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Characterization of two rust fungi related to biological control concept in Hungary
195-199Views:312Weeds cause serious problems in agriculture on a global scale. These plants reduce yield and the quality of crops by competing for water, nutrients and sunlight. The improper or excessive usage of herbicides have led to development of resistance in some weed species while contaminating the environment; therefore, biological control has an increasing role as an alternative method for controlling special weed species.
The aim of this study is to make a brief review of biological control of weeds by pathogens and to characterize two rust fungi (Puccinia lagenophorae and Puccinia xanthii) which are broadly examined recently in a biological control concept and have been found on their hosts, such as common groundsel (Senecio vulgaris L.) and common cocklebur (Xanthium strumarium L.), two common and difficult to manage weeds both in horticultural and agricultural lands also in Hungary.
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Assessment of Environmental Susceptibility/Vulnerability of Soils
62-74Views:100Soils represent a considerable part of the natural resources of Hungary. Consequently, rational land use and proper soil management – to guarantee normal soil functions – are important elements of sustainable (agricultural) development, having special importance both in the national economy and in environment protection.
The main soil functions in the biosphere are as follows: conditionally renewable natural resource; reactor, transformer and integrator of the combined influences of other natural resources (solar radiation, atmosphere, surface and subsurface waters, biological resources), place of „sphere-interactions”; medium for biomass production, primary food-source of the biosphere; storage of heat, water and plant nutrients; natural filter and detoxication system, which may prevent the deeper geological formations and the subsurface waters from various pollutants; high capacity buffer medium, which may prevent or moderate the unfavourable consequences of various environmental stresses; significant gene-reservoir, an important element of biodiversity.
Society utilizes these functions in different ways (rate, method, efficiency) throughout history, depending on the given natural conditions and socio-economic circumstances. In many cases the character of the particular functions was not properly taken into consideration during the utilization of soil resources, and the misguided management resulted in their over-exploitation, decreasing efficiency of one or more soil functions, and – over a certain limit – serious environmental deterioration.
Soil resources are threatened by the following environmental stresses:
– soil degradation processes;
– extreme moisture regime;
– nutrient stresses (deficiency or toxicity);
– environmental pollution.
Environmental stresses caused by natural factors or human activities represent an increasing ecological threat to the biosphere, as well as a socio-economic risk for sustainable development, including rational land use and soil management.
The stresses are caused by the integrated impacts of various soil properties, which are the results of soil processes (mass and energy regimes, abiotic and biotic transport and transformation and their interactions) under the combined influences of soil forming factors. Consequently, the control of soil processes is a great challenge and the main task of soil science and soil management in sustainable development.
The efficient control of these processes necessitates the following consecutive steps:
• registration of facts and consequences (information on land and soil characteristics, land use, cropping pattern, applied agrotechnics, yields, with their spatial and temporal variability);
• evaluation of potential reasons (definition and quantification of soil processes, analysis of influencing factors and their mechanisms);
• assessment of the theoretical, real, rational and economic possibilities for the control of soil processes (including their risk-assessment and impact analysis);
• elaboration of efficient technologies for the „best” control alternatives (best management practice).
Scientifically based planning and implementation of sustainable land use and rational soil management to ensure desirable soil functions, without any undesirable environmental side-effects, require adequate soil information. In the last years such data were organized into a computer-based GIS soil database in Hungary, giving opportunities for the quantification, analysis, modelling and forecasting of the studied environmental stresses and for the efficient and scientifically based prevention, elimination or reduction of environmental stresses and their unfavourable ecological and economical consequences.
Special attention was paid to the assessment of various soil degradation processes, as: (1) soil erosion by water or wind; (2) soil acidification; (3) salinization and/or alkalization; (4) physical degradation (structure destruction, compaction); (5) extreme moisture regime: drought sensitivity and waterlogging hazard; (6) biological degradation; (7) unfavourable changes in the plant nutrient regime; (8) decrease of natural buffering capacity, (9) soil (and water) pollution.
