Fulltext search in archive

The present paper deals with derivation of target stocking in forests of Norway spruce vegetation zone. Target stocking in forests with prevailing ecological and social functions is the stocking when the forest fulfils demanded functions in the best way. For forests in the Norway spruce vegetation zone target stocking was derived by original procedures as an optimum stocking in harmonization of demands on the fulfilment of ecological functions (especially erosion control, hydrological and water protection ones), securing static stability and preconditions for the formation and growth of natural regeneration. We investigated the relations between stocking and indicators of static stability (slenderness coefficient and ratio of crown length to tree height), natural regeneration phases, ground and non-wood vegetation coverage and natural regeneration coverage. The most favourable status of these indicators was found out in stocking 0.7 and in the upper forest limit 0.6.

Seeds and seedlings of Quercus robur, a characteristic tree species of the hardwood floodplain forests along the Rhine River, demonstrated high resistance to complete inundation under controlled conditions. In both experimental trials no significant difference between the different flooding periods (8, 10, and 12 weeks) could be established either for shoot emergence or for the measured morphological growth parameters. Flooding delayed the germination of submerged acorns till the end of inundation. However, seeds of the flooding treatments had significantly higher germination rates than the non-flooded acorns of the control. Likewise, dry weights of seedlings from the flooded seeds were significantly higher than those of seedlings from seeds not flooded. Aboveground growth in the 24-week growth period following flooding was reduced in favour of root development in either trial of the experiment. Restricted leaf development and reduced shoot elongation stalled the growth of young oaks in the seedling trial. The results confirm knowledge from earlier experiments about the flood tolerance of Quercus robur seed and seedlings. They also serve to explain why oak seedlings are widespread on the Rhine floodplain after mast years, but gradually disappear in successive years.

Humans should behave in such a way that they will not endanger the existence of other living entities. After all, human activities affected the tree species composition and wildlife living conditions. Humans are now responsible for the preservation of delicate equilibrium in nature. Two localities were chosen for the research of game damage caused to standing trees - shooting areas Lužánky and Červený jelen, both situated in the vicinity of Jindřichův Hradec in South Bohemia. Seasonal character of tree-damage origin as well as its relation to the chemical content of spruce (Picea abies [L.] Karst.) and pine (Pinus sylvestris [L.]) bark were investigated. This area is typical of high game stock; trees are damaged by browsing and bark stripping. Particular advice for game management with respect to minimizing tree damage is presented. The data set of chemical bark analyses was statistically evaluated by t- and F-test and significant differences in element contents were detected between damaged and undamaged pine bark for N-substances (P = 0.003309), Ca (P = 0.001460), P (P = 0.004343), Mg (P = 0.001419) and K (P = 0.016290). Humans have influenced many changes in the distribution of different animal and plant species. Among others they are responsible for the altered species composition. Typically the extinction of large predators produces changes in food chains. In forest stands influenced by human activities the reasonable game management and the regulation of game stock seems to be one of the main tools in forest protection.

Studies were carried out in southern Poland during 2002-2006 in Scots pine stands under the effect of an outbreak of pine shoot beetles. The qualitative aspects of beetle feeding in tree crowns, studied on the basis of fallen shoots collected on experimental plots, are presented in this paper. The beetle numbers affected the age distribution of damaged shoots and the proportion of multiple attacks. The proportions of one-year-old shoots and the numbers of shoots with more than two attacks increased in the marginal part of the stand in the year of intensive feeding of beetles and in the subsequent year. A similar proportion of shoots with two attacks in both stands under investigations in individual study periods, with no relation to beetle numbers, does not permit to use this characteristic for forecasting purposes. The average length of tunnels in shoots attacked once reached 20 mm at maximum. The average length of tunnels (measured from the place of shoot disruption) was greater in shoots with two attacks than in shoots with a single one (P < 0.0001). The difference was not significant (P = 0.3429) only in stand B during the study season 2004-2005. The majority of the tunnels made in apical portions of shoots with two attacks damaged the tissue of apical shoots. The distance between the base of the second tunnel and the shoot apex in shoots with two attacks, and its significant (P < 0.01) linear relationship with the length of beetle tunnels, indicated a high nutritional quality of apical portions of shoots.

