Showing papers on "Trichoderma harzianum published in 2011"
01 Jan 2011
TL;DR: Isolates of T. harzianum were found to differ in the levels of hydrolytic enzymes produced when mycelium of S. rolfsii, Rhizoctonia solani, and Pythium aphanidermatum in soil was attacked, correlated with the ability of each of the Trichoderma isolates to control the respective soilborne pathogens.
494 citations
TL;DR: In this paper, the influence of different levels of biomass delignification, degree of crystallinity of lignicellulose, composition of enzymatic activities and BSA on the performance of pretreated sugarcane bagasse was evaluated.
165 citations
TL;DR: Trichoderma species are commonly used as biological control agents against phytopathogenic fungi and some isolates are able to improve plant growth and a dramatic increase in the concentrations of Ca 2+, Mg 2+ , P and K + were recorded in the seedling shoot and root among T. harzianum T969 coated seed.
Abstract: Trichoderma species are commonly used as biological control agents against phytopathogenic fungi and some isolates are able to improve plant growth. In this study, the effects of three Trichoderma isolates including Trichoderma harzianum isolate T969, T. harzianum isolate T447 and Trichoderma sp. isolate T in tomato seedling vigor and their nutrient uptake via two inoculants introduction methods (inoculating seed with Trichoderma spore suspension and inoculating nursery soil with Trichoderma fortified wheat) were examined. Seed germination rate was not affected by Trichoderma application, but shoot height, shoot diameter, shoot fresh and dry weight and root fresh and dry weight in tomato seedlings were interestingly (p ≤ 0.05) increased when sown in Trichoderma sp. T and T. harzianum T969 fortified soil and when compared to the control. The soil amended by Trichoderma sp. T and T. harzianum T969 had marked increase in leaf number and leaf area (p ≤ 0.05). Chlorophyll content increased in seedling grown in Trichoderma sp. T amended soil as well as in Trichoderma sp. T and T. harzianum T969 coated seed. A dramatic increase (p ≤ 0.05) in the concentrations of Ca 2+ , Mg 2+ , P and K + were recorded in the seedling shoot and root among T. harzianum T447 soil amended treatment
131 citations
TL;DR: It is shown that T39 reduced downy mildew severity on susceptible grapevines under controlled greenhouse conditions by a direct modulation of defense-related genes and the activation of priming for enhanced expression of these genes after pathogen inoculation.
130 citations
TL;DR: The study explores high P-solubilizing potential of A. niger and T. harzianum, which can be exploited for the solubilization of fixed phosphates present in the soil and produce IAA, thereby enhancing soil fertility and plant growth.
Abstract: Aspergillus niger strain BHUAS01, Penicillium citrinum strain BHUPC01 and Trichoderma harzianum was tested for phosphate solubilizing potential and plant hormones production (indole acetic acid). The fungal strains were tested for their in-vitro phosphate solubilizing potential using Pikovskaya broth containing tricalcium phosphate (TCP) as the sole phosphorus source. All the cultures were found to solubilize TCP but with varying potential. The Aspergillus niger showed maximum amount of soluble phosphate (328 μg mL-1), followed by P. citrinum (301 μg mL-1) and T. harzianum (287 μg mL-1) after 6 days of incubation at 28±2°C. Indole Acetic Acid (IAA) production was estimated maximum in A. niger (85 μg mL-1) followed by T. harzianum (68 μg mL-1) and P. citrinum (52 μg mL-1) after 3 days of incubation at 28+2°C. T. harzianum is a well known biological controlling agent against several soil borne phytopathogens. It showed antagonistic against Fusarium oxysporum and Rhizoctonia solani. Under laboratory conditions, coinoculation of T. harzianum and A. niger showed significant increase in chickpea (Cicer arietinum) growth parameters including shoot length, root length and dry weight of shoot and root followed by single inoculation of T. harzianum and coinoculation of A. niger and P. citrinum over control. The study explores high P-solubilizing potential of A. niger and T. harzianum, which can be exploited for the solubilization of fixed phosphates present in the soil and produce IAA, thereby enhancing soil fertility and plant growth. Coinoculation of T. harzianum and A. niger could be effective biofertilizer and biocontroling agent for chickpea production.
