Trichoderma Species Research Articles

The cotton charcoal rot causal agent, Macrophomina phaseolina, biological and chemical control.

The fungus Macrophomina phaseolina causes charcoal rot disease (CRD) in cotton, whose symptoms develop in the late stages of growth and result in wilting and death. Despite significant research efforts to reduce disease incidences, effective control strategies against M. phaseolina are an ongoing scientific effort. Today's CRD control tends toward green options to reduce the chemicals' environmental footprint and health risks. Here, different Trichoderma species were examined separately and in combination with Azoxystrobin (AS) in semi-field open-enclosure pots and a commercial field throughout a full season. In the pot experiment, the T. asperellum (P1) excelled and led to improvement in growth (13%-14%, day 69) and crops (the number of capsules by 36% and their weight by 78%, day 173). The chemical treatment alone at a low dose had no significant impact. Still, adding AS improved the effect of T. longibrachiatum (T7507) and impaired P1 efficiency. Real-time PCR monitoring of the pathogen DNA in the plants' roots at the harvest (day 176), revealed the efficiency of the combined treatments: T. longibrachiatum (T7407 and T7507) + AS. In a commercial field, seed dressing with a mixture of Trichoderma species (mix of P1, T7407, and Trichoderma sp. O.Y. 7107 isolate) and irrigation of their secreted metabolites during seeding resulted in the highest yields compared with the control. Applying only AS irrigation at a low dose (2,000 cc/ha), with the sowing, was the second best in promoting crops. The molecular M. phaseolina detection showed that the AS at a high dose (4,000 cc/ha) and the biological mix treatments were the most effective. Reducing the AS chemical treatment dosages by half impaired its effectiveness. Irrigation timing, also studied here, is proven vital. Early water opening during the late spring suppresses the disease outburst and damages. The results demonstrated the benefits of CRD bio-shielding and encouraged to explore the potential of a combined bio-chemo pest control approach. Such interphase can be environmentally friendly (reducing chemical substances), stabilize the biological treatment in changing environmental conditions, achieve high efficiency even in severe CRD cases, and reduce the development of fungicide resistance.

Biological control potential of a soil fungus Trichoderma asperellum K1-02 against Neoscytalidium dimidiatum causing stem canker of dragon fruit

Stem canker on dragon fruit caused by the fungus Neoscytalidium dimidiatum negatively impact dragon fruit cultivation and production. The use of Trichoderma species, the biological control agent against stem canker disease is an alternative way instead of use of synthetic fungicides. This study aimed to test the antifungal activities of soil fungi Trichoderma against N. dimidiatum. Ten isolates of Trichoderma species were tested against N. dimidiatum via dual culture assay, and the results showed that percentages of inhibition ranged from 72.75 to 84.45%. Trichoderma species K1-02 was found to be the most effective strain against N. dimidiatum (84.45%). Trichoderma K1-02 was identified based on a morphology and molecular study of internal transcribed spacer (ITS), the second largest subunit of RNA polymerase II (rbp2), and the translation elongation factor 1-alpha (tef1-α) as Trichoderma asperellum K1-02. The pre-colonized plate method demonstrated that T. asperellum K1-02 covered the tested plates at a rate of 60%, which was significantly higher than N. dimidiatum (40%), and T. asperellum K1-02 aggressively covered the mycelia of N. dimidiatum as observed via stereomicroscopy. An enzyme assay was conducted to test the activities of cell wall-degrading enzymes (CWDEs) in cell-free culture filtrate (CF) released by T. asperellum K1-02, and the results showed that the activities of chitinase and β-1,3-glucanase were significantly higher than those of the control (potato dextrose broth alone). Scanning electron microscopy of N. dimidiatum mycelia incubated with cell free CF of T. asperellum K1-02 showed abnormal morphology. Furthermore, an in vivo test was conducted on dragon fruit cladodes to test the ability of Trichoderma with respect to the reduction of canker lesions. The results revealed that the application of 106 spore/mL T. asperellum K1-02 spore suspension suppressed disease development via the reduction of canker areas (0.09 cm2) on dragon fruit cladodes at a significantly higher level than those inoculated by pathogens alone (0.49 cm2). Thus, T. asperellum K1-02 demonstrated antifungal abilities against N. dimidiatum and has the potential to control stem canker on dragon fruit.

