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We monitored the presence of Listeria monocytogenes in environmental sources and to evaluate the phenotypic and molecular characteristics of the isolates recovered. L. monocytogenes was isolated in 12 (11.2%) of the 107 samples from the wild, farm environment, and vegetation. Most isolates (83.3%) were of serotype 1/2a and the remainder (2) were of serotype 4b. All 12 isolates were susceptible to the whole range of antimicrobials tested. These12 strains were carriers of the virulence genes prfA, hlyA, actA, plcA, plcB, inlA, inlB, inlC, and inlJ. The detection of the inlA gene in 4 (33.3%) of 12 strains using the PCR-RFLP suggests the potential of some of these strains to penetrate into epithelial cells of the intestinal barrier. Macrorestriction analysis also confirmed clonal identity of some environmental isolates with food and human isolates. These results indicate that the external environment is a source of potentially pathogenic strains of L. monocytogenes.

The effect of inoculation with Pseudomonas fluorescens and Bacillus subtilis on the yield of fresh and dry mass of English ryegrass (Lolium perenne L.) as well as on the number of rhizospheric microorganisms was studied. The microorganisms were introduced into the soil before sowing. The control plots were not inoculated. The number of microorganisms was determined after the third mowing. The yield was determined after the first, second and third mowing. In comparison with the control, after the first and second mowing, there was a statistically significant increase in the fresh and dry mass in both inoculated variants whereas after the third mowing, a statistically significant increase in the yield of fresh mass was recorded only in the variant with B. subtilis. The use of B. subtilis had a better effect on the total yield of the fresh and dry mass of English ryegrass. The number of the investigated groups of microorganisms, apart from actinomycetes, increased in the inoculated variants. Inoculation of P. fluorescens affected the increase of total number of bacteria and aminoheterotrophs whereas inoculation of B. subtilis affected the increase of the number of azotobacter and fungi.

Sheath rot of rice and leaf blight of wheat caused by Pseudomonas syringae pv. syringae are the important bacterial pathogens of rice and wheat in Iran. The randomly amplified polymorphic DNA (RAPD) method was used to investigate the genetic diversity of 60 strains of P. s. pv. syringae obtained from rice and wheat in different growth stages. Cluster analysis by UPGMA method showed that strains were grouped into two clusters. The AMOVA analysis indicated that about 18% of the total genetic variation existed between two populations of rice and wheat, which showed the lack of host specialization in P. s. pv. syringae strains among rice and wheat. We confirmed that high genetic heterogeneity existed in the P. s. pv. syringae strains which are detectable by RAPD analysis, and that molecular and statistical analysis of RAPD fragments can be used both to distinguish between strains and to determine relatedness between them.

We compared the results of calf maternal nursing and cow performance in 5 beef breeds managed under equal conditions in the region of West Pomerania. The study involved 549 cows and 1 979 calves (1 007 heifers and 972 bulls) of the following breeds: Red Angus, Salers, Hereford, Limousin, and Simmental. The cows and their calves were managed outdoors for one year. Feeding and management systems were the same for all the breeds during the studied period. The calves remained with their mothers until 6 to 9 months of age. Under intensive feeding, we recorded very good calf rearing parameters with very good or good milk performance of the cows. The best results were achieved by the Simmental cows and calves. Both the heifers and calf-bulls of this breed exhibited significantly (P ≤ 0.01) higher weaning weights adjusted to 210 days of age as well as daily gains from birth to weaning. The weaning weights of the calves were higher from 37 to 93 kg and daily gains from 45 to 280 g. The Hereford cows and calves also achieved very good parameters. Relatively poorer in terms of production performance were Red Angus, as compared with the other breeds, and Limousin cows whose calves produced the lowest body weights and had the lowest daily gains as well.