127 citations
TL;DR: Application of beneficial microorganisms, such as SQR-T037 that biodegrades allelochemicals, is a highly efficient way to resolve the problems associated with continuous cropping system.
Abstract: To alleviate the stress of continuous cropping for cucumber continuous cropping (CCC) system, a beneficial fungus Trichoderma harzianum SQR-T037 (SQR-T037) was isolated and applied to soil to degrade allelochemicals exuded from cucumber plants in a Rhizobox experiment. The following phenolic acids (PAs), classified as allelochemicals, were isolated and identified from cucumber rhizospheres: 4-hydroxybenzoic acid, vanillic acid, ferulic acid, benzoic acid, 3-phenylpropionic acid, and cinnamic acid. Mixed PAs added in potato dextrose broth, each with 0.2 gram per liter, were completely degraded by SQR-T037 after 170 h of incubation. In Rhizobox experiments, inoculation of SQR-T037 in the CCC soil also degraded the PAs exuded from cucumber plant roots. This degradation was 88.8% for 4-hydroxybenzoic acid, 90% for vanillic acid, 95% for benzoic acid, and 100% for ferulic acid, 3-phenylpropionic acid, and cinnamic acid at 45 days after plantation. Simultaneously, a significant (p ≥ 0.05) decrease in the disease index of Fusarium wilt and an increase in dry weights of cucumber plants were obtained in pot experiments by application of SQR-T037. This was mostly attributed to degradation of PAs exuded from cucumber roots in CCC soil by SQR-T037 and alleviation of the allelopathic stress. Application of beneficial microorganisms, such as SQR-T037 that biodegrades allelochemicals, is a highly efficient way to resolve the problems associated with continuous cropping system.
122 citations
TL;DR: The results indicated that SQR-T37 was a potent antagonist against R. solani in a mycoparasitic way that decreased the population of the pathogen.
Abstract: Damping-off disease is caused by Rhizoctonia solani and leads to serious loss in many crops. Biological control is an efficient and environmentally friendly way to prevent damping-off disease. Optical micrographs, scanning electron micrographs, and the determination of hydrolytic enzymes were used to investigate the antagonism of Trichoderma harzianum SQR-T37 (SQR-T37) against R. solani. Experiments were performed in pots to assess the in vivo disease-control efficiency of SQR-T37 and bio-organic fertilizer. The results indicate that the mycoparasitism was the main mechanism accounting for the antagonistic activity of SQR-T37. In one experiment, the population of R. solani was decreased from 106 internal transcribed spacer (ITS) copies per gram soil to 104 ITS copies per gram soil by the presence of the antagonist. In this experiment, 45% of the control efficiency was obtained when 8 g of SQR-T37 hyphae per gram soil was applied. In a second experiment, as much as 81.82% of the control efficiency was obtained when bio-organic fertilizer (SQR-T37 fermented organic fertilizer, BIO) was applied compared to only 27.27% of the control efficiency when only 4 g of SQR-T37 hyphae per gram soil was applied. Twenty days after incubation, the population of T. harzianum was 4.12 × 107 ITS copies per gram soil in the BIO treatment, which was much higher than that in the previous treatment (8.77 × 105 ITS copies per gram soil), where only SQR-T37 was applied. The results indicated that SQR-T37 was a potent antagonist against R. solani in a mycoparasitic way that decreased the population of the pathogen. Applying BIO was more efficient than SQR-T37 application alone because it stabilized the population of the antagonist.
115 citations
TL;DR: The interaction of T. harzianum and the AMF with the plant produced a characteristic hormonal profile, which differed from that produced by inoculation with each microorganism singly, suggesting an attenuation of the plant response, related to the hormones SA, JA and ethylene.