Trichoderma Species Problematic to the Commercial Production of Pleurotus in Italy: Characterization, Identification, and Methods of Control

Nine isolates of Trichoderma were obtained from the diverse phases of compost preparation and the production of different commercial varieties of oyster mushrooms Pleurotus spp. with the apparent presence of green mould disease. The isolates were morphologically and genetically characterized. Molecular fingerprinting indicated that the isolates belonged to the species T. pleuroticola and T. harzianum. In order to identify control measures, changes in temperature, pH, and application of fungicides were tested on the present isolates, using known Trichoderma biocontrol strains as a reference. Fungicide effects on the growth of Pleurotus isolates were also assessed. The optimal growth temperatures were 25 °C for Trichoderma isolates and 28 °C for Pleurotus isolates, and Trichoderma always grew faster than Pleurotus. In particular, a reduction of about 30% was recorded for some of the Trichoderma isolates when comparing the colony growth at 25 and 28 °C. Trichoderma isolates developed well within a wide pH range, with the best growth occurring between pH 5 and 7, whereas Pleurotus preferred more alkaline conditions (pH 8 to 9). Prochloraz and metrafenone were found to inhibit Trichoderma growth with different dose responses that did not affect the growth of Pleurotus spp. In particular, metrafenone was the most effective active ingredient that inhibited the majority of the Trichoderma isolates (1–25% growth reduction).

Two new Trichoderma species (Hypocreales, Hypocreaceae) isolated from decaying tubers of Gastrodiaelate.

Species of Trichoderma are widely distributed around the world. In this study, two new species in Trichoderma, named as T.albidum and T.variegatum, were introduced and illustrated. These species were isolated from diseased tubers of Gastrodiaelata in China and identified based on morphological characteristics and multi-gene sequence analyses of three loci that is the internal transcribed spacer regions of the ribosomal DNA (ITS), the translation elongation factor 1-α encoding gene (tef1-α) and the gene encoding the second largest nuclear RNA polymerase subunit (rpb2). Distinctions between the new species and their close relatives were discussed. According to results of the phylogenetic analyses, T.albidum belonged to the Harzianum clade and T.variegatum are grouped with species of the Spirale clade. The expansion of two clades provided research foundations for the prevention and control of tuber diseases in G.elata.

Evaluation of Aeromycoflora of Satish Pradhan Dnyanasadhana College Library, Thane, Maharashtra, India

Fungi with wide range of diverse group are the primary component of environment. Environmental conditions like humidity, temperature, light, moisture are some major factors for their sustainable growth and diversity. The cellulite activity causes the maximum deterioration to library books, covers, materials, binding of papers. Fungal spores also known for many allergic diseases like respiratory syndromes, allergy to the library workers, members and readers. As library is the basic source of most of the cellulosic fungi, as it provides ambient temperature and moisture for their proliferation. The study investigated at the two different intervals of weeks in a month. In this study it revealed that resulted the most abundant species were: Aspergillus spp. (32.3%), spp. (13.8%), Alternaria spp. (23%), Cladosporium sp. (4.6%), Trichoderma species (7%), Chaetomium (1.2%) etc.

Endophytic colonization of five Trichoderma species and their effects on growth of a Eucalyptus hybrid.

The study aimed to evaluate the effectiveness of endophytic colonization via leaf and root inoculation of five Trichoderma species in a Eucalyptus hybrid, as well as the effects of inoculation on plant growth. The experimental design was completely randomized in a 6 × 2 factorial scheme. Plant growth was evaluated during the experimental period at three different times: 20 days after inoculation (d.a.i), 40 d.a.i., and 60 d.a.i. A statistical difference was observed between the inoculation methods during each period and between the Trichoderma species. Plants inoculated with T. asperellum showed the greatest growth among the treatments. Root-inoculated plants produced the greatest growth response. This showed that the presence of Trichoderma in the roots assisted in nutrient assimilation, promoted greater plant growth, when compared with leaf-inoculated plants. Evaluation of the effectiveness of endophytic colonization was performed at each sampling period by collecting leaf samples, and at 60 d.a.i., by collecting leaf, stem, and root samples. T. longibrachiatum and T. harzianum were isolated from leaves at 20 d.a.i., with an increase in the number of colonized plants throughout the evaluation of leaf-inoculated plants. In root-inoculated plants, treatment with T. longibrachiatum, T. harzianum, and T. asperellum presented the highest endophytic colonization in the stem and root samples (at 60 d.a.i.).

