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Two high yielding wheat (Triticum aestivum L.) varieties were pollinated with seven agrarian superior varieties. F₁'s thus obtained were pollinated with diverse winter maize lines/composites and treated with a solution containing 2,4-D and GA₃. The haploid embryos were rescued 13 to 16 days post pollination on MS₁ and MS₄ media. Out of 15, only two crosses viz., (UP 2338 × HD 2285) F₁ × maize and (WH 533 × PBW 343) F₁ × maize resulted in callus development and direct germination via embryo rescue.

Seedling emergence is one of the most important factors in the establishment of optimum plant density for a maximum yield. Seed quality and seedbed conditions affect seedling emergence. Seedbed condition is affected by soil content, especially soil organic matter. Therefore, the objective of this study was to determine the effects of soil organic matter on germination and seedling emergence of three hybrid sunflower (Helianthus annuus L.) cultivars. This research was conducted in 2000 and2001 in field and glasshouse conditions. Perlite and 20 soils with different organic matter contents were used as seedbed conditions. Soil organic matter, environment, and soil organic matter × environment factors had significant effects on seedling emergence. Decreasing soil organic matter content resulted in a decrease of seedling emergence due to the decreases in water content of the soil. This effect was clearer in adverse environmental conditions, especially in the soils with less than 2% organic matter.

A vegetation pot experiment was established to explore the effect of two doses of nitrogen (0.6 and 0.9 gN in the form of ammonium sulphate) and two doses of sulphur (20.6 and 30.6 mg/kg of soil) on the yields and quality of spinach and pepper in comparison with a natural level (7.85 mg/kg). The results of the experiments confirmed that the application of sulphur by means of (NH₄)₂SO₄ in combination with nitrogen had a positive effect on yields and also on the quality of the vegetables. In the sulphur-free variants of spinach the effect was statistically significant and also when the levels of S in the soil were higher. Lower doses of nitrogen under increased levels of sulphur increased the yields statistically significantly (on average by 47%) and the sulphur concentration in the plants increased. The N:S ratio became narrower in proportion with the level of sulphur, particularly under a lower N level. The nitrate content in spinach corresponded with the applied dose of nitrogen and the nitrogen concentration. The sulphur level did not influence the content of C vitamin, but had a positive effect on the content of the essential amino acids cysteine and methionine. A mean level of S₁ in combination with a N₁ dose significantly increased pepper yields, narrowed the N:S ratio and was reflected in dry matter production per 1 g of N. The highest pepper yields were achieved with a dose of S₁, which resulted in the highest dry matter production in the fruit per1 g of N under both levels of N. At the same time increasing the sulphur level reduced the content of nitrate and increased the level of cysteine from 0.11 to 0.305 g/kg.

Pot trials and field studies were carried out to describe the influence of soil pH and rainfall on the phytotoxic effect of the herbicide Merlin 750 WG (isoxaflutole) in maize. Symptoms as bleaching, and root and shoot weight reduction in early growth of maize were found. In pot trials, a statistically significant crop injury in early growth of maize was found only at the herbicide dose of 100 and 130 g/ha followed by 30 mm precipitation directly after herbicide application in soils with pH 6.5 and 7.2. Bleaching and significant weight reduction of maize up to growth stage BBCH 13 were observed in field trials at treatments with early post-emergence application of Merlin and 20 mm precipitations. Bleaching symptoms recovered up to BBCH 19. Significant differences were found in maize shoot weight and cob yield between treatments with and without watering (20 mm irrigation), and between pre- and post-emergence application of Merlin under field conditions. No significant differences were found between herbicide doses tested.

