Search

This work aimed to select promising microorganisms as biological control agents (BCA). Forty-one soil samples were obtained from florihorticultural farms located in Buenos Aires, Argentina. Insect trap techniques and soil serial dilutions were used to obtain isolates of entomopathogenic fungi and fungi of genera Trichoderma, respectively. A total of 20 isolates included five Metarhizium and 15 Trichoderma. The isolates were lyophilized and deposited as reference cultures in the Mycological Collection of the Centro de Estudios Parasitológicos y de Vectores (CEPAVE). We performed dual culture studies of the isolates collected against the pathogens Botrytis cinerea Pers. (1797) and Sclerotinia sclerotiorum (Lib.) de Bary (1884). Eleven isolates were selected for growth promotion studies in tomato plants (Solanum lycopersicum L.). The isolates of Metarhizium taii Liang & Liu (1991) CEP-722, CEP-723 Trichoderma afroharzianum Chaverri, Rocha, Degenkolb & Druzhinina (2015) CEP-753 and CEP-754, molecularly identified by amplification of the ITS and TEF1a zones, presented the best results in the dual culture and growth promotion tests. Subsequent studies will evaluate virulence of fungal strains in insects. [ABSTRACT FROM AUTHOR]

Bacillus sp. is a Plant Growth Promoting Rhizobacteria (PGPR) species that lives in the rhizosphere. This bacterium can produce antifungal compounds that suppress pathogenic fungi, such as Fusarium oxysporum. The aim of this research was isolate, characterize, and obtain Bacillus sp. that can inhibit F. oxysporum which causes twisted disease in shallots. Isolation was done by sampling 10 g of soil from shallot roots, placing it in 9 mL of sterile water, and carrying out a series of dilutions. The first dilution was incubated at 80 °C for 20 minutes to obtain Bacillus sp. on the selective medium HiChrome. Colony morphology, shape, cell color, Gram staining, catalase and endospore staining were observed from obtained isolates. An antagonist test was done to determine the inhibitory effects of isolates against the pathogenic fungus F. oxysporum. Four isolates of Bacillus sp. were obtained with irregular colony shape, dull white color without muccus, edges varying in shape between lobate and undulate, and raised elevation. The results of the antagonist test showed that the four isolates had the ability to inhibit the growth of the pathogenic fungus F. oxysporum with the greatest inhibition shown by isolate BM1 at 30.12%, with an antibiosis mechanism and hyphae swelling.

A total of 30 native Trichoderma isolates were collected from the Agricultural Research Station, Ummedganj- Kota, Rajasthan, India. Out of which 9 native isolates were evaluated for bio-efficacy against Sclerotium rolfsii. Isolate ARS K-21 exhibited maximum inhibition (89.26%), followed by ARS K-11 (83.70%) in dual culture. Subsequent evaluations revealed the compatibility of efficient isolate ARS K-21 with various bio botanicals displaying minimum inhibition with Vermiwash (1.11–3.70%) followed by Beejamarat (0.38–15.92%) and Brahmastra (7.78–19.68%), while ARS K-11 displayed compatibility only with Dasparni ark with a minimum inhibition of 1.11–3.70%. Assessment of abiotic stress tolerance of the isolates revealed that most isolates thrived at 200 mM and 400 mM NaCl salt concentrations, with ARS K-21 and ARS K-24 demonstrating moderate growth levels across higher concentrations, except at 1200 mM. Optimal growth of the isolates occurred at 25 and 30 °C, with deviations leading to growth inhibition. Isolates ARS K-1, ARS K-11, ARS K-12 and ARS K-21 exhibited resilience to temperature extremes. ARS K-21 has shown exceptional growth proficiency across a wide pH spectrum (pH 5 to 8.5) followed by ARS K- 24, highlighting their versatility. Mass multiplication of efficient isolate ARS K-21 enriched with vermicompost led to the standardization of a dosage (30 g/kg soil) for managing collar rot in lentil crops at 5 g inoculum per kg soil of S. rolfsii. [ABSTRACT FROM AUTHOR]

In this survey, two wood-inhabiting species - Xylaria polymorpha and Xylaria longipes (10 strains each) were evaluated in dual culture assay against 6 fungi: Aspergillus niger, Candida albicans, Fusarium solani, Mucor plumbeus, Penicillium polonicum, and Trichoderma viride. Detailed descriptions of the interspecific interactions, morphological changes and comparison of X. longipes and X polymorpha reaction types with each fungus are provided. The results indicate significant inhibitory activity of both X. longipes and X. polymorpha against A. niger, M. plumbeus, P. polonicum, F. solani, C. albicans with differences in reaction types on a strain specific level. Most commonly, co-cultivating resulted in Xylaria species replacing fungi (60.8% of all interactions), with a partial replacement after initial deadlock with mycelial contact as the most frequent type of interaction. Inhibiting activity at a distance occurred in the majority of dual cultures of X. polymorpha with A. niger and P. polonicum (deadlock at a distance), and X. longipes with M. plumbeus (deadlock at a distance followed by a partial replacement). Among all tested cultures, T. viride turned out to be the only fungus suppressing Xylaria (except for X. polymorpha strains that formed a deadlock at mycelial contact). Based on the listed reaction types, for each studied Xylaria strain antagonism index was calculated, revealing that X polymorpha IBK 2720 had the highest value among all screened strains amounted to 20. The results indicate the effectiveness of Xylaria against tested fungi via contact antagonism and provide valuable insights for further investigations of novel biocontrol agents. [ABSTRACT FROM AUTHOR]

This work aimed to select promising microorganisms as biological control agents (BCA). Forty-one soil samples were obtained from florihorticultural farms located in Buenos Aires, Argentina. Insect trap techniques and soil serial dilutions were used to obtain isolates of entomopathogenic fungi and fungi of genera Trichoderma, respectively. A total of 20 isolates included five Metarhizium and 15 Trichoderma. The isolates were lyophilized and deposited as reference cultures in the Mycological Collection of the Centro de Estudios Parasitológicos y de Vectores (CEPAVE). We performed dual culture studies of the isolates collected against the pathogens Botrytis cinerea Pers. (1797) and Sclerotinia sclerotiorum (Lib.) de Bary (1884). Eleven isolates were selected for growth promotion studies in tomato plants (Solanum lycopersicum L.). The isolates of Metarhizium taii Liang & Liu (1991) CEP-722, CEP-723 Trichoderma afroharzianum Chaverri, Rocha, Degenkolb & Druzhinina (2015) CEP-753 and CEP-754, molecularly identified by amplification of the ITS and TEF1α zones, presented the best results in the dual culture and growth promotion tests. Subsequent studies will evaluate virulence of fungal strains in insects. Highlights: • Entomopathogenic fungi are common fungi present in the soil of many environments. • Molecular identification is the only way to identify ascomycete fungi at the species level with a high percentage of reliability. • Plant growth promotion produced from the inoculation of tomato plants with entomopathogenic fungi has great potential for agriculture.

