Natural Fungicides Research Articles

Design, Synthesis, and Antifungal Evaluation of Novel Cuminic Acid Derivatives as Potential Laccase Inhibitors.

In search of novel natural product-based fungicides, 49 cuminic acid derivatives were designed, synthesized, and screened for their in vitro antifungal effects toward seven phytopathogenic fungi and oomycetes. Consequently, several derivatives exhibited strong antifungal activities toward Fusarium graminearum, Botryosphaeria dothidea, and Valsa mali. Among them, compound 2b exhibited the most potent antifungal activity toward B. dothidea (EC50 = 0.96 mg/L), more powerful than chlorothalonil. The in vivo assay against B. dothidea found that the protective and curative effects of 2b were comparable to chlorothalonil. Meanwhile, SEM and TEM observations indicated that 2b could ruin the integrity of mycelial morphology and organelles of B. dothidea. Preliminary mechanism research showed that 2b increased the cell membrane permeability and intracellular ROS level, as well as conspicuously decreased the mycelial dry weight and cell wall chitin contents of B. dothidea. The phytotoxicity test revealed that 2b showed good safety on seeds of mung bean and radish. The in vitro laccase inhibitory activity assay and molecular docking study demonstrated that 2b could be a promising laccase inhibitor. This type of cuminic acid hydrazide derivative would provide valuable inspiration for developing novel fungicides against B. dothidea.

Discovery of New Antifungal Polyketides Cladrioides A-N against Phytopathogenic Fungi from Cladosporium cladosporioides LD-8.

During the search for natural fungicides, 14 new australifungin analogues cladrioides A-S (1-14) and two known ones (15 and 16) were obtained from Cladosporium cladosporioides LD-8. Their structures were elucidated by comprehensive analysis of NMR and HRESIMS data, as well as ECD calculations. Compounds 1 and 2 possess a novel 6/6/5-fused tricyclic scaffold. Most of the compounds exhibited remarkable antifungal activities against the tested phytopathogenic fungi. Among them, compounds 7, 10, and 16 showed excellent activities with IC50 values ranging from 1.71 to 16.63 μg/mL. Their inhibitory activities against A. brassicicola and A. alternata were higher than that of the commercial fungicide hymexazol. Compound 16 displayed potent in vivo antifungal activity against A. solani at 100 μg/mL with an inhibitory rate of 96.82%. The structure-activity relationship of antifungal australifungin analogues was analyzed for the first time. Therefore, our study provides promising candidates for the development of new fungicides for plant protection.

Inhibition of Key Virulence Enzymes of Botrytis cinerea by Flavonoids from the Antarctic Plant Colobanthus quitensis.

This study investigates the antifungal efficacy of flavonoids derived from Colobanthus quitensis against key virulence-related enzymes implicated in the pathogenic mechanisms of Botrytis cinerea. The flavonoids swertiajaponin, schaftoside, vitexin, and saponarin significantly inhibited pectinase, cellulase, and laccase activity. Specifically, swertiajaponin showed mixed inhibition of pectinase and cellulase, characterized by high affinity (low inhibition constant -Ki-) for enzyme-substrate complexes. Schaftoside showed mixed inhibition of pectinase and competitive inhibition of laccase, effectively reducing enzymatic activity by competing directly with the substrate. In contrast, vitexin showed competitive inhibition of pectinase and non-competitive inhibition of laccase, suggesting it induces conformational changes within the enzyme. Finally, saponarin uniquely showed uncompetitive inhibition of laccase, stabilizing the enzyme-substrate complex and thereby markedly reducing catalytic turnover. Supported by kinetic parameters (maximum velocity -Vmax-, Michaelis constant -Km-, and Ki), these findings highlight the potential of flavonoids from C. quitensis as natural fungicides, offering a sustainable and eco-friendly alternative to synthetic fungicides for managing agricultural diseases.