The effect of dimethylarsinic acid (DMA) on the growth of radish and the content of As compounds in roots and leaves of the radish were investigated. Radish was grown in pots in three soils (Fluvisols, Chernozems and Luvisols) amended with 20 mg As/kg of soil in form of DMA. Behavior and transformations of DMA in the soils differed depending on the individual soil type. In the first season, plants grew up at Luvisols only. In the second season the plants were able to grow at Luvisols and Chernozems, too. The roots and leaves of radish from Luvisols had DMA as the dominant arsenic compound present (~ 90% in the extract) in the first season. In the roots of the subsequently growing radish DMA accounted for 20% and arsenite for most of the total arsenic in the extract. In the leaves of the second-crop of radish DMA remained the dominant arsenic compound (~ 60% in the extract) with arsenate and arsenite for the remaining 40%. Roots and leaves of radish grown in Chernozems and Luvisols had a similar pattern of arsenic compounds. Soil properties significantly affected transformation of As species in the soils. At Fluvisols was the lowest As immobilization and about 98% was found as DMA after two years of experiments in the other two soils was higher As immobilization and DMA was recovered to inorganic As (V) - 31% in Luvisols and 78% in Chernozems.

Soil organic matter is important in controlling heavy metal behaviour in soils. This study aims to determine the distribution of organically bound Cd, Pb, and Zn between humic and fulvic acids in 20 samples of heavily polluted Fluvisols. Traditional procedure of alkaline sodium hydroxide/pyrophosphate extraction of humic substances with consequent humic acids precipitation by acidification was used. All of the three metals were bound predominantly on fulvic acids (mean share was 98.4, 82.0, and 95.7% of total organically bound Cd, Pb, and Zn content, respectively). Mainly the level of pollution controlled the amount of metals bound on fulvic acids. On humic acids, a limited amount of specific sorption sites for the metals is expected. Lead content bound on humic acids was negatively correlated with soil pH. The results suggest relatively high potential mobility of organic fractions of heavy metals in soils under this study. The selectivity of alkaline extracting agent is briefly discussed.

An average dry matter yield structure (three cuts per growing season) in relation to agronomically valuable characteristics of six forage grass species and a year of herbage utilization was studied over the period of 1989-2002 in Lithuania. The most productive species of the first cut of two years of herbage utilization were Phleum pratense (P < 0.01) and Festulolium hybrids (P < 0.05) (average dry matter yield were 7.42 and 6.66 t/ha, respectively), moderately productive - Festuca pratensis, Dactylis glomerata and Lolium perenne (5.58, 5.42 and 5.20 t/ha), significantly lower (P < 0.01) yielding was Poa pratensis (4.19 t/ha). During two years of herbage utilization Dactylis glomerata produced significantly (P < 0.01) higher dry matter yield of aftermath - 7.30 t/ha. Other grass species were ranked in the following order: Festulolium hybrids 5.85 t/ha, Festuca pratensis 4.94 t/ha, Poa pratensis 4.57 t/ha, Lolium perenne 4.48 t/ha, and Phleum pratense 3.92 t/ha. Dactylis glomerata and Poa pratensis distinguished by the highest aftermath percent in the structure of the annual dry matter yield (57.7 and 52.2%). Phleum pratense formed an especially poor aftermath - only 34.6%. An average annual dry matter yield data analysis of two years of herbage utilization over the period of 1989-2002 showed that Dactylis glomerata and Festulolium hybrids were most productive (P < 0.01) species.

Incidences of powdery mildew were repeatedly evaluated for two years on 1 420 young seedlings of 20 progenies (of different levels of mildew susceptibility) in a green house, and then for 10 years on 642 seedlings in an orchard. Part of the seedlings in the orchard were pre-selected for the characteristic and others not. Except for the first scoring done in the first year, there was no correlation between mildew incidence on individual seedlings in the green house and their mean performance in the orchard. The seedlings with scores above 6 (resistant or tolerant) at the first stage of evaluation in the green house, however, yielded four times more desirable seedlings after final selection in the orchard than the mean of the total. The progenies that had a better healthy state as a whole yielded more partially resistant genotypes than those with low mean scores. Therefore, the progenies that most rapidly develop infestation on the whole lot should be discarded, whereas those that retain a healthy state longer should be subjected to individual selection according to the previous item.

