Fusarium Spp Research Articles

Photodynamic antimicrobial therapy with Erythrosin B, Eosin Y, and Rose Bengal for the inhibition of fungal keratitis isolates: An in vitro study.

Fungal keratitis is a leading cause of corneal blindness, with current antifungal treatments having limited efficacy. One promising treatment modality is Rose Bengal (RB) photodynamic antimicrobial therapy (PDAT) that has shown mixed success against fungal keratitis. Therefore, there is a need to explore the antimicrobial efficacy of other green-light activated photosensitizers that have deep penetration in the cornea to combat the deep fungal infections, such as Erythrosin B (EB) and Eosin Y (EY). This study will explore PDAT inhibitory effects with different photosensitizers, RB, EB, and EY against two common fungal ocular isolates, Aspergillus spp. and Fusarium spp. Twelve fungal isolates (Fusarium spp., n=6, Aspergillus spp., n=6) were prepared in suspension for evaluation of growth inhibition to PDAT with three photosensitizers, EB, EY, and RB. Custom green light source (λ=518nm, energy density=5.4J/cm2) was applied to the experimental groups for 15min. Fungal growth inhibition was assessed after experimentation by analyzing the area of growth within the irradiated zone on agar plates. All twelve fungal isolates showed no inhibition to EB, EY, and RB without irradiation. Fusarium spp. were more susceptible to PDAT than Aspergillus spp. In all Fusarium solani strains, all photosensitizers with light showed full inhibition within the 47mm diameter irradiation zone. EB, EY, and RB PDAT demonstrated comparable antifungal inhibition against six Fusarium ocular isolates; these findings in conjunction with the deeper tissue penetration of EB and EY, are of interest to treat more advanced and deeper cases of fungal keratitis.

Diversity, characterization, and biotechnological potential of plant growth-promoting bacteria from Bryophyllum pinnatum (Lam.) (Crassulaceae) roots and rhizosphere soil.

Cultivable microbial communities associated with plants inhabiting extreme environments have great potential in biotechnological applications. However, there is a lack of knowledge about these microorganisms from Bryophyllum pinnatum (which survives in severely barren soil) and their ability to promote plant growth. The present study focused on the isolation, identification, biochemical characterization, and potential applications of root endophytic bacteria and rhizosphere bacteria. A total of 73 bacterial isolates were obtained, with 50 derived from rhizospheric soil and 23 from root tissue. The identified strains were categorized into 16 genera, with Bacillus, Priestia, Pseudarthrobacter, Neobacillus, Mesobacillus, and Arthrobacter being the most species-rich genera. Heat stress experiments indicated that almost half (50.7%) of the selected isolates were tolerant to heat stress. Furthermore, most strains present diverse capabilities for biotechnological applications, including the potential for indole-3-acetic acid (IAA) production, organic phosphorus solubilization, inorganic phosphorus solubilization, and nitrogen fixation. Some isolates (21.92%) exhibited broad-spectrum antagonistic activity against various phytopathogenic fungi, including Fusarium spp. Agar plate assays revealed that the Cellulomonas hominis strain LS43 and Bacillus inaquosorum strain LS77 significantly increased the total fresh weight of Arabidopsis (P < 0.05), yet these strains did not significantly affect the primary root length or the number of leaves. Notably, a subset of the strains tested did not significantly increase the growth of Arabidopsis and, in fact, had inhibitory effects on certain growth parameters. This is the first investigation highlighting the potential of root endophytic bacteria and rhizosphere bacteria in association with B. pinnatum in barren soils. Thus, these isolated strains positively influence plant nutrient uptake, stress resilience, and biocontrol to reduce chemical inputs in conventional agricultural practices, highlighting the importance of their development as biofertilizers for improving the quality of barren soil.

CRISPR/Cas12a-based method coupled with isothermal amplification to identify Alternaria spp. isolated from wheat grain samples.