Fruit discoloration and fruit rot disease in longan is a serious disease caused by the pathogenic fungi Pestalotiopsis oxyanthi and Lasiodiplodia pseudotheobromae. This study investigated the potential of antagonistic bacteria as an eco-friendly alternative to traditional fungicides for managing longan diseases caused by these fungal pathogens. Two bacterial isolates, UP-JLS050 and UP-JLS067, demonstrated significant inhibitory activity against the pathogenic fungi P. oxyanthi and L. pseudotheobromae, with high inhibitory activity. The bacterial strains were isolated from leaves and soil in a longan garden, and dual culture methods showed that the isolates UP-JLS050 and UP-JLS067 exhibited the highest inhibitory activity on the fungal pathogens, with percentage inhibitions of 72.67 ± 2.31 and 70.37 ± 1.28 %, respectively. Biochemical methods and molecular techniques, including sequencing of the 16S rDNA gene, were then used to identify the isolates. This confirmed their similarity to Bacillus subtilis and Bacillus amyloliquefaciens with 100 and 99 % identity, respectively. In vitro tests on longan fruit indicated that these antagonistic bacteria, administered at a concentration of 108 CFU/mL, significantly reduced disease incidence by up to 45 % after 9 days of incubation. The incubation of B. subtilis (UP-JLS050) and B. amyloliquefaciens (UP-JLS050) reduced disease incidence by 45 ± 5.77 and 32.5 ± 5.00 %, respectively. [ABSTRACT FROM AUTHOR]

The current study aimed to determine the abundance and diversity of soil characteristics and their relationship with mold abundance and potential in inhibiting Lasiodiplodia theobromae, a potential rhizosphere mold species of Siamese orange plant. The pathogenic mold that causes stem-end rot disease was isolated from stems with rotting symptoms. In contrast, the antagonistic mold was obtained from isolation from the rhizosphere soil of Siamese plants. The samples were collected from Siamese orchards in East Kalimantan. The abundance and diversity of molds on swamp land are higher than on dry land. A total of 28 molds were found in the rhizosphere of Siamese orange plants. Mold abundance was positively correlated with soil moisture, organic matter, C-Organic, and N-total but negatively correlated with temperature and pH. Soil chemical characteristics directly influence mold abundance, while soil chemical characteristics indirectly influence it. 21 out of 28 isolates were Biological Control Agents (BCA). TR37 mold has the highest inhibitory power of 89.31% of the D13.C2 pathogen that causes stem-end rot disease. ITS rDNA sequence homology shows that the TR37 mold identified as Trichoderma reesei, while pathogen Lasiodiplodia theobromae causes stem-end rot disease

White root rot disease (WRD), caused by Rigidoporus microporus, poses a serious threat to various tropical trees, resulting in substantial crop damage and even plant death. However, there is still a lack of information regarding WRD in tea plants. Due to soil-borne in nature, synthetic fungicide is not recommended to control WRD. Therefore, biocontrol using natural microorganisms found in the tea’s rhizosphere has been explored as a potential solution. This study aimed to identify rhizospheric fungi of tea plants with antagonistic properties that can be used as a biocontrol agent against R. microporus. The study involved a field survey and laboratory works had been conducted in a tea plantation at Rancabali, West Java and the Phytopathology Laboratory, Faculty of Agriculture, Universitas Padjadjaran from March to October 2021. The disease incidence and severity were assessed in three blocks of land representing different topographic conditions of the plantation while antagonism tests were conducted using the completely randomized design and dual culture method. The results showed that the highest occurrence of WRD was in the central part of the hill with the disease incidence and severity of 70 and 50%, respectively. Thirteen fungal isolates were obtained from the rhizosphere of tea plants, all of which were found to inhibit the growth of R. microporus. These isolates belonged to the genera of Trichoderma, Gliocladium, Paecilomyces, Penicillium, Aureobasidium, Acremonium and Rhizopus. The considerable inhibition of R. microporus colony growth was performed by the isolates of Aureobasidium sp. (51.23%), Rhizopus sp. (50%), and Trichoderma sp. (43.96%). The results suggested that rhizospheric fungi of tea plants have the potential as biocontrol agents against R. microporus. [ABSTRACT FROM AUTHOR]

The present study was aimed to test the antagonistic activity of endophytic fungi isolated from Aloe vera leaves against a number of plant-pathogenic fungi. The results showed that the highest antagonistic activity was exerted by Penicillium chermesinum against the pathogenic fungus Rhizoctonia solani, with an inhibition rate of 78.57%. Also, Talaromyces verruculosus and P. chermesinum showed their highest antagonistic activities against pathogenic fungus Fusarium 1 with inhibition rates of 61.79% and 61.53%, respectively, while T. verruculosus showed an inhibition rate of 62.91% against the pathogenic fungus Fusarium 2. Most of the endophytic fungi showed the least percentage of inhibition against Macrophomina phaseolina compared to the rest of the pathogenic fungi. The fungal filtrates showed a concentration-dependent inhibition rate against the plant pathogens, with a range of 0.00-48.13%. The highest inhibitory activity of Aspergillus niger was recorded at a concentration of 60% against Fusarium 2, R. solani, and Fusarium 1, with rates of 48.13, 37.39, and 36.66%, respectively. The results also showed the ineffectiveness of all fungal filtrates against the pathogenic fungus M. phaseolina. Chemical analysis of the filtrates of the endophytic fungi which showed antagonistic activity against pathogenic fungi was also conducted by using GC-MS. The results showed the presence of effective compounds with biological effects, such as Pentadecanoic acid, Oleic Acid, Limonene, cis-Vaccenic acid, Hexanedioic acid, bis(2-ethylhexyl) ester, Cycloheptasiloxane, and tetracamethyl-. [ABSTRACT FROM AUTHOR]

Bacillus sp. is a Plant Growth Promoting Rhizobacteria (PGPR) species that lives in the rhizosphere. This bacterium can produce antifungal compounds that suppress pathogenic fungi, such as Fusarium oxysporum. The aim of this research was isolate, characterize, and obtain Bacillus sp. that can inhibit F. oxysporum which causes twisted disease in shallots. Isolation was done by sampling 10 g of soil from shallot roots, placing it in 9 mL of sterile water, and carrying out a series of dilutions. The first dilution was incubated at 80 °C for 20 minutes to obtain Bacillus sp. on the selective medium HiChrome. Colony morphology, shape, cell color, Gram staining, catalase and endospore staining were observed from obtained isolates. An antagonist test was done to determine the inhibitory effects of isolates against the pathogenic fungus F. oxysporum. Four isolates of Bacillus sp. were obtained with irregular colony shape, dull white color without muccus, edges varying in shape between lobate and undulate, and raised elevation. The results of the antagonist test showed that the four isolates had the ability to inhibit the growth of the pathogenic fungus F. oxysporum with the greatest inhibition shown by isolate BM1 at 30.12%, with an antibiosis mechanism and hyphae swelling. [ABSTRACT FROM AUTHOR]

Tomatoes (Lycopersicon esculentum L.) are the most extensively grown vegetable in the world. It belongs to the Solanaceae family and is commonly planted for its tasty fruits. Pests, weeds, diseases, and parasites are just a few of the numerous variables that significantly affect tomato growth and yield. The most common disease affecting tomatoes is fusarium wilt. Fifteen rhizobacterial strains were identified by morphological and biochemical analyses in this work, and they were employed as an antagonist against Fusarium oxysporum f.sp. lycopersici. Fifteen isolates were investigated for their antagonistic properties against Fusarium oxysporum f.sp. lycopersici using an invitro dual culture approach. The growth of Fusarium oxysporum f.sp. lycopersici was suppressed by each isolate. Out of the 15 rhizobacteria isolates, isolate RBS-5 exhibited the highest level of growth inhibition and strongly suppressed the development of Fusarium oxysporum f.sp. lycopersici, resulting in a 57.28 percent reduction in pathogen growth as compared to the control. The development of Fusarium oxysporum f.sp. lycopersici was suppressed by isolates RBS-12, RBS-6, and RBS-15, in decreasing order of merit, compared to the control by 53.7, 51.91, and 51.73 percent. Isolate RBS-13 showed the least amount of pathogen growth inhibition 20.83 percent. The data was statistically analyzed. [ABSTRACT FROM AUTHOR]

