end users. It is based on the knowledge of the theory of the transaction cost analysis, which makes it possible for the members of the distribution channel to make decisions on the number of forms of the organization in order to realize their activities successfully. In this framework and using the example of milk, the article shows the trade practices of retail chains to improve the relationships manufacturer - retailer in the Slovak consumer market.

Secondary dormancy of seeds in relation to the Bromus tectorum-Pyrenophora semeniperda pathosystemOriginal Paper

Katie Karen HAWKINS, Phil ALLEN, Susan MEYER

Plant Protect. Sci., 2013, 49(10):S11-S14 | DOI: 10.17221/30/2013-PPS

Bromus tectorum is a highly invasive annual grass. The fungal pathogen Pyrenophora semeniperda can kill a large fraction of B. tectorum seeds. Outcomes in this pathosystem are often determined by the speed of seed germination. In this paper we extend previous efforts to describe the pathosystem by characterising secondary dormancy acquisition of B. tectorum. In the laboratory approximately 80% of seeds incubated at -1.0 MPa became dormant. In the field, seeds were placed in the seed bank in late autumn, retrieved monthly and dormancy status determined. The field study confirmed the laboratory results; ungerminated seeds became increasingly dormant. Our data suggest that secondary dormancy is much more likely to occur at xeric sites.

A comparative account of the microbial biomass-N and N-mineralization of soils under natural forest, grassland and crop field from dry tropical region, India

Jay S. Singh, D.P. Singh, A.K. Kashyap

Plant Soil Environ., 2009, 55(6):223-230 | DOI: 10.17221/1021-PSE

This study investigated microbial biomass-N (MB-N) and N-mineralization in soils of four different vegetation systems including forest (sal), mixed forest, savanna and cropland ecosystems in the Vindhyan region, India. A change was noted in the above region due to physiographic differences and anthropogenic disturbances. Annually the soil moisture (SM) content across the different study sites ranged from 7.5 to 24.3% being maximum in forest sites compared to savanna and cropland sites. The NH4+-N, NO -3 -N and MB-N concentrations varied from 4.3 to 10.2 μg/g, 1.1 to 5.8 μg/g and 21.3 to 90.2 μg/g dry soil, respectively, with minimum values in the wet and maximum values in the dry season. The trend of seasonal variation in net N-mineralization was similar to that of moisture content but counter to the concentrations of inorganic-N and MB-N. The net N-mineralization rates at different investigated sites ranged from 4.5 to 37.6 μg/g month. Cultivation reduced the N-mineralization and MB-N by 58.5% and 63.5%, respectively. Experiments showed that the percentage contribution of MB-N to total-N was 8.01 to 19.15%. MB-N was positively correlated with the inorganic-N (n = 180,r.80,P < 0.001) but negatively with soil moisture (n = 180, r = 0.79, P < 0.001) and net N-mineralization rates (n = 180, r = 0.92, P < 0.0001). The higher N-mineralization and MB-N in the soil of forest ecosystem was reported compared to savanna and cropland and the order of soil MB-N levels and net N-mineralization followed the sequence: forest (sal) > mixed forest > savanna > cropland.

Baroinactivation of Staphylococcus epidermidis - mathematical model and its verification using human and cow milk

Ljuba Schlemmerová, Milan Houška, Vladimir Špelina, Jan Strohalm, Aleš Landfeld, Hana ŠmuhaŘová, Ilona Němcová, Karel Kýhos, Jiřina Průchová, Pavla Novotná, Pavel Měřička

Czech J. Food Sci., 2009, 27(2):118-126 | DOI: 10.17221/1051-CJFS

Staphylococcus epidermidis, commonly found on the human skin, may contaminate human milk. High-pressure pasteurisation of human milk under normal temperature preserves the majority of its protective agents. The objective of this study was to acquire baroinactivation data and develop a model for model solutions of pH = 6.4 to 7.2 and water activity aw = 0.99, in which baroinactivation of Staphylococcus epidermidis takes place. Decontamination data manifested exponential kinetics and the resulting model was described by the following equations: Dp = Dp, ref × 10 (Pref - P)/Z, Z = -123.90 pH2 + 1635.54 pH - 5210.49; Dp, ref = -8.89 pH2 + 121.02 pH - 408.34. The developed model was verified using pasteurised human milk and UHT-treated skimmed cow milk. The agreement between the experimental data and model-based prediction was very good for human milk. It was proved that the application of a pressure of 350 MPa for 10 min decreased the concentration of the working suspension of S. epidermidis in the model substrate by a minimum of five orders.

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