109 citations
TL;DR: It is concluded that seed biopriming with different salinity tolerant isolates of Trichoderma reduced severity of the effects of salinity though the amelioration was better in Th-14 under present experimental material and conditions.
Abstract: Salt stress is one of the major abiotic stresses limiting crop growth and productivity. This work investigated the potential of five ST isolates of Trichoderma harzianum (Th-13, Th-14, Th-19, Th-33 and Th-50) applied through seed biopriming in reducing the detrimental effects of salinity stress on wheat (Triticum aestivum L.). Growth, physiological and biochemical parameters were studied to characterize salt tolerance. One factor was treatments (T1, T2, T3, T4, T5 and T6) and second factor was four levels of salt stress viz., 0, 2, 4 and 6 dsm−1. In germination test, most of the isolates (Th-14, Th-19 and Th-13) were effective in improving germination percentage and reducing RPG during salinity stress. Seedlings raised from ST Trichoderma isolates had significantly higher root and shoot lengths, CC and MSI than control at all stress levels. The treatments Th-14, Th-19 and Th-13 showed lower accumulation of MDA content whereas proline content and phenolics were higher in treated plants under both non-saline and saline conditions. Highest MDA content was observed in control at salt stress level of 6 dSm−1. It is concluded that seed biopriming with different salinity tolerant isolates of Trichoderma reduced severity of the effects of salinity though the amelioration was better in Th-14 under present experimental material and conditions.
105 citations
TL;DR: It is proposed that TFF treatment at SQR-T037 rate of 107 cfug−1 (i.e., 105 cfugen−1 soil after applied to soil) was the best formulation for controlling Fusarium wilt of cucumber.
Abstract: Pot experiments were carried out over two growing periods to assay the biocontrol efficacy and rhizosphere colonization of Trichoderma harzianum SQR-T037 (SQR-T037) applied as SQR-T037 conidia suspension (TCS), SQR-T037 conidia suspension blended with organic fertilizer (TBF), or SQR-T037 fermented organic fertilizer (TFF). Each formulation had three T. harzianum numbers. In two experiments, Percent Disease Indexes (PDIs) decreased with the increase of SQR-T037 number added to soils. The TFF treatment consistently exhibited the lowest PDIs at same amendment rate of SQR-T037 and 0–8.9%, 25.6–78.9%, and 4.4–50.0% of PDIs were found in TFF, TCS, and TBF treatment, respectively. Soils treated with TFF showed the highest SQR-T037 population in rhizosphere and bulk soil. Decrease of Fusarium oxysporum population in both bulk and rhizosphere soils occurred in the treatment SQR-T037 at 105 and 106 cfug−1 soil rate. The TFF treatment at the SQR-T037 rate of 103 cfug−1 soil significantly (p < 0.05) increased SQR-T037 population within the rhizoplane but had no effect on F. oxysporum population when compared to TCS and TBF. Generally, TFF treatments were superior to TCS and TBF treatments on disease control by sustaining colonization of SQR-T037 and decreasing F. oxysporum abundance in the rhizosphere soil. We propose that TFF treatment at SQR-T037 rate of 107 cfug−1 (i.e., 105 cfug−1 soil after applied to soil) was the best formulation for controlling Fusarium wilt of cucumber.
103 citations
TL;DR: Results suggest that T. harzianum–mediated biocontrol may be related to alleviating R. solani-induced oxidative stress and led to the systemic accumulation of phytoalexins in Trichoderma-inoculated plants.