Abstract Background Use of endophytic fungi, as pathogen control of Bipolaris maydis and Curvularia sp., is an alternative method of control without the use of synthetic pesticides that are more environmentally friendly. This study aimed to determine the potential of endophytic fungi in controlling the growth of pathogens B. maydis and Curvularia sp. in vitro and in spurring the growth of corn plants. It was consisted of three types of testing three endophytic fungal species (Aspergillus_1, Fusarium_2, and Trichoderma_11), namely (1) testing the antagonistic activity of endophytic fungal against pathogens by double culture method, (2) physiological characterization of endophytic fungal as phosphate solvents and chitinase producers, and (3) testing of corn seed vigor with the blotter test method. Results The results of testing endophytic fungal isolates against B. maydis pathogens showed that the three isolates were able to suppress the development of B. maydis, whereas the Trichoderma_11 isolate showed higher suppression results than others. The isolate that showed the best ability to dissolve phosphates is Fusarium_2 with a dissolving index of 1.9 and their effectiveness up to 91.5%. Meanwhile, Trichoderma_11 was able to produce the highest chitinase activity index of 1.9 with an effectiveness of 90.6%. The best corn root lengths and plant height were shown on Fusarium_2 treatment. Similar outcomes were observed when Curvularia sp. was tested. The whole isolates were able to suppress the growth of the pathogen by 16.43–40.44% on the 4th day after incubation. Trichoderma sp. isolate was 72.50% more effective at suppressing than the other two isolates. On day 11, the isolate of Aspergillus sp. was suppressed by 62.50%, while Fusarium sp. showed the lowest suppression of 59.17%. Conclusions Trichoderma_11 isolate was potentially the best biocontrol agent against maydis leaf blight and Curvularia leaf spot in vitro. Meanwhile, the Fusarium_2 isolate had promoted the growth of the corn seedlings.

Abstract Background Trichoderma species are able to cause significant changes in the metabolism of host plants, by that means it trigger the plant growth and increasing plant defense to diverse fungal diseases. Trichoderma harzianum has been identified as potential biocontrol agent of many phytopathogenic fungi. Therefore, the aim of this study was to assess in vitro antagonistic activity against three Diplodia isolates utilizing direct and remote confrontations methods. Results The results revealed that T. harzianum inhibited mycelial growth of the three phytopathogenic fungi compared to the untreated control. The percentage of growth inhibition of T. harzianum against Diplodia isolates ranged between 58 and 79% for direct confrontation and between 31 and 46% remote confrontation. Considerable antagonistic abilities of T. harzianum were exhibited against all tested Diplodia isolates. The results of both confrontations showed that the radial growth of the fungal pathogens was statistically significant (P

At present, knowledge, especially tacit knowledge, has become the core source of value creation. Domain specialists or senior employees are vital to the survival and development of companies because of their tacit knowledge. Therefore, this study investigates and compares the elements that influence construction project workers in sub-Saharan Africa from sharing their tacit knowledge. A survey approach was utilised to evaluate the hypotheses from two sub-Saharan African countries. This study indicates that the mediation effects of organisational culture differ between the countries and reveal that tacit knowledge sharing is not practiced globally but practiced separately in relation to culture. Management is recommended to provide a work atmosphere that promotes workers to share and discuss their knowledge. This study illustrates several theoretical and practical consequences, such as developing a theoretical and practical understanding of dual countries by enhancing the concept of knowledge sharing. [ABSTRACT FROM AUTHOR]

Recent research has shown that the trade-off between customer satisfaction and productivity can be mitigated through three strategic pathways: the (1) operations management (OM) approach, (2) focused service factory, and (3) dual culture strategy, which allow firms to achieve cost-effective service excellence (CESE). We advance that these strategies are also excellent enablers for the development, implementation, and use of digital service technologies, service robots, and artificial intelligence (AI). First, the OM approach reduces process variations in service delivery, creating opportunities for leveraging technology to automate processes. Second, the focused service factory strategy enables high volumes of largely identical service transactions with minimized customer-induced variability, easing service automation. Third, the dual culture strategy ensures that digital automation is firmly customer-centric and achieves service excellence. We advance a set of propositions and research questions aimed at stimulating research at the intersection of the two streams of literature on digital service technologies and CESE. [ABSTRACT FROM AUTHOR]

Holm oaks (Quercus ilex L.) can suffer severe infection by the oomycete Phytophthora cinnamomi Rands; the production of more tolerant plants is, therefore, required. Embryo formation is a key period in the establishment of epigenetic memory. Somatic embryos from three holm oak genotypes were elicited, either over 3 days or 60 days, with methyl-jasmonate, salicylic acid (SA), β-aminobutyric acid (BABA), or benzothiadiazole (all at 50 μM and 100 μM), or 10% and 30% of a filtered oomycete extract (FILT10 and FILT30) to activate plant immune responses. The number of embryos produced and conversion rate under all conditions were recorded. Some elicited embryos were then exposed to P. cinnamomi in dual culture, and differential mycelial growth and the progression of necrosis were measured. The same was performed with the roots of germinated embryos. Within genotypes, significant differences were seen among the elicitation treatments in terms of both variables. Embryos and roots of 60-day BABA, SA, or FILT10 treatments inhibited mycelium growth. The 3-day BABA (either concentration) and 60-day FILT10 induced the greatest inhibition of necrosis. Mycelium and necrosis inhibition were compared with those of tolerant trees. Both inhibitions might be a defense response maintained after primed embryo germination, thus increasing the likelihood of tolerance to infection. [ABSTRACT FROM AUTHOR]

Background: Use of endophytic fungi, as pathogen control of Bipolaris maydis and Curvularia sp., is an alternative method of control without the use of synthetic pesticides that are more environmentally friendly. This study aimed to determine the potential of endophytic fungi in controlling the growth of pathogens B. maydis and Curvularia sp. in vitro and in spurring the growth of corn plants. It was consisted of three types of testing three endophytic fungal species (Aspergillus_1, Fusarium_2, and Trichoderma_11), namely (1) testing the antagonistic activity of endophytic fungal against pathogens by double culture method, (2) physiological characterization of endophytic fungal as phosphate solvents and chitinase producers, and (3) testing of corn seed vigor with the blotter test method. Results: The results of testing endophytic fungal isolates against B. maydis pathogens showed that the three isolates were able to suppress the development of B. maydis, whereas the Trichoderma_11 isolate showed higher suppression results than others. The isolate that showed the best ability to dissolve phosphates is Fusarium_2 with a dissolving index of 1.9 and their effectiveness up to 91.5%. Meanwhile, Trichoderma_11 was able to produce the highest chitinase activity index of 1.9 with an effectiveness of 90.6%. The best corn root lengths and plant height were shown on Fusarium_2 treatment. Similar outcomes were observed when Curvularia sp. was tested. The whole isolates were able to suppress the growth of the pathogen by 16.43–40.44% on the 4th day after incubation. Trichoderma sp. isolate was 72.50% more effective at suppressing than the other two isolates. On day 11, the isolate of Aspergillus sp. was suppressed by 62.50%, while Fusarium sp. showed the lowest suppression of 59.17%. Conclusions: Trichoderma_11 isolate was potentially the best biocontrol agent against maydis leaf blight and Curvularia leaf spot in vitro. Meanwhile, the Fusarium_2 isolate had promoted the growth of the corn seedlings. [ABSTRACT FROM AUTHOR]

Background: Trichoderma species are able to cause significant changes in the metabolism of host plants, by that means it trigger the plant growth and increasing plant defense to diverse fungal diseases. Trichoderma harzianum has been identified as potential biocontrol agent of many phytopathogenic fungi. Therefore, the aim of this study was to assess in vitro antagonistic activity against three Diplodia isolates utilizing direct and remote confrontations methods. Results: The results revealed that T. harzianum inhibited mycelial growth of the three phytopathogenic fungi compared to the untreated control. The percentage of growth inhibition of T. harzianum against Diplodia isolates ranged between 58 and 79% for direct confrontation and between 31 and 46% remote confrontation. Considerable antagonistic abilities of T. harzianum were exhibited against all tested Diplodia isolates. The results of both confrontations showed that the radial growth of the fungal pathogens was statistically significant (P < 0.001) and influenced by the antagonist on 6 days following incubation. Conclusion: The findings may reveal a valuable knowledge that may be further used to find a suitable biological control contrariwise Botryosphaeria dieback caused by Diplodia species. [ABSTRACT FROM AUTHOR]