Manipulated experiments with males of Ips typographus (L., 1758) were conducted in spruce stands in north-western Slovakia. Some of trees were stressed by a lack of water caused by preparation of roofs under canopy. Inoculation experiments with bark beetles were conducted on such trees. According to results, the differences in attack rates between differently positioned trees on slope were not statistically significant (P = 0.389 for bottom and middle and P = 0.924 for bottom and top, and P = 0.530 for middle and top trees, t-test). Also the differences in attacks rate and the speed of entry holes preparation between more stressed and less-stressed trees were not statistically significant (P = 0.321, t-test). Thus the results of inoculation confirmed that low level of water stress does not lead necessarily to higher attack rate and (neither) faster speed of entry holes preparation. The obtained results are discussed.

A dramatic forest decline due to the bark beetle outbreak, which occurs in the Norway spruce stands in the Western Beskidy (southern Poland) since 2003, was started after severe physiological drought during winter time. An analysis describing some spatio-temporal characteristics of this process, with special regard to the patterns of bark beetle occurrence related to root fungal diseases, is presented. In 2003 the bark beetle occurrence level assessed as high and catastrophic was recorded on 40% of the area, while in 2006 - on 59%. The range of Armillaria root disease and bark beetle outbreak increased towards higher altitudes, including the zone above 1,000 m a.s.l. The wind damage in 2004 and 2007, and high temperatures in the summer 2006, further stimulated the increase in bark beetle populations level. Some conclusions on possible development of the outbreak and recommendations concerning related needs in forest protection, are given.

This article presents a review of data and results of investigations from the period 1958-2006 regarding the occurrence of insects of the genus Cephalcia Panzer (Hymenoptera, Pamphiliidae) in Norway spruce stands of the Beskidy Mountains (Western Carpathians, southern Poland). Currently, eight species are known for the area: C. abietis, C. alashanica, C. alpina, C. annulicornis, C. arvensis, C. erythrogaster, C. fulva and C. masuttii. Information regarding each species is given, with details on identification, local occurrence and importance.

From 1997 to 2000 the distribution of Apple stem grooving virus (ASGV) in selected intensive apple orchards was investigated at six sites in the Czech Republic. Detection of ASGV was by ELISA. The virus was found to be commonly distributed; it was detected in over 50 % of the tested trees. Some cultivars were infected up to 100 %, while several were found to be virus-free. A high incidence of infected trees appeared in both older (20 years) and younger (7 to 8 years) orchards. This emphasizes the necessity to initiate the certification of the health condition of nursery material according to the system recommended by the EPPO.

The molecular basis of organ specificity in plant diseases is little characterised. Downy mildew of Arabidopsis caused by the oomycete Peronospora parasitica is characteristically a leaf disease. Resistant host genotypes recognise the pathogen in a gene-for-gene dependent manner and respond with the production of H₂O₂ and the execution of a genetically programmed hypersensitive cell death (HR). We inoculated the roots of Arabidopsis genotypes Col-0, Ws-0 and Wei-0 with the NOCO and WELA races of the pathogen and compared the responses with those observed in infected leaves. Combinations of incompatible genotypes of host and pathogen showed the expected responses of an oxidative burst and the HR in leaves but, surprisingly, roots showed no signs of active defence and appeared completely susceptible to all the P. parasitica isolates tested. RT-PCR showed that the R genes RPP1 and RPP13, which mediate resistance in leaves to P. parasitica isolates NOCO and WELA, respectively, were expressed in leaves as well as in roots. Similarly, NDR1 and EDS1, two components of RPP1-mediated gene signalling pathways, are also expressed in both tissues. Thus, we show for the first time that expression of R genes and at least some of the known downstream components of the signalling cascade are not sufficient for the induction of avirulence gene-mediated defence mechanisms.