The actions against undesirable environmental stresses and their unfavourable consequences are important elements of sustainable, efficient, economically viable, socially acceptable and environmentally sound crop production and agricultural development. These are joint tasks of the state, decision makers on various levels, the land owners, the land users and – to a certain extent – of each member of the society. -
75 years of the chestnut blight fungus Cryphonectria parasitica (Murr.) Barr in Europe
82-85Views:237The chestnut blight fungus Cryphonectria parasitica is a native pathogen in East Asia and has been introduced into North America and Europe. Historical records and population genetic studies revealed at least three major introduction events from Asia into Europe.
Nowadays, chestnut blight is present in almost the entire distribution range of European chestnut, i.e. from the Iberian Peninsula to the Caucasus. The C. parasitica population in most countries has been studied in respect to the diversity of vegetative compatibility (vc) types and the occurrence of hypovirulence. The vc type diversity of the different populations varied considerably. Typically, a high diversity of vc types has been found in areas with a long history of chestnut blight and where sexual recombination between divergent genotypes commonly has occurred. On the other hand, newly established populations often showed a low diversity with only one, or a few vc types present.
Hypovirulence, i.e. the occurrence of C. parasitica isolates infected by Cryphonectria hypovirus 1 has been found widespread in Europe. Natural dissemination and active biological control applications have lead to a high prevalence of the hypovirus and to the recovery of many chestnut stands. Virulent cankers became hypovirus-infected within a short time and ceased expansion. There is concern that the diversity of vegetative compatibility types could increase in Europe through sexual reproduction between C. parasitica genotypes originating from different introductions. A higher level of vegetative incompatibility would not only hamper hypovirus spread within a population but could also select for lower virulence in CHV-1 and subsequently lead to an erosion of biological control. Recent studies, however, indicate that the vc type barriers are not so restrictive than previously assumed and that so far no evidence for an erosion of biological control system in high diversity populations can be observed.
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A dual infection of two microscopic fungi on common milkweed (Asclepias syriaca) in Hajdúság region (East-Hungary)
189-195Views:195Common milkweed (Asclepias syriaca L.) is one of the most noxious and invasive weed species in Hungary. A. syriaca invades arable lands, horticultural and forestry plantations, natural and semi-natural habitats too. In cases of field crops it can cause considerable yield losses mostly in maize (2–10%), soybean (12–32%) and sorghum (4–29%), but only with high rate of coverage. It can also increase these problems that the common milkweed can be serve as reservoir and host for viruses, other pathogens and pests.
Because of the importance of common milkweed and in spite of demand to develop effective biological control, until now has not been developed a proper control program against A. syriaca. The aim of our research was to identify the necrotrophic fungal pathogens, which were involved in notable disease occurrence on this weed in different parts of Hajdúság region of Eastern-Hungary in 2016.
To the isolation of fungi from leaves and their identification were based on morphological colony characters on potato dextrose agar (PDA) and Sabouraud dextrose agar (SDA). To the description of conidia features were used PDA for Alternaria and synthetic low-nutrient agar (SNA) for Fusarium species, respectively. The examination of axenic cultures revealed that the fungi isolated from the leaves of common milkweed were Fusarium sporotrichioides and Alternaria alternata. -
Effects of spray carrier quality on biological activity of terbuthylazine + mesotrione herbicide combination
110-115Views:115Field experiments were conducted to study affects of pH and hardness of spray water on efficacy of a herbicide combination (terbuthylazine + mesotrione) influenced by several pH adjusters and adjuvants in Debrecen, Hungary in 2008, 2009 and 2010. Favourable or unfavourable effects of pH and hardness of spray water could be observed under field conditions. Evaluation of weed control efficacy is suitable for examination of affects of spray water pH and hardness on herbicides. The terbuthylazine and mesotrione herbicide combination is suitable to control monocotyledonous and dicotyledonous weed species, however, significant effects of hardness and pH of spray carrier was observed only in control of monocotyledonous weeds. Certain pH adjusters (e.g. ammonium nitrate) can lessen harmful affects of water hardness effectively. Significant loss of efficacy of sensitive herbicide was found in hard water (by about 50-60%), and surfactants was not able to eliminate that harmful affect. However, biological activity was the same as in soft water with ammonium nitrate which can overcome the antagonism of salts. That pH adjuster had a more significant affect on the efficacy of the herbicide than the surfactant had in that experiment.
