Fulltext search in archive

Dwarf apple rootstocks M 9, M 27, Pajam 1, Pajam 2, Jork 9, J-TE-E, J-TE-F, J-TE-G and J-OH-A were evaluated in a trial conducted in an experimental orchard with cultivars Golden Delicious, Gloster and Melrose. The experimental plantation was established in 1990. Data on: yield (kg/tree), yield efficiency (kg/cm2), trunk cross-section area and suckering were recorded during the period 1991-2000. The cumulative yield per tree was highest on Jork 9 and Pajam 2. Trees on Pajam 1 and M 9 also had good productivity. Yield efficiency was highest on Jork 9, followed by M 27 and J-TE-G. Trees on Pajam 2 were most vigorous. The tree size on M 9 was similar like on Pajam 1. Trees on J-TE-E and J-TE-F grew less than those on M 9. The weakest growth was observed on rootstocks M 27 and J-TE-G. Among the tested rootstocks, J-OH-A produced the highest number of suckers. Suckering was more intensive with Melrose followed by Gloster and Golden Delicious.

The hypothesis, that hypoiodemia of goats causes such a compromise of the immune system, which during subsequent Toxoplasma gondii infections results in clinically more pronounced signs of toxoplasmosis, was verifying in laboratory mouse. Hypoiodemic mice (fed by wheat and supplied by water), normoiodemic mice (fed by wheat and supplied by water containing 1.25 mg KI/l) and the majority of standard mice (fed by commercial grain mixture containing 0.83 mg I/kg) were experimentally infected with T. gondii oocysts or tachyzoites. The susceptibility to acute T. gondii infection was evaluated according to mortality rate. As a criterion of cell-mediated immune function has been chosen the spleen-lymphocyte transformation test (LTT). We observed no difference in LTT between hypoiodemic and normoiodemic mice infected with T. gondii oocysts or tachyzoites and no difference in mortality of both infected groups. Four days after the exposure to 100 tachyzoites of T. gondii (K24 strain), all experimentally infected groups of mice showed statistically significant decrease (P = 0.004) in spleen cells responsiveness to stimulation by all mitogens used - as compared to non-infected standard mice group. Reduced responsiveness of cells was probably caused by T. gondii infection itself - the relation to iodine deficiency has not been found.

The fungus Gymnosporangium sabinae (Dicks.) Winter was found only at three locations during the years 1965 to 1990 in Slovakia, they were the Arboretum at Mlyňany, Topoľčianky and Gbely (JUHÁSOVÁ 1973, 1975, 1998). We noticed a more frequent occurrence of this fungus during recent years. The life cycle, range of woody host plants and degree of damage on pear leaves at selected locations inSlovakia are described.

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.

Viroids as the smallest pathogenic circular single-stranded pathogenic RNAs form populations of quasi-species, whichhas been recently identified by thermodynamic methods like TGGE pre-selection and heteroduplex analysis. It was foundthat replication under thermal stress led to enormously high level of viroid mutagenesis. Mostly multiple mutants havingnon-random distribution of base changes were found. A specific "hot spots" were identified in the regions, wherea characteristic "pathogenicity domains" are localised in different viroids of the pospiviroidae family. Specific viroidmicroevolution was observed upon artificial inoculation of non-host plant species. Our results suggest that viroid propagationunder physiological stress can be assumed as important factor, which is among others, responsible for an appearanceof viroid quasi-species in the nature. Evolution and new viroid patotypes could accumulate due to environmental stressincluding various pollutants may be a potential danger for cultured plants.

The random amplified polymorphic DNA (RAPD) technique was used to evaluate both genetic diversity among 19 soybean accessions included in the Czech National Collection of Soybean Genotypes and their potential as a new source of genetic variations for soybean breeding programs. Only 22 of all the 40 random primers used in RAPD reactions showed polymorphism acceptable for an effective characterisation of these accessions. Altogether 122 highly reproducible RAPD fragments were generated, 55 of them were polymorphic (46%). However, because of the previously observed low degree of RAPD polymorphism in the case of Glycine max, fragments with low level of informativeness were evaluated, too. Presented results enable the selection of genetically distinct individuals. Such information may be useful to breeders willing to use genetically diverse introductions in soybean improvement process.