The SBM (stabiliser of biomass) mechanical plant model is designed for the hydrothermal treatment of biologically degradable materials with using the principle of thermal hydrolysis. The primary task of this equipment is to subject biologically degradable materials to hydrothermal treatment and to recover the materials for a further use or to eliminate them. These entities could use the mechanical plant for economic and environment-friendly methods of handling biologically degradable wastes or materials. The objective of the experiment with various types of biologically degradable materials was to establish the level for the transformation of input characteristics of tested materials after conversion in the SBM mechanical plant and to assess the suitability of the processing by using this method with respect to the use of the final product. Materials tested in the first experiments included stable manure heated or unheated during the processing and maize silage wastes in mixture with wood chips.

The present factorial experiment tested the thawed rumen fluid from frozen rumen contents against fresh rumen fluid from the same slaughtered cattle to estimate in vitro degradation of rapeseed meal (RSM) and grass nuts (GN) as two contrasting feeds at various times. Fresh rumen fluid showed higher (P < 0.05) in vitro dry matter (DMD) and crude protein (CPD) degradation than the thawed rumen fluid at most incubation times. Significant differences (P < 0.05) were found between fresh and differently prepared thawed rumen fluids for mean degradation constants (a, b, c) and effective degradability (P_0.02) of feeds. While the thawed rumen fluids had lower (P < 0.01) degradation than the fresh rumen fluid, their degradation values correlated very well (R² ≥ 0.95) with those for the fresh rumen fluid. It appeared that the thawed rumen fluid can be used to predict in vitro degradation of the selected feeds when frequent access to slaughtered or fistulated animals is restricted. Nevertheless it would be vital to improve the activity of thawed rumen fluid prior to testing its suitability for numerous feeds before recommending its routine use to estimate degradation of ruminant feeds.

Genetic diversity and genetic relationships of Czech apple cultivars were evaluated. Trees of 33 Czech apple cultivars and 97 reference foreign cultivars were analysed using the set of 10 SSR (simple sequence repeat) primer pairs. The total of 89 polymorphic alleles were amplified, while the number of alleles per locus ranged from 4 to 14. The SSR dendrogram, based on the Jaccard's similarity coefficient, divided apple cultivars into three major groups: Cox's Orange Pippin, McIntosh and Golden Delicious ancestries. The clustering highly depended on pedigree and origin of apple cultivars. Spontaneous mutated cultivars were identical with their progenitors. We proved that microsatellite markers were useful for evaluation of genetic resources, collection management and cultivar identification.

The cortical branches of the middle cerebral artery in the otter were described using 60 hemispheres. It was demonstrated that the artery is divided into ten permanent branches. Two rhinal arteries supply the region of the brain located on the border between the old and the archicortex and the neocortex. The other eight branches are divided into three branches running towards the frontal lobe, two branches - to the region of the parietal lobe and three temporal branches which supply blood to the neocortex only. The frontal, parietal and temporal branches descended independently from the main trunk of the middle cerebral artery or first formed a common trunk. Common trunks for specific groups of bifurcations were described as the middle cerebral artery (anterior, superior and posterior).

Globalisation is at the beginning of the new century a double-edged weapon: a strong driving force of economic growth, the development of new technologies and the growth of the level of living in the poor as well as rich countries, but also a controversory process which damages national sovereignty, undermines the local culture and traditions and presents a threat of the economic and social non-stability. The key question of the 21^st century then is, whether the states will be able to keep the process under control or whether they will become its victims.

Significant quantities of Cd have been added to soils globally due to various anthropogenic activities, posing a serious threat to safe food production and human health. Rhizosphere, as an important interface of soil and plant, plays a significant role in the agro-environmental system. This article presents a review of relationship between root excretion and microorganisms and plant resistance to Cd toxicity and possible mechanisms. Root exudates markedly altered in species and quantity under Cd stress. Root exudates can affect Cd absorption by plants through changing the physical and chemical characteristics of rhizospheres. The influence of root exudates on Cd bioavailability and toxicity may include modifying the rhizosphere pH and Eh, chelating/complexing and depositing with Cd ions, and altering the community construction, the numbers and activities of rhizospheric microbes. In this paper, the methods to reduce the transfer of Cd in soil-plant system by adjusting rhizosphere environment are discussed, and some aspects are also proposed that should be emphasized in the future research work.