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Mass occurrence of a Phoma-like fungus on common ragweed (Ambrosia artemisiifolia) in Hajdúság region, East Hungary
55-60Views:233Common ragweed (Ambrosia artemisiifolia L.) is one of the most important, allergenic weed species in Hungary. A. artemisiifolia invades both a broad range of often disturbed areas (brownfields) and either undisturbed ones like waste lands, roadsides, riverbanks and railway tracks. In field crops it can cause considerable yield losses mainly in sunflower, maize, cereals and soybean. In Hungary many inhabitants suffer from allergy caused by Ambrosia pollen which results a serious human-health risk. The aim of the control is to prevent flowering and seed propagation of A. artemisiifolia. Until now the occurrence of numerous pathogenic fungi which attack common ragweed plants have been identified in Hungary, however there is not yet available biological weed control program because of shortage in acceptable effectiveness, and endangering cultural plant species. During our weed surveys in the region of Hajdúság (East-Hungary) we found numerous common ragweed plants showing heavy necrotic lesions on leaves and stems. The objective of this study was to identify the fungus which was isolated from diseased tissues of common ragweed (A. artemisiifolia). The identification of fungus based on morphological characters of colonies and features of conidia and chlamydospores developed on malt extract agar (MEA) plates. After examination of axenic cultures we revealed that the fungus isolated from the leaves ands stems of common ragweed was a Phoma-like species.
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Susceptibility of stem infected sweet corn hybrids to common smut disease
55-57Views:428The common smut of maize (corn smut, Ustilago maydis /DC/ Corda) can cause large economic losses in susceptible sweet corn hybrids as well. The protection against this pathogen is fundamentally based on prevention. Many methods to control corn smut have been recommended or evaluated, including crop rotation, sanitation, seed treatments, modification of fertility, and biological control. In spite of these frequently mentioned control strategies, the host resistance seems to be the only effective method to manage common smut in those areas where Ustilago maydis is prevalent.
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Preliminary estimation of the efficacy of Fusarium sporotrichioides Sherb. as biological control agent against common milkweed (Asclepias syriaca L.)
201-204Views:308A study of fungi responsible for severe leaf spots of common milkweed (Asclepias syriaca L.) in the Hajdúság region (East Hungary), Fusarium sporotrichioides and Alternaria alternata were isolated from infested leaf tissues. F. sporotrichioides was the most virulent fungus in pathogenicity tests conducted on healthy leaves of common milkweed plants. Inoculation of common milkweed (A. syriaca) in different growth stages with F. sporotrichioides yielded similar symptoms as the original ones. Spray mixtures containing 1.0×106 conidia/ml gave effective control when common milkweed plants were sprayed until runoff occurred. Laboratory (wet chamber) and field experiments showed that asexual spores of the fungal pathogen, F. sporotrichioides, exhibited bioherbicidal activity against common milkweed (A. syriaca).
More efficient control efficacy was observable on elder plants (at flowering stage) than younger ones. These results initiate that this fungus may be a biocontrol agent for controlling this invasive weed but should clarify its hosts because it could infect cultivated plants as well.
