Chemical Fungicides Research Articles

Effect Of Plant Part Extracts On Spore Germination Of Puccinia Purpurea Cook

Plant part extracts were applied for the control of diseases caused by microorganisms. Hence, the present investigation deals with aqueous plant extracts of three plants which were screened for their fungitoxicity against spore germination and germ tube length of Puccinia purpurea Cook. Chemical fungicide Hexaconazole 0.05% used as a standard check was found better retardants for spore germination and germ tube length. The result showed that aqueous extract of Pongamia glabra vent parts at 6, 12 and 24 hour incubation period had strong fungitoxicity followed by extract of Tridex procumbens L and Lantana camera L parts in reducing the spore germination. All plant part extracts of selected plants effect on spore germination and germ tube length over control.

Eco-friendly management of Fusarium wilt in tomato using Salvia officinalis methanolic extract: in vitro, in vivo, and molecular docking approaches

Abstract Fusarium wilt, caused by Fusarium oxysporum f. sp. lycopersici, threatens global tomato production, with losses reaching 80%. Although chemical fungicides are effective, their prolonged use risks resistant strains, reduces soil biodiversity, and causes environmental damage, highlighting the urgent need for ecofriendly alternatives. This study investigated the viability of Salvia officinalis (sage) methanolic extract as a biocontrol agent against Fusarium wilt (FW), employing a comprehensive approach that incorporates in vitro, in vivo, and molecular docking techniques. Four distinct isolates of F. oxysporum were identified through molecular techniques, and their virulence was assessed by examining the presence of tomatinase genes. The antifungal properties of S. officinalis extract were found to be compelling, with a total phenolic content of 64.15 mg GAE/g and a remarkable antioxidant activity of 97.04%. In laboratory tests, S. officinalis exhibited potent antifungal activity, inhibiting mycelial growth by between 52.00% and 88.67% at a concentration of 20 mg/ml. Additionally, in vivo experiments demonstrated a significant reduction in disease severity in treated tomato plants. Molecular docking analyses revealed strong binding affinities between key phytochemicals in the extract and target receptors such as tomatinase, highlighting the potential of the extract as a sustainable and effective alternative to chemical fungicides for managing FW in tomato crops.

An Eco-Friendly Bioformulation Plant Jiaosu Containing Strains with Anti-Oomycete Activity Against Phytophthora infestans

Late blight, caused by Phytophthora infestans, is one of the most destructive diseases in potato cultivation. Chemical fungicides are currently the primary means of controlling it, but they pose significant issues, including environmental pollution and the development of resistant strains. Plant jiaosu (PJ), derived from the direct fermentation of various plants, plays a vital part in various fields such as environmental protection, agriculture, daily chemicals, and livestock. This study illustrates that PJ, fermented from lettuce leaves, significantly inhibits the growth of P. infestans. An isolated anti-oomycete bacterium, designated X-1, has 100% homology to Bacillus subtilis in the NCBI database, shown through 16S rDNA sequence analysis. B. Subtilis X-1 effectively inhibits the hyphal growth and sporangia germination of P. infestans, induces morphological changes in the hyphae, and can promote the growth of potato. PJ exerts a synergistic effect with the chemical fungicide Infinito (the main active ingredients are fluopicolide and propamocarb hydrochloride). In summary, this study provides a novel approach for the reutilization of fruit and vegetable waste and offers an environmentally friendly and effective alternative to chemical fungicides for controlling potato late blight.

Proteomic Strategies on the Management of Phytopathogenic Fungi

Phytopathogenic fungi are important causative agents of many plant diseases, resulting in substantial economic losses in agriculture. Proteomics has become one of the most relevant high-throughput technologies, and current advances in proteomic methodologies have been helpful in obtaining massive biological information about several organisms. This review outlines recent advances in mass spectrometry-based proteomics applied to the study of phytopathogenic fungi, including analytical platforms such as LC-MS/MS and MALDI-TOF, as well as quantitative strategies including TMT, iTRAQ, and label-free quantification. Key findings are presented from studies exploring infection-related protein expression, virulence-associated factors, post-translational modifications, and fungal adaptation to chemical fungicides, antimicrobial peptides, and biological control agents. Proteomic analyses have also elucidated mechanisms of resistance, oxidative stress response, and metabolic disruption following exposure to natural products, including essential oils and volatile organic compounds. The proteomic approach enables a comprehensive understanding of fungal biology by identifying proteins related to pathogenicity, stress adaptation, and antifungal resistance, while also facilitating the discovery of molecular targets and natural compounds for the development of sustainable antifungal strategies that reduce risks to human health and the environment.