Alternaria fungal species are considered major plant pathogens, infecting various crops and resulting in significant agricultural losses. Additionally, these species can contaminate grain with multiple mycotoxins that are harmful to humans and animals. Efficient pest management relies on timely detection and identification of phytopathogens in plant and grain samples, facilitating prompt selection of a crop protection strategy. Conventional identification tools, such as morphological characterization and identification based on polymerase chain reaction (PCR)-based methods, are time-consuming and laboratory-bound, limiting their implementation for on-site diagnostics essential in the agricultural industry. Isothermal amplification methods, including nucleic acid sequence-based amplification (NASBA), loop-mediated isothermal amplification (LAMP), and recombinase polymerase amplification (RPA), enable nucleic acid amplification at constant temperatures, making them ideal for point-of-care diagnostics without the need for thermal cycling equipment. Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 12a (Cas12a)-based identification, coupled with such isothermal amplification methods, represents an emerging nucleic acid-based technology for detecting plant pathogens at high accuracy and sensitivity. This study aimed to develop a CRISPR/Cas12a-based method integrated with RPA amplification for specific detection of Alternaria spp. isolated from wheat grain samples. The developed method targeted the β-tubulin gene was successfully identified Alternaria strains within a 20-min RPA amplification followed by a 30-min CRISPR/Cas12a reaction and visualization of results. Specificity test included pathogenic fungal species commonly hosted wheat grain, such as Fusarium spp. Bipolaris sorokiniana, and Nigrospora oryzae revealed high specificity of the method for Alternaria species. Furthermore, the method exhibited high sensitivity, detecting Alternaria DNA down to 100 copies, validated by real-time fluorescence readout. A fluorescence assay was employed to visualize the results of RPA and CRISPR/Cas12a reaction, demonstrating substantial implementation potential of the method in point-of-care detection of Alternaria spp. In conclusion, we present the CRISPR/Cas12a-based method as a potentially sustainable approach for the rapid, precise, and specific nucleic-acid-based identification of Alternaria species in grain samples.

Epidemiology and Prognostic Factors Associated With Mold-Positive Blood Cultures: 10-Year Data From a French Prospective Surveillance Program (2012-2022).

While invasive fusariosis and lomentosporiosis are known to be associated with fungemia, overall data on mold-related fungemia are limited, hampering early management. This study aimed to describe the epidemiology of mold-positive blood cultures. Epidemiological and clinical data on mold-positive blood cultures from 2012 to 2022 were obtained from the RESSIF database. Pseudofungemia was excluded using modified Duthie and Denning criteria. Univariable and multivariable Firth logistical regression was used to study factors associated with 90-day mortality. Fusarium spp accounted for 67.5% of the 80 events, involving predominantly Fusarium fujikuroi spp complex (FFSC), Neocosmospora spp, and Fusarium oxysporum spp complex (FOSC). Lomentospora prolificans was the second most frequent (10%), followed by Trichoderma spp, Aspergillus spp, and Mucorales (5% each).Most patients had a history of hematological malignancy (HM) (70%). Forty-three percent had undergone allogeneic hematopoietic stem cell transplantation. Cutaneous and pulmonary lesions were common (43% each). Median time to blood culture positivity was 72 hours.HM and neutropenia were commonly reported in patients with FFSC, Neocosmospora spp, and L. prolificans fungemia. Pulmonary lesions were frequent in cases of L. prolificans fungemia. Patients with gastrointestinal conditions were frequently diagnosed with FOSC molds. HM (75%), particularly acute myeloblastic leukemia, was frequent in patients with Aspergillus spp fungemia. All patients with Trichoderma spp fungemia were exposed to corticosteroids.Day 90 mortality was 53%. Independent predictive factors of day 90 mortality included L. prolificans (odds ratio [OR], 33.3), Aspergillus spp fungemia (OR, 14.2), and corticosteroid exposure (OR, 7.85). Underlying conditions and clinical presentation vary between genera and could be considered to guide early management.

Morphological and Molecular Characterization of Fusarium spp Associated with Solanaceous Seeds in Burkina Faso

Morphological and Molecular Characterization of Fusarium spp Associated with Solanaceous Seeds in Burkina Faso

Molecular Identification and Antifungal Susceptibility of Fusarium spp. Clinical Isolates.