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A morphological survey of Ustilago trichophora, a smut fungi and evaluation as bioherbicidal agent for barnyard grass (Echinochloa crus-galli)
91-93Views:169Ustilago trichophora (Link) Kunze is a widespread smut fungus in all over the world. This fungus is pathogenic on species of Echinochloa genus. The subject of present research was that smut fungi occurrence on barnyard grass (Echinochloa crus-galli). Numerous barnyard grass plants with symptoms of smut galls caused by Ustilago trichophora on stems were collected from two counties, víz. Hajdú-Bihar (East-Hungary) and Jász-Nagykun-Szolnok (Middle-Hungary). The infested plants were examined in laboratory, which included the observation of the symptoms and the morphological properties of the spores and the colonies developed from sporidia. The results suggested that this fungus could be effective against barnyard grass weed so the biological control of this weed plant (Echinochloa cruss-galli) can be managed by using Ustilago trichophora biopreparates. As Ustilago trichophora can produce abundant sporidia in liquid culture, a high effectiveness control should be apply by Ustilago trichophora smut fungus as a mycoherbicide in Echinochloa weed control.
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Biological control of sweet chestnut on Pécsbánya, Hungary
77-81Views:252The supervision of plant hygiene of sweet chestnut grove on Pécsbánya (South Hungary) started more than four years ago. Hypovirulent strains were applied as a biological process to control Cryphonectria parasitica fungus which causes the chestnut blight disease. By now the performed interventions have shown obvious results, the vitality of the trees has greatly improved, the amount of harvested nuts is increasing, and the hypovirulent strain has been spreading within the area. During plant health inspection the galls of chestnut gall wasp (Dryocosmus kuriphilus) was found in the year of 2015, which is the obvious symptom of new occurrence of the pest. The pest was eradicated by destroy galls, which allows taking out of consideration the damage by now in this area.
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Biological potential of plant pathogenic fungi on weeds: A mini-review essay
59-66Views:166The invasion of weeds into productive areas has substantial negative effects on native ecosystems as well as agricultural production systems globally. Consequently, the task of maintaining or restoring these systems will become increasingly challenging without consistent, ongoing management efforts. The intensifying emergence of herbicide resistance in numerous weed species, coupled with the unintended pollution caused by synthetic herbicides, underscores the growing necessity for alternative, environmentally friendly, and sustainable management techniques, such as the utilisation of bioherbicides. Plant pathogenic microbes play an important role in biologically management of weeds, with the utilization of plant pathogenic fungi emerging as a promising area of study for novel research trends aimed at weed management without reliance of herbicides and to mitigate environmental pollution. A potential solution to decreasing pesticide usage involves the development of bioherbicides containing fungal active ingredients. Among the most commonly utilised fungi in bioherbicides are genera like Alternaria, Colletotrichum, Cercospora, Fusarium, Phomopsis, Phytophthora, Phoma, and Puccinia. Increased weed resistance to herbicides has influenced new strategies for weed management, with some fungi from genera such as Colletotrichum and Phoma already employed for weed control. Nonetheless, it is evident from reviews that further research is imperative in this domain, with particular emphasis on analysing the efficacy of each plant pathogenic fungi.
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Composition and role of hoverfly (Diptera: Syrphidae) communities in an organic apple orchard
57-61Views:123The use of hoverfly (Syrphidae) larvae in biological control is gaining more attention where the damage by their prey, aphids is significant, especially in agricultural fields and orchards, where they lower the number of aphids. The present study focuses on one hand on faunistics, on the other hand on testing the different available collecting methods for later research. Collecting in an organic apple orchard near Debrecen yielded 525 specimens of Syrphidae mostly by netting but also with white tray traps. Collected species are differentiated according to their feeding (94.1% aphidophagous). The three species found in greatest numbers are Sphaerophoria scripta (Linnaeus, 1758), Melanostoma mellinum (Linnaeus, 1758) and Episyrphus balteatus (De Geer, 1776). The available information on their biology is reviewed and their potential value of hoverflies in biological control is discussed.