Comparison and Analysis of Resistance Differences in Alternaria alternata from Fungicides with Three Different Mechanisms

The pathogen Alternaria alternata infects a variety of plants and crops, notably poplars, and results in large financial losses. Using twelve chemical fungicides for fungicide sensitivity tests (FSTs) on A. alternata, the result showed that prochloraz (PCZ), mancozeb (MZ), and fludioxonil (FLU) have potent inhibitory effects against the pathogen through different mechanisms. To investigate how the pathogen responded to fungicide-induced stress, transcriptome and physiological investigations were carried out after treatments with three fungicides at their corresponding 50% effective concentration (EC50) doses. The MZ treatment produced a distinct genetic response; FLU treatment produced the greatest number of differentially expressed genes (DEGs), followed by PCZ. DEGs from FLU treatment were mostly engaged in ribosome biosynthesis, those from MZ treatment in lipid and carbohydrate metabolism, and those from PCZ treatment in carbohydrate metabolism, according to Gene Ontology (GO) analysis. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis revealed that FLU and PCZ treatments were associated with ribosome biogenesis, whereas MZ treatment was linked to the pyruvate metabolic pathway. Collinear trend analysis indicates that MZ exhibits a unique pattern, with FLU treatment causing the most significant overexpression of genes, followed by PCZ. The six categories of 88 elevated DEGs associated with fungal resistance include tyrosinase, ATP-binding cassette (ABC) transporters, major facilitator superfamily (MFS) transporters, antioxidant and cellular resilience genes, as well as genes involved in cell wall and membrane biosynthesis. Notably, the pathways involved in the synthesis of melanin and ergosterol exhibited the strongest response to FLU. The results of a correlation analysis between physiological indices and resistance-related genes indicated that melanin content, malondialdehyde (MDA) content, and tyrosinase activity were positively correlated with the majority of resistance-related DEGs, whereas soluble protein content, superoxide dismutase (SOD) activity, and catalase (CAT) activity were negatively correlated, which is consistent with the observed trends in the measured physiological indicators. Taken together, this study provides a theoretical basis for developing more effective fungicides and chemical control strategies against A. alternata.

Applications of endophytic fungi in plant disease control.

Diseases caused by pathogenic microorganisms (bacteria, fungi, and viruses) have resulted in the quality and yield of crops, which has seriously affected the development of the agricultural economy. The prolonged use of chemical fungicides for prevention and control can lead to environmental pollution, hindering the sustainable development of safe and eco-friendly agriculture while also promoting the resistance of pathogenic microorganisms. Nevertheless, non-pathogenic endophytic fungi that form symbiotic relationships with plants still exhibit significant antagonistic effects on pathogenic microorganisms, even in small concentrations. These fungi pose no threat to human health and are highly beneficial to the ecological environment, making them an ideal alternative to chemical fungicides. They are increasingly being recognized and have been subjected to comprehensive research. Based on this, this article summarizes the types of endophytic fungi with biocontrol effects in recent years. It focuses on elucidating the mechanisms of their biocontrol from physiological and molecular perspectives. In addition, the application and development challenges of biocontrol agents (BCAs) derived from these fungi are also discussed, including difficulties in elucidating their mechanisms of action during research and development, challenges in strain selection and improvement, difficulties in controlling environmental adaptability, and stringent storage conditions. The aim is to develop more effective endophytic fungi as emerging biocontrol resources for agricultural production.