In the present study, 51 fungal endophytes (FEs) were isolated, purified and identified from the healthy leaf segments of ten grapevine varieties based on the spore and colony morphologies and ITS sequence information. The FEs belonged to the Ascomycota division comprising eight genera viz., Alternaria, Aspergillus, Bipolaris, Curvularia, Daldinia, Exserohilum, Fusarium and Nigrospora. The in vitro direct confrontation assay against Colletotrichum gloeosporioides revealed that six isolates viz., VR8 (70%), SB2 (83.15%), CS2 (88.42%), MN3 (88.42%), MS5 (78.94%) and MS15 (78.94%) inhibited the mycelial growth of test pathogen. The remaining 45 fungal isolates showed 20–59.9% growth inhibition of C. gloeosporioides. Indirect confrontation assay manifested that the isolates MN1 and MN4a showed 79.09% and 78.18% growth inhibition of C. gloeosporioides followed by MM4 (73.63%) and S5 (71.81%) isolates. Isolate S5 and MM4 were found to produce azulene and 1,3-Cyclopentanedione, 4,4-dimethyl as antimicrobial volatile organic compounds, respectively. The 38 FEs showed PCR amplification using internal transcribed spacer universal primers. The BLAST search revealed highest similarity with the existing sequences in the database. The phylogenetic analysis revealed the occurrence of seven distinct clusters each corresponding to single genus. [ABSTRACT FROM AUTHOR]

Fusarium oxysporum is the primary cause of fusarium wilt, one of the major diseases that harm shallots. 50% of yield can be lost due to fusarium wilt. It is anticipated that endophytic fungus will inhibit the growth of Fusarium wilt disease in shallots. The endophytic fungi from shallot plants that have the potential to act as biological control agents for the fungal disease F. oxysporum are suggested to be chosen in this study. Using Malt Extract Agar (MEA) medium, endophytic fungi were isolated from healthy shallot plant components (roots, tubers, stems, and leaves). Using dual culture and volatile techniques, the antagonistic potential of endophytic fungi against F. oxysporum was examined. Using shallot seeds, pathogenicity studies for endophytic fungus were conducted in vitro. Twelve endophytic fungal isolates were able to impede the growth of F. oxysporum using the dual culture method; the percentage of inhibition reached 72.52% at seven days post-inoculation. The endophytic fungus was also able to stop F. oxysporum mycelial growth using the volatile compound test, with a percentage inhibition ranging from 4.08 - 27.37%. The findings of the pathogenicity test demonstrated that the four isolates posed a risk to the shallot seeds. The most successful isolate in preventing the growth of F. oxysporum was the endophytic fungus AB4D1, which is a member of the Trichoderma asperellum species. [ABSTRACT FROM AUTHOR]

White rot, caused by Stromatinia cepivora (Anamorph: Sclerotium cepivorum Berk), is a serious soil-borne disease of the onion that restricts its cultivation and production worldwide. Herein, we isolated and characterized a plant growth-promoting rhizobacterium Stenotrophomonas maltophilia from healthy onion roots and an endophytic bacterium Serratia liquefaciens from healthy bean leaves. Both isolates showed strong fungistatic activity against S. cepivora using the dual culture and culture filtrate methods. This effect might be due to the presence of several volatile compounds, especially menthol in both culture filtrates as shown with a GC-MS analysis. Additionally, the root drench application of cell-free culture filtrates of S. maltophilia and S. liquefaciens significantly reduced the incidence and severity of white rot disease on treated onion plants, which was associated with the activation of both enzymatic (POX and PPO) and non-enzymatic (phenolics and flavonoids) antioxidant defense machineries of S. cepivora-infected onion plants. Moreover, the culture filtrates of both bacterial bioagents remarkably enhanced the growth (as expressed by root length, plant height, and number of leaves) and yield parameters (as indicated by bulb circumference, fresh weight of the bulb, and bulb yield per plot) of treated onion plants under field conditions during two successive seasons (2020/2021 and 2021/2022). This might be because of a reduced disease severity and/or the accumulation of the main auxin, indole-3-acetic acid (IAA), and its precursor, the amino acid tryptophan. Our findings suggest that both bioagents might be utilized as eco-friendly alternative control measures to reduce the utilization of chemical fungicides entirely or partially for the safer production of onion in S. cepivora-infested soils. [ABSTRACT FROM AUTHOR]

Black point disease of wheat contributes to high economic losses every year. The overuse of fungicides resulted in pathogenic fungal resistance, health and environmental hazards that necessitate the formulation of safe biocontrol agents. Dual cultural assay of Trichoderma viride and Trichoderma harzianum strains proved their highest efficiency against Alternaria alternata with inhibition percentages of 75.04 and 67.83%, while the lowest activity was detected against Drechslera halodes with growth inhibition of 51.54 and 43.92%, respectively. Alternaria alternata and D. halodes strains exhibited carbendazim resistance, while Fusarium proliferatum was the most susceptible one. Chemical analysis of T. harzianum and T. viride extracts using gas chromatography-mass spectrometry indicated that 6-pentyl-α-pyrone and cyclooctanol compounds were the main active constituents representing about 26.43 and 32.74% respectively. The tested bioagents were highly effective against the fungal strains causing black point disease of wheat so that these biocontrol agents could be used in formulation of natural fungicides avoiding the harmful impact of the synthetic fungicides. Abbreviations: FCZ; Fluconazole Antifungal agent, GC-MS; Gas chromatography-Mass spectrometry, MIC; Minimum inhibitory concentration, MFC; Minimum fungicidal concentration, PDA; Potato dextrose agar, T.H; Trichoderma harzianum, 1. T. V; Trichoderma viride

Rice is the global staple food, contributing over half of the world's agricultural production. Excessive fungicide use in rice farming poses environmental, fungicide resistance, and beneficial microbial disruption concerns, making biocontrol, particularly bacteria, a promising biocontrol agent due to their rapid growth, ease of handling, and robust colonization attributes. Endophytes are endosymbionts residing within host plants, playing a pivotal role in plant health without inciting any pathogenic effects. In this study, we investigated the antagonistic potential of four characterized bacterial endophytic strains, viz., Bacillus velezensis strains A6 and P42, B. pseudomycoides HP3d and Paenibacillus polymyxa PGSS-1 against major foliar rice pathogens viz., Magnaporthe oryzae and Cochliobolus miyabeanus. Against M. oryzae, all the endophytic strains exhibited significant per cent inhibition (50.00-66.67%) and the highest inhibition of 66.67% was achieved by B. pseudomycoides strain HP3d, while the lowest inhibition of 50 and 51.11% was by B. velezensis strain A6, P42, and P. polymyxa PGSS1, respectively. These endophytes outperformed the positive control, P. fluorescens which showed 44.44% inhibition. Similarly, against C. miyabeanus, 31.25-43.75% inhibition was recorded, of which B. velezensis strain A6 exhibited the highest inhibition (43.75%), while B. velezensis strain P42 showed the lowest (31.25%). Furthermore, a double Petri dish assay was conducted to evaluate the volatile compounds produced by these endophytes against the two rice pathogens. It was observed that the volatile compounds produced by B. pseudomycoides strain HP3d and P. polymyxa strain PGSS1 significantly and effectively inhibited the growth of M. oryzae by 88.89% when compared to P. fluorescens (50.00%), whereas B. velezensis strain A6 showed the lowest inhibition (33.33%). Against the brown spot pathogen, C. miyabeanus, the endophytes demonstrated inhibition ranging from 56.25-87.50%, with B. pseudomycoides strain HP3d and P. fluorescens achieving the highest inhibition (87.50%) and B. velezensis strain P42 showing the lowest (56.25%). These results highlight the significant and varied inhibitory effects of volatile compounds released by these endophytes against fungal pathogens of rice. Overall, our findings highlight the promising biocontrol potential of these endophytic strains under in vitro conditions with B. pseudomycoides strain HP3d and P. polymyxa PGSS1 showing exceptional efficacy and they can be deployed in the field for the management of foliar fungal pathogens in rice. [ABSTRACT FROM AUTHOR]