On one-year-old and two-year-old plantations of lemon balm observations on the occurrence of plants showing symptoms of fungal diseases were made in 1998-2001. Many fungi were isolated from roots, stem bases and leaves separately on mineral medium. Species of Fusarium, Phoma and Rhizoctonia solani were obtained from the roots and stem bases whereas Alternaria alternata, Phoma spp., Septoria melissae and Botrytis cinerea were most often isolated from the leaves showing symptoms of necrosis.

The fungal population colonizing the seeds of fodder galega cultivated in pure stand was greater than that cultivated in mixed stand. No significant differences were observed in the species composition of the obtained fungal colonies. In all analyzed combinations, Alternaria alternata was predominantly isolated from the seeds. Other saprophytic fungi were represented by the following species: Epicoccum purpurascens, Cladosporium cladosporioides as well as fungi representing genera Mucorales: Mucor hiemalis and Rhizopus nigricans. Among the pathogens, Botrytis cinerea was most often isolated. The mineral and SNA medium as well as the process of superficial disinfecting of seeds reduced the number of isolated fungi.

Apple cultivars were crossed according to the half-diallel and topcross mating design. Apple scab resistance of seedlings was estimated by using a 0-5 scale: 0 - no infection on leaves, 5 - more than 75% of leaf area infected. Percentage of scab resistant seedlings in crosses involving cultivars Prima varied from 35.8% to 67.6%, involving cultivars Florina and Arbat - 51.9-59.5% and 53.5-72.5%, respectively. Significant differences for resistance to scab were found among the crosses. Both general combining ability (GCA) and specific combining ability (SCA) were highly significant. The significance of GCA for scab resistance shows that genetic variability exists for this trait and selection should result in genetic progress, because the mean square for GCA was larger than that calculated for SCA. Therefore, selection of parents on its phenotype should be effective for development of resistant apple cultivars. The significant SCA estimates indicate that a large number of resistant seedlings from particular crosses should be selected.

Within the EU project DREAM there is a programme of work investigating the molecular basis of virulence and avirulence in Meloidogyne chitwoodi and which involves partners from the Netherlands, France and Scotland. In Wageningen AFLPs are being used to examine genetic diversity between populations of M. chitwoodi. Partners in Wageningen and INRA are using M. javanica and M. incognita as model systems to isolate genes producing secreted proteins that could be implicated in the host pathogen interaction. They will search for homologous sequences in M. chitwoodi. At Rennes two-dimensional electrophoresis (2DE) studies are being conducted. The PCR based suppressive subtractive hybridisation (SSH), has been used at PRI and SCRI to compare avirulent and virulent nematodes and infected plant material (resistant and susceptible) at different times after infection.

The monitoring was carried on in the years 1996-2000 in the polyfactorial P-A field trial in Lukavec, Pelhřimov district. The given locality is characterized by low fertility sandy-loamy cambisoils, by long-term average annual rainfall of 653 mm, by average annual temperature of 7°C and its altitude is 620 m. The field trial included different organic fertilizations; graduate N-doses, different soil tillage as well as different forecrops. It manifested in this group of field trials that the forecrop value of red clover and dung manured potatoes before winter wheat was practically the same in the given locality. The optimal N dose for potato yields was about 80 kg N.ha^-1. In oats the yields after red clover with using the Horsch system in spring were significantly lower than after embedding of red clover in autumn. In cereals, graduated N doses increased the numbers of ears (panicles) per m2, but the mass of 1000 grains often decreased. In addition, N content in grain and straw increased with N doses, while pH annually decreased by 0.1 to 0.4.

Present study focuses on making best possible use of male gametophytic generation in carnation breeding program. Exploration of pollen population revealed the existence of variability in terms of pollen morphology and histochemical content among as well as within varieties and species of Dianthus caryophyllus and D. chinensis sufficient to make selection. Pollen grain size and histochemical content were found to be associated with germination capacity and pollen tube growth rate. In addition, pollen germination capacity and elongation of pollen tube in response to presence of culture filtrate from F. oxysporum. f.sp. dianthi causal organism of fusarium wilt in carnation was found to be governed by pollen grain size and histochemical content of pollen grains. Entire result suggests the possibility of selecting the desired pollen grains from a pollen population and possibility of attempting selective pollination in carnation breeding program.