Uncovering the key miRNA-target network of tea plants in resistance to sooty mold disease

BackgroundSooty mold (SM) disease severely threatens tea plant health, reducing yield and quality. Driven by climate change and intensive farming practices, SM prevalence in China has surged, causing significant economic losses and forcing farmers to rely on chemical fungicides, which compromise environmental sustainability. Despite its impact, the molecular mechanisms underlying tea plant defenses against SM remain unclear.ResultsIntegrated transcriptomic, sRNAome, and degradome analyses revealed that differentially expressed genes (DEGs) exhibited infection-level-dependent expression patterns. Post-transcriptional regulation by miRNAs was identified through sRNAome-degradome mapping, with six miRNA-target defense pairs validated by 5′ RLM-RACE and qRT-PCR. Co-expression network analysis showed that two miRNA-target pairs, PC-5p-33681_128-auxin response factor (CsARF) and ppe-MIR535b-p3-1ss12TC-aldehyde dehydrogenase (CsALDH), play crucial roles in responding to SM infection. Furthermore, 5′ RLM-RACE and dual-luciferase assays revealed that the PC-5p-33681_128 and ppe-MIR535b-p3-1ss12TC could regulate the expression of CsARF and CsALDH by mRNA cleavage, respectively.ConclusionThis study elucidates miRNA-mediated defense networks in tea plants against SM, offering actionable targets for breeding SM-resistant cultivars via genetic engineering or marker-assisted selection. Implementing these strategies could reduce yield losses, stabilize farmer incomes, and minimize environmental harm from fungicide overuse. This work advances climate-resilient practices for the global tea industry by linking molecular insights to sustainable agriculture.

Effectiveness of biological and chemical fungicides for diseases control in barley (Hordeum vulgare)

Background/Objective. In the cultivation of barley in Mexico, diseases cause economic losses; chemical control has been the most effective way to mitigate their effects; however, it is necessary to explore other environmentally friendly control strategies. The objective was to compare, under field conditions, the effectiveness of biological and chemical fungicides for the control of pathogens that cause the main barley diseases. Materials and Methods. In spring-summer 2022, five experiments were conducted in different environments. The design was randomized complete blocks with three repetitions. Esmeralda was the variety used. Two biological fungicides (SERENADE® OPTI and Trichoderma Sub) were evaluated; and one, chemical (Azimut® 320 SC). They were applied three times. The diseases occurred naturally. The variables measured were: days to heading (DH), days to physiological maturity (DPM), plant height (PH), grain yield (YIELD), final disease severity: foliar (FFOLS), yellow rust (FYRS), leaf rust (FLRS). Results. The analysis of variance showed significant variation for YIELD, FYRS and FLRS (p≤0.01). In YIELD, the best biological fungicide was SERENADE® OPTI with a yield of 3,555 kg ha-1, compared to the control (3,086 kg ha-1). For FYRS and FLRS the most effective was Azimut® 320 SC, followed by Trichoderma Sub. Conclusion. The efficacy of the chemical for foliar diseases was 38 %, yellow rust 91 %, and leaf rust 100 %. Chemical control continues to be the most effective for controlling pathogens that cause barley diseases.

Development of a kaolin-based Bacillus velezensis BF01 composite for application in biocontrol of postharvest strawberry diseases.

Biological control agents are promising alternatives to conventional fungicides for managing postharvest diseases but their practical use is hindered by variable effectiveness and by application challenges. One promising yet underexplored approach involves utilizing bacteria that produce volatile organic compounds (VOCs) with antifungal properties. In this study, Bacillus velezensis BF01, a strain with significant antifungal activity, was identified and isolated. Volatile organic compounds produced by this strain inhibited the growth and conidial germination of Botrytis cinerea, Fusarium oxysporum, and Colletotrichum gloeosporioides. Gas chromatography-mass spectrometry identified 90 VOCs, with ketones, esters, nitrogen compounds, aldehydes, and alcohols as the dominant components, many of which exhibited antifungal or plant resistance-inducing properties. To enhance practical application, B. velezensis BF01 was incorporated into a kaolin-based composite, which maintained long-term viability under refrigerated conditions and inhibited fungal growth through the controlled release of volatile organic compounds. This composite significantly extended the shelf life of strawberries by reducing postharvest decay. The development of a kaolin-based B. velezensis BF01 composite provides an effective and sustainable biocontrol strategy for postharvest disease management. By improving bacterial stability and facilitating the controlled release of antifungal volatile organic compounds, this approach offers a practical alternative to chemical fungicides, highlighting its potential in extending fruit shelf life and improving food safety. © 2025 Society of Chemical Industry.