Spatial variability of soil mineral nitrogen N_min (N-NH₄⁺, N-NO₃^-) in a soil profile down to 60 cm was determined in a 19-ha experimental field in Prague-Ruzyně for four years. Winter wheat was grown in the years 2000 and 2001, oats in 2002 and mustard in 2003. Root length distribution and depth of the crops were determined at four locations representing different soil conditions within the experimental field. The coefficient of variation as the measure of the variability of nitrate N in topsoil and subsoil (0-30 and 30-60 cm, respectively) in the experimental years ranged between 18-39 and 20-37%, respectively. It was mostly the same or slightly greater in subsoil than in topsoil in respective years. The variability of ammonium N in topsoil and subsoil ranged between 4-58 and 11-27%, respectively. It was similar in topsoil and subsoil, except for autumn 2000. There was a positive relation between nitrate content in top and subsoil on all sampling terms. We did not find a relationship between N_min contents in experimental years. Spatial dependencies were evaluated on the basis of model variogram parameters. The nugget value expressed as a percentage value of the total variogram's sill was used for the class of spatial dependence determination. When a spatial dependence of the observed factor was found it was within a range of medium-strong dependence. Only in two cases a strong spatial dependence was found. A considerable variability was also found out in the variogram's range, which was between 61 and396 m. All these facts pose a problem for further actions, such as appropriate design of a sampling grid, measured data spatial interpolation and application maps design.

The aim of this study was to determine the effect of cadmium (10, 20, 30 and 40 mg Cd/kg of soil) contamination in soil with the application of different substances (compost, brown coal, lime and bentonite) on the intake of nitrogen by some plants. The correlations between the nitrogen content in the plants and the cadmium concentration in the soil, as well as the plant yield and the content of micro- and macroelements in the plants were determined. Plant species and cadmium dose determined the effects of soil contamination with cadmium on the content of nitrogen. Large doses of cadmium caused an increase in nitrogen content in the Avena sativa straw and roots and in the Zea mays roots. Soil contamination with cadmium resulted in a decrease of nitrogen content in the Avena sativa grain, in above-ground parts and roots of the Lupinus luteus, in the above-ground parts of the Zea mays and in the above-ground parts and roots of Phacelia tanacaetifolia. Among the experimental different substances, the application of bentonite had the strongest and a usually negative effect on the nitrogen content in plants. The greatest effect of bentonite was on Avena sativa grain, above-ground parts Zea mays and Lupinus luteus and Phacelia tanacaetifolia. The content of nitrogen in the plants was generally positively correlated with the content of the macroelements and some of the microelements, regardless of the substances added to the soil.

Tilletia controversa and Tilletia caries were specifically detected in wheat plants by PCR using primers TILf (5´-CAC AAG ACT ACG GAG GGG TG-3´) and TILr (5´-CTC CAA GCA ACC TTC TCT TTC-3´). DNAs from uninfected wheat, rye, barley and triticale were not amplified. Natural infection of control plants by other species of fungi as Alternaria spp., Erysiphe graminis and Fusarium spp. proved the specificity of the test because even in this case no unspecific products were formed. This method can be very useful both for seed producers and for state officers checking the seed quality.

Sewage sludge application in agriculture is the simplest method of its management. Its content of organic and inorganic toxic components is a barrier to such management. Particular attention should be paid to the content of heavy metals whose presence in sewage sludge and later in soil poses hazard for plants, animals and people. The investigations aimed to determine the effect of vermicomposts obtained from tannery sludge on development of the root system and biomass of shoots as well as heavy metal concentrations in these organs. In the first year after the vermicomposts application their effect on the maize biomass increase was equal to the farmyard manure treatment but significantly worse than the mineral fertilization. The consecutive fertilizer effect of vermicomposts of tannery sludge ted on the increase in biomass of the shoots and roots of winter rape, sunflower and oats was comparable with the farmyard manure effect but notably better than the mineral fertilization. Heavy metal concentrations in individual plants were diversified; in the plants from vermicompost treatment they were as a rule lower than in the plants from mineral or farmyard manure treatment. Absorbed heavy metals accumulated primarily in the root systems, whereas the extremely high chromium content in vermicomposts did not cause its excessive accumulation in the cultivated plants.

