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The objective of this study was to establish the genetic relationship among cultivars commonly used as donors for resistance to Plum pox virus (PPV) in order to identify the putative sources of resistance to PPV. The plant material tested represented the European, Central Asian and Chinese ecogeographical groups of cultivated apricots as well as the wild Dzhungar-Zailij population of Prunus armeniaca L. Forty-eight native accessions as well as the resistant (or tolerant) cultivars Harlayne, Stark Early Orange (SEO), Goldrich, Vestar and two hybrid forms Vestar × SEO (LE 3276) and Velkopavlovická × SEO (LE 2904) were screened by means of SSR analysis. To elucidate genetic relationships among apricot germplasm, a dendrogram was produced using neighbor joining (NJ) analysis of Nei's pair-wise genetic distances over 14 polymorphic SSR markers. On the dendrogram, resistant cultivars were separated into two different clusters suggesting two different sources of resistance to PPV. As was expected from pedigrees, SEO, Vestar, LE 2904 and LE 3276 were grouped together in a cluster adjacent to the European cultivars. Resistant cultivars Harlayne and Goldrich were within another group containing Central Asian apricots and Dzhungar-Zailij form.

The aim of the work was to determine the effect of fungicides: Topsin M 70 WG, Bravo 500 SC, and Sportak 45 EC in two concentrations on the growth of fungi: Aspergillus niger, Epicoccum purpurascens, Cladosporium sphaerospermum, Mortierella isabellina and Penicillium verrucosum var. verrucosum on PDA and Murashige-Skoog medium (MS). The smallest index of linear growth rate of the fungi had Topsin M 70 WG for fungi: E. purpurascens and P. verrucosum var. verrucosum on PDA and MS medium and for M. isabellina and C. sphaerospermum on MS in concentrations of 71.42 mg/l and 107.13 mg/l. The highest index of linear growth had Bravo 500 SC in concentrations of 0.5 ml/l and 0.75 ml/l on PDA for E. purpurascens and A. niger. The lowest index of linear growth on MS for E. purpurascens, C. sphaerospermum and P. verrucosum var. verrucosum was noted down. The highest effectiveness in control of linear growth all tested species of fungi was found for fungicide Sportak 45 EC in concentration of 0.55 ml/l and 0.825 ml/l on MS and PDA. Among all tested fungicides used in vitro propagation fungicides from imidazoles group are recommended.

In order to investigate cross-protection mechanisms between stresses of different origins, greenhouse experiments were conducted to determine whether resistance levels to the fungal pathogen P. capsici were affected on wounded plants. To this purpose, tomato roots were wounded at 24h-intervals and allowed to age for up to 7 days before inoculation. Data from preliminary experiments indicate first (0-48 h old wounds) an increase in disease severity in wounded as compared to unwounded tomato plants infected with P. capsici. Then, as the wounds age, disease severity decreases to the point that plants wounded 3 days before inoculation are less susceptible than nonwounded plants. Here, with the use of tomato mutant lines, we suggest the involvement of ethylene (C₂H₄) and jasmonates (Ja) in the development of these responses towards P. capsici upon wounding of tomato plants.

Chamaecyparis lawsoniana is often attacked by other pathogens (from genera: Phytophthora, Pythium, Fusarium, Rhizoctonia) both when the quicksets are taken root and later, when the young plants are planted. The aim of the study was to determine an effect of saprobiotic fungi isolated from soil with quicksets Chamaecyparis lawsoniana on the growth of Phytophthora cinnamomi and Rhizoctonia solani. In our experiment, method series biotic was used (MAŃKA 1974). This method allowed to determine index of impendence for plants by Phytophthora cinnamomi and Rhizoctonia solani with the help of summary biotic effect. The results of observation on the biotic interaction of saprobiotic fungi isolated from soil with quicksets Chamaecyparis lawsoniana, analysed as biotic series and Phytophthora cinnamomi and Rhizoctonia solani showed, that this of fungal community did not limited growth of these pathogens. Summary biotic effects were negative. Environment of saprobiotic fungi more promoted growth of Rhizoctonia solani than Phytophthora cinnamomi. It means, that in the soil under Chamaecyparis lawsoniana crop, Rhizoctonia solani could have a better of conditions for growth than Phytophthora cinnamomi.