Abstract: Trichoderma harzianum is an effective biocontrol agent against the devastating plant pathogen Rhizoctonia solani. Despite its wide application in agriculture, the mechanisms of biocontrol are not yet fully understood. Mycoparasitism and antibiosis are suggested, but may not be sole cause of disease reduction. In the present study, we investigated the role of oxidant-antioxidant metabolites in the root apoplast of sunflower challenged by R. solani in the presence/absence of T. harzianum NBRI-1055. Analysis of oxidative stress response revealed a reduction in hydroxyl radical concentration (•OH; 3.6 times) at 9 days after pathogen inoculation (dapi), superoxide anion radical concentration (O2•−; 4.1 times) at 8 dapi and hydrogen peroxide concentration (H2O2; 2.7 times) levels at 7 dapi in plants treated with spent maize-cob formulation of T. harzianum NBRI-1055 (MCFT), as compared to pathogen-inoculated plants. The protection afforded by the biocontrol agent was associated with the accumulation of the ROS gene network: the catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) and ascorbate peroxidase (APx), maximum activity of CAT (11.0 times) was observed at 8 dapi, SOD (7.0 times) at 7 dapi, GPx (5.4 times) and APx (8.1 times) at 7 dapi in MCFT-treated plants challenged with the pathogen. This was further supported by the inhibition of lipid and protein oxidation in Trichoderma-inoculated plants. MCFT stimulated the accumulation of secondary metabolites of phenolic nature that increased up to five-fold and also exhibited strong antioxidant activity at 8 dapi, eventually leading to the systemic accumulation of phytoalexins. These results suggest that T. harzianum–mediated biocontrol may be related to alleviating R. solani-induced oxidative stress.
TL;DR: It is shown that some generalist strains of M. anisopliae were as good at germinating in RE as T. harzianum, although germination rates of the specialized acridid pathogen Metarhizium acridum and the B. bassiana strains were significantly lower.
Abstract: Metarhizium anisopliae and Beauveria bassiana are ubiquitous insect pathogens and possible plant symbionts, as some strains are endophytic or colonize the rhizosphere. We evaluated 11 strains of M. anisopliae and B. bassiana, and two soil saprophytes (the non-rhizospheric Aspergillus niger and the rhizosphere-competent Trichoderma harzianum) for their ability to germinate in bean root exudates (REs). Our results showed that some generalist strains of M. anisopliae were as good at germinating in RE as T. harzianum, although germination rates of the specialized acridid pathogen Metarhizium acridum and the B. bassiana strains were significantly lower. At RE concentrations of <1 mg ml(-1), M. anisopliae strain ARSEF 2575 showed higher germination rates than T. harzianum. Microarrays showed that strain 2575 upregulated 29 genes over a 12 h period in RE. A similar number of genes (21) were downregulated. Upregulated genes were involved in carbohydrate metabolism, lipid metabolism, cofactors and vitamins, energy metabolism, proteolysis, extracellular matrix/cell wall proteins, transport proteins, DNA synthesis, the sexual cycle and stress response. However, 41.3% of the upregulated genes were hypothetical or orphan sequences, indicating that many previously uncharacterized genes have functions related to saprophytic survival. Genes upregulated in response to RE included the subtilisin Pr1A, which is also involved in pathogenicity to insects. However, the upregulated Mad2 adhesin specifically mediates adhesion to plant surfaces, demonstrating that M. anisopliae has genes for rhizosphere competence that are induced by RE.
TL;DR: A transformation system for banana was developed and the endochitinase gene ThEn-42 from Trichoderma harzianum was expressed together with the grape stilbene synthase (StSy) gene in transgenic banana plants under the control of the 35S promoter and the inducible PR-10 promoter, respectively.
Abstract: The most devastating disease currently threatening to destroy the banana industry worldwide is undoubtedly Sigatoka Leaf spot disease caused by Mycosphaerella fijiensis. In this study, we developed a transformation system for banana and expressed the endochitinase gene ThEn-42 from Trichoderma harzianum together with the grape stilbene synthase (StSy) gene in transgenic banana plants under the control of the 35S promoter and the inducible PR-10 promoter, respectively. The superoxide dismutase gene Cu,Zn-SOD from tomato, under control of the ubiquitin promoter, was added to this cassette to improve scavenging of free radicals generated during fungal attack. A 4-year field trial demonstrated several transgenic banana lines with improved tolerance to Sigatoka. As the genes conferring Sigatoka tolerance may have a wide range of anti-fungal activities we also inoculated the regenerated banana plants with Botrytis cinerea. The best transgenic lines exhibiting Sigatoka tolerance were also found to have tolerance to B. cinerea in laboratory assays.