This paper deals with the influence of Mg, N and the content of chlorophylls and carotenoids on photosynthetic productivity of two new genotypes of winter wheat, Lara and Perla, at two localities, Donji Miholjac and Kutjevo, during the vegetation periods 1997/1998 and 1998/1999. The applied parameters were determined by standard methods. The results showed effects of Mg concentration on all examined parameters with the exception of chlorophyll b content. The highest correlation coefficient was with the N concentration, significant correlation between the leaf area and N concentrations and between the leaf area and chlorophyll a. Statistical analysis showed very significant relationship between the content of organic matter and examined parameters with a large number of significant correlations. The most important correlation was found between the content of organic matter and N concentration, and between chlorophyll a, chlorophyll b, carotenoids and the content of organic matter. The link between N, Mg and other examined parameters was firm and significant as well as under strong influence of external factors.

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.

Twelve carbonaceous materials were investigated for adsorption of Cd, Cu and Ag from water solutions. Before the adsorption experiments the chemical and structural characterization of all materials were made. The batch adsorption experiment was used. The kinetic of the adsorption process was very fast for the first five hours but very slow for approximately the next 65 hours. Nevertheless the maximum amount of metal removed was achieved during the first stage of about five hours. Biological materials (milled wood, bark, cork) exhibited a very low affinity for adsorption of metals. The best results were obtained for materials in an intermediate degree of carbonisation with a high content of oxygen rich functional groups. Although the highly carbonised materials exhibited low ability to adsorb copper or cadmium, their capacity to bind silver was very high.

The distribution of cadmium, lead and zinc in exchangeable, organic, and 2M HNO3-extractable fractions as well as the effect of heavy metal concentrations on soil microflora was investigated. Six sampling transects were chosen in theLitavkaRiveralluvium in 1999-2001. Concentrations of all metals increased with decreasing distance from the source of contamination. The concentrations of Cd and Zn in exchangeable fraction were higher than in organically bound fraction, a reverse trend was found in Pb speciation. All measured parameters of soil microbial activity were affected by heavy metal concentrations. The decrease in CFU was most significant in the case of oligotrophic bacteria and spore-forming bacteria. Significant inhibition of C-biomass occurred in soils highly contaminated by heavy metals. The Cbiomass:Cox ratio decreased with increasing soil pollution. Generally, the values of enzymatic activities were highest in the soil above the source of contamination and they were decreased as approaching the source of contamination. Our results demonstrate that several parameters of microbial activity could be used as good indicators of increasing concentrations of Cd, Pb, and Zn in soil.

In a microplot experiment conducted in 1999 and 2000 on light soil triticale and field beans were grown as sole crops and in the intercrop system. Two pure stand plant densities were established: 200 and 400 plants/m² for triticale and 50 and 100 plants/m² for field beans. Four possible intercropping combinations were obtained by adding densities of both crops. Triticale was a better competitor than field beans in all intercrops resulting in competitive balance index significantly greater than zero. The number of pods per plant of field beans was significantly reduced in all intercropping combinations compared to the pure stands, however quality of grain of the legume was unaffected by competition. Intercrop comprising 200 plants/m² of triticale and 50 plants/m² of field beans was most productive in the experiment but addition 50 more plants/m² of the legume decreased significantly grain yield of intercrop by 16.2%. The results also show that effective triticale-field beans intercrop for light soil may be designed as additive one, based on 400 plants/m² of triticale.

The influence of tillage (conventional and non-tillage) on selected soil microbial properties was studied. The experiment focused on tillage that was launched in Prague-Ruzyne in 1997. The experiment included the following variants: conventional tillage, protective tillage (without post harvest residues), protective tillage (with residue biomass - mulch), protective tillage (covered by pea crop residues for winter wheat, with fore crop). In the field experiment there were tested: enzymatic activities (activity of urease, dehydrogenase, arylsulfatase and invertase) and microbial biomass. The microbial biomass and soil microbial processes were affected by tillage. Our results show the positive influence of protection tillage on selected biological parameters, especially in variants where soil was supplied with organic matter.