The paper is a part of solution of the research plan of the FBE MUAF in Brno, No. GAMSM 431100007, and it is focused on analysis of factors influencing intensity of competition fight among the existing firms in the Czech dairy industry - describing their actual situation and their possible development in the future relating to the expected integration of the Czech Republic into the European Union. All analysed factors are important and significantly intensify competition fight among the existing firms in the industry. The level of concentration is low - 16% of businesses in the industry control 60% of market, but almost 30% of businesses in the industry have only 3% share in the market, growth of the industry is slow - about 5% annually, and barriers of exit from the industry are significant. Situation of the next four factors (level of fixed and storage costs, product differentiation and switching costs, size of capacity augmentation, diversity of competitors) is similar.

Relations between the level of milk yield and the economic results of dairy cows breeding were analysed on the base of operational and economic data received from 135 agricultural enterprises. The analysis was aiming at the optimization of milk production expressed by means of the cost function. By evaluating the above-mentioned relations, there was recorded a tendency of the faster growth of milk yield compared to the costs for market milk for one feeding day of a dairy cow. On the base of the expense function, there was expressed the maximum profit for a litre of market milk, the maximum profit for a dairy cow per year and the interval of profitability of milk production in 2000.

An analysis is made of the root system morphogenesis and architecture in several tens of European mountain ash trees aged up to 60 years at seven different sites. Although the root system variability is considerable, certain dependences can be derived. European mountain ash forms an anchoring root system. Limiting factors of the root system morphogenesis are the groundwater table (roots do not penetrate into soil horizons affected by underground water), prevailing direction of wind (elliptic root system develops in the wind direction), and the slope (in the uphill direction the roots are shorter, exhibit the more or less horizontal growth and reach into deeper soil horizons than roots growing in the downhill direction). An unambiguous correlation was found between the rooting depth of anchor roots and the number and reach of lateral roots (the longer the anchors, the fewer the lateral roots and the smaller their reach). The shorter the anchor roots, the more intensive the branching of not only the anchors themselves but also of superficial roots.

The studies aimed at monitoring development of phagocytic and bactericidal activity in carps in the course of their ontogenetic development. The studies were performed using the techniques described by Mantur et al. (1986a, b), adapted to fish. Results were expressed in thrombocyte phagocytic index (Ipt), percentage of phagocyting thrombocytes (%tp), percentage of ingested bacteria (%bp) and in the index of intracellular killing by thrombocytes (Ibt). Number of thrombocytes was also examined using the technique of Dessi. Results of testing thrombocyte capacity to ingest the standard Staphylococcus aureus 209P strain showed that Ipt and %tp increased gradually in carps between the age of 3 and 17 months. In older carps, 19 to 29 months of age, as well as in spawners the growth in activity paralelled the ontogenetic development within Ipt values while %tp values remained at a similar level. Phagocytic activity of thrombocytes expressed in Ipt was reflected also by %bp values, which was particularly evident in fish aging 23 months to 5 years. In the case of Ibt, values of the index were not related in any way to stage of ontogeny or sex of the fish. Number of thrombocytes in carps aged 3 months to 5 years was increasing in parallel to their ontogenetic development.

A translocation from Aegilops ventricosa carrying genes Yr17, Lr37 and Sr38 was verified in cultivars Hussar, Eureka, Torfrida, Renan, Rendezvous, Rapier and Brigadier by the molecular marker SCARSC-Y15. Of the cultivars recently registered in the Czech Republic, only the western European cultivars Corsaire, Apache, Complet and Bill possessed the translocation carrying Yr17, Lr37 and Sr38. Cultivars Corsaire, Apache, Bill and Complet were highly or medium resistant to yellow rust and leaf rust in 1999-2001 field trials at Prague-Ruzyně, although virulence to Yr17 was found in the 2001 virulence survey also in the Czech Republic. Cultivars Corsaire, Apache and Bill displayed an above average resistance to stem rust, whereas Complet was susceptible.