TL;DR: The in vitro experiment revealed that all of the tested microorganisms were apparently able to trigger PGP-properties, and the promotive action on peanut nodulation, N2-fixation performance and vegetative characters was obvious with the dual inoculation with Bradyrhizobium plus S. marcescens.
TL;DR: The T. harzianum isolates T-30 and T-78 showed the greatest mycoparasitic potential against F. oxysporum, which could lead to improved biocontrol of this phytopathogen.
TL;DR: The results show that nox1 is involved in T. harzianum ROS production and antagonism against P. ultimum, and genes related to protease, cellulase, and chitinase activities were differentially upregulated in the interaction of aNox1-overexpressed transformant with this pathogen.
Abstract: The synthesis of reactive oxygen species (ROS) is one of the first events following pathogenic interactions in eukaryotic cells, and NADPH oxidases are involved in the formation of such ROS. The nox1 gene of Trichoderma harzianum was cloned, and its role in antagonism against phytopathogens was analyzed in nox1-overexpressed transformants. The increased levels of nox1 expression in these transformants were accompanied by an increase in ROS production during their direct confrontation with Pythium ultimum. The transformants displayed an increased hydrolytic pattern, as determined by comparing protease, cellulase, and chitinase activities with those for the wild type. In confrontation assays against P. ultimum the nox1-overexpressed transformants were more effective than the wild type, but not in assays against Botrytis cinerea or Rhizoctonia solani. A transcriptomic analysis using a Trichoderma high-density oligonucleotide (HDO) microarray also showed that, compared to gene expression for the interaction of wild-type T. harzianum and P. ultimum, genes related to protease, cellulase, and chitinase activities were differentially upregulated in the interaction of a nox1-overexpressed transformant with this pathogen. Our results show that nox1 is involved in T. harzianum ROS production and antagonism against P. ultimum.
TL;DR: Evaluated interactions between four arbuscular mycorrhizal fungi and the beneficial fungus Trichoderma harzianum, inoculated in a greenhouse nursery, with regard to their effects on melon crop growth under conventional and integrated-system field conditions, and the biocontrol effect against Fusarium wilt found the AMF-inoculated plants were effective in controlling Fusaria wilt.
TL;DR: There is evidence that the change in phytohormone levels is one of the direct mechanism by which T22 promotes rooting and shoot growth, with notable advantages for rootstock production during nursery processes.
Abstract: The aim of this research was to explain the direct plant growth-promoting activity of Trichoderma harzianum strain T-22 (T22), hypothesizing the involvement of different classes of plant growth regulators. Seven days after the transfer to root-inducing medium, in vitro-cultured shoots of GiSeLa6® (Prunus cerasus × P. canescens) were inoculated with T22. Root and shoot growth were significantly affected by T22 (+76 and +61%, respectively). Ten days after inoculation, the levels of indole-3-acetic acid (IAA), trans-zeatin riboside (t-ZR), dihydrozeatin riboside (DHZR), gibberellic acid (GA3) and abscisic acid (ABA) were analyzed by high performance liquid chromatography coupled with mass spectrometry. The results showed that after T22-inoculation, IAA and GA3 significantly increased in both leaves (+49 and +71%, respectively) and roots (+40 and +143%, respectively) whereas t-ZR decreased (−51% in leaves and −37% in roots). Changes in DHZR were observed in T22-inoculated roots (−32%) but not in leaves, whereas the levels of ABA did not differ between the two treatments. The extraction method allowed the simultaneous extraction of phytohormones. There is evidence that the change in phytohormone levels is one of the direct mechanism by which T22 promotes rooting and shoot growth, with notable advantages for rootstock production during nursery processes.
TL;DR: Under field conditions where the soil was inoculated with two pathogens, the results showed that S. philanthi RL-1-178 could protect the chili pepper plants from S. solanacearum infection better than S. mycarofaciens SS-2-243 or T. harzianum NR- 1-52.