This paper deals with the recent sissoo (Dalbergia sissoo Roxb.) decline in the plain land (locally called as terai) of Nepal. This study has made an attempt to find the possible causal factor of this decline. The study has made some initiative in this aspect and has made a comparative study of 30 different sissoo forest (both natural and plantation) stands. The symptoms of the sissoo decline were found to be varied. But in most of cases, the top dying of crown was found to be the most prevalent. The top dying starts from the top of the tree and progressively proceeds downwards to the stem. The leaves become yellow. Until now, it has been assumed that only the plantation forests have been affected but this study observed the sissoo decline also in natural forest sites. We analysed various components of physical soil characteristics and we did not find any correlation between the physical soil factors and the sissoo decline. We concluded from this study that the soil is not the sole responsible factor involved in the sissoo decline Furthermore, this paper discusses various aspects of the sissoo decline and possible causal factors concerned. Finally, future management strategies regarding the sissoo management are suggested.

Carbon and nitrogen transformations in soil are microbially mediated processes that are functionally related. The fate of C and N was monitored in a clay-textured soil (Typic Haplocambid) which was either unamended (control) or amended with various plant materials at the rate of 10 g residue C/kg soil. To evaluate C mineralization, soils were incubated for 46 days under aerobic conditions. Nitrogen mineralization/immobilization was evaluated at the end of eight-week incubation experiment. All CO₂ evolution data conformed well to a first-order kinetic model, C_m = C₀ (1 - e^-Kt). The product of K and C₀ (KC₀) was significantly correlated with some chemical and biochemical properties of the plant residues, including N concentration (r = 0.83, P < 0.001), C:N (r = -0.64, P < 0.05) and lignin:N (r = -0.81, P < 0.001). Among the plant residue composition characteristics, N concentration (r = 0.96, P < 0.001), C:N (r = -0.69, P < 0.01) and lignin:N (r = -0.68, P < 0.01) were significantly correlated with the net rates of N mineralization/immobilization (N_m/i).

N fertilization has a substantial influence on sunflower (Helianthus annuus L.) seed yield and quality. It was also well established that high-yielding sunflower hybrids had more N requirement than old cultivars such as open-pollinated ones. However, in Turkey, no sufficient information regarding the response of new developed oilseed sunflower hybrids to nitrogen fertilization under irrigated conditions. Therefore, a 2-year study was conducted to determine the effects of nitrogen application rates on the growth, yield, and yield components of two oilseed sunflower hybrids (AS-508 and Super 25) under irrigated conditions. In this study, all plant parameters were significantly influenced by applied nitrogen fertilizer rates. Yield response to nitrogen rates was positive and linear. Our research data indicated that under irrigated conditions N rate of 120 kg/ha was adequate for sunflower production in this region.

The apparent uptake of mineral nitrogen (N_min) from top- and subsoil layers during the growth of winter wheat (Triticum aestivum L.) was studied in Prague-Ruzyne on clay loam Chernozem soil in years 1996-2003. Two (N0, N1) and three treatments, unfertilized (N0), fertilized with 100 kg (N1) and 200 kg (N2) nitrogen per hectare were observed in years 1996-2000 and 2001-2003, respectively. The apparent uptake of nitrogen from soil layers was calculated from the changes of N_min content between sampling terms. Most of available mineral N in the soil down to 90 cm was almost fully depleted between tillering and anthesis in treatment N0. The uptake from subsoil layers was delayed and it continued during the period of grain filling in fertilized treatments. Nitrogen fertilization reduced utilization of N from subsoil. The apparent uptake of N from the zone 50-120 cm ranged from 21 to 62 kg N/ha in N0 and from 15 to 60 kg N/ha in N1 in years 1996-2000. In years 2001-2003 the corresponding values (50-130 cm) were 24-104 kg, 43-130 kg and 29-94 kg N/ha in treatments N0, N1 and N2, respectively. The uptake from 120 (130)-150 cm was around zero in a half of experimental years, and it reached at maximum 12 kg/ha in N0 in 1997. There was a strong linear relation between the amount of N_min in spring and the depletion of nitrogen from the zone 50-120 (130) cm, R² = 0.94, 0.91 and 0.99 in N0, N1 and N2, respectively.