This paper presents research results of the performance of HSM-904 grapple skidder using a full tree harvesting method in a non-native aspen Populus deltoides plantation in even terrain conditions in Shafaroud, Northern Iran. Patch cutting as a silvicultural method was used in the plantation (2,000 ha). To evaluate the newly introduced machine to a ground skidding system in the aspen plantation and the possibility to increase the production rate, an empirical time study was conducted. The elements of the skidding work phase were identified and 58 cycles were recorded for the study. The models for effective time consumption, total productivity and work phase models are calculated. The average load per cycle was 2.2 m³, the average one-way skidding distance was 253 m. The average travel speed of unloaded skidder was 5.53 km.h^-1 and the average speed of loaded skidder was lower than the speed of the unloaded one by 2.94 km.h^-1. The average output in the study was 7.1 m³ per effective hour and the unit cost was 13.9 USD.m^-3.

The research was aimed to estimate above- and below-ground carbon stock in Tankawati natural hill forest of Bangladesh. A systematic sampling method was used to identify each sampling point through Global Positioning System (GPS). Loss on ignition and wet oxidation method were used to estimate biomass and soil carbon stock, respectively. Results revealed that the total carbon stock of the forest was 283.80 t.ha^-1 whereas trees produce 110.94 t.ha^-1, undergrowth (shrubs, herbs and grass) 0.50 t.ha^-1, litter fall 4.21 t.ha^-1 and soil 168.15 t.ha^-1 (up to 1m depth). The forest in the study area is a reservoir of carbon, as it has a good capacity to stock carbon from the atmosphere. To realize the forest sector potentiality inBangladesh, the carbon sequestration should be integrated with the Clean Development Mechanism (CDM) carbon trading system of the Kyoto Protocol.

Field experiments were conducted at two different locations (Barani Agricultural Research Institute Chakwal and farm field Talagang, district Chakwal) for two crop-growing seasons in northern rainfed Punjab, Pakistan to assess the yield and micronutrient uptake of chickpea (Cicer arietinum). The treatments were four combinations of two levels of sulfur (15 and 30 kg/ha) from two sources (gypsum and ammonium sulfate) and a no-sulfur control. Application of sulfur resulted in a significant increase in seed yield up to 17% over control. Ammonium sulfate was a more efficient source of sulfur as compared to gypsum at both the locations. Sulfur application resulted in a significant increase in micronutrient uptake by plant; however effect of sulfur application on soil pH at the end of experiment was not significant. Availability of soil zinc and copper increased with sulfur application at the end of two year experiment. Tissue copper and iron and soil available copper and iron correlated negatively with soil pH. Sulfur should be applied to chickpea grown under rainfed conditions in order to increase seed yield, to improve nutritional composition of product and to enhance efficiency of other fertilizers.

The aim of the study was to select wheat-Aegilops biuncialis addition lines carrying Aegilops biuncialis chromosomes differing from those which were introgressed into the wheat-Ae. biuncialis addition lines produced earlier in Martonvásár, Hungary. In the course of the experiments new wheat-Ae. biuncialis addition lines carrying chromosomes 2U^b, 6M^b, 6U^b; 5U^b, 3U^b, 7U^b; 5M^b, 6M^b and 7M^b were selected. The 2U^b disomic addition line is relatively stable, as 91% of the progenies contain this chromosome pair. The 6M^b disomic addition line proved to be dwarf and sterile, but it still exists as a monosomic addition line. Progenies analysed from the 6U^b monosomic addition line did not carry the 6U^b chromosome. One plant containing the 5U^b, 3U^b and 7U^b chromosomes and one plant carrying 5M^b, 6M^b and 7M^b chromosomes showed very low fertility. Each of the plants produced a single seed, but seeds of the parent plants are still available. Line No. 49/00 carried a submetacentric Ae. biuncialis chromosome pair and the chromosome number 44 has been constant for several generations. After FISH no hybridisation site was observed on the Ae. biuncialis chromosome pair using the pSc119.2 and Afa family repetitive DNA probes, so it was not possible to identify the Ae. biuncialis chromosome pair. However, the use of wheat SSR markers and the (GAA)_n microsatellite DNA probe allowed it to be characterised more accurately. These new lines facilitate gene transfer from Ae. biuncialis into cultivated wheat and the selection of U and M genome-specific wheat SSR markers.