Chilli (Capsicum annum L.) is one of the most important vegetable and spices crop grown across the world for the value for its valuable fruits and is popularly known as "red pepper" which belongs to night shade family Solanaceae. Isolate of Fusarium spp. were collected from the different location of villages of Bharuch districts. Six native Trichoderma spp. isolates viz., BVVT-1, BVDT-1, BJGT-2, BJGT-1, BNBT-2 and BJST-1 were isolated from the rihzospheric soil of chilli wilt infected fields. The maximum number of colony 4×10-4 was observed in BVVT-1 and minimum number observed as 1×10-4 in BJGT -1 and BNBT-2 isolate. The anti-fungal efficacy of native Trichoderma spp. studied using dual culture method revealed strong antagonism of isolate BVVT-1 against most virulent Fusarium spp. whereas remaining five isolates i.e., BVDT-1, BJGT-2, BJGT-1, BNBT-2 and BJST-1 isolates also appeared as potential antagonists. The six native isolates were also tested in pot condition against susceptible Eagle C4 chilli variety. The T2 treatment (BVVT-1 isolate) recorded significantly highest 17.60 cm shoot length and higher root length of 7.20 cm which remained at par with T1 treatment (BVDT-1 isolate) i.e., 6.83 cm root length. While the lowest root length 4.67 cm and shoot length 13.20 cm was recorded in BNBT-1 isolate and it also recorded the highest 36.67 per cent disease incidence with lowest 63.33 per cent disease control, so it was considered as least effective among all the isolates. The results concluded that the BVVT-1 isolate was the most effective and found to be best as it recorded the highest 83.33 per cent disease control with lowest 16.67 per cent disease incidence. [ABSTRACT FROM AUTHOR]

Fusarium genus is a wide host phytopathogen causing significant losses in multiple crops, including hops. There is limited information on the sustainable management of Fusarium spp. in hop fields. Trichoderma is an endophytic fungus used in agriculture as a biological control agent (BCA) and as a plant growth promoter. It has been used to antagonize Fusarium spp. in other crops. The objective of the current study was to identify indigenous hop field Trichoderma isolates with biocontrol and hop growth promotion capabilities. Three isolates of Fusarium and eleven autochthonous Trichoderma isolates collected from sustainable hop fields were evaluated in this work. Direct confrontation tests (the physical interaction between the pathogen and BCA and their competition for space and nutrient resources) and membrane tests (the capacity of the BCA to produce metabolites or enzymes through a cellophane film and inhibit the development of the pathogen) assessed the antagonism of these Trichoderma isolates against Fusarium culmorum, F. sambucinum, and F. oxysporum. A bioassay with hop plantlets inoculated with a spore suspension of Trichoderma was performed to assess its hop growth enhancement. T. hamatum (T311 and T324), T. virens T312, and T. gamsii T327 showed high growth inhibition of Fusarium spp. phytopathogens and high plant growth promotion. Native Trichoderma isolates from sustainable hop-producing soils have great potential as BCAs and hop growth promoters. [ABSTRACT FROM AUTHOR]

Rigidoporus microporus, which causes white root rot disease (WRD) in Hevea brasiliensis, is a looming threat to rubber plantation in Malaysia. The current study was conducted to determine and evaluate the efficiency of fungal antagonists (Ascomycota) against R. microporus in rubber trees under laboratory and nursery conditions. A total of 35 fungal isolates established from the rubber tree rhizosphere soil were assessed for their antagonism against R. microporus by the dual culture technique. Trichoderma isolates can inhibit the radial growth of R. microporus by 75% or more in the dual culture test. Strains of T. asperellum, T. koningiopsis, T. spirale, and T. reesei were selected to assess the metabolites involved in their antifungal activity. Results indicated that T. asperellum exhibited an inhibitory effect against R. microporus in both volatile and non-volatile metabolite tests. All Trichoderma isolates were then tested for their ability in producing hydrolytic enzymes such as chitinase, cellulase and glucanase, indole acetic acid (IAA), siderophores production, and phosphate solubilization. From the positive results of the biochemical assays, T. asperellum and T. spirale were selected as the biocontrol candidates to be further tested in vivo against R. microporus. The nursery assessments revealed that rubber tree clone RRIM600 pretreated with only T. asperellum or with the combination of T. asperellum and T. spirale was able to reduce the disease severity index (DSI) and exert higher suppression of R. microporus compared to other pretreated samples, with the average DSI below 30%. Collectively, the present study demonstrates that T. asperellum represents a potential biocontrol agent that should be further explored to control R. microporus infection on rubber trees. [ABSTRACT FROM AUTHOR]

Utilizing Heterobasidion partitivirus 13 strain an1 (HetPV13-an1) and 15 strain pa1 (HetPV15-pa1) in co-infection is considered a potential biocontrol approach against Heterobasidion root and butt rot. Both partitiviruses mediate debilitating effects in most Heterobasidion host isolates and are generally transmitted efficiently between host strains. In this investigation, we conducted transmission experiments in the laboratory (in vitro) using several H. parviporum isolates to test whether using dual partitivirus infections is a more efficient way of transmitting viruses to new hosts compared to using single partitivirus infections, and whether co-occurring single-stranded RNA (ssRNA) viruses are co-transmitted during the process. The results showed that H. parviporum donors carrying both partitiviruses, HetPV13-an1 and HetPV15-pa1, transmitted HetPV15-pa1 more efficiently to recipients than the same donors infected with only HetPV15-pa1. In contrast, the transmission of HetPV13-an1 did not differ significantly between donors infected with both or only one partitivirus. Altogether, the transmission rates of HetPV13-an1 and HetPV15-pa1 were high on artificial media. Moreover, the transmission of the ssRNA viruses Heterobasidion ourmia-like virus 1(HetOlV1-pa7) and 4 (HetOlV4-an1) as well as Heterobasidion ambi-like virus 3 (HetAlV3-pa4) across different recipients were found to be variable. This study demonstrated for the first time the transmission of ambi- and ourmiaviruses between H. parviporum isolates in dual cultures and showed that H. parviporum mycelia can be cured of these ssRNA viruses using heat treatment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Endophytic fungal strains were isolated from leaves, stems, and roots of Angelica gigas. The fungal strains were identified based on their morphological characteristics and molecular analysis of the internal transcribed spacer (ITS). A total 35 species of endophytic fungi were identified. The diversity between the endophytic fungal communities differed depending on the tissues of A. gigas. The isolated endophytic fungi were screened for antifungal activity against a pathogenic fungus, Phoma sp. Y11, using a dual culture method. Fourteen species of endophytic fungi showed the standout inhibition effect against the Y11 strain. The results suggest that the endophytic fungi isolated from A. gigas could be used as a biological control agent against leaf spot disease of A. gigas.

Holm oaks (Quercus ilex L.) can suffer severe infection by the oomycete Phytophthora cinnamomi Rands; the production of more tolerant plants is, therefore, required. Embryo formation is a key period in the establishment of epigenetic memory. Somatic embryos from three holm oak genotypes were elicited, either over 3 days or 60 days, with methyl-jasmonate, salicylic acid (SA), β-aminobutyric acid (BABA), or benzothiadiazole (all at 50 μM and 100 μM), or 10% and 30% of a filtered oomycete extract (FILT10 and FILT30) to activate plant immune responses. The number of embryos produced and conversion rate under all conditions were recorded. Some elicited embryos were then exposed to P. cinnamomi in dual culture, and differential mycelial growth and the progression of necrosis were measured. The same was performed with the roots of germinated embryos. Within genotypes, significant differences were seen among the elicitation treatments in terms of both variables. Embryos and roots of 60-day BABA, SA, or FILT10 treatments inhibited mycelium growth. The 3-day BABA (either concentration) and 60-day FILT10 induced the greatest inhibition of necrosis. Mycelium and necrosis inhibition were compared with those of tolerant trees. Both inhibitions might be a defense response maintained after primed embryo germination, thus increasing the likelihood of tolerance to infection.