Abstract: The objective of this study was to screen Streptomyces spp. for biological control of root and stem rot (Sclerotium rolfsii) and bacterial wilt (Ralstonia solanacearum), the very destructive diseases of chili pepper in Thailand. About 265 isolates of Streptomyces spp. were tested for their inhibitory effects on S. rolfsii mycelial growth on dual culture plates. Then, 14 promising isolates were further tested for their effects on R. solanacearum growth. Three effective isolates further identified as S. mycarofaciens SS-2-243, S.philanthi RL-1-178 and S. philanthi RM-1-138 were selected and proved to produce both antifungal and antibacterial substances in the culture medium. S. philanthi RM-1-138 strongly inhibited seed germination and seedling growth of chili pepper in laboratory tests. Therefore, it was not used in the following studies. When tested in greenhouse conditions, the efficacy of S. philanthi RL-1-178 in suppressing Sclerotium root and stem rot of chili pepper was approximately equal to that of Trichoderma harzianum NR-1-52 or that of carboxin treatment. S. mycarofaciens SS-2-243 and S. philanthi RL-1-178 suppressed Ralstonia wilt of chili pepper in a way that was similar to streptomycin sulfate treatment and it was observed that T. harzianum NR-1-52 had no effect on the bacterial wilt. Under field conditions where the soil was inoculated with two pathogens, the results showed that S. philanthi RL-1-178 could protect the chili pepper plants from S. rolfsii and R. solanacearum infection better than S. mycarofaciens SS-2-243 or T. harzianum NR-1-52. S. philanthi RL-1-178 treatment resulted in 58.75% survival of chili pepper plants and its efficacy was not significantly different from the carboxin-and-streptomycin sulfate treatment.
TL;DR: Fermentation days, temperature, inoculum and vinegar-production residue demonstrated significant effects on the SQR-T037 biomass and the yield of 6PAP, based on fractional factorial design, which is a way to offer a high value-added use for agro-industrial wastes.
TL;DR: Results show that application of essential oils in integration with the bio-agent T. harzianum may be considered as an applicable, safe and cost-effective method for controlling such soilborne diseases.
Abstract: Carnation, caraway, thyme, peppermint and geranium essential oils have been found to have inhibitory effects against the mycelial growth of Fusarium solani, Rhizoctonia solani, Sclerotium rolfsii and Macrophomina phaseolina under in vitro conditions. Complete inhibition of fungal growth was observed with the use of 4% carnation and geranium oils. Mycelial growth of the tested fungi showed more sensitivity to high concentrations of thyme than to caraway and peppermint oils. Moreover, essential oils used to coat seeds resulted in a significant reduction of root rot incidence of bean, at both pre- and post-emergence stages under greenhouse conditions. Under field conditions seeds coated with essential oils at a concentration of 4% sown in soil treated with the bio-agent Trihoderma harzia- num, gave pronounced protection to emerged bean seeds against the invasion of root rot pathogenic fungi. Compared to the control, the above treatment resulted in a reduction of disease incidence at the pre-emergence stage. This reduction was calculated to be between 47.3 and 55.4% compared with a 16.1% reduction with the use of the Rizolex-T treatment. At the post-emergence stage, all applied treat- ments were able to reduce the percentage of root-rot incidence. Reduction ranged between 41.4 and 47.1% over the untreated control. Reduction in disease incidence was reflected in a yield increase of 15.1-28.8% and 40.1-50%, in seeds coated with one of the different essential oils, or combined with T. harzianum soil treatments, in the respective order. Seeds coated with the fungicide Rhizolex-T caused a yield increase estimated as 11.3% over the check treatment. These results show that application of essential oils in integration with the bio-agent T. harzianum may be considered as an applicable, safe and cost-effective method for controlling such soilborne diseases.