The Potential of Trichoderma-Mediated Nanotechnology Application in Sustainable Development Scopes.

The environmental impact of industrial development has been well-documented. The use of physical and chemical methods in industrial development has negative consequences for the environment, raising concerns about the sustainability of this approach. There is a growing need for advanced technologies that are compatible with preserving the environment. The use of fungi products for nanoparticle (NP) synthesis is a promising approach that has the potential to meet this need. The genus Trichoderma is a non-pathogenic filamentous fungus with a high degree of genetic diversity. Different strains of this genus have a variety of important environmental, agricultural, and industrial applications. Species of Trichoderma can be used to synthesize metallic NPs using a biological method that is environmentally friendly, low cost, energy saving, and non-toxic. In this review, we provide an overview of the role of Trichoderma metabolism in the synthesis of metallic NPs. We discuss the different metabolic pathways involved in NP synthesis, as well as the role of metabolic metabolites in stabilizing NPs and promoting their synergistic effects. In addition, the future perspective of NPs synthesized by extracts of Trichoderma is discussed, as well as their potential applications in biomedicine, agriculture, and environmental health.

Peptide analogs of a Trichoderma peptaibol effectively control downy mildew in the vineyard.

Plasmopara viticola, the agent of grapevine downy mildew, causes enormous economic damage and its control is primarily based on synthetic fungicides. The European Union (EU) policies promote reducing reliance on synthetic plant protection products. Biocontrol agents (BCA) such as Trichoderma constitute a resource for the development of biopesticides. Trichoderma species produce secondary metabolites such as peptaibols, whose poor water solubility hampers their practical use as agrochemicals. To identify new bio-inspired molecules effective against P. viticola, some water-soluble peptide analogs of the peptaibol trichogin were synthesized. In grapevine leaf disk assays, various peptides at 50 µM completely prevented P. viticola infection after zoosporangia inoculation. Microscopic observations carried out with one of the most effective peptides showed that it causes membrane lysis and cytoplasm granulation of both zoosporangia and zoospores. Among the effective peptides, 4r was selected for a two-year field trial experiment. In the vineyard, the peptide administered at 100 µM (equivalent to 129.3 g/ha) overall reduced significantly disease incidence and severity on both leaves and bunches, allowing protection levels similar to those obtained with a cupric fungicide. In the second-year trial, reduced dosages were also tested, and results indicated that even by reducing the peptide concentration by 50 or 75%, a significant decrease in the disease level was obtained at the end of the trial. The peptide did not show any phytotoxic effect. Previously, peptide 4r had been demonstrated to be active against other fungal pathogens, including the grapevine fungus Botrytis cinerea. Thus, this peptide may be a candidate for broad-spectrum fungicide whose biological properties deserve further investigation.

Trichoderma Species and Their Biological Mechanisms

Biocontrol agents (BCA) are an important tool for preventing crop losses and increasing plant food production in agriculture. Providing an eco-friendly and more sustainable alternative to chemical pesticides and fertilizers. A number of biocontrol applications are often conducted on the fungus Trichoderma, which is one of the most widely used and studied organisms in the field due to its numerous biocontrol traits, including parasitism, secondary metabolite production, antibiosis which induced plant defense mechanisms. It is well known that several Trichoderma species act as mycoparasites. Certain species within this group also possess the ability to oppose many organisms, including nematodes and plant pests, hence exhibiting their versatility as a biological control agent. The utilization of bioformulations incorporating Trichoderma species or other beneficial microbes for plants, such as plant growth-promoting bacteria (PGPB), has gained significant traction in the agricultural industry. The present review provides a comprehensive summary of the biocontrol studies conducted on six commonly utilized Trichoderma species. It focuses on elucidating their biocontrol attributes and explores the potential of incorporating these fungal genera into Trichoderma-based formulations for safeguarding against plant diseases. Furthermore, it discusses the viability of Trichoderma as a substitute for chemical pesticides and fertilizers.