Simple Summary: Rice, together with wheat and corn, is among the most important food crops for mankind. Half of the world's population consumes rice, mainly in Asia, southern Europe, tropical America, and parts of Africa. Rice sheath blight, caused by Rhizoctonia solani, is one of the main diseases in rice production. The control of this pathogen is difficult due to its ecological behavior, broad host range, and the high survival rate of sclerotia under various environmental conditions. In this research, after morphological and molecular identification of fungal isolates, five superior isolates, including Trichoderma virens, Trichoderma harzianum, Curvularia lunata, Aspergillus fumigatus, and Aspergillus awamori were studied in the in vitro and greenhouse trials, towards their potential to inhibit R. solani. The statistical analysis showed a significant difference between the effectiveness of fungi used in the volatile metabolites assay and in terms of height and fresh weight of plants in the greenhouse. It can be concluded that T. virens and A. fumigatus are the most effective antagonists in rice sheath blight disease control. The rice sheath blight disease, caused by Rhizoctonia solani J.G. Kühn fungus, is a major disease of Oryza sativa L. occurring all over the world. Therefore, efforts need to be undertaken to limit the spread of this pathogen, preferably by using environmentally friendly methods. In the present study, 57 fungal isolates were recovered by surface sterilization technique from 120 rice samples collected from paddy fields in Guilan province, Iran. Biological characterizations of the isolated taxa were performed in vitro, in the dual culture, volatile metabolites, and slide culture methods. Among the studied isolates, Trichoderma virens (J. H. Miller, Giddens and A. A. Foster) Arx was most effective in inhibiting the mycelial growth of R. solani in the dual culture (44.16% inhibition level), while Aspergillus fumigatus Fresen and T. virens had a 62.50–68.75% inhibition efficiency by volatile metabolites. In the slide culture, all of the isolates, except for T. harzianum Rifai, were effective in inhibiting the hyphae growth of R. solani. Under greenhouse conditions, rice plants inoculated with these potential antagonistic fungi showed a reduction in disease severity by even 41.4% as in the case of T. virens. Moreover, phenotypic properties of rice, such as plant height, fresh weight, and dry weight were increased in the plants inoculated with all antagonistic fungi tested, compared to the infected plants, except for the fresh weight of plants inoculated with Curnularia lunata (Wakker) Boedijn. The present in vivo and in vitro studies revealed that T. virens and A. fumigatus are the most effective antagonists in rice sheath blight disease control and could be applied in agricultural practice. [ABSTRACT FROM AUTHOR]

Abstract Background High losses of sorghum crops due to fungal diseases, such as grain mold and stalk rot, are economically harmful and cause increased use of environmentally damaging chemical fungicides, which also are detrimental to human health. Hence, finding safe and effective ways to manage fungal diseases of sorghum is urgently needed. Results In the present study, the antagonistic activities of Trichoderma viride and T. harzianum against different pathogenic fungal strains were evaluated in vitro using a dual culture assay. Furthermore, the anti-mycotic activity of Trichoderma spp. culture filtrates was evaluated against different fungal strains using a food poisoning technique. Additionally, the antifungal activities of ethyl acetate extracts of T. viride and T. harzianum against different pathogens were evaluated using a disk diffusion method. As indicated by the dual culture assay, T. harzianum suppressed 66.8, 69.5, 68.7, 54.6, 84.12, and 71.39% of the mycelial growth of Curvularia lunata, Exserohilum rostratum, Fusarium chlamydosporum, F. incarnatum, F. proliferatum, and Macrophomina phaseolina, respectively. T. viride was more effective for controlling the growth of these pathogens, inhibiting 81.0, 89.0, 63.0, 70.7, 84.4, and 71.8% of mycelial growth, respectively. Both E. rostratum and M. phaseolina showed resistance to carbendazim fungicide at all tested concentrations, whereas the fungicidal concentrations of carbendazim against C. lunata, F. chlamydosporum, and F. incarnatum strains were 2.50, 1.50, and 2.00 ppm, respectively. Furthermore, F. proliferatum was sensitive to carbendazim fungicide at all tested concentrations. Antifungal assays of the ethyl acetate extracts of T. viride and T. harzianum indicated the potent activity of these extracts against fungal phytopathogens with different susceptibility patterns. F. chlamydosporum was the most sensitive to the extracts of T. viride and T. harzianum with minimum inhibitory concentrations of 0.5 and 1.0 mg/disk, respectively. Conclusion The potent suppression of sorghum phytopathogens by T. viride and T. harzianum makes them potential sources of safe and effective natural fungicides compared to carbendazim fungicide.

Olive quick decline syndrome (OQDS), which is caused by Xylella fastidiosa, poses a severe threat to the agriculture of Mediterranean countries and causes severe damage to the olive trees in Italy. Since no effective control measures are currently available, the objective of this study was the screening of antagonistic bacteria that are potentially deployable as biocontrol agents against X. fastidiosa. Therefore, two approaches were used, i.e., the evaluation of the antagonistic activity of (i) endophytic bacteria isolated from two different cultivars of olive trees (Leccino and Ogliarola salentina) and (ii) epiphytic bacteria isolated from the phyllospheres of different host plant species of X. fastidiosa. In vitro dual culture tests showed that 12 out of 200 isolates inhibited X. fastidiosa growth, with appearances of clear zones between 4.0 and 38.6 mm. 16S rRNA gene sequencing revealed different species of the genera Paenibacillus, Bacillus, Pantoea, Microbacterium, Stenotrophomonas, Delftia, and Pseudomonas. Furthermore, an investigation for antimicrobial activity identified 5 out of the 12 antagonistic bacteria, Paenibacillus rigui, Bacillus subtilis, Bacillus pumilus, Microbacterium oxydans, and Stenotrophomonas rhizophila, that were able to produce culture filtrates with inhibitory activities. Our results are promising for further investigation to develop an eco-sustainable strategy to control X. fastidiosa using biocontrol agents or their secreted metabolites. [ABSTRACT FROM AUTHOR]

Chickpea wilt caused by F. oxysporum f. sp. ciceri. Antagonist's effect evaluation of four bio-agents were conducted under in- vitro condition and these results were revealed that, the per cent inhibition over control was found maximum (78.02%) into the Trichoderma viride followed by T. harzianum (72.14%) and it was found minimum into the T. koningii (48.61%). T. hamatum was found least effective (58.16%) to inhibit the mycelial growth of Fusarium oxysporum f. sp. ciceri. [ABSTRACT FROM AUTHOR]

Inducing hydrolytic enzymes production and antibiosis is an attractive process for industrial applications. The approach can be used to repress pathogenic microorganisms. Using a dual culture of Aspergillus fumigatus and Aspergillus flavus, the activities of cellulase, polygalacturonase, chitinase, β-1,3-glucanases, protease, xylanase, and β-glucosidase were 1.78, 3.87, 2.98, 2.79, 6.91, 2.89 U, and 1.43 U∙mg-1 of protein. Meanwhile, the activities were 0.87, 2.78, 0.58, 1.69, 4.45, 2.06, and 0.89 U.mg-1 of protein for A. flavus alone and 0.98, 2.98, 0.87, 1.89, 4.98, 2.58, and 0.91 U.mg-1 of protein for A. fumigatus alone. The cellulase, polygalacturonase, and chitinase activities were studied at different temperatures; 40 °C and 50 °C, which were better temperatures than 20 °C in terms of enzymes activity for A. fumigatus and the dual culture compared to A. flavus. The highest antimicromial activity was observed using the dual fungal culture, where the inhibition zones were 3.13, 3.47, 2.27, 1.77, 1.03, and 2 mm compared with A. fumigatus alone or A. flavus alone, against Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Aspergillus fumigatus, Mucor circinelloides, and Fusarium moniliforme, respectively. [ABSTRACT FROM AUTHOR]