This research was instigated by the fact that during the last decade annually repeated shallow disk tillage on the same field became frequent practice in Hungary. In order to study the changes of soil condition associated with disk tillage and to assess it is consequences, long-term tillage field experiments with different levels of nutrients were set up in 1991 (A) and in 1994 (B) on Chromic Luvisol at Gödöllö. The effects of disk tillage (D) and disk tillage combined with loosening (LD) on soil condition, on yield of maize and winter wheat, and on weed infestation were examined. The evaluation of soil condition measured by cone index and bulk density indicated that use of disking annually resulted in a dense soil layer below the disking depth (diskpan-compaction). It was found, that soil condition deteriorated by diskpan-compaction decreased the yield of maize significantly by 20 and 42% (w/w), and that of wheat by 13 and 15% (w/w) when compared to soils with no diskpan-compaction. Averaged over seven years, and three fertilizer levels, the cover % of the total, grass and perennial weeds on loosened soils were 73, 69 and 65% of soils contained diskpan-compaction.

The research objective was to investigate the influence of different pipe drainage systems on the concentration and quantity of atrazine leached in drainage water, as well as in surface (0-30 cm) and sub-surface (30-60 cm) soil horizons in the production of agricultural crops on drained Gleyic Podzoluvisol. Investigations involved four different variants of drainpipe spacing (15, 20, 25 and 30 m, i.e. four variants in four repetitions). In a particular trial year, the same crop was grown and the same agricultural practices applied in all trial variants. Maize was grown in the first two trial years and wheat in the last year. Soil and water samples were qualitatively and quantitatively analysed for the presence of atrazine by gas chromatography. Atrazine concentrations in drainage water ranged from those within the limits tolerated for drinking water (out of the growing season) up to 458 ng.dm^-3. Maximum quantity of leached atrazine was recorded in 1998 (0.500 g.ha^-1), namely, from atrazine application in May 1997 to March 1998 incl., 0.630 g.ha^-1 or 0.052% of the initially added quantity was leached. Maximum atrazine concentration in the surface soil layer was recorded in traces or it was not recorded at all (0.013 mg.kg^-1), whereas no atrazine was recorded in the subsurface layer during the trial period. Analysis of variance produced no statistically significant difference in the atrazine concentration and leaching in drainage water and in the surface soil layer between different variants of pipe drainpipe spacing.

Partial characterization of iron binding compounds in spinach above ground biomass and differences between binding of Cd, Zn and Fe in spinach biomass were investigated on two soils treated by sewage sludge in model pot experiment. After application of sludge to both soils, Cd and Zn accumulation in spinach biomass was increased in sludge treatments. Total Fe content in biomass showed opposite trend with these treatments and was decreased 2.5-2.7 fold. Results of sequential analysis of spinach biomass showed lower portions of iron in all individual fractions of both sewage sludge treatments compared to control treatments. The largest differences in iron content between control and sludge treatments were determined in ethyl acetate fraction. While majorities of Cd and Zn were found in fractions methanol + H2O and H₂O and methanol + H₂O + HCl, iron content determined in these two fractions was only 7-8% in control treatments and 15-20% in sludge treatments of total iron. In fraction, Fe portion was 87.7-90.7% in treatments without sludge and 76.1-83.5% in sludge treatments in spinach biomass. Results showed tighter iron binding to plant cell membranes in contrast to cadmium and zinc.

The results document changes in the herb vegetation of a South-Moravian floodplain forest in the period of 1978-1997. It is shown that hydrological measures strongly changed the floodplain forest in the area of the Dyje river near Lednice na Moravě. The herb vegetation in the area of the confluence of the Morava and the Dyje rivers was conserved nearly unchanged after artificial floods.

