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Journal ArticleDOI

Improvement of antagonism and carbendazim tolerance in native Trichoderma isolates through ethyl methane sulfonate (EMS) mutagenesis

28 May 2014-Archives of Phytopathology and Plant Protection (Taylor & Francis)-Vol. 47, Iss: 13, pp 1645-1657
TL;DR: RAPD-PCR results suggested the uniqueness of mutants, which was useful in differentiating mutant and wild Trichoderma isolates.
Abstract: Genetic enhancement of TCT4 and TCT10 was aimed in the present paper. Trichoderma reesei (TCT10/M18) mutant isolate evolved by ethyl methane sulfonate mutations was found to exhibit altered properties compared to its parent isolates. This mutant grew well in the potato dextrose agar (PDA) medium containing carbendazim (50 ppm). RAPD-PCR results suggested the uniqueness of mutants, which was useful in differentiating mutant and wild Trichoderma isolates. These mutants established well in the rhizosphere of rough lemon seedlings. The seedlings treated with carbendazim followed by an application of carbendazim-resistant mutant (TCT10/M18) resulted in a better seedling emergence and a less dry root rot disease caused by Fusarium solani in nursery conditions.
Citations
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2,133 citations

01 Apr 2017
TL;DR: It was observed that Trichoderma inoculation significantly elevated these enzyme levels compared to that of seedlings exposed to Pb, suggesting that the development of stress-tolerant plant-fungus associations may be a promising strategy for mycoremediation and soil amelioration measures.
Abstract: Lead (Pb) is a heavy metal and one of the main environmental pollutants, toxic to plants, animals and humans. Pb contaminated soils affect crop productivity. The availability of heavy metals to plants and their toxicity depends on complex rhizospheric reactions involving not only exchange processes between soil and plants but also microbial activities. Here, we evaluated the Pb induced oxidative stress in Sunflower, Helianthus annus and also determined the protective role played by the plant growth promoting fungus Trichoderma sp. against this stress. In this study, six isolates of Trichoderma sp. (WT1 to WT6) were screened for the tolerance against different concentrations of Pb. Then we investigated whether Trichoderma sp. (WT2) could be used to combat the Pb induced oxidative stress in Helianthus annus seedlings. Pot cultures containing 350 and 750 ppm of lead concentrations with and without Trichoderma sp. inoculated soil were maintained. Results indicated significant reduction in root and shoot lengths of seedlings grown in Pb amended soils after 30 days. The seedling samples were collected in two phases. The levels of SOD, POD and CAT were moderate in 1 phase. After prolonged exposure to Pb, plants grown in uninoculated soil were found to show decreased activities of antioxidant marker enzymes. We observed that Trichoderma inoculation significantly elevated these enzyme levels compared to that of seedlings exposed to Pb. The development of stress-tolerant plant-fungus associations may be a promising strategy for mycoremediation and soil amelioration measures.

17 citations

01 Jan 2001
TL;DR: In this paper, the effect of three fungicides (benomyl, hymexazol, oxyquinoleine) on the viability of sclerotia of Sclerotium rolfsii was tested in natural and sterilized soils.
Abstract: The effect of three fungicides (benomyl, hymexazol, oxyquinoleine) on the viability of sclerotia of Sclerotium rolfsii was tested in natural and sterilized soils. A similar test was carried out in natural soil combining each of these fungicides with one of four isolates of Trichoderma harzianum. In addition, the mycelial growth of the T. harzianum isolates and S. rolfsii was monitored on agar media amended with these fungicides at three concentrations. Benomyl reduced the antagonistic ability of the T. harzianum isolates in the soil, oxyquinoleine yielded variable results, while hymexazol improved the antagonism of T. harzianum isolates. In an agar medium, benomyl inhibited all T. harzianum isolates, as did oxyquinoleine. By contrast, hymexazol had only a negligible effect on the growth of the antagonist.

14 citations

01 Jan 1999
TL;DR: Brassica cultivars Ebony and Indian mustards, and Rangi rape residues reduced the soil level of Tylenchulus semipenetrans, and in a greenhouse reduced levels on the roots of orange seedlings, and the benefits from reduced nematode levels may have been negated by the increase in pythium infection.
Abstract: Summary. Brassica cultivars Ebony and Indian mustards, and Rangi rape residues reduced the soil level of Tylenchulus semipenetrans by up to 76% compared with unamended soil, and in a greenhouse reduced levels on the roots of orange (Citrus sinensis) seedlings. Paratrichodorus lobatus reached high levels in pots containing unamended soil but was not detected in pots containing amended soils. However, Pythium ultimum was isolated more frequently from roots, and propagule numbers of Pythium spp. were significantly higher in amended soils. Soil amendment did not affect growth of orange seedlings, and the benefits from reduced nematode levels may have been negated by the increase in pythium infection. In field experiments at 3 citrus orchards cleared for replanting, and at 1 established orchard between tree rows, brassica cultivars were grown in situ (20 kg seed/ha) as green manure crops. Highest crop production was at a site with heavier soil under drip irrigation, where Ebony and Yellow mustards produced 13–15 kg fresh weight/m2. Although soil levels of T. semipenetrans were reduced by 79–91% by incorporation of green manures, brassica cultivars including Ebony, Indian and Yellow mustards, and Humus and Rangi rapes, were no more effective than were self-seeding weeds. At 1 site, incorporation of a poor stand of Ebony mustard (but not of weeds) produced higher soil levels of T. semipenetrans; Paratrichodorus sp. numbers declined after mustard incorporation at this site but increased after weeds. Growth and soil incorporation of either brassicas or weeds increased soil levels of Pythium spp., but fusarium levels were decreased by incorporation of weed and Indian mustard residues. Growth of citrus measured at 2 field sites did not differ between soils amended with brassica or weed residues.