The attacks of adult Apate monachus (Fabricius) on pomegranate (Punica granatum L.) and carob (Ceratonia siliqua L.) trees in a plant nursery in southern Italy was described. The adult beetles produce circular holes and large sinuous tunnels on young trees that can involve the trunk and branches. The same plant can be affected by large numbers of such access holes. The adults appear during late June and reach a peak during the first three weeks of July. Given the increase in the spread of cultivation of these trees and, therefore, in the rate of spread of this pest species, further damage to crops is expected.

Genetic variability of four polymorphisms (CAPN1, CAST, SCD, and FASN) was evaluated and the relationships between them and the beef quality traits (tenderness and fatty acid composition) in Czech crossbred cattle population were assessed. Totally 331 animals were genotyped using multiplex PCR-RFLP. For the CAST NM174003.2:c.155C>T the CC genotype was associated with higher Warner-Bratzler shear force (CC > CT, P < 0.001; CC > TT, P < 0.05) and our results (CC > TT > CT) suggest a possible effect of overdominance. The CAPN1 AF252504.2:c.947G>C did not significantly influence the beef tenderness (strongly influenced by misbalance between the genotype frequencies) suggesting the breed specific effect of this marker. Our association study of the SCD AB075020:c.878T>C polymorphism revealed a positive effect of allele C on myristoleic acid content (CC > CT > TT, P < 0.01). The significant influence of FASN AF285607:g.17924A>G on fatty acid profile was confirmed in the content of myristoleic acid (AG > GG, P < 0.05), palmitoleic acid (AA > AG > GG, P < 0.05, P < 0.001), stearic acid (AA > GG, P < 0.05), myristic acid (AG > GG, P < 0.05), and palmitic acid (AG > GG, P < 0.05). Thus in our population the SNPs of FASN and SCD appeared to be useful markers for selection of animals according to the fatty acid profile as well as SNP of CAST for beef tenderness.

In the present study the polymorphism of the myocyte enhancer factor 2D (MEF2D) gene was analyzed as a genetic marker candidate for carcass traits in Polish Holstein-Friesian cattle. Four novel single nucleotide polymorphisms (SNPs): HQ692911:g.93C>T in exon 8, JX088659:g.69C>T in intron 8, JX0692914:g.47C>T in intron 9 as well as JX088658:g.100G>A in the 3'flanking region were identified by DNA sequencing. By applying the PCR-RFLP method, the SNPs (g.93C>T/HaeIII and g.47C>T/Tsp45I) were genotyped in 401 Polish Holstein-Friesian bulls and their association with carcass traits was analyzed. Statistical analysis showed that the g.93C>T SNP was significantly associated with weight of lean (WLVC) and fat in valuable cuts (WFVC). Animals with the TT genotype had significantly higher WLVC (P < 0.05) and lower WFVC (P < 0.05) than those with the CC and CT genotypes. No significant relationship with carcass traits was found for the g.47C>T SNP (P > 0.05) in intron 9. Moreover, we found a significant effect of the combined genotypes onWFVC (P < 0.01), percent of lean (PLVC) (P < 0.05), and fat (PFVC) in valuable cuts (P < 0.01). This suggested that MEF2D is a strong candidate gene that affects carcass traits in cattle.

