Trichoderma harzianum
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Trichoderma harzianum |
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| Scientific name | ||||||||||||
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| Rifai |
Trichoderma harzianum is a hose fungus from the family of the crust ball fungus relatives .
Taxonomy
Most Trichoderma strains do not have a sexual stage, but only produce asexual spores . Some strains that are not used for biological pest control are also known to have a sexual stage. If present, this belongs to the genus Hypocrea within the ashes . Traditional taxonomy was based on differences in morphology , primarily that of the asexual sporulation apparatus; nowadays, however, more molecular biological approaches are being pursued. As a result, the original nine species were split into at least 33.
Genetic analysis
Most strains are strictly to an asexual life cycle adapted . In the absence of meiosis , chromosome plasticity is the norm, meaning that the different strains have different numbers and sizes of chromosomes. Most cells have numerous nuclei, with some vegetative cells having more than 100. Various asexual genetic factors such as parasexual recombination , mutations and others contribute to the variation between the cell nuclei within a single organism ( thallus ). Therefore the mushrooms are highly adaptive and evolve very quickly. There is great diversity in the genotypes and phenotypes of the wild strains.
While the wild strains are highly adaptive and can be heterokaryotic (they contain cell nuclei of different genotypes within the same organism and are therefore highly variable), those used for biological pest control in commercial agriculture are homokaryotic (the cell nuclei are genetically similar or identical) or it should be. As a result, the strains used commercially are genetically different and not variable. This is extremely important for quality assurance.
Synonyms
The following synonyms are known:
- Sporotrichum narcissi Tochinai & Shimada, (1930)
- Trichoderma lignorum var. Narcissi (Tochinai & Shimada) Pidopl., (1953)
- Trichoderma narcissi (Tochinai & Shimada) Tochinai & Shimada, (1931)
use
Trichoderma harzianum is used as a fungicide , whereby the preparations used are applied to the leaves or seeds of the treated plants or in the soil and are intended to protect against various fungal pathogens there . Commercial products such as 3Tac have been used successfully against infestation with Botrytis , Fusarium and Penicillium .
The species is also used to make enzymes .
Mycoparasitism
Trichoderma species are fungi that occur in almost all soils. Occasionally they are the predominant cultivable fungi in the soil. They also survive in many other different habitats.
Trichoderma species colonize plant roots, and some strains grow in the rhizosphere during their development . They also attack, parasitize or otherwise obtain their nutrients from other fungi. They have developed numerous mechanisms both for attacking other fungi and for promoting plant growth in the course of their evolution. Various Trichoderma strains have been used successfully to control almost every phytopathogenic fungus for which research has been made. However, there are more efficient and less efficient strains, and also fungi, which can be controlled extremely inefficiently.
Trichoderma species, on the other hand, are the main source of contamination and yield loss on mushroom growers.
swell
- I. Yedidia, N. Benhamou, I Chet: Induction of defense responses in cucumber plants ( Cucumis sativus L.) by the biocontrol agent Trichoderma harzianum . In: Appl. Environ. Microbiol. . 65, 1999, pp. 1061-1070.
- John Bissett: A revision of the genus Trichoderma . III. Section Pachybasium . In: Canadian Journal of Botany . 69, No. 11, November 1991, pp. 2373-2417. doi : 10.1139 / b91-298 . Retrieved December 7, 2014.
- W. Gams , W. Meyer: What Exactly Is Trichoderma harzianum ? . In: Mycologia . 90, No. 5, Sep. - Oct. 1998, pp. 904-915.
Individual evidence
- ↑ Trichoderma harzianum Rifai . In: GBIF Taxonomy Backbone . GBIF . Retrieved August 7, 2019.
- ↑ 3Tac product page . Retrieved on August 7, 2019 ( page no longer available )