The objective of the paper was to determine an appropriate concentration of available sulphur in soil for the initial growth of plants. Based on previous researches two methods of soil extraction were used to acquire information on the soil reserve: water extraction (H₂O 1:5, w/v) and extraction in 0.5M ammonium acetate with addition of NH₄F (KVK-UF soil test). Spring barley was used as a test crop to determine the soil reserve of sulphur and its response to sulphur addition to the soil. A collection of 48 samples of topsoil from agriculturally important localities in the CR was made up for this purpose and the parameters of the nutrient status of the soil were remarkably different. A set of soils was used to establish short-time vegetation experiments in a plant growth chamber according to the scheme: A) control - without sulphur application and B) response variant with application of 30 mg S/kg of soil in the form of (NH)₄SO₄; nitrogen in variant A was adjusted by application of NH₄Cl. Index of nutrient efficiency (IE = Y/N where Y = yield and N = nutrient concentration in the plant) and boundary lines of the point field were used to evaluate the efficiency of barley nutrition with sulphur. The efficient soil reserve of sulphur for the soil test H₂O (1:5) when the ICP analytical technique was used was indicated in the range of 8-11 mg S/kg; 6-10 mg S/kg for sulphate detection on a SKALAR analyser. The efficient utilisation of sulphur by barley plants for the KVK-UF soil test was in the range of 7-12 mg S/kg. The conversion of the KVK-UF S-test to the index of soil reserve of sulphur by adding up a variable portion of the CEC value to the value of sulphur determined by the soil test (0.0167CEC + 9.1667) improved the closeness of the relationship between soil and plant.

In 2001-2004, the influence of various ways of farming unmanaged grasslands on the mineral nitrogen content in lysimetric waters was monitored. Field trials with 11 variants were performed 420 m above sea level, at depths of 0.2 and 0.4 m, 4-5 times annually. The average amount of N_min released per ha per year in lysimetric waters ranged from 0.84 to 5.12 kg. The upper layer to a depth of 0.2 m had a higher content. The conclusive difference, in comparison with properly farmed control, was with the black fallow and in the variant where fallow followed mulching. With the exception of this method of farming the pratotechnics of unmanaged grasslands - mulching did not increase the load of rhisosphere, either by the overall mineral nitrogen, or by the concentration of N-NO₃^-. Even by using fallow for a four-year period, a conclusive increase in the content of N_min was not observed.

The goal of the investigations was to assess the average contents of heavy metals (Pb, Zn and Cd) in the surface soil layer (0-30 cm), in drainage water and their uptake by growing plants, in the experimental amelioration field for four different variants of drainpipe spacing (15, 20, 25 and 30 m) during the three-year period. Maize and winter wheat were grown in all variants throughout the trial period. In all variants of drainpipe spacing, heavy metals in soil, drainage water and plant material were within the limits. The highest average level of Pb was 13.5 mg/kg, Zn 88 mg/kg and Cd 0.7 mg/kg in soil. Drainage water concentration of heavy metals was below 50 µg/dm³ for Pb, below 2 µg/dm³ for Cd, while the highest average value of Zn amounted to 20 µg/dm³. In grain of the crops grown, the concentration of Pb was below 0.4 mg.kg-1 and that of Cd below 0.1 mg/kg.