Biopriming of Tomato Seeds with Native Trichoderma Species for Enhanced Seedlings Vigour

The present research was carried out to investigate the effect of tomato seed biopriming using six native Trichoderma isolates under laboratory conditions. The seeds of tomato were primed in Trichoderma isolates and as a control treatment seeds were treated in sterile distilled water. It was observed that all the six native Trichoderma isolates showed good performance with respect to growth, germination percentage and vigour index of tomato seedlings as compared to control. Among the different Trichoderma isolates tested, T5 isolate showed highest shoot growth (5.44 cm), root growth (3.74 cm), germination percentage (90.0%) and seedling vigour index (826.37) followed by T4 isolate. The lowest shoot growth (4.22 cm), root growth (3.07 cm), germination percentage (56.7%) and seedling vigour index (412.70) were recorded in untreated control.

Exploration of rhizosphere-dwelling nematophagous Trichoderma spp. using novel ‘bait technique’ with root-knot nematode Meloidogyne incognita

Throughout the world Trichoderma spp. are majorly used as biocontrol agents for managing the economically important plant-parasitic nematodes. We employed a novel strategy to investigate the variety of rhizosphere dwelling Trichoderma species using the nematode Meloidogyne incognita as prey bait. Nine nematophagous Trichoderma spp., validated morphologically and molecularly, were discovered during the expedition in several agroclimatic zones of India. Molecular phylogenetic analysis of these species along with the reported Trichoderma spp. from ‘Harzianum clade’ from India indicated the true identity of Indian T. harzianum sensu stricto to be disputed. Nematophagous nature of the isolated species was confirmed through the presence of extracellular lytic enzymes, secondary metabolites, volatile organic compounds, Huperzine A, and tri-gene cluster variability. Besides, the most promising T. yunnanense isolate, shortlisted based on its in vitro potential against M. incognita, showed the highest levels of nematode parasitism, egg hatching inhibition and juvenile mortality compared to all other isolates and species. Expression of green fluorescent protein in T. yunnanense helped tracking its infection in the juveniles and further validated the nematode parasitizing capacity. The chosen isolate decreased the multiplication factor of M. incognita in pot culture assays and in organically produced capsicum in nematode-infected sick soil. It is interesting that the isolate also markedly increased the plant growth and yield, which was a bonus. Therefore, the performance of T. yunnanense demonstrated through various strategies instills high confidence to propose it as a prospective species for developing as commercially potent nematode biocontrol agent.

Antioxidant and L-asparaginase activities of culturable endophytic fungi from ornamental Dendrobium orchids.

This study reports the antioxidant potential and L-asparaginase production of culturable fungal endophytes from Dendrobium orchids in Malaysia. Twenty-nine isolates were screened using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay to determine their free radical scavenging activities and antioxidant capacity (IC50 and AEAC). L-asparaginase production of fungal endophytes was detected by the qualitative plate assay, and the enzyme activities estimated via the Nesslerization method. All 29 endophytic isolates exhibited various degrees of radical scavenging activities (35.37%-77.23%), with Fusarium fujikuroi (D1) identified as having the highest antioxidant capacity (IC50 6.097 mg/mL) and the highest AEAC value (11.55 mg/g). For L-asparaginase production, the majority of the isolates (89.66%) showed positive results, especially among the culturable species of Fusarium, Trichoderma, and Daldinia. Most Fusarium spp. were able to produce L-asparaginase (80.77%), but the highest L-asparaginase activity was detected in Daldinia eschscholtzii (D14) with 2.128 units/mL. Results from this study highlighted the potential of endophytic fungi from medicinal orchids (Dendrobium sp.) as natural sources of bioactive compounds to be developed into novel antioxidants and anticancer drugs.

