Trichoderma harzianum

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

Substrate evaluation for multiplication of Trichoderma spp.

Abstract: Cow dung, neem cake, coir pith, sorghum grains, saw dust, and rice bran, either alone or in certain combinations, with or without additives such as jaggery and wheat flour, and having differential moisture levels were evaluated as substrates for mass production of Trichoderma harzianum and T. viride . Pre-boiled sorghum grains, coir pith + neem cake (1:1), cow dung + neem cake (1:1) + wheat flour (10%) maintained high populations of T. harzianum and T. viride within 10 days of inoculation. Jaggery and wheat flour served as nutritional supplements and enhanced the conidial yield from 23.66 x 108 to 34 x 108 and 45.6 x 108 colony forming units g–1 respectively. An increase in the number of viable propagules up to 30 days was noted regardless of the substrates and its moisture levels. Although highest initial population of Trichoderma spp. was observed in sorghum grains, propagule viability was low in that compared to other substrates. Coir pith + neem cake (1:1) at 35% and 45% moisture gave longer shelf life for Trichoderma propagules.

Cymbopogon citratus L. essential oil as a potential antifungal agent against key weed moulds of Pleurotus spp. spawns

Abstract: The essential oil of Cymbopogon citratus L. (250-1500 p.p.m.) was tested in vitro for antifungal activity against seven Pleurotus spp. spawn-contaminating fungi, viz. Aspergillus flavus, A. fumigatus, A. niger, Alternaria alternata, Penicillium citrinum, Curvularia lunata and Trichoderma harzianum. Oil-enrichment resulted in significant (p < 0.05) reduction of growth for the pathogens examined. Fungal spore production inhibited up to 80% at 250 p.p.m. of the oil except for C. lunata, which was inhibited by only 30%. In the higher oil concentration (1500 p.p.m.) employed, fungal sporulation was completely retarded. Lemongrass oil reduces spore germination in A. flavus, A. fumigatus, A. alternata, P. citrinum and T. harzianum, with the effects dependent on oil concentration. However, lemongrass oil at 250 p.p.m. accelerated spore germination for A. niger and P. citrinum. Indeed, further increase in oil concentration shows complete inhibition. Among the pathogens, C. lunata was found to be most resistant strain, while A. niger was the most sensitive strain against lemongrass oil.

Evaluation of antifungal, phosphate solubilisation, and siderophore and chitinase release activities of endophytic fungi from Pistacia vera

Abstract: Fungal endophytes use different strategies to protect host plants from abiotic and biotic stress. In this study, we isolated endophytic fungi from Pistacia vera and characterised their antifungal activity against Aspergillus flavus, Rhizoctonia solani and Sclerotinia sclerotiorum, and their release of some factors that can alter plant growth capability. Trichoderma harzianum TH 5-1-2, T. harzianum TH 10-2-2 and T. atroviride TA 2-2-1 exhibited the highest growth inhibition percentages in dual culture assays against A. flavus, R. solani and S. sclerotiorum, respectively. Among the fungal endophyte cultures, ethyl acetate extracts of T. harzianum TH 10-2-2, T. harzianum TH 5-1-2 and T. atroviride TA 2-2-1 exhibited the highest growth inhibition of S. sclerotiorum, R. solani and A. flavus, respectively. Phosphate solubilisation was induced by Byssochlamys nivea BN 1-1-1 in culture. Large amounts of siderophore production were observed with Quambalaria cyanescens QC 11-3-2 and Epicoccum nigrum EN1, but Trichoderma spp. also produced siderophore in lower amounts. Trichoderma harzianum TH 5-1-2 produced the highest chitinase activity (2.92 U/mL). In general, among the endophytes isolated, Trichoderma spp. appear to have the most promise for promoting healthy growth of P. vera.

A Novel l-Amino Acid Oxidase from Trichoderma harzianum ETS 323 Associated with Antagonism of Rhizoctonia solani

Abstract: Trichoderma spp. are used as biocontrol agents against phytopathogens such as Rhizoctonia solani, but their biocontrol mechanisms are poorly understood. A novel l-amino oxidase (Th-LAAO) was identified from the extracellular proteins of Trichoderma harzianum ETS 323. Here, we show a FAD-binding glycoprotein with the best substrate specificity constant for l-phenylalanine. Although the amino acid sequence of Th-LAAO revealed limited homology (16−24%) to other LAAO members, a highly conserved FAD-binding motif was identified in the N-terminus. Th-LAAO was shown to be a homodimeric protein, but the monomeric form was predominant when grown in the presence of deactivated Rhizoctonia solani. Furthermore, in vitro assays demonstrated that Th-LAAO had an antagonistic effect against Rhizoctonia solani and a stimulatory one on hyphal density and sporulation in T. harzianum ETS 323. These findings further our understanding of T. harzianum as a biocontrol agent and provide insight into the biological function of l-a...

Involvement of Trichoderma harzianum Epl-1 Protein in the Regulation of Botrytis Virulence- and Tomato Defense-Related Genes.

Abstract: Several Trichoderma spp. are well known for their ability to: (i) act as important biocontrol agents against phytopathogenic fungi; (ii) function as biofertilizers; (iii) increase the tolerance of plants to biotic and abiotic stresses; and (iv) induce plant defense responses via the production and secretion of elicitor molecules. In this study, we analyzed the gene-regulation effects of Trichoderma harzianum Epl-1 protein during the interactions of mutant Δepl-1 or wild-type T. harzianum strains with: (a) the phytopathogen Botrytis cinerea and (b) with tomato plants, on short (24 h hydroponic cultures) and long periods (4-weeks old plants) after Trichoderma inoculation. Our results indicate that T. harzianum Epl-1 protein affects the in vitro expression of B. cinerea virulence genes, especially those involved in the botrydial biosynthesis (BcBOT genes), during the mycoparasitism interaction. The tomato defense-related genes were also affected, indicating that Epl-1 is involved in the elicitation of the salicylic acid pathway. Moreover, Epl-1 also regulates the priming effect in host tomato plants and contributes to enhance the interaction with the host tomato plant during the early stage of root colonization.