During growth, kernel of cereals can be provided with carbohydrate and nitrogen (N) from the translocation of pre-anthesis accumulated reserves stored either in the vegetative plant parts or from current assimilation during kernel development. This study was conducted to assess the effects of nitrogen level and cultivars on dry matter and N accumulation and mobilization during pre-anthesis and post-anthesis. Twenty two-rowed spring barley (Hordeum vulgare L.) cultivars were grown on a non-calcareous chernozem soil in four growing seasons (1995-1998) atNovi Sad (45°20'N, 15°51'E,86 m a.s.l.) at two nitrogen levels. Dry matter accumulation before anthesis ranged from less than 50% in unfavorable to 90% in favorable growing conditions. Dry matter translocation occurred in favorable growing conditions only. Pre-anthesis accumulated N represented 57-92% and 54-129% of total N at maturity at the low and high N levels, respectively. Translocated N represented 41-85% and 37-153% of grain N at the low and high N level, respectively. N losses occurred in favorable growing conditions when anthesis N exceeded 150 kg/ha. N accumulation during grain filling was in negative correlation with dry matter and N accumulation before anthesis. The N harvest index was 0.57-0.63 and 0.71-0.74 in unfavorable and favorable growing conditions, respectively. Selection of genotypes with a higher ability of pre-anthesis reserve utilization or genotypes with longer leaf area duration after anthesis may be two possible solutions in spring barley breeding for Mediterranean growing conditions.

In 1997 and 1998 we used samples of harvested grain to verify the possibility of distinguishing 14 winter wheat genotypes and six triticale genotypes and detecting the impurity on the basis of the detection of polymorphism of prolamin kernel proteins using the methods of the PAGE ISTA. On the basis of the identity index two sister prolamin lines with different percentage of participation, which was based on the weather conditions of the year of harvest, were discovered in seven wheat genotypes (Astella, Brea, Hana, Ilona, Siria, Sofia and Šárka) and two triticale genotypes (Tornádo and KM 779). A foreign genotype was detected in the Hana and Astella varieties. The identity index of the impurity to the Astella and Hana variety (i.e. ii = 0.28 and ii = 0.20, respectively) was considerably lower. In an unknown genotype (impurity) we detected the gliadin block Gld 1B3, which is the genetic marker of rye translocation T1BL.1RS, the Sr31 gene of resistance to black rust, higher cold resistance and the marker of poor baking quality (presence of secalin genes). The results proved the potential practical application of the method of electrophoretic detection of polymorphism of prolamin proteins as markers of impurities of foreign genotypes in a seed sample.

Market varieties of hops are classified to several groups according to their use in the brewing industry - aroma, bitter (dual-purpose), high-alpha ones. Saaz and other genetically related varieties form a separate group among the aromatic hops. The group called fine aroma hops has a low content of a-bitter acids (3-4% w/w), its content of b-bitter acids is in the range of 4-7% w/w and cohumulone ratio in the interval of 23-26% rel. The composition of hop oils is characterised by the content of b-farnesene in the range of 15-20% rel. and trans-a-bergamotene at the amount of ca. 1% rel. Most market varieties of hops are of hybrid origin. It holds true about the Czech varieties Sládek, Bor, Premiant and Agnus. The content of a-bitter acids in bitter varieties is in the range of 7-10% w/w while the content of a-bitter acids in high-alpha hops is higher than 10% w/w.

The influence of accelerated ageing test (AAT), i.e. of higher temperature and humidity, on the content and composition of phenolic compounds in the grains of five cultivars of wheat (Triticum aestivum L.) was studied in the years 1998 and 1999. Total polyphenols were determined spectrophotometrically by Folin-Ciocalteau's phenolic reagent and free phenolic acids by an HPLC method in control samples and after deterioration treatment (AAT) in the Ebi, Estica, Nela, Samanta and Šárka cultivars. Statistical significance of deterioration treatment, cultivar, cultivation site, and harvest year was proved. Content of total polyphenols increased during deterioration and levels of the individual free phenolic acid changed depending on their structures. Mean contents of total polyphenols varied from 600 to 960 mg/kg of dry matter. The increase caused by the AAT ranged between 0-20%, the greatest mean increase was observed in the cultivar Nela (by 19%). Sinapic acid (as high as 540 mg/kg of dry matter), 3-hydroxy-benzoic acid and 7-hydroxycoumarin were determined as the major phenolic acids and coumarins. A decrease of free phenolic acids containing methoxy groups in their molecules (sinapic and vanillic acids) and an increase of phenolic acids with free hydroxy groups (caffeic and gallic acids) was observed after deterioration treatment. Statistically significant (P ≤ 0.05) effect of AAT on the content of free phenolic acids was observed.