Results of scoring the reaction to powdery mildew of 240 winter barley varieties that were gradually included in 392 Czech Official Trials conducted at 21 locations were analysed. The reaction of the varieties was determined on the basis of the level of infection by the disease. Therefore, the data can also be used to assess the disease severity in years and at locations. Several characteristics indicative of disease severity were considered, including the disease severity coefficient (= average infection of susceptible varieties in trials with a high disease severity/the proportion of such trials). The value of the coefficient is inversely proportional to disease severity. The highest powdery mildew severity was found in 1976, and the years 1988, 1990 and 2003 were characterised by high infection of the examined varieties. In contrast, the disease was practically absent in 1979 and 1982, and its severity was also low in 1978, 1981, 1985, 1991 and 1998. Very low disease severity was found for the period 1977-1982 when insufficient disease severity was found on average in 78% of the trials and high disease severity in only 6% of the trials. The highest disease severity was found at locations Trutnov, Horažďovice and Chrastava. The analysis of data from a large number of field trials conducted at various locations for a period of 30 years confirmed that powdery mildew is an important disease of winter barley in the Czech Republic. Known genetic sources of resistance and current methods, such as marker assisted selection, enable breeders to solve this problem.

Greenhouse trials were conducted during 2005 to investigate the effect of six soil applied herbicides on common cocklebur (Xanthium strumarium L.) sowed at a depth of 4 cm and 7 cm, and determine the potential injury to maize by the herbicides and the influence of sowing depths. The efficacy of all herbicides was high, regardless of sowing depth and, generally, the coefficient of efficacy ranged from 86.3% to 100.0%. Most of the herbicides had no significant phytotoxic effect on maize plant density/container, height and fresh weight of maize. Exceptions were Atranex-90WDG and Cyatral-SCZ, which caused serious injury to maize (33% and 37%, respectively) if seeded at a depth of 7 cm, and significantly reduced height and fresh weight of the plants.

In the autumn of 2006 and summer 2007 the coreid species Leptoglossus occidentalis Heidemann, 1910 was detected in the Czech Republic for the first time as a new alien insect species. It is native to North America, where it causes important seed losses on coniferous trees, especially pines. From Europe it is known since the end of the last century, when it was introduced to Italy. Its repeated finding could indicate a vital population of this species in the Czech Republic, not only introduced individuals.

The risk of Pb contaminated soil after treatment with different remediation techniques was assessed. Soil vitrification (microwaves) reduced Pb orally available from the stomach and intestinal phase measured by a physiologically based extraction test. Solidification of Pb (Slovakite) did not reduce the concentration of orally available Pb and increased the Pb uptake by Thlaspi goesingens for 2-times compared to plants grown on the original soil. Soil extraction with 40 mmol/kg EDTA removed 57.6% of Pb. However, the concentration of orally available Pb and Pb uptake by T. goesingens increased. The concentration of mobile soil Pb also increased for 14-times measured by a toxicity characteristic leaching procedure. Soil leaching with 10 mmol/kg biodegradable chelator [S,S] ethylenediamine disuccinate and using a horizontal permeable reactive barrier for Pb accumulation from the washing solution removed 17.8% of Pb, but increased Pb uptake by T. goesingens by 3-times and slightly increased the concentration of Pb in the intestinal phase. Leaching did not significantly effects Pb availability from the stomach phase or Pb mobility.

The Czech University of Agriculture in Prague in cooperation with the Business Exchange in Hradec Králové operates an electronic business system EBS, which enables on-line exchange trade negotiations through the Internet. The system fully takes the advantage of possibilities and technologies of e-business, bringing thus forward new opportunities for making use of the exchange trade with agricultural and food commodities on the EU liberal market. The whole procedure is a part of the Agrarian www portal AGRIS.