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The effect of and interaction between the biological bases and the agrotechnical factors on maize yield
83-87Views:167The effect of and interaction between the biological bases and the agrotechnical factors on maize yield In our research, we examined the effect of the hybrid, the nutrient supply, the number of plants and the abiotic factors (temperature, amount of precipitation) on the yield, crop quality and yield stability of maize. We devoted special attention to the natural nutrient utilization ability and fertilizer reaction of maize. The experiment took place in Hajdúszoboszló on chernozem soil, on a nearly 8 ha field. The size of one plot was 206 m2; therefore, this experiment was half-industrial. We tested six hybrids with different genetic characteristics and growing seasons.We analysed the correlation between the nutrient supply and the yield of maize hybrids with a control treatment (treatment without fertilization) and with N 80, P2O5 60, K2O 70 kg ha-1 and N 160, P2O5 120, K2O 140 kg ha-1 fertilizer treatments. The yield increasing effect of the fertilizer also depended on the number of plants per hectare to a great extent. The number of plants of the six tested hybrids was 60, 70, and 80 thousand plants ha-1.In 2015, the highest yield was produced by hybrid P9241 with N80+PK and 70 thousand plants per hectare. With the N160+PK fertilizer dosage, the same hybrid responded the best, followed by hybrids P9486 and DKC4717. Using the same fertilizer treatment, the 80 thousand plants per hectare population density resulted in decrease in the yield with most of the examined hybrids. In 2016, with the increase in the number of plants per hectare, even with non-fertilised treatment (control treatment), the yield could be increased in the case of each hybrid.Averaged over the different hybrids and fertilizer treatments, applying 80 thousand plants ha-1 instead of 60 thousand resulted in 1.0 ha-1 yield increase. In 2017, the number of plants had a slighter effect. With N160+PK treatment, in most cases no significant difference can be observed. The value of LSD5%: plant number: 0.20 t ha-1, hybrid: 0.28 t ha-1, interaction: 0.48 t ha-1. With N160+PK treatment, the hybrids produced yields between 10.07 and 12.45 t ha-1. When examining the three years in the average of the number of plants, with treatment without fertilisation, the average yield of hybrids reached 7.53 t ha-1. With N80+PK treatment, this value was 9.71 t ha-1 and with doubling the fertilizer dosage, this value increased to 10.42 t ha-1. No economic profit was gained as a result of applying double dosage of fertilizer; therefore, the N80+PK dosage can be considered ideal. -
Genetic progress in winter wheat quality and quantity parameters
71-75Views:173Wheat production is significant branch of Hungarian crop production (with about 1 million hectares of sowing area). Weather anomalies resulted by climate change have increased the importance of biological basis in wheat production. Yield quality and quantity parameters of three wheat genotypes sown on chernozem soil type after maize pre-crop were studied in a long-term field experiment. Yield amount of the studied genotypes varied between 2894 and 8074 kg ha-1 in 2017 and between 5795 and 9547 kg ha-1 in 2018 depending on the applied treatments. Based on our results it can be stated that in both studied crop years the highest yield increment was realized by the application of the nutrient supply level of N30+PK. As the result of the application of the optimum mineral fertilizer level – in contrast to the control – resulted in significant yield increment in both crop years. The results of the long-term field experiment prove that water utilization of the studied wheat varieties / hybrids was improved by the application of the optimal nutrient supply. Furthermore, the water utilization of the latest genotypes was more favorable by both the control and the optimum nutrient supply level treatments. Analyzing the quality parameters of winter wheat using the NIR method it has been stated that the quality results of the well-known genotype (GK Öthalom) were better than those of the new genotypes. A negative correlation between winter wheat quality and quantity parameters has also been confirmed. As the result of the mineral fertilizer application protein and gluten content of winter wheat increased to a significant extent.