Control of cucumber downy mildew disease under greenhouse conditions using biocide and organic compounds via induction of the antioxidant defense machinery

Cucumber as an important vegetable crop faces a variety of abiotic and biotic stresses, especially the recently appeared fungicide-resistant strains of Pseudoperonospora cubensis, the causal agent of downy mildew disease. Herein, the present study aimed to evaluate the effect of Trichoderma asperellum strain T34 as a biological commercial product and potassium phosphite (KPHI) against P. cubensis and investigate the ability of these compounds to activate the plant defense system to suppress P. cubensis infection. In two separate experiments, the foliar applications with T34 or KPHI significantly reduced the severity of downy mildew disease and the area under the disease progress curve compared to water control. Scanning electron microscopy (SEM) of P. cubensis treated with T34 and KPHI showed shrunken and distorted sporangiophores and sporangia. Moreover, two tested compounds enhanced cucumber plants’ growth and yield parameters under greenhouse conditions. The tested compounds protected the membrane permeability of infected cucumber leaves and significantly reduced electrolyte leakage (EL %) compared to water control. These findings were associated with activating enzymatic antioxidant enzymes (catalase, peroxidase, and polyphenol oxidase). Our findings suggest that T34 and KPHI can be environmentally safe alternatives to chemical fungicides to control downy mildew disease in cucumber and other cucurbit crops.

BcatrB mediates pyrimethanil resistance in Botrytis cinerea revealed by transcriptomics analysis

Gray mold, caused by Botrytis cinerea, poses an escalating threat to ginseng production in China. Excessive application of chemical fungicides has resulted in severe resistance development. To elucidate the resistance mechanism of B. cinerea to pyrimethanil, transcriptomic comparisons were conducted between resistant (HRG21) and sensitive (FSG43) strains following exposure to pyrimethanil for 2 and 6 h. GO and KEGG analyses identified differential expression of genes associated with ABC and MFS transporters as well as methionine biosynthesis. qRT-PCR validation confirmed a marked upregulation of ABC (BcatrA, BcatrB, BcatrD, BcatrO, and Bmr3) and MFS (Bchex1 and BcmfsM2) transporter genes in HRG21, whereas in FSG43, ABC (BcatrA, BcatrB, BcatrD, and BcatrO) and MFS (Bchex1) transporter genes were downregulated. No significant transcriptional changes were observed in Mrr1, a transcription factor gene, following pyrimethanil exposure. Molecular docking analysis identified potential binding sites and interaction targets for five key transporters (BcatrB, BcatrA, BcatrD, Bmr3, and Bchex1). Furthermore, exogenous methionine supplementation partially mitigated pyrimethanil toxicity in FSG43. However, amino acid sequences of enzymes involved in methionine biosynthesis (BcmetC, BcStr2, Bcmet2, Bcmxr1, and Bcmxr2) exhibited no variation between FSG43 and HRG21. The results indicate that BcatrB plays a central role in pyrimethanil resistance, while methionine contributes only marginally to resistance mechanisms.

Actinobacteria as Proficient Biocontrol Agents for Combating Fungal Diseases in Forest Plant Species.

Treating fungal pathogens with biocontrol agents and their bio-products is a cost effective, environmental friendly and suitable alternative strategy for managing fungal phytopathogens, minimizing the need for synthetic chemical fungicides. Actinomycetota/Actinobacteria are globally accepted as a major contributor and potent biological control agents in controlling fungal plant diseases. The objective of this review is to evaluate the promising biocontrol efficacy of Actinomycetota in managing fungal pathogens causing diseases in forest plant species, an area that has received less attention compared to crops. It aims to highlight the importance of Actinomycetota, mechanisms of the biocontrol process against phytopathogens, the commercial applications of Streptomyces spp. as effective biocontrol agents and research trends, emphasizing their role as an environmentally sustainable alternative to synthetic fungicides. Additionally, the study identifies possibilities and provides recommendations for future research on Actinomycetota's potential as proficient biocontrol agents against fungal pathogens in forestry.