TL;DR: The role, and functions of some major biocontrol genes present in the Trichoderma species viz., Trichodingma harzianum, Trichodma viride, TrICHoderma atroviride , Trichodyma reesei, Trchoderma hamatum and Trichodema longibrachiatum are explained.
Abstract: Accepted 25 November, 2011 In the world, the traditional agricultural practices are getting affected by various problems such as disease, pest, drought, decreased soil fertility due to use of hazardous chemical pesticides, pollution and global warming. As a result, there is a need for some eco-friendly biocontrol agents that help in resolving the previous mentioned problems. The various types of biological control agents such as bacteria and fungi are involved in biocontrol activity. Among them, fungal genus Trichoderma plays a major role in controlling the plant diseases. The species of Trichoderma are known to produce different kinds of enzymes which have a significant role in biocontrol activity like cell wall degradation, biotic and abiotic stress tolerance, hyphal growth, antagonistic activity against plant pathogens. By the advance techniques laid in the molecular biology, we can easily isolate, characterize, clone, sequence and express the functions of these genes and can study their functions and role in the biocontrol mechanism. This review article explains about the role, and functions of some major biocontrol genes present in the Trichoderma species viz., Trichoderma harzianum , Trichoderma viride , Trichoderma atroviride , Trichoderma reesei , Trichoderma hamatum and Trichoderma longibrachiatum .
TL;DR: A method was developed for microencapsulation of Trichoderma conidia with sugar through spray drying that resulted in a flow-able powder with over 99% conidia, which could be used in a variety of formulation developments from seed coatings to sprayable formulations.
TL;DR: An extracellular serine protease producing fungi were isolated from the effluent sample collected from a sago industry in Salem and was identified as Graphium putredinis and Trichoderma harzianum.
Abstract: An extracellular serine protease producing fungi were isolated from the effluent sample collected from a sago industry in Salem and was identified as Graphium putredinis and Trichoderma harzianum. Intergenerically developed fusant produced high amounts of protease in soya bean meal amended minimal medium than the parents, G. putredinis and T. harzianum. The enzyme was purified by Sephadex G 100 column chromatography. The proteases of G. putredinis and T. harzianum had optimum pH and temperature of 7.0–8.0 and 50–60 °C respectively. At 37 and 60 °C, the parental proteases were respectively stable for 1 day and 15 min and the fusant was stable for 2 days and 10 min. The Km and Vmax were 0.65, 1.25 and 0.40 mg/ml and 2.00, 1.60 and 2.60 IU/mg protein for G. putredinis, T. harzianum and fusant respectively with a molecular weight of 31, 20 and 33 kDa. The effect of metal ions showed that, at 5 mM concentration of Hg2+, the residual protease activity of parent and fusant was 5.47, 2.48 and 9.76% respectively; Cu2+, Ca2+ and Zn2+ did not greatly affect the enzyme activity. In 5 mM EDTA showed residual activity between 60.76 and 85.66%. PMSF (2 mM) completely inhibited the protease activity of all the three fungi studied. All the three fungal enzymes retained maximum residual activity of 66.00, 63.80 and 76.74% with the commercial detergent Rin Advanced. With Kite, all the enzymes had more or less same level of residual activity (54–55%). With SDS and sodium perborate (0.2%) the residual activities were 58.25–73.82 and 61.58–70.24% respectively. Wash performance analysis revealed that fusant protease with Rin Advanced at 60 °C yielded good result.
TL;DR: The biocontrol agents established in the soil and their CFU increased significantly and being greater in pathogen infested soils than non infested soil during 4 months period.
TL;DR: T1 and T2 isolates and their combination were more effective than other treatments in controlling the disease, such that it reduced disease severity from 20 to 44% and increased the dry weight from 23 to 52%.