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Identification and biological examination of some inland Monilinia species
27-29Views:154The aim of this study was to identify and biologically analyse some Monilinia species from Hungary. 146 M. fructigena and 28 M. laxa species out 174 infectious fruit from all over the country were used for the study. For further study 10 isolates were used and apple fruit was inoculated with them according to Koch postulate. 1–2 mm ochre exogen stromas were observbed on infectious plant parts and growing signs on culture of all isolates were identical to M. fructigena. To affirm classical identification, isolates with molecular biological method were also prepared using PCR reaction. Control isolates of M. laxa, M. fructigena and M. fructicola were used. The size of PCR product showed that all isolates had a 415 bp band which was typical of M. fructigena. Results support the previous observation that M. fructigena and M. laxa species occure all over Hungary.
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The specification of the growing temperature on PDA of chestnut blight pathogen (Cryphonectria parasitica (Murr.) Barr) to optimize timing for biocontrol treatments by hypovirulent strains
29-32Views:185The most destructive pathogen for the European chestnut trees is the blight fungus Cryphonectria parasitica (Murr.) Barr. The biological control is the only effective possibility to apply in situ biocontrol by hypovirulent strains against compatible virulent (wild) fungus strains. The infested bark tissues can inoculate by drilling holes surrounding and putting into agar discs interwoven by the appropriate vegetative compatible group (VCG) hypovirulent fungus strains. This latest can pass those virus-like particles (VLPs) by parasexual contact (called hypha-anastomosis)which responsible to hypovirulence. A laboratory experiment was made to find the optimal times to carry out the treatments. The intensity of growth of fungal colonies were analysed on different temperatures. The growth of the fungus on low temperature were rather slow,according to our expectations. On higher temperature the colony progress were the same as on the optimal 20–25 °C. These observations and the environment determine the date of the field applications under Hungarian weather conditions. It means the optimal treatment periods can be May or end of September to middle October in Hungary.
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The possibilities of the development of functional dairy products
33-36Views:188Because of our new aged world’s emerging stress, over exhausting and move less lifestyle the pollution, the not appropriate food consuming and the low calories in the consumed food there are more and more the called „civilian” disorders.
Many people have diabetes and osteoporosis others fight with lung, cardiovascular system, problems and find cancers of many kinds without age exemptions.
There could be a solution in changing lifestyle. In the developed side of the world there are presence of food lines with higher content in nutritious and/or vitamins and fibers such as: kalium, calcium, selen, magnesium, plus it contains less saturated fat. Because of that there is a new word in dietetics as functional foods.
Food having more inner content and/or biological values, so healthier, are called functional foods. Those foods components picked carefully for healthiness by modern knowledge of dietetics.
One of the best raw materials for functional food is the milk. It is already healthy by itself. The Körös-Maros Biofarm Ltd. has a goal of developing and marketing, health protecting organic functional foods in hungaricum products from cured milk. The Jedlik Ányos project helps the Ltd. to achieve this goal. We just finished an antioxidant test and we check if the antioxidant in present in the milk than we check the final product of the presence of the original antioxidant and the form and amount of it.
It had been feeding, for two weeks for three herd of cows selected for age, milk output and consanguinity. All of the three herd had been feeding with basic forage. One of the herds had been getting vitamin-E in the amount of 250 mg/bwkg the other group got licopin in the amount of 200 mg/bwkg once a day each by each orally, the third herd was the control group.
After two weeks we toke a sample of every herd were processed the samples into yogurt and cheese. Than we checked the raw milk, the cheese and the yogurt for antioxidant content with HPLC method. The test ended with good results by finding a great amount of antioxidant, in not only the raw milk but also in the final product. -
Environmentally-benign plant protection possibilities against domestic Monilinia spp. in organic apple and stone fruit orchards
101-105Views:170In this study, possibilities of environmental-friendly plant protection against domestical brwon rot species were summarized for oecological pome and stone fruit orchards. Symtomps of the two most important brown rot species (Monilinia fructigena (Aderh. & Ruhl.) Honey and Monilinia laxa (Aderh. & Ruhl.) Honey) were described and then cultivar susceptibility to brown rot was discussed. Furthermore, mechanical, agrotecnical, biological, and other control possibilities (stone powders, plant extracts and restricted chemical materials) were shown.