Evaluation of Antagonists and the Effectiveness of Application Methods against Sheath Blight Disease of Rice under Pot Conditions

Rice sheath blight caused by Rhizoctonia solani is one of the main disease of rice in the Chhattisgarh region. Three potential Trichoderma species were evaluated against sheath blight disease of paddy under pot conditions. The Trichoderma spp. Obtained/ isolated from three discrict Rajnandgaon, Raipur and Durg of Chhattisgarh were compared for their efficacy with check fungicide hexaconazole for foliar sprays. This experiment was conducted under pot condition in completely randomyzed design (CRD) with three replications during kharif 2016 and 2017. Among the three potential Trichoderma spp., highly effective species against sheath blight pathogen was evaluated. The disease severity was recorded 14 days after inoculation. The results of comparative foliar application of Raipur, Durg and Rajnandgaon Trichoderma isolates showed that all isolates of Trichoderma spp. significantly reduced the sheath blight disease severity in rice under pot conditions at 30 DAT and 60 DAT planting. Among the Trichoderma isolates, foliar spray of Durg isolate (TD3) was effectively showed 26.24% reduction in disease severity at 30 DAT and 24.85% reduction in disease severity at 60 DAT over control treatment. The highest disease severity was reduced by check fungicide hexaconazole. The Durg isolate (TD3) at 30 DAT and 60 DAT also increased the yield per plant as compared to Raipur (TR2) and Rajnandgaon isolates (TR1).

In Vitro Study of the Compatibility of Four Species of Trichoderma with Three Fungicides and Their Antagonistic Activity against Fusarium solani

Strawberry wilt is a disease caused by Fusarium solani, which it provokes the death of the plant. Farmers mainly use chemical methods for its control, which has a negative impact on the environment and human health. Given the growing demand for organic agricultural products, compatible alternatives must be sought for disease management that can reduce the doses of fungicides. A combination of pesticides and biological control agents could be an alternative for the management of F. solani. Consequently, investigations on fungicide compatibility and synergistic effects are recommended in relation to the biological control of strawberry wilt. In this study, potential antagonism was calculated according to the class of mycoparasitism and the percentage inhibition of radial growth in order to later design a compatibility model of the different species of Trichoderma with three protective fungicides at different concentrations. The potential antagonism showed that Trichoderma asperellum presented high compatibility with the fungicides Captan and Mancozeb added in concentrations of 450, 900, and 1350 mg L−1. The use of antagonistic strains together with the fungicide Chlorothalonil in its three concentrations showed a negative effect on the growth of Trichoderma species, which caused low and null compatibility against the MA-FC120 strain of F. solani in vitro.

Trichoderma agriamazonicum sp. nov. (Hypocreaceae), a new ally in the control of phytopathogens

The genus Trichoderma comprises more than 500 valid species and is commonly used in agriculture for the control of plant diseases. In the present study, a Trichoderma species isolated from Scleronema micranthum (Malvaceae) has been extensively characterized and the morphological and phylogenetic data support the proposition of a new fungal species herein named Trichoderma agriamazonicum. This species inhibited the mycelial growth of all the nine phytopathogens tested both by mycoparasitism and by the production of VOCs, with a highlight for the inhibition of Corynespora cassiicola and Colletotrichum spp. The VOCs produced by T. agriamazonicum were able to control Capsicum chinense fruit rot caused by Colletotrichum scovillei and no symptoms were observed after seven days of phytopathogen inoculation. GC-MS revealed the production of mainly 6-amyl-α-pyrone, 1-octen-3-ol and 3-octanone during interaction with C. scovillei in C. chinense fruit. The HLPC-MS/MS analysis allowed us to annotate trikoningin KBII, hypocrenone C, 5-hydroxy-de-O-methyllasiodiplodin and unprecedented 7-mer peptaibols and lipopeptaibols. Comparative genomic analysis of five related Trichoderma species reveals a high number of proteins shared only with T. koningiopsis, mainly the enzymes related to oxidative stress. Regarding the CAZyme composition, T. agriamazonicum is most closely related to T. atroviride. A high protein copy number related to lignin and chitin degradation is observed for all Trichoderma spp. analyzed, while the presence of licheninase GH12 was observed only in T. agriamazonicum. Genome mining analysis identified 33 biosynthetic gene clusters (BGCs) of which 27 are new or uncharacterized, and the main BGCs are related to the production of polyketides. These results demonstrate the potential of this newly described species for agriculture and biotechnology.

Evaluation of Trichoderma spp. on Fusarium oxysporum f. sp. asparagi and Fusarium wilt Control in Asparagus Crop.