Occurrence, Farmer’s knowledge and Current Management Practices of Alternaria Leaf Spot in Kales, Kiambu county, Kenya

Alternaria Leaf Spot (ALS) significantly impacts kale production in Kenya, with high-quality and quantity losses reported in Kiambu County. This study assessed ALS occurrence, farmers' knowledge, and management practices in the Githunguri and Lari sub-counties. Data on demographics, farm characteristics, ALS incidence, and management were collected. Results showed ALS prevalence in 82% of fields, with 42.2% of farmers indicating it affects all growth stages. Most farmers (60% in Githunguri and 54% in Lari) relied on synthetic fungicides for control, yet 35.6% in Githunguri and 40% in Lari found them less effective. Multinomial logistic regression revealed that household head age, disease incidence, and total farm size were significant negative predictors of farmers' knowledge about ALS. Conversely, factors like the number of farming seasons per year, years of kale farming experience, training reception, and household members involved in farming positively influenced knowledge levels. The study concludes that while ALS is prevalent, reliance on chemical fungicides is common despite reported ineffectiveness, possibly due to improper use. Enhancing farmers' knowledge is essential for sustainable ALS management.

Identification of potent phytochemicals against Magnaporthe oryzae through machine learning aided-virtual screening and molecular dynamics simulation approach.

Identification of potent phytochemicals against Magnaporthe oryzae through machine learning aided-virtual screening and molecular dynamics simulation approach.

Evaluating the Antifungal Effectiveness of Three Plant Extracts in Controlling Panama Wilt in Banana Plants

Aims: This study aimed to evaluate the antifungal potential of Mikania micrantha, Senna alata, and Datura metel extracts against Fusarium oxysporum, the causal agent of Panama wilt in banana and to determine the optimal concentration of the most effective extract for fungal suppression. Study Design: Laboratory-based experimental research using in-vitro assays to assess the antifungal activity of selected plant extracts. Place and Duration of Study: The study was conducted at the Laboratory of the Institute for Agro-technology and Rural Sciences, University of Colombo, Sri Lanka, from February to July 2024. Methodology: The fungal pathogen was isolated from infected banana plant roots and cultured on Potato Dextrose Agar (PDA). Aqueous extracts of the plants were prepared and incorporated into PDA media. In Experiment 1, fungal colonies were exposed to five treatments: control (no application), M. micrantha extract, D. metel extract, S. alata extract, and a commercial fungicide. In Experiment 2, different concentrations (25%, 50%, 75%, and 100%) of the most effective extract from Experiment 1 were tested against Fusarium oxysporum. Fungal growth was monitored for seven days, and colony diameter measurements were statistically analyzed using SAS software, with Duncan’s Multiple Range Test at a 5% significance level. Results: Significant differences (p < 0.05) in fungal growth inhibition were observed among treatments. D. metel extract demonstrated the highest antifungal activity with a F. oxysporum growth inhibition of 68.4%, second only to the commercial fungicide (82.6%). The inhibitory effect was dose-dependent, with 100% D. metel extract achieving the highest suppression of F. oxysporum growth (77.9%), closely approaching the efficacy of the commercial fungicide. Conclusion: D. metel extract demonstrated strong antifungal potential against F. oxysporum, making it a promising alternative to chemical fungicides for managing Panama disease in bananas. Further research is needed to explore its field efficacy, mode of action, and possible integration with other biocontrol strategies for enhanced disease management.

Evaluation of the Effect of Different Fungicides on Potato Brown Leaf Spot Alternaria alternata in Greenhouse