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Possibilities of Weed Beet (Beta vulgaris, L. ssp. marritima) Regulation
133-136Views:101Weed infestation regulation in sugar beet belongs to the most difficult growing measures, the aim of our work was to find out, if active substances contained in preparations Roundup and Fazor influence number, weight and germination of clusters in plants of weed beets. Statistically significant differences in germinability were found among control and all variants in which preparation Fazor was applied. The Roundup treatment did not have significant influence on germination. Presented results are only preliminary and one-year results, more experiments are necessary to determine the effects of the studied applications.
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The potential of biological control on invasive weed species
73-75Views:101Sorghum halepense is one of the invasive species in Europe. This study was made to identify the morphology of fungi on invasive weed species samples on the roots of Sorghum halepense. The samples were collected in the region of Debrecen. The experiment was conducted under laboratory conditions to determine the microscopic form of fungi. The samples were put on PDA and for identification of fungi is based on the morphological characteristics of the features and colonies of conidia that were developed in Petri dishes.
The examination of the culture revealed that the fungus from the root of Sorghum halepense was Aspergillus niger. Pathogenicity and the relationship between the fungus and Sorghum halepense are still uncertain so in the future pathogenicity tests and re-isolations from plants are very important steps.
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Studies of Expression of Peptaibol Synthetase of Trichoderma reesei
188-190Views:144Because of the potential importance of peptaibols in the biological control of plant diseases, a transgenic, a T. reesei strain carrying a tex1-promoter: goxA fusion plasmid was constructed for furthur studies. The peptaibol synthetase gene (which is highly similar to T. virens tex1) was identified in the genome sequence of T. reesei. A 900 bp 5’ upstream noncoding fragment, presumed to include the promoter region of tex1, was cloned into the pSJ3 plasmid (which contains the Aspergillus niger goxA gene encoding glucose oxidase). Finally, we transformed T. reesei with the tex1-promoter: goxA fusion containing pSJ3 plasmid.
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Selenium speciation analysis of selenium-enriched food sprouts
23-28Views:218In this present study, we prepared selenium-enriched pea and wheat sprouts. During our research we aimed not only to measure the total selenium content of the sprouts but to identify different selenium species.
Scientifical researches show why the analytical examination of different selenium (Se) species is necessary: consumption of all kind of Se-species is useful for a person who suffers in selenium deficit, while there is significant difference between effects of different Se-species on person, in whose body the Se-level is just satisfactory. Biological availability, capitalization, accumulation, toxicity of Se-species are different, but the main difference was manifested in the anti-cancer effect of selenium.
During our research selenium was used in form of sodium selenite and sodium selenate, the concentration of the solutions used for germination was 10 mg dm-3. Control treatment meant germination in distilled water. Total selenium content of sprout samples was measured after microwave digestion by inductively coupled plasma mass spectrometry (ICP-MS). Different extraction solvents were applied during sample preparation in order to separate different Se-species (0.1 M and 0.2 M HCl or 10 mM citric acid buffer). We wanted the following question to be answered: Which extraction solvent resulted the best extraction efficiency? Selenium speciation analysis of sprout sample extracts was performed by high performance liquid chromatography with anion exchange column, detection of selenium species was performed by ICP-MS.
Evaluating our experimental results we have been found that significant amount of selenium of inorganic forms used during germination transformed into organic selenium compounds. There was difference between the amount of Se-species in pea and wheat sprouts and selenium uptake and repartition of selenium species were depended on Se-form used during germination. In addition the chromatogram analysis made us clear as well, that the citric acid solvent proved to be the most effective extraction solvent during sample preparation int he view of organic Se species.
