Show Advanced search options Hide Advanced search options
The Role of Trichoderma in the Rhizosphere of Tomato Plants
Published May 11, 2003

It is well established that microorganisms are closely associated with the roots of plants can directly influence plant growth and development. Species of Trichoderma, on the other hand are primarily studied for their ability to control plant disease. The ability of species of Trichoderma to directly promote or inhibit plant growth has been not...ed for many years.
Tomatoes were treated with different Trichoderma strains by seed treatment and soil inoculation. The Trichoderma were grown on malt-agar medium and conidia were washed off by sterile water for making suspension which contained 107 CFU/ml (colony forming unit/ml). The suspension was used for seed treatment and for the soil inoculation by watering as well. The artificial soil inoculation was made by Trichodermas growing on grounded maize were mixed in mould and tomato seed were sown in it. Tomato seeds were also sown in bags made of close-meshed material which allowed the soil microorganisms to colonize the roots but it simultaneously protected the roots from soil contamination. Roots were put on Trichoderma selective medium to check the root colonization of the Trichoderma.
The tomato plants were bedded out in a field in four repetition. After harvesting by hand the results supported by statistics shown that there was significant differences between the yield of the untreated and treated tomato plants by Trichoderma strains.

Show full abstract
Studies of Expression of Peptaibol Synthetase of Trichoderma reesei
Published December 6, 2005

Because 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.

Show full abstract
Sour cherry anthracnose and possibilities of the control with special regard to resident Glomerella population in sour cherry plantations of East Hungary
Published November 10, 2010

Anthracnose is considered one of the most destructive diseases for sour cherry production due to the rapid development of the disease on fruits. Glomerella cingulata (Stoneman) Spauld. & H. Schrenk (anam.: Colletotrichum gloeosporioides (Penz.) Penz. & Sacc. in Penz.) has been the fungal pathogen responsible for anthracnose in last deca...des. Yield losses greater than 90% may occur under epidemic conditions. C. acutatum (J.H. Simmonds, 1968) strains were isolated of sourcherry plantations in East Hungary and this pathogen, new for Hungarian microbiont became recently dominant. Contrarily to the former species it is certainly transmitted with ants during fruit ripening. About third of strains proved to be cutinase producers that enable them to actively penetrate via cuticule, and these strains infect directly berries of blackberry, grape and tomato as well as plum and apple. Most of cutinase negative strains could also infect these fruits after mechanic injury. All strains of both species produce amylase, cellulase, lecithinase, lipase, polyfenoloxydase and protease in vitro, although the activity of these enzymes highly varied in the medium. The only C. acutatum strains produced noticeable amount of chitinase. Strains, tolerant to recently applied fungicides to control the anthracnose, could be isolated of sour cherry plantations that might be the cause of ineffectiveness of control measures in 2010. The mycofungicide containing mixture of three Trichoderma species in oil carrier could efficiently depress the development of anthracnose in ripening sour cherry.

Show full abstract
The effect of different herbicide on the number and activity of living microorganisms in soil
Published May 23, 2006

Sustainable plant growth, considering the difficulties of weed elimination, cannot be effective without the application of herbicides. However, these chemicals have enormous ecological implications, including effects on the microbiological communities of soils. It is advisable to use herbicides that have minimal secondary effects on the environ...ment and soil-living microorganisms. In contrast, herbicides with prolonged growth stimulating or inhibiting effects are not suitable, because both types have strong influences on the number and activity of bacteria, thus causing changes in the ecological equilibrium.
Preceding small plot experiments, laboratory tests were carried out to study the effect of herbicides used in maize cultures on the number of bacteria and growth of microscopic fungi.
Substances that were observed to have stronger influences were applied in small plot experiments set up in the experimental garden of the Department of Plant Protection of the University of Debrecen. We studied the effects of four herbicides (Acenit A88EC, Frontier 900 EC, Merlin SC and Wing EC) on the microbiological properties of the soil. These herbicides were used in different concentrations in maize culture, and we investigated the effects in different soil layers.
In the laboratory experiments, we determined the total number of bacteria and microscopic fungi and examined the growth of Aspergillus niger, Trichoderma sp. and Fusarium oxysporum on peptone-glucose agar containing herbicides.
During the small plot experiments, soil samples were collected 3 times a year from 2-20 cm depth. The total numbers of bacteria and microscopic fungi were determined by plate dilution method, while the method of most probable number (Pochon method) was used to determine the numbers of nitrifying bacteria and cellulose decomposing bacteria. To evaluate the microbiological activity of the soil samples we measured carbon-dioxide release (after 10 days incubation), nitrate production (after 14 days incubation) and the concentration of C and N in the biomass.
We can summarize our results as follows:
• In laboratory experiments, herbicides caused a decrease in the number of bacteria and inhibited the growth of microscopic fungi.
• Frontier 900 EC and Acenit A 880 EC had the strongest inhibiting effect on microorganisms.
• In small plot experiments, herbicide treatment decreased the total number of bacteria and microscopic fungi.
• Herbicides caused a significant increase in the number of nitrifying and cellulose decomposing bacteria.
• Different herbicides containing the same active compound had similar influences on soil microoorganisms.
• A significant increase was observed in the physiological processes of tolerant microorganisms surviving the effects of herbicides

Show full abstract
Studies on the Suitability of Different Mould Media Compositions for the Mycological Evaluation of Hay Samples
Published May 11, 2003

t evaluating mould contamination of hay samples in more than the half of the cases Mucor spp. (and Trichoderma spp. in a smaller extent) overgrew slower developing moulds, spoiling the assessment of total mould CFU and the detection of fastidious organisms, among others the toxinogenic Fusaria. In parallel microbiological evaluation of hay samp...les comparing to the ISO 7954 medium as reference a) the overgrowth inhibiting effect of Rose Bengal (ISO 7954-RB); b) the combined inhibiting effect of Rose Bengal and Dichloran (dichloro-mononitroaniline) in DRBC; c) the inhibition of Dichlorane in ISO 7954 (ISO 7954-DC); d) the lowering of nutrient levels to 1/4 (1/4 N ISO 7954, 1/4 N-DRBC and 1/4 N-DC); e) the inhibiting effect of dinitro – salicylic – acid (DSA), a reducing sugar binding compound, as a potential growth inhibitor (RBC-DSA) were studied. The results showed, that 1) MSZ-ISO 7954 medium codified by the official method was unsuitable for the detemination of mould count and for the detection of toxinogic spp. in hay samples. In half of the cases the overgrowth of Mucor has spoiled CFU enumeration and recognition of toxinogenic moulds; 2) Inhibitor supplemented DRBC medium (King et al., 1979) enabled early CFU enumeration by uniforming colony sizes and by efficient suppression of Mucor, but the pink background colour of the medium was disturbing the observation of tints of conidia, which were characteristical to toxinogenic moulds like Fusaria. The hypha-staining property of Rose Bengal did not prove very important; 3) According to the recent stage of our studies, the ISO 7954-Dichloran combination can be recommended for the mycological evaluation of hays and dried roughages. CFU can be enumerated early, Mucor suppressed in the same extent as with DRBC and colours are easily observable; 4) 2-4-Dinitrosalicylic-acid (DSA) proved unsuitable as inhibitor, for its poor efficiency and for its intense yellow background coulour.

Show full abstract
1 - 5 of 5 items