One of the successful strategies to increase the yield of potatoes is the management of diseases and pests during the whole growing period. Potato brown spot caused by Alternaria alternata (Fr) Keissler is one of the most destructive diseases of potatoes worldwide. The present study compared two different fungicide programs under greenhouse conditions during 2022. Firstly, the resistance of five local potato varieties (Lora, Kofre-hemaloni, Kofre-Gibson, Evalovetion, and Morabell) was evaluated under greenhouse conditions to the pathogen to find the most susceptible variety for further experiment. The degree of infection by the pathogen was calculated. The study demonstrated that the Lora variety had the most tolerance, and the Morabell variety was sensitive to the pathogen. Then, the effects of three common chemical fungicides (Mancozeb®80%, Penconazole®20%, and Topguard®30% (Flutriafol (6.94% + tebuconazole (20.8%) were tested against the pathogen using the most sensitive potato variety (Morabell) in CRD (Completely Randomized Design) under greenhouse condition. The means of infection was calculated over ten days. Specific doses of the fungicides had a significant effect in reducing disease. The severity of the disease decreased with the increased use of all the applied fungicides. The study revealed that Mancozeb and Penconazole with 1g per liter doses were the most effective treatment in controlling brown leaf spots in potatoes.

Unlocking the Potential of <i>Pseudomonas aeruginosa</i> SWUC02: Cell-Free Supernatant and Extracts for Controlling Anthracnose Disease and Inducing Resistance in Yellow Chilli Seedling

Chilli anthracnose is a significant constraint in chilli production and quality in cultivated areas worldwide. Alternative methods are being explored to avoid the use of chemical fungicides, including plant elicitors produced by beneficial microorganisms to enhance plant defense responses. However, studies on the use of biotic elicitors to control chilli anthracnose are limited. In this study, we investigated the efficacy of cell-free supernatant derived from Pseudomonas aeruginosa SWUC02 (CF-SWUC02) and its extracts on the antimicrobial activity and systemic resistance in yellow chilli seedlings. The anthracnose pathogen, Colletotrichum truncatum CFPL01, was isolated and assessed for its pathogenicity in yellow chilli and other varieties, exhibiting varying levels of susceptibility to anthracnose. CF-SWUC02 exhibited potential antimicrobial activity against several phytopathogens. Furthermore, it affected the mycelial growth and conidial germination of virulent C. truncatum CFPL01. The dichloromethane extract exhibited the highest efficacy in suppressing the growth of C. truncatum CFPL01, while the ethyl acetate extract demonstrated a significant reduction in anthracnose severity on both leaves and seedlings. The ethyl acetate extract also increased phenylalanine ammonia-lyase activity in treated seedlings, demonstrating the induction of plant immunity. In summary, the elicitor compounds present in CF-SWUC02 have the potential to reduce anthracnose severity either directly through pathogen inhibition or indirectly via stimulation of the plant defense responses. These findings provide valuable insights for the development of sustainable and effective strategies for the control of chilli anthracnose.

Polyherbal nanoformulation: a potent antifungal agent on fungal pathogens of Coffea arabica

Agriculture is the backbone of all countries which dictates the major economy of the country. The management of pathogens is critical in the field of agriculture. Many species of pathogenic fungi infect a broad range of hosts including cash crops and agricultural crops. Coffee is one of the most important commercial crop in the economy of many countries in the world. Coffea arabica is infected by several fungal species and results in decrease in the quality and quantity of coffee berries. Infection of fungi in plants not only kills the plants and fruit yield but also affect human being through toxin intoxication. Chemical fungicides are the primary choice for the control of plant pathogenic fungi. However, these chemicals pollute the environment, disturb the normal flora, fauna and aquatic environment. The intake of fungicides through inhalation or ingestion results in serious health consequences including immunological, endocrinal, neurological, gynaecological, and carcinogenic effects. Hence, it is a challenge to find a novel alternative green solution to control both pathogenic fungi and to detoxify the fungal toxins. Green nanotechnology can be adopted to develop eco-friendly nanoformulation to control fungal pathogens. In this study, fungal pathogens were isolated from infected coffee plants and identified through sequencing. The novelty of the study stands on uniqueness of Polyherbal nanoformulation which was synthesized by using Triphala. Antifungal studies were carried out by using a developed Polyherbal nanoformulation. From the results, fungal pathogens were identified as Cladorrhinum flexuosum, Rigidoporus vinctus, Mucor circinelloides, Mucor lusitanicus, and Nigrospora oryzae. On treating these fungal pathogens with PHNF, the radial growth of fungal strains was effectively controlled even at lower concentration of 3.125 µg/ml. The specific contribution of PHNF is ‘synergism’ which plays a significant role in controlling the growth of tested fungal pathogens. On further exploration of PHNF in field conditions will help to optimize the dosage for the commercial development of nano based fungicide for the benefit of farmers as well as a solution to global problem. In addition, these PHNF can be formulated to nanosprays and nanomaterials to control the fungal growth during post-harvest condition.