An endophytic fungus of soyabean (Glycine max) roots, Fusarium oxysporum, was used to study its activity under heavy metals (Cd²⁺, Mn²⁺ and Zn²⁺) stress and the role of rock phosphate (RP) in alleviation of the stress. F. oxysporum growth, amino acids and protein were increased by increasing RP concentration (1-6 g/l) after 8 and 14 days. Heavy metals (HM) have a stressing effect on F. oxysporum - a significant decrease of amino acids, protein and accumulation of sugar at 1mM/l follows a descending order of Cd²⁺ > Mn²⁺ > Zn²⁺. RP is altering the stressing effects of metal on F. oxysporum by a significant growth improvement at 3 and 6 g/l RP, increase of amino acids, protein and decrease of sugar. The solubilization of RP increased under HM application, which may be attributed to an increase of the adsorption of HM by increasing RP concentration. RP has the highest adsorption affinity for Cd²⁺ (81%) followed by Zn²⁺ (71%) and Mn²⁺(55%).

The use of plants to remove heavy metals from soil (phytoremediation) is expanding due to its cost-effectiveness as compared to conventional methods and it has revealed a great potential. Since contaminants such as Pb or Cd have a limited bioavailability in the soil, methods to facilitate their transport to the shoots and roots of plants are required for successful phytoremediation. The objective of this study was to investigate the effects of addition of different rates (0, 3, 6 and 12 mmol/kg) of ethylene diaminetetraacetate (EDTA) on heavy metal availability in soils contaminated with 50 mg/kg Cd (CdCl₂), 50 mg/kg Cu (CuSO₄), 50 mg/kg Pb [Pb(NO₃)₂] and 50 mg/kg Zn (ZnSO₄), and on the capacity of canola (Brassica napus L.) and Indian mustard (Brassica junceaL.) plants to uptake Cu, Cd, Pb and Zn in a growth chamber. Results indicated that EDTA application increased heavy metal availability and uptake by plants. Significant differences were obtained in both species and plant parts. As for plant species tested, canola was more effective in the uptake of Cu, Cd, Pb and Zn. Root heavy metal uptake of both species was higher than shoot heavy metal uptake.

The influence of various forms of farming on unmanaged grasslands was monitored with regard to the accumulation of the above-ground biomass (litter + mulching) and its influence on the leakage of rainfall and the amount of elements in lysimetric waters. In 2001-2005, the highest accumulation was observed in variants 1× mulched in the later term and on green fallow (on average 2.11-1.13 t of dry matter/ha). In comparison with the control site, a conclusive increase always occurred. An interannual increase of dry matter amounted to 0.4-5.2% of the total above-ground biomass. A negative correlative dependency on rainfall leakage on this material was discovered; at a depth of 0.4 m 4-10% of the rainfall leaked, but it had a significant influence on the wash out of Ca, Mg and S. The leakage of water affected a wash out of N_min, P, K, Ca, Mg and S more than the weight of dry matter of the above-ground biomass. With the exception of P, the elements showed a downward tendency over five years. The above-mentioned forms of farming annually increased the accumulation of the above-ground biomass by 0.05-0.16 t of dry matter/ha; however, they do not endanger underground waters by washing out minerals. After a five-year period, a disturbance of the ecological stability of grassland did not occur.

