The experiment consisted in monitoring the count of moulds and three selected Trichoderma sp. isolates (T1 - Trichoderma atroviride, T2 - Trichoderma harzianum, T3 - Trichoderma harzianum) in vegetable (onion and tomato) waste composted with additives (straw, pig manure). Additionally, the aim of the study was to determine the type of interaction occurring between autochthonous fungi isolated from composts after the end of the thermophilic phase and Trichoderma sp. strains applied in the experiment. Number of microorganisms was determined by the plate method, next the identification was confirmed. The rating scale developed by Mańka was used to determine the type of interactions occurring between microorganisms. The greatest count of moulds in onion waste composts was noted in the object which had simultaneously been inoculated with two strains T1 - T. atroviride and T3 - T. harzianum. The greatest count of moulds was noted in the tomato waste composts inoculated with T2 - T. harzianum strain. Microscope identification revealed that Penicillum sp., Rhizopus sp., Alternaria sp. and Mucor sp. strains were predominant in onion waste composts. In tomato waste composts Penicillium was the predominant genus, followed by Rhizopus. The test of antagonism revealed the inhibitory effect of Trichoderma isolates on most autochthonous strains of moulds. Tomato waste composts proved to be better substrates for the growth and development of Trichoderma sp. isolates. The results of the study show that vegetable waste can be used in agriculture as carriers of antagonistic microorganisms.
In view of the ecological hazards of chemicals, pot experiments were conducted to determine the efficacy of Trichoderma sp. against Macrophomina phaseolina. Greenhouse evolution of the interaction between M. phaseolina isolates and Trichoderma sp. isolates revealed a very highly significant (p = 0.0000). M. phaseolina isolate x antagonist isolate interaction for all the following parameters: preemergence damping-off, postemergence damping-off, survival, plant height, and dry weight. This interaction implies that a single isolate of antagonist can be highly effective againstan isolate of M. phaseolina, but may have only minimal effectsonotherisolatesof M. phaseolina. Therefore, isolates of antagonist should be tested against as many isolates of M. phaseolina as possible, as this will improve the chance of identifying antagonist isolates effective against several isolates of M. phaseolina.
Potato (Solanum tuberosum L.), an important food crop in the world, is susceptible to many fungal pathogens including Alternaria solani and Fusarium oxysporum causing Fusarium wilt and early blight diseases. Mycoparasitic fungi like Trichoderma encode chitinases, cell wall degrading enzymes, with high antifungal activity against a wide range of phytopathogenic fungi. In this study, a binary vector harboring endochitinase gene of ~1,000 bp was constructed and used to transform potato nodes through Agrobacterium-mediated transformation. Out of several primary transformants, two transgenic potato lines were verified for transgene insertion and integration by Southern blot. In a pot experiment for Fusarium resistance, the transgenic potato lines didn’t show any symptoms of disease, instead they remained healthy post infection. The transgenic potato lines exhibited 1.5 fold higher mRNA expression of endochitinase at 7 days as compared to 0 day post fungus inoculation. It was evident that the mRNA expression decreased over days of inoculation but was still higher than at 0 day and remained stable upto 30 days post inoculation. Similarly, for A. solani infection assay, the mRNA expression of the endochitinase gene was 3 fold higher 7 days post inoculation compared to expression at 0 day. Although the expression decreased by1.2 fold during subsequent days post infection, it remained stable for 30 days, suggesting that protection in transgenic potato plants against fungal pathogens was achieved through an increase in endochitinase transcript.
In this work, response surface optimization strategy was employed to enhance the biodegradation process of fresh palm oil mill effluent (POME) by Aspergillus niger and Trichoderma virens. A central composite design (CCD) combined with response surface methodology (RSM) were employed to study the effects of three independent variables: inoculum size (%), agitation rate (rpm) and temperature (°C) on the biodegradation processes and production of biosolids enriched with fungal biomass protein. The results achieved using A. niger were compared to those obtained using T. virens. The optimal conditions for the biodegradation processes in terms of total suspended solids (TSS), turbidity, chemical oxygen demand (COD), specific resistance to filtration (SRF) and production of biosolids enriched with fungal biomass protein in fresh POME treated with A. niger and T. virens have been predicted by multiple response optimization and verified experimentally at 19% (v/v) inoculum size, 100 rpm, 30.2°C and 5% (v/v) inoculum size, 100 rpm, 33.3°C respectively. As disclosed by ANOVA and response surface plots, the effects of inoculum size and agitation rate on fresh POME treatment process by both fungal strains were significant.