Production and Characterisation of Microencapsulated Particles of Harugana madagascariensis: a Natural Fungicide with an Improved Delivery Potential

Production and Characterisation of Microencapsulated Particles of Harugana madagascariensis: a Natural Fungicide with an Improved Delivery Potential

Synthesis and Antifungal Evaluation of Cinnamic Acid-Geraniol Hybrids as Potential Fungicides.

Cinnamic acid and geraniol are two well-known antifungal natural products and widely applied in food and cosmetics industries. To discover novel natural product-based fungicide candidates with more potent activity and good ecological compatibility for the management of plant diseases, a series of cinnamic acid-geraniol hybrids were prepared by means of molecular hybridization and their chemical structures were well confirmed by spectral analysis. The antifungal activities of the target compounds against three phytopathogenic fungi Fusarium graminearum, Gaeumannomyces graminis (Sacc.) Arx et Oliver var. tritici (Sacc.) Walker, and Valsa mali were evaluated. Among them, compounds 5 e and 5 f showed the remarkable antifungal activity against G. graminis with the EC50 values of 82.719 and 91.828 μg/mL, respectively; while compounds 5 f and 6 b exhibited the obvious antifungal activity against V. mali. It suggested that compound 5 f can be further optimized for the design of novel broad-spectrum fungicide molecules as the secondary lead compound. In addition, some interesting structure-antifungal activity relationships were obtained. This work will provide some reference and guidance for the further discovery of novel fungicide candidates based on cinnamic acid and geraniol.

Comparative analysis of antifungal properties in medicinal plant extracts for sustainable agriculture

The escalating environmental repercussions of pesticide use in pest and disease management underscore the urgency for alternative strategies. One promising avenue involves harnessing natural antifungal properties present in plant extracts. This study aimed to assess the antifungal efficacy of aqueous and ethanolic extracts from five medicinal plants, viz., C. sativa L., S. moorcraftiana L., S. nigrum L., F. vesca L., and R. pseudoacacia, which were screened for their antifungal activity against various soil-borne fungi, viz., A. niger, A. flavus, A. terreus, R. stolonifer, M. mucedo, F. oxysporum, A. alternata, P. notatum, C. cladosporioides, and C. lunata. Phytochemical analysis exhibited the presence of phenols, alkaloids, tannins, flavonoids, quinines, and terpenoids. Results revealed potent antifungal activity across all tested fungi, significantly inhibiting mycelial growth compared to control. S. nigrum and C. sativa extracts exhibited the highest efficacy against multiple fungal pathogens. The inhibition in mycelial growth in ethanolic and aqueous plant extracts of C. sativa against A. niger varies between 3.00 mm to 6.00 mm and 4.00 mm–6.33 mm, against A. flavus 3.33 mm–11.66 mm and 4 mm–12.66 mm, A. terreus (3.00 mm–6.00 mm and 3.66 mm–7.00 mm), R. stolonifer (3.00 mm–5.33 and 3.66 mm–6.33 mm), M. mucedo (8.33 mm–17.66 mm and 9.66 mm–18.66 mm), F. oxysporum (6.66 mm–12.33 mm and 7.33 mm–13.33 mm), A. alternata (4.66 mm–11.33 mm and 5.33 mm–14.00 mm), P. notatum (9.33 mm–23.00 mm and 9.66 mm–24.33 mm), C. cladosporioides (4.33 mm–8.66 mm and 5.33 mm–9.66 mm), and C. lunata (14.00 mm–20.33 mm and 17.00 mm–21.33 mm) in different concentrations of plant extracts respectively. Likewise, the inhibition in mycelial growth in ethanolic and aqueous plant extracts of S. nigrum against A. niger at different concentrations varies between 8.00 mm to 17.66 mm and 9.00 mm–18.66 mm, A. flavus (8.33 mm–12.66 mm and 9 mm–14 mm), A. terreus (2.33 mm–5.66mm and 3 mm–7 mm), R. stolonifer (13.33 mm–20.33 mm and 17.66 mm–24.66 mm), M. mucedo (10.66 mm–12.00 mm and 11.66 mm–13.00 mm), F. oxysporum (15.66 mm–22.33 and 18.00 mm–24.00 mm), A. alternata (10.66 mm–13.00 mm and 11.66 mm–14.00 mm), P. notatum (5.33 mm–13.33 mm and 6.33 mm–18.66 mm, C. cladosporioides (3.33 mm–7.66 mm and 4.00 mm–8.00 mm), and C. lunata (3.66 mm–6.33 mm and 4.66 mm–6.66 mm), respectively. These findings suggest that these plant extracts have the potential to be natural fungicides, providing promising alternatives for disease management in agriculture.