The effects of phosphate solubilizing bacterium (Bacillus FS-3) application on phosphorus contents of tomato (Lycopersicon esculentum L.) plant, growing performance and phosphorus forms in soil were evaluated under greenhouse condition. Five different phosphorus fertilizer treatments (normal superphosphate, triple superphosphate, di-ammonium phosphate, phosphoric acid, and rock phosphate) with and without bacterium (Bacillus FS-3) were applied in pots as 344 kg P/ha. Basal fertilizers were applied to all the pots as 180 kg N/ha (NH₄NO₃ 33% N), 100 kg K/ha (K₂SO₄ 50% K₂O). The results obtained showed that phosphorus availability from soil increased with phosphate solubilizing bacterium (PSB) application. The amount of plant available form of soil phosphorus fraction (resin-Pi + NaHCO₃-Pi + NaHCO₃-Po + NaOH-Pi + NaOH-Po) increased with PSB application. In all fertilizer types, bacteria application converted approximately 20% of less available phosphorus into labile forms. Statistically significant differences were obtained in shoot and root dry weight of tomato plants treated with PSB application. In all of the fertilizers, plant shoot and root weight and P uptake were greater with PSB applications than without PSB. The highest shoot-root dry weight and P uptake of plant were determined in triple superphosphate (TSP) with PSB application treatment. The data in the present study suggest that the application of PSB (FS-3) may increase the availability of soluble phosphate by dissolving the inorganic forms of phosphate and that bacterial strain tested in this study has a potential to be used as a bio-fertilizer in sustainable and organic agriculture.

The effect of three seedling treatments: T₀, normal germination; T₁, cotyledons removed; T₂, cotyledons removed 5 days earlier than in T₁; and two phosphorus levels (P₀ and P₃₀) on nodulation and nodule function in soybean [Glycine max (L.) Merr.] were investigated in nutrient solution culture. The number of nodules formed at P₀ was in the order T₂ > T₀ > T₁, but it was T₀ > T₂ > T₁ at P₃₀. Nodule dry weight per plant had the same tendency as the nodule number. Nodule size (dry weight per nodule) in seedlings ranged from 0.601 to 1.089 mg in the order T₀ > T₁ > T₂, regardless of P level. For example, nodule size in T₀ was larger by 86% and 52% than T₂ at P₀ and P₃₀, respectively. Furthermore, regardless of P level, a specific acetylene reduction activity (ARA, µM C₂H₄/h/g nodule) increased with P content in seedlings, but no significant difference was found (P < 0.05). Leghemoglobin (Lb) content was not significantly affected by P level; however, seedlings (T₀ and T₁) significantly affected the Lb content per unit plant biomass (P < 0.05). All these results suggest that seedling P content plays a key role in nodulation and nodule function of soybean.

The aim of the present paper was to determine the impact of gypsum treatment of soils on initial growth and nutrient uptake by spring barley. Topsoil from 36 different farmed fields was used for the research. Two variants were established for each soil: control - without gypsum application, and response variant - with the application of 3.3 ppm CaSO₄.2 H₂O. Barley was grown on these soils for 21 days in a plant growth chamber under controlled conditions of cultivation. Concentrations of nutrients (N, NO₃^-, P, S, K, Mg, Ca, Na, Fe, Mn, Zn, Cu, B and Mo) were determined in the yield of barley shoot biomass. Paired t-test was used for the evaluation of results. After the gypsum treatment the yield of barley shoot biomass was significantly higher (by 15% on average) and nitrogen utilisation was better on all soils. The concentration of sulphur increased five times on average and Ca concentration increased by 22%. Significant increases were measured in Mg, Mn and Cu. Insignificant differences were recorded in K, Na, Fe and Zn. The uptake of anion nutrients (P, B and Mo) was influenced significantly. The concentration of P and Mo decreased on average by 28% and 31%, respectively. B concentration was higher by 10% on average.

In several cases ethylenediaminetetraacetic acid (EDTA) proved to be an efficient mobilising amendment during chemically enhanced phytoextraction of heavy metals. The presence of Fe-(hydr)oxides and their dissolution after the addition of EDTA can limit the phytoextraction of the targeted heavy metals due to the high stability of the formed Fe(III)EDTA complexes. This study has focused on the influence of Fe- and Mn-oxides and hydroxides dissolution on heavy metal uptake by Zea mays in a two-year EDTA-enhanced phytoextraction process. Incubation experiments and speciation modelling proved the increased concentrations of Mn and Fe through the dissolution of Mn-and Fe-(hydr)oxides. Furthermore, increased Fe and Mn accumulation was observed in maize plants after the second year of the phytoextraction process. Therefore, the presence of Mn- and especially Fe-(hydr)oxides proved to be a limiting factor during EDTA-enhanced phytoextraction of heavy metals from contaminated soils.