Abstract Background Endophytic bacteria are an association between bacteria and plant tissue that could play a role as a biocontrol agent. Main body Endophytic bacteria were isolated from several high root plants in Aceh, Indonesia. This study aimed to detect the chemical compounds of the potential endophytic bacteria as a biocontrol agent against Fusarium oxysporum f. sp. lycopersici (FOL). There were 198 endophytic bacterial isolates detected in roots of 9 higher plant. The hypersensitive reaction showed that 193 isolated endophytic bacteria were non-pathogenic. There were 13 isolated endophytic bacteria that worked to inhibit FOL between 50.0 and 89.2%; such endophytic bacteria were isolated from Solanum lycopersicum L., Psidium guajava L., Dendrocalamus asper (Schult with f.) Backer ex Heyne, Pinus merkusii L., Theobroma cacao L., and Albizia chinensis L. Molecular identification using 16S rRNA gene sequence confirmed that the endophytic bacteria were derived from species Pseudomonas aeruginosa, P. mosselii, Arthrobacter sp., Bacillus cereus, B. thuringiensis, and Serratia marcescens. P. aeruginosa that showed the highest inhibition was analyzed using GC-MS analysis. The analysis identified that antibiotics as Pyrrolo [1,2-a]pyrazine-1,4-dione, hexahydro-3-(2-methylpropyl)- was produced by P. aeruginosa succeeded in suppressing FOL. Conclusion The study recommends the species P. aeruginosa, as effective endophytic bacteria for the control of FOL pathogen.

A total of 132 mycoparasitic Pythium isolates were obtained from the soil samples taken from fruit orchards, vegetable fields, carnation greenhouses, sugarbeet fields and cereal fields in the West Mediterranean region of Turkey. The Oomycetes were isolated by using; surface soil dilution plate, sclerotia bait and precolonised plate methods. Isolates were identified as P. acanthophoron, P. amasculinum, P. lycopersicum, P. oligandrum, P. periplocum and P. paroecandrum, according to their morphological and molecular characteristics. The most commonly isolated mycoparasitic species were P. amasculinum and P. lycopersicum. The majority of the mycoparasites came from soil samples taken from the sugarbeet growing areas. It was determined that all isolates showed high mycoparasitic activity against Botrytis cinerea and Rhizoctonia solani, however Sclerotinia rolfsii was resistant. It can be concluded that the mycoparasitic Pythium species can be used as biocontrol agents against B. cinerea and R. solani.

Trichoderma is the most studied and used fungal agent in biological disease control worldwide. Its prospection is a necessary routine, in order to select more effective and specific strains for the different existing agro pathosystems. This work reports the in vitro antagonism (Mycelial Growth Inhibition - MGI) of five Trichoderma isolates, obtained from rhizospheric and organic soil of medicinal plants cultivated in Brazil, to five different phytopathogenic fungi and their molecular identification based on actin (act), calmaldulin (cal), rDNA gene (ITS) and translation elongation factor 1-α (tef1-α). Regarding the fungus Macrophomina phaseolina, the MGI varied between 63.33 and 67.03%; for Fusarium verticillioides between 67.20 and 85.92%; Phaeocytostroma sacchari between 84.00 and 92.90%; in the case of Sclerotinia sclerotiorum, the inhibition was total (100%), and for Sclerotium rolfsii, the antagonism was between 62.03 and 79.07%. According to the molecular phylogeny performed, concatenated analysis of the genetic markers revealed that the five antagonist fungi belong to the Trichoderma afroharzianum species. It is concluded that the T. afroharzianum isolates evaluated showed good levels of in vitro control of the plant pathogenic fungi in question and will be studied via in vivo tests and in plant growth promotion. [ABSTRACT FROM AUTHOR]

The study's major goal was to find more efficient antagonist fungus for soil-borne diseases of chilli and tomato plants. Trichoderma species (T.asperellum and T.viride) were investigated for antifungal potential against Pakistani and American soil-borne pathogenic isolates of Pythium aphendermatum, P. capsici, P. infestant, and F. oxysporum. In-vivo conformation aggressiveness was tested using Trichoderma strains that had been identified morphologically and molecularly. Both biocontrol agents (T.asperellum and T.viride) were found effective to suppress the pathogenic Fusarium oxysporum isolate; T.viride, on the other hand, suppressed Phytophthora spp. (40%) and T.asperellum reduced growth up to 70% of Pythium aphendermatum isolates from the United States of America. T.viride and T.asperellum showed similar degrees of inhibition against pathogenic fungi (Pythium, Phytophthora, and Fusarium) of Pakistani isolates (60-90%). Both BCA fungi were treated simultaneously and maximum inhibition was observed up to 90%. Whereas T. asperllum was found more efficient than T. viride to inhibit the infection by Pythium, Phytophthora, and Fusarium species. When antagonistic fungi were coupled, the Trichoderma strain demonstrated broad spectrum antagonism effect, which is a critical characteristic for the economic sustainability of any biocontrol agent. [ABSTRACT FROM AUTHOR]

Black point disease of wheat contributes to high economic losses every year. The overuse of fungicides resulted in pathogenic fungal resistance, health and environmental hazards that necessitate the formulation of safe biocontrol agents. Dual cultural assay of Trichoderma viride and Trichoderma harzianum strains proved their highest efficiency against Alternaria alternata with inhibition percentages of 75.04 and 67.83%, while the lowest activity was detected against Drechslera halodes with growth inhibition of 51.54 and 43.92%, respectively. Alternaria alternata and D. halodes strains exhibited carbendazim resistance, while Fusarium proliferatum was the most susceptible one. Chemical analysis of T. harzianum and T. viride extracts using gas chromatography-mass spectrometry indicated that 6-pentyl-α-pyrone and cyclooctanol compounds were the main active constituents representing about 26.43 and 32.74% respectively. The tested bioagents were highly effective against the fungal strains causing black point disease of wheat so that these biocontrol agents could be used in formulation of natural fungicides avoiding the harmful impact of the synthetic fungicides. Abbreviations: FCZ; Fluconazole Antifungal agent, GC-MS; Gas chromatography-Mass spectrometry, MIC; Minimum inhibitory concentration, MFC; Minimum fungicidal concentration, PDA; Potato dextrose agar, T.H; Trichoderma harzianum, 1. T. V; Trichoderma viride [ABSTRACT FROM AUTHOR]

Wilt caused by Fusarium sacchari, is one of the major diseases of sugarcane (Saccharum spp.) causing considerable economic loss. Trichoderma spp. are important biocontrol agents which have been exploited effectively for the management of several plant diseases including wilt in various crops. The present study was undertaken to evaluate the antagonistic potential of Trichoderma spp. against sugarcane wilt pathogen. A total of 103 Trichoderma isolates comprising of 43 isolates established from sugarcane rhizosphere soils as well as 60 endophytic isolates established from root, leaf and stalk tissue of sugarcane were assessed for their antagonistic activity against F. sacchari by dual culture technique. We observed considerable variability in the inhibitory activity of the 103 isolates against the pathogen with inhibition ranging from 1.4% to 27.2% (SER42). In general, the endophytic Trichoderma isolates were more effective in inhibiting F. sacchari as compared to rhizospheric isolates in dual culture studies. Twelve most promising endophytic isolates were selected and assessed further for production of soluble inhibitory metabolites against F. sacchari by poison food technique. Variability was observed among the Trichoderma isolates in inhibition of F. sacchari growth with inhibition ranging between 1.4% (SER 43) to 44.2% (SER10). Overall, based on the in vitro assays, Trichoderma isolate SER 10, isolated from root tissue of sugarcane, was found most promising showing 44.2% inhibition of F. sacchari growth in poison food and 26.3% inhibition in dual culture studies. This is the first study reporting biocontrol potential of endophytic Trichoderma spp. against F. sacchari, a causative agent of wilt in sugarcane.