Role of Lichen Extracts as a Potential Source of Natural Fungicides

Plant pathogens and the diseases they cause are major to humanity. Each year, we lose more than thirty percent of crops worldwide to bacterial and fungal diseases. Lichen is a composite organism made up of two unrelated species: algae and fungi. These two components live together and behave as a single organism. When two organisms live together in this way, they provide mutual benefits to one another. They are referred to as symbionts. Lichens produce many rare secondary products not found in other plants. The uniqueness of many aromatic products sparked early chemical interest in lichen compounds. Lichens are an underutilized source of industrially important as it proven many biological activities, and yet there is much more to study about their efficacy. Lichen bioactive metabolites showed promising use in biopharmaceutical applications and for the preparation of new formulations or innovations to support human life. This review aims to summarize the research and development trends from the past and present in the bioactive fungicides against plant pathogens.

Novel Fungicide from Waste Oil Palm Fruit Bunch for Sustainable Management of Tomato Wilt Disease Caused by Fusarium oxysporum - experimental and in silico studies

Tomato wilt, a widespread and persistent disease caused by the fungus Fusarium oxysporum, can be effectively controlled through biological approaches, promoting ecosystem sustainability and enhancing agricultural productivity and quality. This study explored the use of empty oil palm fruit bunch (EOPFB) waste as a natural fungicide to control tomato Fusarium wilt disease through in vitro, pilot scale, and molecular docking experiments. EOPFB aqueous extract showed the highest mycelium growth inhibition of 68.3 %, with the commercial fungicide Mancozeb exhibiting a moderate 42.30 % inhibition, and sterile distilled water having a negligible effect of 0.24 %. The inhibition rate varied with concentration, peaking at 72.63 % at 0.15 g/mL and dropping to 54.80 % at 0.01 g/mL. In terms of wilt disease incidence and severity, EOPFB performed best, recording the lowest incidence of 47.20 % and severity of 15.58 %. Mancozeb followed closely, with an incidence of 46.30 % and severity of 26.23 %. Sterile distilled water, on the other hand, showed the highest incidence of 76.28 % and severity of 56.17 %. Molecular docking simulations corroborated the experimental results, validating the potency of EOPFB as an inhibitor of trypsin from F. oxysporum, and identifying 2-amino-5,6-dimethyl-3 H-pyrimidine-4-one as the primary active compound responsible for the fungicidal activity. This phytochemical, abundant in the crude ethanolic extract of EOPFB, was found to have a higher binding affinity (6.1 kcal/mol) than Mancozeb (4.8 kcal/mol), at the trypsin target. These findings demonstrate the potential of EOPFB, an agricultural waste product, as a sustainable and eco-friendly solution for managing tomato Fusarium wilt disease, contributing to increased tomato production. It also highlights the potential of 2-amino-5,6-dimethyl-3 H-pyrimidine-4-one as a lead compound for the development of novel, natural fungicides, and underscores the value of EOPFB as a rich source of bioactive compounds with agricultural and biotechnological applications.

Antifungal agents: A systematic review

The aim of the study was to evaluate the antifungal activity of different drugs and preparations. The current findings demonstrated that the drugs and medicinal plant extracts that were examined for antifungal properties against various species. These species demonstrated antifungal activity almost on par with the commercial fungicide used as a positive control, even at low dosages. For further of the bioactive substances causing the noted antifungal activity, more research is required. Natural fungicides generated from plants could provide new active molecules, especially those with antifungal properties. The high percentage of active extracts in the species under investigation, which were chosen based on known ethnobotanical data, supports the applicability of this method for choosing plant species when looking for a certain activity.

