Trichoderma harzianum

About: Trichoderma harzianum is a research topic. Over the lifetime, 4731 publications have been published within this topic receiving 96796 citations.

Food attraction and population growth of fungivorous nematodes with different fungi

Abstract: Food attraction of the fungivorous nematodes Aphelenchus avenae and Aphelenchoides spp. to seven fungal species (Pyrenochaeta lycopersici, Botrytis cinerea, Rhizoctonia solani strains AG 3 and AG 2-1, Verticillium dahliae, Pochonia bulbillosa, Mortierella hyalina and Trichoderma harzianum) was determined on agar plates by counting the number of test nematodes present on the mycelium of each fungus 24 h after inoculation. Population growth of A. avenae and Aphelenchoides spp. on five of the seven fungi included in the attraction test (P. lycopersici, R. solani strain AG 3, V. dahliae, P. bulbillosa and T. harzianum) was also determined on agar plates by counting nematode numbers every week during a 6-week period. A. avenae and Aphelenchoides spp. were attracted to all the fungi tested. A. avenae was preferentially attracted to V. dahliae (P < 0.0001), and Aphelenchoides spp. did not show any preference except for low attraction to R. solani. A. avenae and Aphelenchoides spp. reproduced on all fungal species tested. After 6 weeks of incubation, the highest number of nematodes was found on P. lycopersici and P. bulbillosa, while the lowest number occurred on R. solani for A. avenae and on T. harzianum for Aphelenchoides spp. The suitability of a fungus as a host was not clearly related to the attraction to that fungus.

Trichoderma Isolates Inhibit Fusarium virguliforme Growth, Reduce Root Rot, and Induce Defense-Related Genes on Soybean Seedlings.

Abstract: Sudden death syndrome (SDS) caused by Fusarium virguliforme is among the most important diseases affecting soybean in the United States. The use of biological control agents (BCAs) such as Trichoderma spp. can be a valuable resource to suppress F. virguliforme populations. Therefore, this research focused on screening possible BCAs against F. virguliforme and evaluating mycoparasitism and the induction of systemic resistance as mechanisms underlying the antagonistic activity of selected BCAs against F. virguliforme. In total, 47 potential BCAs, including 41 Trichoderma isolates and 6 Mortierella isolates, were screened in a dual-plate assay. The most effective isolates belonged to the Trichoderma harzianum species and were able to inhibit F. virguliforme radial growth by up to 92%. Selected Trichoderma isolates were tested in the greenhouse and in a microplot study. They reduced root rot caused by F. virguliforme when the plants were coinoculated with the pathogen and the BCA. The tested BCA's ability to reduce F. virguliforme growth may be related to several mechanisms of action, including mycoparasitism and induction of defense-related genes in plants, as revealed by monitoring the expression of defense-related genes in soybean. Our results highlight the potential of native Trichoderma isolates to inhibit F. virguliforme growth and reduce SDS severity, providing the basis for future implementation of biological control in soybean production. More efforts are needed to implement the use of these approaches in production fields, and to deepen the current knowledge on the biology of these highly antagonistic isolates.

Role of the Morphology and Polyphosphate in Trichoderma harzianum Related to Cadmium Removal

Abstract: This study concerns the metabolism of polyphosphate in Trichoderma harzianum, a biocontrol agent with innate resistance against most chemicals used in agriculture, including metals, when grown in the presence of different concentrations of cadmium. The biomass production was affected by the concentration of metal used. Control cultures were able to accumulate polyphosphate under the conditions used. Moreover, the presence of cadmium induced a reduction in polyphosphate content related to the concentration used. The morphological/ultrastructural aspects were characterized by using optical and scanning electron microscopy, and were affected by the heavy metal presence and concentration. The efficiency of cadmium removal revealed the potential of the microorganism for use in remediation. The data indicate the potential for polyphosphate accumulation by the fungus, as well as its degradation related to tolerance/survival in the presence of cadmium ions.

Trichoderma harzianum t22 induces in maize systemic resistance against fusarium verticillioides

Abstract: SUMMARY Fusarium verticillioides is one of the most common plant pathogenic fungi affecting maize causing ear and kernel rot. Nearly the totality of the fungal strains are able to produce mycotoxins known as fumonisins at very different levels. However, information on the ability of the biocontrol fungus Trichoderma harzianum to induce systemic resistance in maize against F. verticillioides is still lacking. We now show that, upon root colonization by T. harzianum, F. verticillioides consistently reduces maize disease symptoms. The enhanced activation of SA- and JA/ ET-dependent defence responses indicates that resistance in maize is caused by a better perception of the fungal pathogen due to the effect of Trichoderma inocula. Seed biopriming with T. harzianum could be a useful strategy to control F. verticillioides infection and fumonisin accumulation under field conditions.