1 citations

References
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Journal ArticleDOI
TL;DR: A new DNA polymorphism assay based on the amplification of random DNA segments with single primers of arbitrary nucleotide sequence is described, suggesting that these polymorphisms be called RAPD markers, after Random Amplified Polymorphic DNA.
Abstract: Molecular genetic maps are commonly constructed by analyzing the segregation of restriction fragment length polymorphisms (RFLPs) among the progeny of a sexual cross. Here we describe a new DNA polymorphism assay based on the amplification of random DNA segments with single primers of arbitrary nucleotide sequence. These polymorphisms, simply detected as DNA segments which amplify from one parent but not the other, are inherited in a Mendelian fashion and can be used to construct genetic maps in a variety of species. We suggest that these polymorphisms be called RAPD markers, after Random Amplified Polymorphic DNA.

13,764 citations


"Improvement of antagonism and carbe..." refers methods in this paper

  • ...The random amplified polymorphic (RAPD) DNA procedure developed (Williams et al. 1990; Witkowska & Bien 1991), which involves simultaneous amplification of several anonymous loci in the genome using primers of arbitrary sequence, has been used for genetic, taxonomic and ecological studies of several fungi (Fungaro et al....

    [...]

  • ...The random amplified polymorphic (RAPD) DNA procedure developed (Williams et al. 1990; Witkowska & Bien 1991), which involves simultaneous amplification of several anonymous loci in the genome using primers of arbitrary sequence, has been used for genetic, taxonomic and ecological studies of…...

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  • ...PCR reactions were conducted according to Williams et al. (1990)....

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Journal ArticleDOI
TL;DR: A method is presented for the rapid isolation of high molecular weight plant DNA which is free of contaminants which interfere with complete digestion by restriction endonucleases, and which yields total cellular DNA.
Abstract: A method is presented for the rapid isolation of high molecular weight plant DNA (50,000 base pairs or more in length) which is free of contaminants which interfere with complete digestion by restriction endonucleases. The procedure yields total cellular DNA (i.e. nuclear, chloroplast, and mitochondrial DNA). The technique is ideal for the rapid isolation of small amounts of DNA from many different species and is also useful for large scale isolations.

10,481 citations


"Improvement of antagonism and carbe..." refers methods in this paper

  • ...Randomly amplified polymorphic DNA (RAPD) The extraction of total genomic DNA of wild and mutant Trichoderma isolates was done according to Murray and Thompson (1980)....

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Journal ArticleDOI

2,133 citations

Journal ArticleDOI
TL;DR: The genus Trichoderma comprises a great number of fungal strains that act as biological control agents, the antagonistic properties of which are based on the activation of multiple mechanisms, such as plant growth factors, hydrolytic enzymes, siderophores, antibiotics, and carbon and nitrogen permeases.
Abstract: The genus Trichoderma comprises a great number of fungal strains that act as biological control agents, the antagonistic properties of which are based on the activation of multiple mechanisms. Trichoderma strains exert biocontrol against fungal phytopathogens either indirectly, by competing for nutrients and space, modifying the environmental conditions, or promoting plant growth and plant defensive mechanisms and antibiosis, or directly, by mechanisms such as mycoparasitism. These indirect and direct mechanisms may act coordinately and their importance in the biocontrol process depends on the Trichoderma strain, the antagonized fungus, the crop plant, and the environmental conditions, including nutrient availability, pH, temperature, and iron concentration. Activation of each mechanism implies the production of specific compounds and metabolites, such as plant growth factors, hydrolytic enzymes, siderophores, antibiotics, and carbon and nitrogen permeases. These metabolites can be either overproduced or combined with appropriate biocontrol strains in order to obtain new formulations for use in more efficient control of plant diseases and postharvest applications.

1,338 citations


"Improvement of antagonism and carbe..." refers background in this paper

  • ...Most of the time, fungicides produce undesirable effects on non-targeting organisms, and so the use of microorganisms that antagonise plant pathogenic fungi is risk-free (Benitez et al. 2004)....

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