An investigation on antifungal preparation: A comprehensive review

The study’s objective was to assess the antifungal efficacy of various medications and formulations. Medicinal plant extracts and medications that were tested for antifungal qualities against different species were shown to have antifungal capabilities. Even at modest dosages, these species showed antifungal activity that was nearly identical to that of the commercial fungicide used as a positive control. More research is needed to determine which bioactive compounds are responsible for the observed antifungal action. Plant-based natural fungicides may yield novel active compounds, particularly those with antifungal qualities. The relevance of this strategy for selecting plant species when seeking a certain activity is supported by the high percentage of active extracts in the species under inquiry, which were selected based on established ethnobotanical data.

Organic fungicides and diphenylamine shift microbiomes of ‘Fuji’ apples during storage

The native microbiome plays an important role in biocontrol efficacy, but less is known about how the microbiome responds to conventional and organic natural product fungicides. This study investigated the effects of the conventional fungicide fludioxonil and the organic fungicide natamycin, with and without the superficial scald inhibitor diphenylamine (DPA) on the microbiomes of ‘Fuji’ apples from 1 to 28 d of storage at 0.5 °C plus 7 d at 20 °C. We hypothesized that fungicide applications would shift the microbiome, with a more pronounced effect from natamycin due to the target specificity of fludioxonil. We also predicted that the antioxidant properties of DPA would shift both bacterial and fungal microbiomes. We found that natamycin resulted in modest fungal shifts and fludioxonil resulted in no observed shifts, while DPA strongly affected the fungal microbiome over time. Chemical treatment was not a predictor of bacterial microbiome variation, but bacterial communities shifted throughout storage. However, many of the trends that occurred during storage were reversed during the 7-d shelf life period at 20 °C after storage. Time in cold storage decreased the relative abundance of Pseudomonas, while DPA application reduced the relative abundance of Aureobasidium, both notable biocontrol genera. These results highlight how chemical applications such as DPA may have unintended effects on beneficial microbes that protect fruit from pathogen infection.

LC-MS based metabolomics identification of natural metabolites against Fusarium oxysporum.

Fusarium is a soil-borne pathogen that poses a serious threat to the quality and yield of hundreds of crops worldwide, particularly tobacco production. Using metabolomics technology, we investigated natural metabolites from disease-conducting soil (DCS) and disease-suppressing soil (DSS) of tobacco rhizosphere as fungicides to control tobacco Fusarium wilt (TFW), which is mainly caused by Fusarium oxysporum. Furthermore, the antifungal mechanisms of these natural metabolites were preliminarily elucidated through various assessments, including antifungal activity determination, chemotaxis effect tests, PI staining experiments, and measurements of extracellular conductivity and protein content. Metabolomics results showed that the DCS with three different disease grades (G1, G5 and G9 groups) had significantly higher levels of 15, 14 and 233 differential rhizosphere metabolites (DRMs) and significantly lower levels of 72, 152 and 170 DRMs compared to the DSS (G0 group). According to KEGG pathway analysis, these DRMs were found to be enriched in the caffeine metabolism, biosynthesis of phenylpropanoids, galactose metabolism and tyrosine metabolism, etc. Linustatin, scopoletin and phenylpropiolic acid were picked out from these DRMs and found to have suppressive activity against F. oxysporum through correlation analysis and antifungal experiments. The three DRMs showed strong inhibitory effects on the growth and spore germination of F. oxysporum at concentrations of 0.5 mM or higher in each test period. Furthermore, F. oxysporum showed a phobotaxis effect against these three DRMs at concentrations as low as 0.25 mM. Finally, we found that the three DRMs had an inhibitory effect on F. oxysporum by destroying the integrity of the cell membrane and increasing the membrane permeability of F. oxysporum. This study firstly reports the inhibition activity of phenylpropiolic acid and linustatin on F. oxysporum, providing a practical and environmentally friendly method for biocontrol of TFW by using natural fungicides.