Polyclonal antibodies were raised against three immunogens- a-lactalbumin (LA), -lactoglobulin A (LGA) and B (LGB). Using these antibodies the procedures of an indirect competitive enzyme immunoassay (ELISA) were constructed, optimized a nd characterized for determination of indi vidual immunogens. It was found that ELISA of LA is very specific without any inter­ ferences of other whey proteins. However, in ELlSAs of both lactoglobulins A and B were demonstrated very high interferences of the other genetic varian t (cross-reactivities 20-280% depending on antibody and immu nogen). An excellent sensitivity of ELISA for all proteins (detection limits for LA, LGA and LGB were 13, 0.4 and 54 ng/ml, respectively) makes it possible to analyze milk samples diluted more than 1000 times. Average values of variation coefficient were in the range 16-27%. A compari­ son of whey protein determinations in raw cow's milk by ELISA and by capillary electrophoresis resulted in the best similarit y in results of LA concentration. The decrease of LA, LGA and LGB concen trations was detected by using capillary electrophoresis for an analysis of whey from heat-treated milk, while ELISA of the same milk sample showed the increase of LGB immunoreac­ tivity to 700%.

The infestation of barley grains by fungi of the genus Fusarium was studied on malting barley from Kromei'iz (360 samples) and one sample from Kojet!n in Czech Republic. Most frequent species in the season 1997-1998 were: F. culmorum (over 70% of the isolates), F. poae (over 20% of the isolates), F. avenaceum (over 2%). Much less frequent were: F. stilboides v. stilboides, F. aqaeductum v. aqaeductum, F. merismoides v. merismoides and F. gigas. The isolates of F. culmorum were highly pathogenic when barley was artificially inoculated; those of F. poae had low pathogenity. Five varieties of spring barley at growth stage 1-5 on the Feekes scale reacted to F. culmorum as follows: I) Tolar (most resistant), 2) Akcent, Lumar and Rubfn (intermediate), 3) Krona (most susceptible). An application of fungicides on a plot inoculated with F. avenaceum and F. graminearum increased the yield of grain by 0.46 to 1.71 t/ha. Most effective fungicides against the pathogens were: metconazole, tebuconazole and prochloraz. The effect of the combination tebuconazole + triadimefon + prochloraz was found to be most effective. For determi­ nation of six trichothecene mycotoxins in fungal mycelium, macroconidia and spring barley, high resolution capillary gas chro­ matography with electron capture detection was used. Only toxin T-2 and nivalenol (NIV) were detected in fungal mycelium, and a low level of NIV was found in spring barley, variety Rubfn (lower than legislated limit- 2 mglkg of cereals).

We tested the hypothesis, suggested by literature data, that in Rumex obtusifolius L. the germination of matured seeds harvested from dry standing shoots and achene morphology are correlated. In these seed materials the level of germination is determined by the incidence of primary seed dormancy. The regression of the percentage of germinating seeds on achene, perianth and seed size and mass were calculated for seed materials of 30 plants. The materials in which achene morphology was investigated were selected ex post from a set of seed materials of 241 plants to cover the range of variation of germinability of individual plants which was between 0-66%. There was no relationship between any characteristic of achene quality and germination except for a positive correlation between germination percentage and achene mass calculated only for seed materials of plants which pro­ duced germinable seeds (i.e. when plants with 0% germination were excluded from the analysis). The second part of the study investigated the effects of size variation on germinability among seeds harvested from one plant and after removal from the perianth. This variation was tested using sets of 20 size-assorted groups of 50 seeds, each originating from a particular plant; materials from six plants were tested. There were significant differences in the average germination between plants. However, in the material from the same plant there was no consistent relationship between seed mass and percentage of germination. We conclude that there exists no direct relationship between achene, perianth or seed size or mass and incidence of primary seed dormancy.