Abstract: The Fusarium disease, caused by Fusarium oxysporum has been observed in different areas of Iran in recent years. Current biocontrol studies have confirmed the effectiveness of the Trichoderma species against many fungal phytopathogens. In this study, biocontrol effects of Trichoderma isolates alone and in combination were evaluated against F. oxysporum pathogen. This study shows the ability of Trichoderma harzianum isolates which had been isolated from soil and as such, lentil roots were compared to the combination of the three fungal lentil Fusarium root. Three isolates ( T. harzianum ) T1, ( Trichoderma asperellum ) T2, ( Trichoderma virens ) T3, were selected base on good antagonist effect after screening tests for antifungal combination effects against Fusarium disease pathogen in greenhouse. In dual culture tests, three (T1, T2 and T3) isolates covered and colonized the colony of the pathogen. In other experiment, three (T1, T2 and T3) isolates covered and colonized the colony of the other Trichoderma isolates. Microscopic studies revealed hyphal coiling (hyperparasitism) of isolates T1 and T2 around F. oxysporum hyphae. Volatile metabolites of all isolates reduced the mycelial growth of fusarium pathogen. T1 and T2 isolates and their combination were more effective than other treatments in controlling the disease, such that it reduced disease severity from 20 to 44% and increased the dry weight from 23 to 52%. All treatments showed significant differences with control plants. Keywords: Fusarium rot, lentil, combination, Trichoderma , biocontrol
TL;DR: Data presented throughout this article suggest the high value of T. harzianum as a source of genes able to facilitate the achievement of producing plants resistant to abiotic stresses without alteration of their phenotype.
TL;DR: In bio-efficacy tests, formulations derived with the addition of glycerol at 3 or 6% in the production medium could protect the tomato plants from Fusarium wilt incidence by 44–50%.
TL;DR: It was determined that the best carbon source was glucose and the best nitrogen source was peptone for lipase production and that other metallic ions did not affect the enzyme activity.
Abstract: Th is is the fi rst report about the characterization of Trichoderma harzianum lipase. A novel strain of Trichoderma harzianum IDM14D was isolated from soil. Th e isolated strain was cultivated for lipase production in shake fl asks at 30 °C for 7 days. For lipase production, it was determined that the best carbon source was glucose and the best nitrogen source was peptone. Maximum biomass was produced at a concentration of 1.25 g/L, in 7 days. Th e optimum pH and temperature for activity of the enzyme were 8.5 and 40 °C, respectively. Th e lipase was stable at a pH range of 8.0-10.0 and at 40 °C for 60 min. Ca 2+ and Mn 2+ enhanced lipase activity but it was determined that other metallic ions did not aff ect the enzyme activity. Th e K m and V max values of the crude enzyme for p-nitrophenyl butyrate hydrolysis were found to be 7.15 mM and 7.067 mM/min, respectively.
TL;DR: Evaluated isolates of Trichoderma harzianum regarding biocontrol of common bean seed-borne pathogens, plant growth promotion, and rhizosphere competence reduced the incidence of Aspergillus, Cladosporium, and S. sclerotiorum.
Abstract: The objective of this work was to evaluate isolates of Trichoderma harzianum regarding biocontrol of common bean seed-borne pathogens, plant growth promotion, and rhizosphere competence. Five isolates of T. harzianum were evaluated and compared with commercial isolate (Ecotrich), Carboxin+Thiram, and an absolute control. Bean seeds of the cultivar Jalo Precoce, contaminated with Aspergillus, Cladosporium, and Sclerotinia sclerotiorum, were microbiolized with antagonists, and seed health tests were carried out. Isolates were evaluated on autoclaved substrate and in field conditions. Ten days after sowing (DAS), plant length was measured. To test rhizosphere competence, isolates were applied in boxes containing autoclaved washed sand, and root colonization was evaluated at 10 DAS, using five plants per box. The most effective isolates in the seed health tests were: CEN287 and CEN289 to control Aspergillus; the commercial isolate to control Cladosporium; and CEN287 and CEN316 to control S. sclerotiorum. Isolates CEN289 and CEN290 promoted bean growth in greenhouse and field. Seed treatment with T. harzianum reduces the incidence of Aspergillus, Cladosporium, and S. sclerotiorum in 'Jalo Precoce' common bean seeds.