Los objetivos de este trabajo fueron: determinar la factibilidad de la utilización combinada de dos métodos de control biológico: la aplicación del hongo antagonista Trichoderma spp. y la biofumigación con la parte aérea de Brassica juncea en el estadio de fin de fructificación; evaluar su efecto sobre el crecimiento del patógeno Fusarium graminearum. Se trituraron plantas de B. juncea y se colocaron en recipientes de plástico en dosis de 5 y 10 g. Sobre el material triturado se apoyó una caja de Petri con agar papa glucosado al 2%, que contenía un disco con micelio de F. graminearum o Trichoderma spp. o ambos hongos. Los recipientes de plástico se cerraron e incubaron a 25±2°C en oscuridad durante 7 días. Finalizado este período, se midió el diámetro de las colonias. Se obtuvieron los siguientes resultados: i) cuando se biofumigaron por separado, no se observó efecto fungistático de B. juncea sobre Trichoderma spp. ni sobre F. graminearum; ii) en ausencia del biofumigante, Trichoderma spp. inhibió significativamente el crecimiento de las colonias de F. graminearum, iii) la combinación de Trichoderma spp. y la biofumigación con B. juncea mostró un efecto sinérgico sobre el control del crecimiento miceliar de F. graminearum. Los resultados in vitro sugieren que el crecimiento de Trichoderma spp. y su potencial efecto de biocontrol sobre F. graminearum, no son afectados por la biofumigación con B. juncea. La utilización combinada de Trichoderma spp. y la biofumigación con B. juncea, tendría un efecto sinérgico sobre el control del crecimiento de F. graminearum.

Rigidoporus microporus, which causes white root rot disease (WRD) in Hevea brasiliensis, is a looming threat to rubber plantation in Malaysia. The current study was conducted to determine and evaluate the efficiency of fungal antagonists (Ascomycota) against R. microporus in rubber trees under laboratory and nursery conditions. A total of 35 fungal isolates established from the rubber tree rhizosphere soil were assessed for their antagonism against R. microporus by the dual culture technique. Trichoderma isolates can inhibit the radial growth of R. microporus by 75% or more in the dual culture test. Strains of T. asperellum, T. koningiopsis, T. spirale, and T. reesei were selected to assess the metabolites involved in their antifungal activity. Results indicated that T. asperellum exhibited an inhibitory effect against R. microporus in both volatile and non-volatile metabolite tests. All Trichoderma isolates were then tested for their ability in producing hydrolytic enzymes such as chitinase, cellulase and glucanase, indole acetic acid (IAA), siderophores production, and phosphate solubilization. From the positive results of the biochemical assays, T. asperellum and T. spirale were selected as the biocontrol candidates to be further tested in vivo against R. microporus. The nursery assessments revealed that rubber tree clone RRIM600 pretreated with only T. asperellum or with the combination of T. asperellum and T. spirale was able to reduce the disease severity index (DSI) and exert higher suppression of R. microporus compared to other pretreated samples, with the average DSI below 30%. Collectively, the present study demonstrates that T. asperellum represents a potential biocontrol agent that should be further explored to control R. microporus infection on rubber trees.

Phytopatogenic fungi cause severe economic losses worldwide. Rhizoctonia solani Kühn is a pathogenic fungi affecting several crops, controlled mainly by agrochemicals. Biological control has arisen as another option for managing this pathogen. In this study, we evaluated the biocontroller potential of five orchid mycorrhizal fungi (OMF) isolated from terrestrial Chilean orchids on R. solani. We compared the biocontroller effect of these OMFs with that of Trichoderma harzianum Rifai in an in vitro dual culture experiment. We found that R. solani can be controlled in vitro by OMF isolated from native orchids. The OMF isolated from Chloraea virescens and C. lamellata showed the best biocontroller results, which were similar, or even higher, than with T. harzianum. Thus, OMFs could become a relevant alternative for the integral control of R. solani, contributing to the reduction in the use of agrochemicals in crops.

Background: High losses of sorghum crops due to fungal diseases, such as grain mold and stalk rot, are economically harmful and cause increased use of environmentally damaging chemical fungicides, which also are detrimental to human health. Hence, finding safe and effective ways to manage fungal diseases of sorghum is urgently needed. Results: In the present study, the antagonistic activities of Trichoderma viride and T. harzianum against different pathogenic fungal strains were evaluated in vitro using a dual culture assay. Furthermore, the anti-mycotic activity of Trichoderma spp. culture filtrates was evaluated against different fungal strains using a food poisoning technique. Additionally, the antifungal activities of ethyl acetate extracts of T. viride and T. harzianum against different pathogens were evaluated using a disk diffusion method. As indicated by the dual culture assay, T. harzianum suppressed 66.8, 69.5, 68.7, 54.6, 84.12, and 71.39% of the mycelial growth of Curvularia lunata, Exserohilum rostratum, Fusarium chlamydosporum, F. incarnatum, F. proliferatum, and Macrophomina phaseolina, respectively. T. viride was more effective for controlling the growth of these pathogens, inhibiting 81.0, 89.0, 63.0, 70.7, 84.4, and 71.8% of mycelial growth, respectively. Both E. rostratum and M. phaseolina showed resistance to carbendazim fungicide at all tested concentrations, whereas the fungicidal concentrations of carbendazim against C. lunata, F. chlamydosporum, and F. incarnatum strains were 2.50, 1.50, and 2.00 ppm, respectively. Furthermore, F. proliferatum was sensitive to carbendazim fungicide at all tested concentrations. Antifungal assays of the ethyl acetate extracts of T. viride and T. harzianum indicated the potent activity of these extracts against fungal phytopathogens with different susceptibility patterns. F. chlamydosporum was the most sensitive to the extracts of T. viride and T. harzianum with minimum inhibitory concentrations of 0.5 and 1.0 mg/disk, respectively. Conclusion: The potent suppression of sorghum phytopathogens by T. viride and T. harzianum makes them potential sources of safe and effective natural fungicides compared to carbendazim fungicide. [ABSTRACT FROM AUTHOR]

Eggplant is a solanacea affected by Vascular Wilt (VW) associated with Fusarium oxysporum f sp melongena that destroys vascular tissue, causing chlorosis and finally plant death, generating losses between 70 and 90 % of production in established crops of the department. from Córdoba, Colombia. The objective was to identify native strains of Trichoderma spp. for the biocontrol of Fusarium spp, in eggplant. Five strains of Trichoderma spp were isolated from the field: TC05, TM04, TS03, TC02, TM01 and five strains of Fusarium spp: FM01, FS02, FC03, FC04, FS05, in the laboratory using dual cultures under a completely randomized design (CRD) with five repetitions in a 5x6 factorial arrangement, where the first factor corresponded to the strains of Fusarium spp. and the second to the strains of Trichoderma spp. and a control, was measured to the strains of Fusarium spp. the diameter of the colony to determine the percentage of inhibition and the biocontrol efficiency of Trichoderma spp. being the TC05 strain the best to inhibit between 73 and 91,2 % the five strains of Fusarium spp; Subsequently, at home mesh, the biocontrol of VW was evaluated under a completely randomized design with five treatments and nine repetitions, pre-inoculating eggplant seedlings with strain TC05 in doses 1x108, 1x107, 1x106 CFU mL-1, a commercial strain of Trichoderma spp. dose 1x108 CFU mL-1 and a control (control with water), and 10 days after inoculation (DAI) with the strain FS02. The results at 45 DAI, the leaf disease indices and the vascular discoloration index were lower with Trichoderma spp, compared to the control with an incidence of 45 % with VW. It is concluded that the native strain TC05 has the potential to be used in the integrated management of the VW of eggplant in Córdoba, Colombia. [ABSTRACT FROM AUTHOR]