A grown-up specimen of Juglans ×intermedia Carr. walnut was accidentally found in the stand of black walnut (Juglans nigra L.) in the Židlochovice Forest Enterprise in the forest district Velký Dvůr, Stand No. 224 D10. The tree was photographed, leafy shoots and fruits were sampled for later analyses. The paper brings a description of growth habit, rough bark, morphology of leaves, current year shoots and fruits. Discussed are dissimilarities from the parental species (J. nigra and J. regia L.).

In the framework of Slovakia preparation for entering the European Union, there was done a Phare-ACE survey in years 1999-2000. The name of this survey was "Micro-economic analysis of farming households restructuring in pre-accession period to the EU". This survey was done in two regions of Slovakia, characterized by different natural conditions, production and economic conditions. This project was aiming not only at private farmers but also at other legal entities producing agricultural products. The first monitored group consisted of 412 private farmers, farming in average 43.2 ha of agricultural land. The second group consisted of 150 businesses, having 1,866 ha of agricultural land in average.

The paper is focused on the evaluation of the development of financial situation of agricultural co-operatives in the CzechRepublic in 1997-2000 operating in both productive and marginal regions. The comparison of financial situation in these two groups of agricultural firms comes from the classification of firms according to productive regions. Presented results cover firms from the sample of agricultural firms observed in the RIAE Praha. Development tendencies of agricultural co-operatives in these two regions are analysed by means of chosen debt, liquidity, activity and profitability indicators. Non-financial indicators enlarging the above mentioned characteristics of firms' financial situation are suggested and analysed in the last part of this paper.

For 6 years the flight activity of pests on winter and spring oilseed rape was studied from spring till harvest, using yellow traps. In all years the flight intensity was higher in winter rape than in spring rape. The dominant insect pests of winter oilseed rape were Ceutorhynchus obstrictus, C. napi, C. pallidactylus, Dasineura brassicae, Meligethes aeneus, Phyllotreta atra and Ph. nigripes; subdominant were Athalia rosae, Brevicoryne brassicae and Psylliodes chrysocephala. In spring rape the dominant species were Brevicoryne brassicae, Ceutorhynchus obstrictus, Dasineura brassicae, Meligethes aeneus, Phyllotreta atra and Ph. nigripes; subdominant were Athalia rosae, Ceutorhynchus napi, C. pallidactylus and Psylliodes chrysocephala. Dasineura brassicae was not evaluated from trap catches. The damage by D. brassicae is higher to pods on axillary branches than on the main inflorescence. The occurrence of pests on spring rape was tied to a unsuitable phenophase of the plants at the time of flight activity and to the suitability of food. Winter rape requires a higher intensity of chemical treatment against pests than spring rape.

Two samples of commercial wheat flour from the last year's harvest were stored for three months (in the period from November to April) under different conditions. The ambient temperature and humidity varied during the storage in the dependence on the year season. Certain analytical characteristics (moisture, wet gluten and its extensibility, acidity and falling number) and alveograph behaviour of flour were determined at regular intervals. Flour moisture, acidity, and falling number changed with the time of storage but no explicit influence of the storehouse conditions and the initial flour properties was proved. Viscoelastic properties of weaker flour samples changed during storage more markedly than those of stronger flours in the sense of a significant improvement of their quality.

We determined partial nucleotide sequences of several different field isolates of PMTV with well-characterized biological properties from the Czech Republic and Denmark. Subsequently we were trying to elucidate the correlation between nucleotide sequences of various isolates, their biological properties and geographical origin. From the comparison with other known sequences we can conclude, that PMTV genome is relatively conserved.