The aim of this study was to estimate potential relationships between insulin-like growth factor I gene polymorphisms (IGF1/TasI and IGF1/SnaBI) and the growth parameters of calves as well as their subsequent milk performance. The study involved a total of 191 Polish Holstein-Friesian var. Black-and-White calves. Both polymorphic sites were determined with Amplification Created Restriction Sites-Polymerase Chain Reaction (ACRS-PCR). In the case of the IGF1/SnaBI polymorphism, the genotype and allele frequencies were as follows: TT - 0.27, CT - 0.55, CC - 0.18, T - 0.54, and C - 0.46. The CC genotype was favourable and associated with higher body weight at the 2^nd month of age of calves (WT60) and their daily body weight gains from the 1^st to the 2^nd month (P ≤ 0.05) as well as subsequent milk, fat, and protein yield (P ≤ 0.01). For the IGF1/TasI polymorphism, the highest frequency of the AA genotype (0.69) was found. Allele frequencies were 0.75 and 0.25 for the A and C alleles, respectively. In the association study, the AC genotype was significantly associated with higher WT60 and average daily gains in the periods from the 2^nd to the 3^rd month of age and for the whole rearing period (P ≤ 0.05) as well as subsequent milk, fat, and protein yield (P ≤ 0.01). Combined genotypes were also included into the analysis. The highest yields of milk as well as fat and protein were found in cows with the CC/AA combination. No clear relationships between body weight and genotype combination were found.

Polymorphisms of DGAT1 and STAT5A genes in Xinong Saanen and Guanzhong goat breeds were investigated. PCR-RFLP, SSCP, and DNA sequencing were used to identify three SNPs: DQ380250:g.407_408insC in the DGAT1 gene, AJ237937:g.6798C>T and g.6852C>T in the STAT5A gene. In DGAT1 g.407_408insC locus, the frequencies of C^- allele were 0.79-0.85, and frequencies of C⁺ allele were 0.21-0.15. At STAT5A g.6852C>T locus, frequencies of C allele were 0.70-0.72, and frequencies of T allele were 0.30-0.28. Compared with goats with DGAT1 C^-C^-, those with C^-C⁺ genotype had greater milk fat (P < 0.05). The goats with STAT5A CT had greater milk yield than those with CC genotype (P < 0.05). The results showed that does with C^-C^-CT and C^-C⁺CT yielded more milk than those with C^-C^-CC(P < 0.05). In addition, does with C^-C⁺CT had the highest milk fat in comparison with other combination genotypes (P < 0.05).

The suppressive biological control of mites on oilseeds can be successful under the circumstances of the ratio of prey and predators being I : 20 to 1 : 50 and the original infestation not being higher than 500 specimens per 1 kg. Preventive biological control was carried out in empty oilseed stores after they were cleared. The predators which were released in the stores 2000 specimen s being evenly distributed over an area of 100 m² were successful and suppress the population of acaroid mites.

Changes were studied in the endogenous level of glutathione (total and oxidised), and in the amount of free thiol groups as caused by the herbicide atrazine on two species of plants with different sensitivity to it. The activities of two enzymes related to glutathione metabolism (glutathione reductase and glutathione S-transferase) were also determined. The application of the herbicide on leaf increased the levels of total and oxidised glutathione in pea and wheat plants. Increased activity glutathione S-transferase in wheat plants was found.

The study has been elaborated on the basis of a continuous analysis of economic results of a selected sample of agricultural enterprises operating in different climatic and productional conditions. Long-term tendencies and their influencing factors are defined on the basis of this analysis. The goal of this study is to evaluate the influence of external conditions on the economy of agricultural enterprises and on their economic results and to analyze the influence of the accession of the Czech Republic to the EU on the change of economic conditions of agricultural enterprises. On the basis of this study, the authors measures which would intensify the influence of agricultural enterprising on the rural development and which would improve the quality of life of rural inhabitants.