Celery flavonoid-rich extract significantly reduces cucumber powdery mildew severity and enhances plant defense responses

This study assesses the antifungal efficacy of celery flavonoid-rich extract (CFRE) against cucumber powdery mildew, caused by Podosphaera fusca, in a controlled greenhouse setting. The application of CFRE at a concentration of 4 mg mL− 1 resulted in a remarkable 97% reduction in disease severity. High-performance liquid chromatographic (HPLC) analysis identified apigenin as the predominant flavonoid in CFRE. Furthermore, CFRE treatment induced a robust defense response in cucumber leaves, marked by elevated levels of flavonoids, phenolics, chlorophyll, and defense enzymes such as β-1,3-glucanase, chitinase, peroxidase, phenylalanine ammonia-lyase, and polyphenol oxidase. The study also observed upregulation in the expression of three investigated genes associated with β-1,3-glucanase, chitinase, and phenylalanine ammonia-lyase. Notably, a positive correlation was established between the activity of defense enzymes and their gene expression, as well as between defense enzymes and antioxidant compounds. These findings underscore the potential of CFRE as an environmentally benign alternative to chemical fungicides for managing P. fusca infections.

ОЦЕНКА ВЛИЯНИЯ ДВУХ ШТАММОВ ЭНДОФИТНЫХ БАКТЕРИЙ РОДА BACILLUS НА СОСТАВ ВНУТРЕННЕЙ МИКРОФЛОРЫ ФИТОФАГОВ ЯРОВОЙ ПШЕНИЦЫ

The article presents research materials on assessing the effect of treating spring wheat seeds and plants with biopreparations based on two endophytic bacteria Bacillus mojavensis PS17 and Bacillus amyloliquefaciens RECB-95 on the species composition and quantity of the internal microflora of such phytophages as wheat thrips (Haplothrips tritici) and striped grain flea beetle (Phyllotreta vittula). Spring wheat was cultivated in Laishevskiy district of the Republic of Tatarstan during three growing seasons from 2020 to 2022. The stationary field experiment design included the study of the following options: control (no treatment); seed treatment with PS17 at a dose of 0.5 l/t + plant spraying with PS17 at a dose of 0.5 l/ha; seed treatment with PS17 at a dose of 1.0 l/t + plant spraying with PS17 at a dose of 1.0 l/ha; seed treatment with PS17 at a dose of 1.5 l/t + plant spraying with PS17 at a dose of 1.5 l/ha; seed treatment with RECB-95 at a dose of 1.0 l/t + plant spraying with RECB-95 at a dose of 1.0 l/ha; seed treatment and plant spraying with chemical fungicides. The objects of the research were phytophagous insects (striped flea beetle and wheat thrips) living on spring wheat of Ulyanovskaya 105 variety. Wheat was cultivated in gray forest soil with the following agrochemical parameters: initial humus content of 3.2% (according to Tyurin), mobile phosphorus and potassium (according to Kirsanov) – 233-240 mg/kg of soil, and 176-189 mg/kg of soil, pH of salt - 5.7. The experiment was repeated three times, the plots were placed sequentially, the area of each plot was 110 m2. The system of primary and pre-sowing soil preparation included stubble cultivation, plowing, pre-sowing and post-sowing harrowing, pre-sowing application of azophoska at a dose of 150 kg/ha. During the studies, a decrease in the number of microorganisms in the body of the striped grain flea beetle was noted from 14.50 - 18.40 CFU×104 (in the untreated control variant) when using the PS17 strain to 0.10 - 0.20 CFU×104 (at a dose of 1.0 l/t) and to 4.73 CFU×104 when using the RECB-95 strain; in the body of the wheat thrips, an increase in the number of microorganisms was noted from 1.94 CFU×104 (in the untreated control variant) to 3.20 - 7.20 CFU×104 when using the RECB-95 strain. A change in the species composition of microorganisms, both fleas and thrips, was also noted when using both biological products.