The role of reactive oxygen intermediate (ROI) accumulation in resistance and susceptibility of plants to parasitic fungi is still little understood. We examined the spatial and temporal occurrence of different ROIs in barley after inoculation with the biotrophic fungus Blumeria graminis f.sp. hordei (Bgh, barley powdery mildew fungus). Using histochemical analyses, we collected correlative data indicating that H₂O₂ and O₂^*- play different roles in background penetration resistance to Bgh. To study the role of O₂^*- in detail, we isolated barley cDNAs encoding a NADPH oxidase GP91PHOX homologue and a RACB homologue, which may be involved in NADPH oxidase activation. Interestingly, transient silencing of RACB or GP91PHOX via sequence-specific RNA interference enhanced penetration resistance of barley to Bgh. Together, data reveal rather a negative than a positive role of superoxide generation in background resistance of barley to Bgh.

Two constructs containing the coat protein gene (CP) of PPV-SwC - in (+) and (-) sense - were obtained and used to transform Nicotiana benthamiana plants via Agrobacterium tumefaciens. Transformed lines were analysed for the integration of the CP gene by PCR and Southern blot. Sixty transgenic lines were selected. Expression of CP gene was investigated by immuno-western blot using a monoclonal antibody specific for PPV-SwC. Various levels of CP expression were detected in transgenic plants. R1 lines were challenged with the homologous virus and with isolates belonging to D, M and EA PPV groups. A variable degree of resistance was obtained, going from complete susceptibility to immunity. Susceptible plants showed a slight delay in symptoms expression when compared to non transformed control. No correlation was established by CP expression level and observed resistance.

The main goal of this work was to calibrate and evaluate the CERES-Barley and CERES-Wheat crop models. The experimental fields used for the model evaluation are situated in three different production regions (maize, sugar beet and potato main growing regions, respectively) with altitudes of 179, 204 and 560 meters above the sea level. Grain yield and date of anthesis together with maturity dates served as reference for the model evaluation. Two evaluation approaches were tested in this study. The first one uses historical data series and it is based on long-term field experiments with capability to reflect interannual weather variability. The second approach uses results of one-year multiple treatment experiment. The model evaluation is then based on a set of treatments differing e.g. in sowing date or an amount of used nitrogen fertilizer. Grain yields simulated by both models are acceptable when compared with experimental results: the coefficient of determination for historical series varied from 0.69 to 0.86 for evaluation of CERES-Barley at the three examined sites and reached values of 0.60 and 0.86 for the CERES-Wheat model at two experimental sites. The lower coefficient of determination of the wheat model was recorded at the locality with the highest altitude and coldest winter conditions. There, also the worst reliability of simulated phenological development was noted. At the second locality where the CERES-Wheat model was tested and at all three localities where CERES-Barley was applied, the simulated duration of vegetation period and anthesis dates were relatively accurate and yielded strong statistical correlation. The one-year multiple treatment experiment proved to be useful to determine the models sensitivity to differences in crop management. The combination of both approaches seems to be the best solution for evaluation of similar crop models if the detail long term experimental data are not available.

Seven cultivars of common buckwheat were tested in field trials under two levels of nitrogen fertilisation on two experimental sites during 1998-2000. The aim of the experiments was to evaluate the influence of cultivar, nutrition and year on main technological quality parameters (thousand achenes weight, volume weight, proportion of fractions on sieves 4.5 and 4 mm, proportion of husks and yield of groats). The differences were observed between buckwheat cultivars in all observed parameters of technological value. Nitrogen fertilisation before sowing (50 kg.ha^-1) did not influence any parameter. On the contrary, buckwheat technological value was influenced by sequence weather (particularly rainfalls) during flowering and achenes formation periods (July). The influence of year was manifested especially on development of endosperm and husks of achenes. Better growing conditions on experimental site Uhříněves caused lower values of volume weight, lower proportion of pericarp (husks) and considerably higher proportion of fraction over 4.5 mm.