Reptiles have recently become a popular group of pet animals. A relatively large number of studies on the morphology of the oral cavity and method of feeding in adult individuals have been published. Nevertheless, embryological descriptions of reptile body parts or structures are rare. In this study, we describe the morphology of the developing tongue, in particular its dorsal surface, in pre-hatched green iguanas. Microscopic examination of the oral cavity of early embryos revealed that the tongue was divided into three different areas: apex, corpus and radix. The dorsal lingual surface was smooth and covered by nonkeratinised stratified squamous epithelium with slight prominences in some cases. In the underlying mesenchyme of the tongue, striated muscular tissue was formed. The epithelium thickness was reduced during formation of the lingual papillae and in later stages remained simple cuboidal. No developing taste buds could be recognised in the lingual epithelium.

A disadvantageous tendency of resigning from milk production by small and medium sized farms has been observed in the recent years in the provinces of Southern Poland. It results from the low profitability of milk production on these farms and therefore the difficulties in reaching the income parity. It leads to a decline in the bovine population not compensated by an increase in the yield per animal and it poses a serious hazard to protecting the natural resources which is the function dairy farms perform in this region. The problem is serious since in the analyzed region, milk is acquired from 75% of farms keeping herds of up to 10 cows. Moreover, grasslands constitute a notably high share in the arable land structure, and for maintaining them cow keeping is a crucial condition. Hitherto functioning system of EU payments proved insufficient; therefore the Polish government intends to provide an additional financial support for dairy farms. The authors intended to reason that despite the hardly important participation of the analyzed regions in total milk production in Poland, an additional support for small and medium sized dairy farms from the state budget is socially necessary, in the first place because of the additional functions fulfilled by these farms.

A wide array of antioxidative and anti-inflammatory substances derived from edible plants have been reported to possess chemopreventive and chemoprotective activities. Among the most extensively investigated and well-defined dietary chemopreventives is curcumin. Using the Ames test and in vivo micronucleus test, chemiluminescence test, blastic transformation test, and comet assay, we examined the antimutagenic effects of the chemically identified chemoprotective substance curcumin (diferuloylmethane) in the pure form on mutagenicity induced by three reference mutagens: aflatoxin B₁ (AFB₁), 2-amino-3-metylimidazo[4,5-f]quinoline (IQ), and N-nitroso-N-metylurea (MNU), and the effect of curcumin on the immunosuppression caused by these mutagens. Curcumin in the pure form showed a clear antimutagenic and immunomodulatory activities on mutagenicity and immunosuppression induced by reference mutagens.

In conifers and other plants with long reproductive cycles, transformed embryogenic tissues can serve as a convenient source of plant material for the testing of insecticidal or fungicidal transgene efficiency. In this report, transgenic embryogenic tissue was obtained after the transformation of somatic embryos of Norway spruce (Picea abies (L.) Karst.) by Agrobacterium tumefaciens with the gus-intron chimeric gene. The stable integration of transgenes was confirmed by PCR and Southern hybridization. The transformation was successful only in a suitable embryogenic cell line sensitive to Agrobacterium. Out of the nine embryogenic lines tested only one gave transgenic callus.

The effects of three tillage systems: no-tillage (NT), reduced tillage (RT) and conventional tillage (CT), and three levels of fertilization (0, 258 and 516 kg/ha NPK (58:18:24)), on the maize yield during ten years (1999-2008) were analyzed on the chernozem soil type in Zemun Polje, Serbia. Statistical analyses showed significant effects of all three factors i.e., year, soil tillage and amount of fertilizers, and their interactions on the maize yield. The ten-year averages showed that the highest yields were observed with CT (10.61 t/ha), while the averages with RT and NT were lower (8.99 t/ha and 6.85 t/ha, respectively). The results of the influence of the amount of the applied fertilizers on maize yield showed that the lowest yield was in the zero level of fertilization 7.71 t/ha, while the yield was raised when the 258 kg/ha and 516 kg/ha NPK were applied (9.18 t/ha and 9.56 t/ha, respectively). Analyzing the influence of the soil tillage systems on maize production with respect to the amounts of applied fertilizers, this research revealed the benefits of CT under the presented agroecological conditions, irrespective of the level of applied fertilizer.