Ability of five strains of Trichoderma pseudokoningii (antagonists) to suppress radial growth of Fusarium verticillioides (Sacc.) Nirenberg (= Fusarium moniliforme Sheldon) was examined in vitro These were T. pseudokoningii strai n1 (IMI 380933), strain 2 (IMI 380937), strain 3 (IMI 3809 39), strain 4 (IMI 380940) a nd strain 5 (IMI 380941). Each strain was paired with pathogen by inoculating at opposite ends of 9 cm petri plates using three pairing methods. Gradings were assigned to varied growth inhibition of pathogen by antagonists and analysed using GLM procedure (SAS). Growth suppression of F. verticillioides by all strains of T. pseudokoningii was significantly different (R2 = 0.98, p = 0.05) from control in all pairing methods. It differed significantly (p > 0.0003) among the strains in all pairing methods. Growth suppression also differed significantly among (p>0.0001) and within (p > 0.018) pairing methods. Growth suppression was best when antagonists were inoculated before pathogen. Suppression mechanisms include mycoparasitism and competition for space and nutrients. T. pseudokoningii strains 3 and 4 had the best (p = 0.05) growth suppression of F. verticillioides and could be used as biocontrol agents for endophytic F. verticillioides in maize plant. This experiment was conducted in the search for resedent microorganisms that might be capable of checking F. verticillioides within maize plant by competitive exclusion in subsequent experiment.
Six isolates of Trichoderma spp. (belonging to species; Trichoderma harzianum and T. longibrachiatum) were applied as seed or soil treatments to suppress damping-off of seedlings of ten cotton cultivars under greenhouse conditions. In most cases, cultivar x isolate interaction was a highly significant (p < 0.01) source of variation in the tested seedling growth parameters: incidence of disease, seedling height, and seedling dry weight. This interaction implies that a single isolate of Trichoderma can be highly effective in controlling the disease on a cotton cultivar but may have minimal efficiency in controlling the disease on another cultivar. It was also found that, in most cases, cultivar x isolate x application method was a highly significant source of variation (p < 0.01) in the tested growth parameters. Cotton cultivars showed differences in the disease reaction to the biocontrol agents. In the experiments evaluating the Trichoderma antagonists and their effect on seedling disease, a highly significant (p < 0.01) experimental treatment interaction was found. This interaction suggests that the outcome of cultivar x isolate interaction is markedly affected by the application method. Thus, the application method should be chosen to maximize the outcome of this interaction. The degree of the control of seedling disease in cotton differed according to the isolates of antagonists, the application method and cultivars.
Fusarium avenaceum, F. oxysporum, Alternaria alternata, Botrytis cinerea, Rhizoctonia solani, Mucor sp., Aspergillus niger, Penicillium spp. were the most often isolated species from fiber seeds. The antagonistic action of Trichoderma lignorum T 13–82 in relation to seed contaminants was evaluated. The use of Trichodermin-BL, based on that antagonist, applied as pre-sowing seed treatment and on growing plants decrease diseases incidence. The application of Trichodermin-BL improved a set of biometrical and physiological parameters during crop vegetation, increased the yield and raised flax fiber quality.
Clethodim herbicide (Cle) and three Trichoderma strains (Tri) were applied either alone or in combination (Cle + Tri) for controlling weeds, root knot nematodes (Meloidogyne arenaria) and Rhizoctonia root rot disease (Rhizoctonia solani) as well as for evaluating their effects on total microbial count in the rhizosphere and the number of Rhizobium nodules on roots in two faba bean cultivars cultivated in naturally heavily infested fields. The evaluated characters were very similar for the two tested cultivars (Nubariya 1 and Sakha 3). Treatment with Cle alone highly reduced the fresh and dry matter of tested weeds (Amaranthus viridis, Cynodon dactylon and Cenchrus ciliaris), followed by Cle + Tri and Tri alone. Cle + Tri highly reduced nematode parameters viz. numbers of J2 in soil or roots, females, eggs, galls and egg-masses when compared with each treatment alone. Tri alone caused a great decrease in Rhizoctonia root rot infection, followed by Cle + Tri and Cle alone. Total microbial count and Rhizobium nodules were affected only with Cle treatment. Plant growth parameters (shoot length, shoot fresh and dry weight and numbers of branches and leaves) and yield parameters (fresh pod and dry weight, seed number per pod, seed weight and ash pod weight of plant) were greatly improved for Cle + Tri treatments when compared with either Tri or Cle alone.
A representative group of hydrophilic fungi from the genus Trichoderma isolated from lignocellulose composts with varying degrees of maturity was analyzed for their ability to biodegrade a harmful anthraquinone dye, i.e. Remazol Brilliant Blue R (RBBR). In RBBR-containing post-culture liquids, there were determined the degree of RBBR decolorization, horseradish peroxidase-like, superoxide dismutase-like, and xylanase activities, and the concentrations of low-molecular phenolic compounds. The study results demonstrated that Trichoderma asperellum, T. harzianum, and T. lixii strains isolated from compost containing larger amounts of easily available lignocellulose fractions, i.e. grasses, exhibit higher RBBR decolorization effi ciency ranging from 0.3 to 62% than T. citrinoviride strains isolated from compost II, which contained greater quantities of hardly degradable lignocellulose. The decolorization of remazol blue R by the investigated Trichoderma strains intensified signifi cantly with the increase in peroxidase activity and it was correlated with a decline in the content of low-molecular phenolic compounds. The dynamics of changes in the horseradish peroxidase-like, superoxide dismutase, and xylanase activities in the aqueous post-culture liquids of the investigated fungal strains depended largely on the duration of the culture. Given their ability to adapt to water environments, e.g. wastewater, and to decolorize and detoxify the RBBR anthraquinone dye, Trichoderma fungi can be used for bioremediation of such environments.