Among the key diseases affecting the asparagus crop (Asparagus officinalis L.), vascular wilting of asparagus caused by Fusarium oxysporum f. sp. asparagi stands out worldwide. This disease significantly shortens the longevity of the crop and limits economic production. Traditional control measures have been largely ineffective, and chemical control methods are difficult to apply, making biological control approaches, specifically the use of Trichoderma, an economical, effective, and risk-free alternative. This study aimed to identify the main factors that affect the efficacy of biopesticides studied as Biological Control Agents (BCAs) against Fusarium wilt in asparagus and to assess the efficacy of Trichoderma-based biopesticides under greenhouse and semi-field conditions. We evaluated the response of three Trichoderma spp. (T. atroviride, T. asperellum, and T. saturnisporum) to environmental variables, such as temperature and water activity, and their antagonistic capacity against Fusarium oxysporum f. sp. asparagi. All three Trichoderma species inhibited the growth of the pathogen in vitro. A decrease in water activity led to a greater reduction in the growth rate. The efficacy of the three biological control agents decreased with higher temperatures, resulting in minimal inhibition, particularly under conditions of restricted available water in the environment. The effect of the fungal inoculum density was also analyzed at two different temperatures. A direct correlation between the amount of inoculum and the score on the Disease Severity Index (DSI) was observed. A notable reduction in DSI was evident in treatments with high inoculum density (106 conidium/mL) for all three species of Trichoderma tested at both temperatures. In greenhouse and semi-field tests, we observed less disease control than expected, although T. asperellum and T. atroviride showed lower disease severity indices and increased the dry weight of seedlings and crowns, whereas T. saturnisporum resulted in the highest disease rate and lowest dry weight. This work highlights that the efficacy of Trichoderma as BCAs is influenced by various factors, including the quantity of soil inocula, and environmental conditions. The study findings have strong implications for selecting appropriate Trichoderma species for controlling specific pathogens under specific environmental conditions.

Hongos Trichoderma como control biológico agrícola en México

Environmental pollution, food sufficiency, and health are among the main challenges for sustainable crop production in Mexico. The main tool for plant protection is chemical pesticides, but environmental safety and risks to animal and human health have prompted the community and scientists to propose alternatives for their integrated management. This has encouraged the inclusion of biological products, such as species of the antagonistic fungus Trichoderma spp., which act against pests and pathogens in different crops, and are environmentally benign, effective and economically viable. The aim of this paper was to compile information on Trichoderma spp. regarding their taxonomy, ecology, use as biological control, isolation, culture, morphological and molecular identification, mode of action, distribution of native species, and availability of international commercial products and those produced in Mexico. For this purpose, information was selected from indexed journals and suppliers of Trichoderma spp. on open data digital platforms. The exposed information could be useful for Mexican farmers, to know, accept and use biological control with Trichodermaspp. in their crops, for the benefit of quality agriculture and pesticide-free crops. In addition, research could be generated to develop new autochthonous products based on Trichodermaspp. that are more effective against pests and diseases native to Mexico.

Trichoderma Species from Soil of Pernambuco State, Brazil.

Trichoderma is an important fungal genus, known mainly for its potential for the biological control of phytopathogens. Accurate identification of these fungi is essential for research and applications involving them, to be addressed correctly. The objectives of this study were to isolate, identify, and report the species richness of Trichoderma species that occur in the soil of different regions of Pernambuco, Brazil. DNA sequences of portions of the translation elongation factor 1-α (TEF1) gene region were generated for 56 isolates of Trichoderma, obtained from the Zona da Mata, Agreste, and Sertão regions of Pernambuco. According to the phylogenetic analysis based on these sequences, these fungi belong to two Sections-Trichoderma (35 isolates) and Pachybasidium (21 isolates). These fungi have been resolved in nine species, including Trichoderma afroharzianum, Trichoderma asperelloides, Trichoderma asperellum, Trichoderma koningiopsis, and five possible new species to be confirmed in further studies. This study shows that the soils of Pernambuco host a diversity of Trichoderma species and consequently of biological resources with potential for application in agriculture.

Pathogenicity of Trichoderma afroharzianum in Cereal Crops.