It is well established that race-specific resistance selects for the specifically matching genes effecting virulence in the pathogen. As well, the use of different R-genes in time makes virulence complexity, VC (the number of virulences per pathogen genotype), to increase. Moreover, it becomes obvious here that the wind-dispersed cereal rusts and mildews are obligate nomads and highly mobile. As a consequence of these points and as a result of modelling, VC was expected to increase in the direction of predominant winds, e.g. from west to east across Europe, and it did by approximately one or more virulences per 1000 km. Starting from the barley mildew pathogen, comprehensive evidence is also available from leaf rust on wheat covering some 5000 km from Western Europe into Siberia. The impact of our findings for population genetics across Europe and Asia is supposed to be considerable and worth further elucidating, e.g., within the 6^th EU Framework Programme.

The pure cultures of the fungus Leptosphaeria maculans were isolated from the rapeseed leaves collected in Moravia. Two isolates were collected on the basis of their ability to produce yellow colour. The isolate producing yellow colour was classified as aggressive, while the isolate without the ability to produce yellow colour was not aggressive. The sensitivity to these isolates was verified in 11 rapeseed genotypes. This test was based on the method from the document Crucifer Genetics Cooperative (information document from the Department of Plant Pathology, University of Wisconsin). This method is based on the inoculation of cruciferous leaflets with suspension from the isolate of the pathogen observed. The scale from 0 to 9 was used for evaluation (0 = no darkening around the wound, 9 = accompanied by profuse sporulation in large, more than 5 mm, lesions with diffuse margins). The infection degree of the aggressive isolate ranged in different genotypes from 1.45 to 4.5, the results of the non-aggressive isolate ranged from 1.0 to 1.5. Based on these results the aggressive isolate was used for further tests of the selected breeding lines. The tests involved selected breeding materials, registered varieties, control varieties with different sensitivity to the isolate of Leptosphaeria maculans and control varieties included in state trials. The maximal difference in the sensitivity exhibited by individual genotypes was five degrees.

The effectiveness of fenarimol and difeconazole, DMIs fungicides, and dodine was tested in two experimental orchards and in greenhouse in two seasons. In 2001 monitoring of resistance to dodine was conducted also in some commercial orchards located in main apple production. In both experimental orchards fenarimol gave significantly poorer control of apple scab than difenoconazole when curative treatments were applied. The same results were obtained in greenhouse tests using for inoculation the suspension of conidia of V. inaequalis from these orchards. In many monitored orchards, in each region, a high level of dodine resistant isolates in population of V. inaequalis (even more than 40%) was noted. Only in six from 65 tested orchards there was less than 1% resistant isolates in population of the fungus.

Method ISTA SDS-PAGE was used for separation, detection and evaluation of high molecular weight glutenin subunits (HMW) in the different wheat species. The relation has been studied between the HMW glutenin subunit alleles and the bread-making quality of 25 world wheat cultivars and 21 regional varieties common wheat varieties (Triticum aestivum L.), 17 winter spelt wheat (Triticum spelta L.), 3 durum wheat cultivars (Triticum durum DESF.), 9 cultivars of Triticum turgidum L. and 5 cultivars of Triticum polonicum L. The highest frequency of occurrence of HMW glutenin subunits 2*, 13 + 16 and 5 + 10 were found in world wheat cultivars. In Slovak wheat varieties were analysed subunits 0, 7 + 9 and 5 + 10, 2 + 12. The HMW subunits 0, 7 + 8 with Glu-score 4 were determined in Triticum durum DESF. Three electrophoretical profile groups of different HMW glutenin subunits were found in Triticum turgidum L. and Triticum polonicum L. and six electrophoretical profile groups were determined in Triticum spelta L. The verified correlations between bread-making quality and specific HMW subunits of glutenin can be utilised by wheat breeders using SDS-PAGE of proteins as a screening test for the prediction of bread-making quality of wheat.