Many factors, most notably climate, soil, genotype and fertilising, can influence barley grain composition and its nutritive value. The aim of the research was to evaluate the impact of mineral N rate in different management systems in the static long-term experiment with three years field rotation of grain maize, wheat and barley on the chemical composition of winter barley and its nutritive value for ruminants. Crude protein content and metabolizable crude protein content were increasing with increased mineral N rates. Higher yield meant lower crude protein and metabolizable crude protein content in all mineral N rates. The average crude protein content of barley grain, presented in DLG tables (1997), which is 12.4%, was in MM and SM reached by fertilising rate 110 kg N/ha. A significant impact of mineral N fertilising on crude ash, ether extract and crude fibre content could not be confirmed, nitrogen-free extract content was decreasing with increased mineral N rates. A significant impact of the management system on the Weende analysis parameters, net energy for lactation, metabolizable energy and metabolizable crude protein could not be confirmed. At both analyses a significant impact of the season was confirmed on crude protein content and nitrogen-free extract content. Although the protein content was increasing with increased mineral N rate from 9.2-14.2% (for 35%) ME content and NEL content did not significantly differ considering mineral N rate; ME/ha and NEL/ha increasing with increased mineral N rates was the result of the yield increasing with increased mineral N rates.

Height and diameter growth and volume production of 22 different clones of poplars were evaluated in Sliepkovce populetum at the age of 12 years. The populetum is situated on medium-heavy and medium humic uninundated alluvia of the Laborec river; typologically, the group of forest types is Ulmeto-Fraxinetum populeum. The results of evaluation documented that among the poplars under study the clones Gigant, OP-229 and BL achieved the best growth and maximum volume production while their mean height amounted to 22.9-23.8 m, mean diameter to 31.9-33.2 cm and average annual volume increment was 25.1-28.3 m³ per 1 ha. The growth of P. Rochester 20/66 poplar was considerably much slower: its mean height amounted to 17.3 m, mean diameter to 18.7 cm and average annual volume increment was 6.3 m³ per 1 ha. It will be necessary to carry out further studies to obtain more detailed values for these clones.

There are 80% municipalities under one thousand inhabitants in the CzechRepublic. The population trend observed in the region ofSouth Bohemia has proved a long-term and gradated depopulation of such small municipalities. While population has fallen in municipalities under one thousand inhabitants, towns and municipalities with more than one thousand inhabitants show the opposite trend. The possibility of changing this trend seems to lay in the state help for small municipalities parallel with the expected change of the situation after the EU accession because it is very probable, that many young families will be looking for the financially more convenient living in the country.

The analysis is made in the set of the selected foodstuffs wholesales in the Slovak Republic and shows their differences from the viewpoint of the size (sale place 15 m2-1 300 m2 , storage space 106 m2-6 500 m2 ), number of workers (1-81) and yearly turnover (219 thousand SKK-2 748 thousand SKK). The main part of wholesales is operated by owners (83%) and a small part (17%) is on lease. From the viewpoint of location, the wholesales are situated in the centre of town (50%) and village (27%). The rest is located in the habitations and suburbs of town. The competitive wholesales (43%) are situated in the distance from 11 to 500 m. The highest labour productivity was obtained at the wholesale with location in the suburbs of town and the distance from competitive firms is about 500-1 000 m. Suitable results were achieved in the wholesales on lease with location in the suburbs of towns. The efficiency of wholesales was affected by the main factors, including the number of workers, size of sale place and storage space which determined up to the 92% of the volume of yearly turnover.