Species of the genus Trichoderma occur ubiquitously in soils, on plant roots and in decaying plant residues. Due to its competitiveness and mycoparasitic potential against other microorganisms, particular strains of Trichoderma spp. are used in agriculture as biocontrol agents against plant pathogens. However, Trichoderma afroharzianum has been recently reported as a pathogen causing ear rot disease on maize in Germany, France and Italy, leading to massive infections on maize cobs. This raised the question, whether and to what extent Trichoderma spp. can infect cereal crops other than maize and cause disease symptoms and yield losses. To address this question, two varieties of wheat, barley and sorghum were grown in the greenhouse and artificially inoculated with T. afroharzianum by both spray and point inoculation at the time of flowering. Disease severity was scored weekly, and thousand-kernel weight and colonization rate were determined after harvest. As early as 14 days after inoculation, the first visual symptoms appeared on wheat and barley as tan or brown discoloration of the base of a floret within the spikelets. After spray inoculation, clear discolorations of the entire ear were seen, while point inoculation only showed symptoms at the injection site and above. No visible symptoms were observed on sorghum millet. The colonization rate on wheat and barley grains was significantly increased compared to the control, while thousand-kernel weights (TKWs) were significantly reduced. No differences in colonization rate and TKW compared to the control were observed in sorghum. This is the first report of Trichoderma afroharzianum infecting wheat and barley, causing disease symptoms and significantly reducing thousand-kernel weights.

Effects of a compound Trichoderma agent on Coptis chinensis growth, nutrients, enzyme activity, and microbial community of rhizosphere soil.

Root rot diseases are prevalent in many Coptis chinensis Franch. production areas, perhaps partially due to the overuse of synthetic fertilizers. Synthetic fertilizers can also lead to soil degradation. Trichoderma is widely used in biofertilizers and biopesticides. This study applied a combination of four Trichoderma species (compound Trichoderma agent, CTA) to C. chinensis and evaluated its effects on growth, as well as rhizosphere soil nutrients, enzyme activities, and microbial community structure. The purpose of this study was to estimate the potential of using CTA as a biofertilizer for C. chinensis, and determine if it could, at least partially, replace synthetic fertilizers to control root rot disease and maintain soil fertility. CTA, compound fertilizer and sterile water were applied to C. chinensis plants. After 60 days, the soluble sugar, soluble protein, chlorophyll of leaves, and individual weight of each plant were measured. The rhizosphere soil nutrient content, enzymatic activity, and the microbial community were also determined. The results were analyzed to evaluate the effect of CTA on C. chinensis growth and soil fertility. CTA increased the soluble protein, chlorophyll, and individual weight of C. chinensis plants while compound fertilizer decreased chlorophyll. CTA increased the activities of urease and catalase in rhizosphere soil, whereas the compound fertilizer decreased urease, catalase, and alkaline phosphatase activities. CTA elevated soil pH, while compound fertilizer reduced it. CTA had no significant effects on soil nutrients and organic matter. CTA decreased the fungal number and alpha-diversity of fungi and bacteria, and both the fungal and bacterial communities were significantly different from the other two. CTA increased B/F value, which improved the rhizosphere microbial community. Both CTA and the compound fertilizer significantly altered the soil microbial community. The relative abundance of Ascomycota was higher and Basidiomycota was lower after CTA treatment than after the other two treatments, indicating that the soil treated with CTA was healthier than that of the other two treatments. CTA decreased harmful Ilyonectria mors-panacis and Corynebacterium sp. And increased beneficial Ralstonia picketti. Trichoderma spp. could exist in C. chinensis rhizosphere soil for a long time. The functional prediction results demonstrated that CTA reduced some rhizosphere phytopathogenic fungi. Correlation analysis showed that CTA elevated rhizosphere pH and enzyme activities. In summary, synthetic fertilizers damaged soil fertility, and the overuse of them might be responsible for root rot disease, while CTA could promote C. chinensis growth, improve soil and decrease the incidence and severity of C. chinensis root rot disease. Therefore, as a biofertilizer, CTA can, at least partially, replace synthetic fertilizers in C. chinensis production. Combining it with organic fertilizer will increase the potential of Trichoderma.