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The dynamics of biodiversity structure of soil microorganisms under the impact of biopreparations during potato growing season
67-74Views:159The use of biological preparations such as Phytotsid and Planryz contributes the increase of the general number of soil bacteria population by 13.0–36.1% in the case of potato variety Scarbnytsya and by 4.5–24.6% for potato variety Oberig compared with control. It also increases the number of saprophyte microflora, which compete with plant pathogens, micromycetes, and causes 1.2–1.8 times reduction in the number of soil fungi – Fusarium and Alternaria. During the application of Rovral Akvaflo the Shannon ecological index of species biodiversity is lower than during the biopreparation use. The decrease of species biodiversity was observed as well as strengthening the dominance of some species (dark pigmentation in fungi).
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Inhibition of the spread of Sclerotinia sclerotiorum in aquaponics
5-8Views:290Sclerotinia sclerotiorum, which causes white mold, is a widespread pathogen. In 2020, a new host plant of this fungus, the watercress (Nasturtium officinale) was identified in Hungary in an aquaponic system. During the cultivation of watercress S. sclerotiorum was detected on the plant, the fungus caused a 30% yield loss. Fungicides should not be used against fungi in aquaponic systems. Non-chemical methods of integrated pest management should be used. These include biological control (resistant species, predators, pathogens, antagonist microorganisms), manipulation of physical barriers, traps, and the physical environment. In the aquaponic system, the removal of the growing medium (expanded clay aggregate pellets) solved the damage of Sclerotinia sclerotiorum 100%. By removing the expanded clay aggregate pellets, the environmental conditions became unfavorable for the development and further spread of the S. sclerotium fungus.
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Examination the effects of different herbicides on the soil microorganisms of a calcareous chernozem
121-126Views:91Pesticides play a key role in fighting weeds, pests and parasitic fungi. According to surveys, pests reduce the yield of agricultural crops by 35% worldwide. Pests, fungi and weeds account for 14%, 12% and 9% yield loss, respectively (Gáborjányi et al., 1995). Chemicals have contributed to increasing and maintaining the yields of crop production for decades. Today, agricultural production (in spite of many efforts) is unthinkable without the use of pesticides (herbicides, insecticides and fungicides). On the other hand, these chemicals contribute to the pollution of the atmosphere, surface and underground waters, and agricultural soils, especially if they are applied improperly.
The sustainable agricultural production pays attention to environment-friendly cultivation-technologies; but at the same time it makes an effort to produce good quality and economical products. The examination of the herbicides’ secondary effects, fits into this chain of idas namely, how the herbicides affect – stimulating or inhibiting – the soil microbiological processes, prevention of soil fertility.
In the course of the experimental work the effect of herbicides on soil biological properties were examined in different maize (Zea mays) cultures. We wanted wished to know that how the herbicides affect the quantity change of soil microorganisms, the life of different physiological groups of bacteria and the activity of microorganisms. A small pot experiment was set up in 2008 with the application of two herbicides - Acenit A 880 EC and Merlin 480 SC – in the breeding house of the Department. The moisture content and nutrient supply were at optimal level in the experiment.
On the basis of results the following can be stated:
1. It can be stated that the two herbicides and all their doses affected negatively the number of total soil bacteria, the
inhibiting effects were significant. The quantity of microscopical fungi increased by the effect of Merlin 480 SC and decreased in the treatments of Acenit A 880 EC.
2. The Acenit A 880 EC had stimulating effect on the nitrate mobilization. The CO2-production was stimulated by the basic doses of herbicides; the other treatments did not influence the CO2-production significantly.
3. The quantity of microbial biomass-carbon –except for only one treatment- decreased significantly by the effect of herbicides. Besides it, the quantity of microbial biomass-nitrogen increased significantly in the treatments of Acenit A 880 EC.
4. The biomass of test plant decreased in the treatments of herbicides, their quantities were smaller than in the control. In the pots treated by Merlin 480 SC, parallel with the increase of doses decreased the quantity of plant-biomass.