Field trials were conducted at two sites Troubsko near Brno and Prague-Ruzyně in 1996-1999 with three varieties of safflower (Gila, CW-74, Sironaria). Three rates of nitrogen fertilization were used: N0 = no fertilization, N₁ = 40 kg/ha, N₂ = 80 kg/ha. Sowing rates were 50 and 70 germinable seeds per m2. The average values of oil content were highest in seeds of CW-74 variety (27.2%). Gila had on average the lowest oil content (24.5%). Linoleic acid was dominant in all three safflower varieties. Variation in content of linoleic acid in different years was not so high as in oil content. The highest average content of linoleic acid was found in Gila variety (81.2%), the lowest in Sironaria (77.4%). At Ruzyně average seed yield on dry basis was 2.7 t/ha and average straw yield was 7.56 t/ha. At Troubsko seed yield was 2.56 t/ha and straw yield was 3.69 t/ha (by 50% lower than at Ruzyně). The effect of year of growing and site on seed yields and on other parameters was highly significant. N fertilization increased safflower seed yield at Troubsko site only, where the dose of 40 kg/ha N increased the yield by 0.08 t/ha on average of years and the dose of 80 kg/ha N increased the seed yield by 0.2 t/ha in comparison with no nitrogen fertilization treatments. Increased N rates and especially higher plant density resulted in an increase in straw yields. Neither were thousand seed weight nor number of flower heads influenced significantly by different N rates or the above-mentioned differences in plant density.

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.

Due to the transformation of the agricultural subjects realized after 1990, the new ownership relations occurred in the sectors of agriculture and food processing. The entrepreneurs started to build their activities on the base of market economy principles. The farmers started founding of specialized or universal-trading organizations aimed to sale of the agricultural production. The legal forms of the companies were cooperatives or companies incorporated. In practice, the subjects proved the reasonability of their existence not only on the side of agricultural production sale, but also on the side of purchasing inputs necessary for the agricultural production process. One of the best trading organizations is Agropork-družstvo in Brno, which is specialized in purchasing and sale of pigs, cows and recently poultry as well.

The complex solution of farming in worse natural conditions and exploitation of land fund result from the successive transformation of agricultural policy and the preparation of agrarian sector for the accession of Slovakia into the European Union. The character of this policy will have the immediate impact on economy mainly of enterprises farming in less-favoured areas (LFA). In the study, we present the actual data about the allocation of agricultural land and agricultural farms into the LFA using the database of information system on land and the soil quality database which is managed by the Research Institute of Agricultural and Food Economics.

Changes in fruit weight, firmness and soluble solids content during the ripening period of Karešova cv. Including relationships between these characteristics were studied in 1998-2001. These years differed from each other in the amount and distribution of rainfall and in the course of temperatures. The length of ripening period fluctuated from 14 to 21 days. An increase in average fruit weight during the ripening period was 0.1 g per day. The actual increase in fruit weight was in a close correlation with the amount of rainfall in a few previous days. After heavy rainfalls, above 40 mm, fruit weight increased by nearly 1 g within in a few days. In the course of the ripening period fruit firmness decreased from about 2.5 N at the beginning of the period to about 1.5 N at its end. This decrease seems to be mainly the function of time during ripening. However, a low correlation between the amount of rainfall in the previous days and the decrease in firmness was also found. This correlation could be connected with negative regression of fruit firmness on the weight of the fruit. In the more rainy years 1998 and 1999 these decreases in firmness were more significant than in the other two years. Soluble solids content (SSC) increased from about 12% Brix at the beginning of the period to about 16% at its end. There were also found positive correlations between the weight of fruits and SSC. Taking into account contributions of all studied factors and their changes a conclusion was drawn that Karešova cv. should be harvested within one week from the beginning of its ripening period.

In three investigated stands the highest increment (8.8 m3/ha per year, i.e. 1.5% of the actual stand volume, measured at the end of the control period) was reached by Jawornik I stand in the initial period of the growing up stage, and Tworylczyk stand in the advanced growing up stage (7.4 m3/ha per year, i.e. 1.2% of the actual stand volume). Jawornik II stand, in the optimum stage, the aging phase, had the lowest increment (3.9 m3/ha per year, i.e. 0.7% of the actual stand volume). The process of a natural volume loss was the most intensive in Tworylczyk stand (7.6 m3/ha per year), a little less intensive in Jawornik II stand (7.1 m3/ha per year), and the least intensive in Jawornik I stand (5.8 m3/ ha per year). The analysis of tree loss, recruitment, and increment, and the relations between these processes, can form the basis for a conclusion that stable stands developed in the Carpathian primeval beech forests in the years 1988-1998. Such steady processes can be used for the development of a stable, multifunctional model of the forest managed by the selection system, or the Swiss irregular shelterwood system in the Carpathian beech stands of a similar structure.