Synthetic and Natural Antifungal Substances in Cereal Grain Protection: A Review of Bright and Dark Sides.

Molds pose a severe challenge to agriculture because they cause very large crop losses. For this reason, synthetic fungicides have been used for a long time. Without adequate protection against pests and various pathogens, crop losses could be as high as 30-40%. However, concerns mainly about the environmental impact of synthetic antifungals and human health risk have prompted a search for natural alternatives. But do natural remedies only have advantages? This article reviews the current state of knowledge on the use of antifungal substances in agriculture to protect seeds against phytopathogens. The advantages and disadvantages of using both synthetic and natural fungicides to protect cereal grains were discussed, indicating specific examples and mechanisms of action. The possibilities of an integrated control approach, combining cultural, biological, and chemical methods are described, constituting a holistic strategy for sustainable mold management in the grain industry.

Antimicrobial activity, foaming properties, and interacting mechanism of rhamnolipids in presence of silk fibroin through spectroscopy, molecular docking, and microbiological experiments

As a type of biosurfactant, rhamnolipids (RLs) are multifunctional skin-care ingredients, and the molecular interaction of RLs with silk fibroin (SF) is a more complicated process than has long been believed. The interaction and functional properties of them, and their potential as fungicidal agents for agricultural products and as organic preservatives for cosmetics were assessed in this paper. The SF addition makes the RLs aggregation easier through the complexes formation, which decreases the applied concentration of surfactant. The results of spectroscopic analyses and molecular docking suggest that hydrogen bonding and van der Waals forces are significant contributed to the binding mechanism between the two substances. The addition of SF notably enhances the foaming capacity and stability of RLs. The certain antibacterial and antifungal properties of RLs are basically not affected by the SF addition, even the SF-RLS system demonstrates an unobvious synergistic inhibitory impact on Glomerella cingulate (GC). The results offer a theoretical framework for the utilization of RLs as natural fungicides and preservatives in presence of nutritional components, considering the properties of RLs as nontoxic, biodegradable, environmentally friendly, and good compatibility.

Bakanae Disease Resistance in Rice: Current Status and Future Considerations

Bakanae disease is mainly caused by Fusarium fujikuroi and is a significant fungal disease with a number of disastrous consequences. It causes great losses in rice production. However, few studies have focused on the details of bakanae disease resistance in rice. Here, we summarize and discuss the progress of bakanae disease resistance in rice. Besides rice germplasm screening and resistance-related gene/quantitative trait locus (QTL) exploration, the route of pathogen invasion in rice plants was determined. We further discussed the regulation of phytohormone-related genes and changes in endogenous phytohormones in rice plants that are induced by the pathogen. To achieve better control of bakanae disease, the use of natural fungicides was assessed in this review. During rice—F. fujikuroi interactions, the infection processes and spatial distribution of F. fujikuroi in infected seedlings and adult plants exhibit different trends. Fungal growth normally occurs both in resistant and susceptible cultivars, with less abundance in the former. Generally, bakanae disease is seed-borne, and seed disinfection using effective fungicides should always be the first and main option to better control the disease. Besides the friendly and effective measure of using natural fungicides, breeding and utilization of resistant rice cultivars is also an effective control method. To some extent, rice cultivars with low grain quality, indica subspecies, and some dwarf or semi-dwarf rice germplasms are more resistant to bakanae disease. Although no highly resistant germplasms were obtained, 37 QTLs were located, with almost half of the QTLs being located on chromosome 1. Using omics methods, WRKYs and MAPKs were usually found to be regulated during rice—F. fujikuroi interactions. The regulation of certain phytohormone-related genes and changes in some endogenous phytohormones induced by the pathogen were clear, i.e., it downregulated gibberellin-related genes and repressed endogenous gibberellins in resistant genotypes, but the opposite results were noted in susceptible rice genotypes. Overall, exploring resistant germplasms or resistance-related genes/QTLs for the breeding of rice with bakanae disease resistance, expanding research on the complex mechanism of rice—F. fujikuroi interactions, and using cost-effective and eco-friendly innovative control methods against the disease are necessary for present and future bakanae disease management.