In 1998 and 1999 a total of 84 samples of corn, predominantly from localities in southern and central Moravia, were collected either directly from fields (entire ears at harvest maturity) or as grain from merchants. The objectives of the experiments were (a) to determine, on the basis of the results from mycological and toxicological analyses, the basic spectrum of fungal contaminants of corn in the Czech Republic with special reference to the genus Fusarium, and (b) to determine by enzyme immunoassay the presence of major toxic metabolites such as deoxynivalenol (DON), T-2 toxin (T-2), zearalenone (ZEA), and fumonisins (FUM) in grain samples. From naturally infected corn, representatives of seven fungal genera were isolated under in vitro conditions in both harvest years. Most frequent were species of the genus Fusarium (mean contamination of 44.6%). The next frequent genus was Stemphylium (29.3%). Eight species of Fusarium were found. In both years the most frequent species was Fusarium graminearum (1998 - 42.75%, 1999 - 41.8%), followed by F. culmorum. DON was found in 95.2% of the samples; its content ranged from 25 to 285 µg/kg. The content of T-2 varied more than that of DON, ranging from 12 to 875 µg/kg. Zearalenone content was more varied than that of the trichothecene-type compounds; 17% of the samples did not contain ZEA, the maximum content was 110 µg/kg. No FUM were found in 17% of the samples; in the others, FUM ranged from 12 to nearly 1000 µg/kg. Compared with the other three compounds, fumonisins showed generally the highest levels.

An effective and fast method for determination of deoxynivalenol (DON) in cereals and flours has been developed. The immunoaffinity column was used for the isolation of DON from wheat, corn, rice and flour extract. The determination was carried out by using the HPLC/UV method. The limit of detection was 0.02 mg/kg. The recoveries for the assay range 0.1 to 2 mg/kg were generally higher than 80%, ranging from 83 to 96% with an average relative standard deviation of 3.8%. The trueness of the method using the DON test - HPLC column was established by use of certified reference material CRM 379. The certified value was 0.67 mg/kg. The result obtained from three replicates was 0.68 ± 0.05 mg/kg. The corresponding confidence interval at 95% probability ranged from 0.63 to 0.73 mg/kg. A comparative study of the DON testTM - HPLC/UV and the Mycosep 225 - GC/ECD methods was carried out. Six naturally contaminated wheat samples were analysed by both methods. Linear regression analysis demonstrates that DON testTM - HPLC is a statistically significant predictor of the GC/ECD method using the Romer Mycosep 225 column.

Field resistance can contribute to reductions in epidemic progress of Septoria tritici in winter wheat. Crop growth andcanopy architecture are identified as key mechanisms of field resistance. Near isogenic lines differing for dwarfing (Rht)and photoperiod sensitivity (Ppd) genes, enabled the study of target traits in a constant background of genetic resistance.Epidemics were consistently earlier in shorter crops across a range of environments. The mechanism for this effect wasidentified as an increase in spore arrival due to a reduction in the required dispersal distance between infective tissueand emerging upper culm leaves.

The occurrence and virulence of wheat yellow rust in Hungary was studied in the period of 1999-2001. Yellow rust in Hungary occurred only in traces in 1999, strongly spread and reached epidemic level in Röjtökmuzsaj (West Hungary) in 2000, and the epidemic explosion was in the whole country in 2001. Surveys of yellow rust showed the importance of pathotypes, whose virulence spectra (virulent for Yr2, Yr3, Yr6, Yr7, Yr8, Yr9, Yr17, YrA+, YrCV, YrSD) were able to math the unknown resistance genes. Among 78 Hungarian and foreign cultivars 29 were strongly infected by yellow rust.

In 1999-2001 in field trials two different apple scab control strategies were compared: (i) the current strategy - conventional disease management (CDM) and (ii) integrated disease management (IDM), according to scab infection periods. A new scab warning equipment METOS^R-D was used for detection of infection periods and forecast of disease intensity at three levels: light, moderate and severe. According to CDM apple-trees were sprayed 9 times a season. Scab warning equipment gave a possibility to optimize the use of fungicides against scab and to reduce the total spray applications per season in average till 6.3 in very susceptible cultivars and 5 in moderately susceptible ones. This is 30 and 44% less spray applications comparing with CDM. Annual spray program ranged from 5 till 8 spray applications of very susceptible cultivars. CDM and IDM gave high scab control in apple-trees and there was not found any essential difference in scab incidence between two control strategies.