A simple method for identification and characterization of telomere-binding proteins is described in this article. After Sodium Dodecyl Sulphate-Polyacrylamide gel electrophoresis (SDS-PAGE), proteins are eluted, renatured and used for retardation analysis with labelled oligonucleotides corresponding to human and plant of telomeric sequences. We show here that this method is efficient to recover sequence-specific DNA-binding abilities of putative telomere-binding proteins.

The lack of recombination in some genomic regions represents a serious obstacle in mapping studies. In this review, we describe methods that are currently used to overcome this problem. Main attention is given to the comparison of methods that are based on the principle of radiation hybrid mapping. We also discuss a strategy called HAPPY mapping (mapping based on the analysis of approximately HAPloid DNA samples using the PolYmerase chain reaction). In addition to reviewing the methods used by other authors, we also summarize our experience with deletion mapping of Y-chromosome in dioecious model plant species (Silene latifolia).

The stability of plant nuclear genome is a necessary condition for the faithful transmission of genetic information through cell lineages. When DNA damage occurs due to various impairments, cells start a number of repair processes including ligation of broken chromosomes. As a result, dicentric chromosomes can be formed. Dicentrics are easily detectable as anaphase bridges during following mitosis. Using Arabidopsis as a model plant, we developed a sensitive cytogenetic assay to identify specific chromosomal rearrangements. Here we show Arabidopsis tert^-/- and atm^-/- mutants and their chromosome rearrangements and fusions analysed by fluorescence in situ hybridization (FISH). The method is based on successive rounds of FISH with chromosome-specific probes and the comparison of resulting FISH images.

To answer many questions of evolutionary developmental biology, it is necessary to identify genes which could be responsible for the studied traits. In this review, I have summarised the methods that are currently used to identify these genes. Mainly the PCR-based methods of gene cloning are discussed here, with the special attention given to the comparison of primer design strategies and PCR amplification strategies. In addition to the review of methods used by other authors, an overview of our experience with PCR-based gene cloning in dioecious model plant species Silene latifolia is included.

This review is a short introduction to phylogenetic analysis. Phylogenetic analysis allows comprehensive understanding of the origin and evolution of species. Generally, it is possible to construct the phylogenetic trees according to different features and characters (e.g. morphological and anatomical characters, RAPD patterns, FISH patterns, sequences of DNA/RNA and amino acid sequences). The DNA sequences are preferable for phylogenetic analyses of closely related species. On the other hand, the amino acid sequences are used for phylogenetic analyses of more distant relationships. The sequences can be analysed using many computer programs. The methods most often used for phylogenetic analyses are neighbor-joining (NJ), maximum parsimony (MP), maximum likelihood (ML) and Bayesian inference.

The key focus of the project "Bringing the datawarehouse for agriculture into practice" is to develop an IT solution for the implementation of data integration in agriculture. This solution is elaborated in cooperation with a whole range of bodies in the Czech Republic; the lead partner is the Pardubice region where the pilot phase of datawarehouse implementation is being performed. Apart from Czech legal subjects, partners from Finland, Estonia and Poland are also participating in the eFarmer operation. The datawarehouse project is one of the biggest subprojects of the eFarmer operation and is directly connected to the subproject of "Analysis of data and information flow and storage in rural regions", which was carried out within the eFarmer operation in the last period.

he study was undertaken to determine a possible role of polyamines (putrescine, spermidine, spermine) as antioxidants in salt tolerance of Chamomilla recutita and Origanum majorana. Salinity generally induced variable changes in growth, contents of oil and flavonoids of both plants; foliar application of any polyamines counterbalanced the effects of salinity. In general, the degree of stimulation differed according to the type and concentration of the used additive and the type of the plant.