Uptake and transport of antibiotic kasugamycin from leaves to roots in rice (Oryza sativa L.) seedlings

AbstractKasugamycin (KSM), an aminoglycoside antibiotic, has been widely used as a natural fungicide to control plant diseases, particularly for managing rice blast. However, its uptake mechanism and transport in rice remain to be explored. In this article, rice seedlings were treated by the foliar spraying method, and the content of KSM in rice leaves, stems and roots under different treatments was detected by high‐performance liquid chromatography tandem mass spectrometry (HPLC‐MS/MS), respectively. Results showed that leaf‐applied KSM could be transported to the phloem and migrate to roots and stems after uptake by leaves. Concentration, temperature and pH had significant effects on the uptake of KSM. Compared with the control, the competitive inhibitors d‐glucose and phlorizin both inhibited the uptake of KSM, demonstrating that sugar transporter proteins were involved in the uptake process. The energy inhibitors dinitrophenol (DNP) and carbonyl cyanide chlorophenylhydrazone (CCCP) also significantly inhibited the uptake of KSM, indicating that the uptake of KSM required energy consumption. Thus, the uptake of KSM by rice was an active process involving sugar transporter proteins, and it could migrate downward through the phloem. This study contributes to the promotion of the scientific application of antibiotics and the biological control of crop diseases. It will also provide a theoretical basis for the development of root‐targeted pesticides and transport pesticides with phloem mobility.

Sheath Blight and Bacterial Blight Resistance in Rice: Mechanisms, Progress and Future Perspectives for Sustainable Rice Production

Rice (Oryza sativa L.) is a staple food for nearly half of the world's population, including Pakistan. But several diseases are always posing a threat to rice farming, with bacterial blight and sheath blight being the two most common causes. R. solani is the main source of rice sheath blight and stood crop’s most destructive diseases. Reviewing published data on pathogenicity and disease management is crucial to developing effective crop protection against sheath blight. It also helps identify research gaps that need more in-depth investigation. Although there has been progress in identifying rice and pathogen-related genes linked to pathogenesis, the underlying processes are still unknown. Research on the applications of; agronomic techniques, chemical control, biological control, and genetic improvement in disease management strategies has been conducted. Optimizing the application of nitrogen fertilizer in combination to plant-plant spacing can minimize the transmission of infection, whereas SMART agricultural technologies; like crop monitoring using Unmanned Aerial Systems help detect and treat sheath blight disease early on. Biological agents and natural fungicides can be used to effectively prevent sheath blight while reducing the negative effects on the environment. Genetic strategies that hold potential to control sheath blight include the use of exogenous dsRNA to suppress pathogen gene expression, genome editing to create rice lines less susceptible to sheath blight, and the development of transgenic rice lines that over express or silence genes related to pathogenesis. The pathogen’s flexibility, the absence of resistant rice types, the lack of single resistance genes for breeding, and farmers' restricted access to informative programs about optimum management methods all work against effective crop protection against sheath blight.

Antifungal properties of Andrographis paniculata extracts as potential biofungicides: a review

Andrographis paniculata, commonly known as the king of bitters, has been studied for its potential as a natural fungicide due to its several bioactive compounds, including andrographolides. The primary objective of this study was to demonstrate the possible efficacy of A. paniculata against a wide range of fungal diseases in terms of the properties of A. paniculata extracts that could potentially be used as a bio-fungicide. The presence of alkaloids, flavonoids, phenols, terpene derivatives compounds, and other phytochemical constituents makes the A. paniculata extract more precise in its mode of action against the variety of phytopathogenic fungi. Various physiological and biochemical changes in crops result in unintended physiological issues, degradation, and subsequent financial losses during storage. Synthetic fungicides have been applied to control plant diseases caused by phytopathogenic fungi. However, their application has drawn criticism because of adverse effects. Therefore, a possible solution would be to apply botanical fungicides, which have been proven to be generally non-phytotoxic, systemic, and rapidly disposable in nature. Botanical fungicides are endowed with benefits such as resistance inhibition, being ecofriendly, effective, elective, and more affordable than synthetic fungicides. Therefore, the medicinal herb, A. paniculata has been proven to be effective in controlling pathogens of agricultural crops and increased their shelf-life when used as a substitute for synthetic chemicals. Due to their antimicrobial capabilities against fungal, bacterial, and viral infections, various medicinal herbs have been investigated and employed for crude extraction globally. Andrographis paniculata extracts have broad-spectrum antifungal activity, indicating potential efficacy against a diverse variety of fungal infections.

Antagonistic activity of biocontrol agent Trichoderma spp. against Fusarium sp., the causal agent of Ananas comosus fruitlet rot

Pineapple (Ananas comosus) is a significant crop, with an annual production exceeding 25 million tons. However, fusariosis can severely impact its cultivation, a fungal disease that causes fruitlet rot and results in substantial yield losses. To decrease dependency on chemical control methods, biocontrol agents (BCAs) present a promising alternative. Among these, Trichoderma species are noteworthy due to their diverse antagonistic mechanisms. The efficacy of each mechanism can be assessed through fungal confrontation assays. This study aimed to isolate, identify, and evaluate in-vitro nine Trichoderma spp. strains as potential BCAs against Fusarium sp. associated with pineapple fruitlet rot. The antagonistic fungi were isolated from rhizosphere soils in both open-field and greenhouse pineapple farms in Misiones province, Argentina. Identification of the fungi required both morphologic and genetic data. In the in-vitro assays, the capabilities for direct competition for substratum, production of metabolites, and mycoparasitism were evaluated. The results indicated that isolates T. harzianum TC7, T. harzianum TC9, T. asperellum TU3, and T. asperellum TU4 had statistically superior inhibitory effects against Fusarium sp. These isolates can be potentially used in formulating natural fungicides to reduce pineapple fruitlet rot caused by Fusarium, promoting sustainable production practices. Keywords: pineapple, confrontation, mycoparasitism, metabolites, ITS region

Antagonistic activity of biocontrol agent Trichoderma spp. against Fusarium sp., the causal agent of Ananas comosus fruitlet rot

Pineapple (Ananas comosus) is a significant crop, with an annual production exceeding 25 million tons. However, fusariosis can severely impact its cultivation, a fungal disease that causes fruitlet rot and results in substantial yield losses. To decrease dependency on chemical control methods, biocontrol agents (BCAs) present a promising alternative. Among these, Trichoderma species are noteworthy due to their diverse antagonistic mechanisms. The efficacy of each mechanism can be assessed through fungal confrontation assays. This study aimed to isolate, identify, and evaluate in-vitro nine Trichoderma spp. strains as potential BCAs against Fusarium sp. associated with pineapple fruitlet rot. The antagonistic fungi were isolated from rhizosphere soils in both open-field and greenhouse pineapple farms in Misiones province, Argentina. Identification of the fungi required both morphologic and genetic data. In the in-vitro assays, the capabilities for direct competition for substratum, production of metabolites, and mycoparasitism were evaluated. The results indicated that isolates T. harzianum TC7, T. harzianum TC9, T. asperellum TU3, and T. asperellum TU4 had statistically superior inhibitory effects against Fusarium sp. These isolates can be potentially used in formulating natural fungicides to reduce pineapple fruitlet rot caused by Fusarium, promoting sustainable production practices. Keywords: pineapple, confrontation, mycoparasitism, metabolites, ITS region