Accurate identification of Fusarium species requires molecular identification. Treating fusariosis is challenging due to widespread antifungal resistance, high rates of treatment failure, and insufficient information relating antifungal susceptibility to the clinical outcome. Despite recent outbreaks in Mexico, there is limited information on epidemiology and antifungal susceptibility testing (AST). We aimed to analyse the distribution of Fusarium species from a referral centre in Mexico with DNA sequencing and to describe AST to the clinical outcome. We conducted a retrospective study on clinical isolates of Fusarium. They were identified by translation elongation factor-1α gene amplification and sequencing. AST was performed to determine minimal inhibitory concentrations (MICs). A total of 35 Fusarium isolates from 26 patients were included. The most common was Fusarium solani species complex (FSSC) in 51.5%, of which Fusarium petroliphilum and Fusarium oxysporum species complex were the most frequent with 37% and 20%, respectively. AST did not show MICs above the epidemiological cut-off value. Fusariosis was diagnosed in 19 patients, mostly with hematologic neoplasm; the overall mortality rate was 32%. Fusarium petroliphilum from the FSSC was found most frequently. Elevated mortality and MICs for all tested antifungals were found, with higher MIC50 among F. solani SC than F. oxysporum SC or F. fujikuroi SC.

The main diseases of spring wheat and the use of biofungicides in the northern Forest-Steppe of Ukraine

The purpose of the research was to identify the most common diseases of spring wheat grown in the Northern Forest-Steppe and to identify the most effective biological products used in the experiment against diseases of spring wheat. Methods. The experimental studies were conducted during 2021–2024 in the Northern Forest-Steppe in the field experiments of the Plant Protection Department of the National Research Center “Institute of Agriculture NAAS” in Chabany village, Fastiv district, Kyiv region. Object of research: spring wheat variety Rannіa 93. Weather conditions during the years of research contributed to the development of diseases. Results. As a result of the crops’ inspections, the following diseases were detected: powdery mildew (Blumeria grumines (DC.) Speer. (BLUMGR), leaf septoria (Septoria trittici Roberge ex Desm. (SEPTTR), ear blight (Sertoria nodorum (Berk.) Berk (SEPTNO), pyrenophora tritici-repentis (Died.) Drechsler and root rot (Fusarium (FUSASP), Bipolaris sorokiniana (Sacc.) Shoemaker (BIPOSO), Gaeumannomyces graminis (Sacc.) Arx &amp; L.L.Olivier (GAEUGR), Pseudocercosporella herpotrichoides (Fron) Deighton (PSEUHE), Alternaria spp. ) (ALT), Fusarium spp. (FUSASP), brown rust Puccinia recondita f. sp. tritici Rob. ex Desm (P. triticina Erikss). Conclusions. The growing seasons of 2021–2024 were favorable for the development of wheat diseases, but the effectiveness of biological products during the spring wheat growing season was low and at the end of the growing season was less than 30%. The surveys conducted after three treatments showed that there is no significant effectiveness in relation to the control in variants with the use of different biological products based on different active ingredients. When applying biological products during the growing season, spring wheat yielded 0.1-0.9 t/ha more than in the control. The highest yield increase was in the variant with the use of a mixture of Sporazin 2 l/ha + Phytophyt 0.05 l/ha + Biostimix 0.5 l/ha + Xampan 0.25 l/ha, Sporomax T 1- 2 kg/ha + Sporomax B 2 kg/ha + Xampan 0.25 l/ha. Thus, the preserved yield indicates that the treatment of spring wheat crops with biological products has a positive effect on plants. Therefore, the use of biofungicides in the protection of spring wheat requires further research, and the study of the protection problem remains relevant.

Bioprospecting of rhizobacteria with antagonistic activity against Fusarium spp., a parasite of cucumber (Cucumis sativus)

Objective: To identify bacteria of genus Bacillus which, isolated from the tomato and cucumber rhizosphere, have an antagonistic effect against Fusarium spp. isolated from cucumber plants in Culiacan, Sinaloa. Design/Methodology/Approach: Both the in vitro and in vivo antagonisms of rhizobacterial isolates against Fusarium spp. on cucumber plants were evaluated. Bacteria with the highest antagonistic effect were identified based on their morphological and molecular characteristics. Results: Isolates FA15 and FA16 showed the highest in vitro biological efficacy against Fusarium spp., with 50.0% and 61.36% inhibition of mycelial growth, respectively. Rhizobacterium FA15 achieved the highest biological efficacy (88.89%) against Fusarium spp. in cucumber plants, while rhizobacterium FA16 recorded a 59.27% efficacy. The morphological and molecular characterization of isolates FA15 and FA16 confirmed a 100% molecular identity between FA15 and Bacillus velezensis and FA16 and B. subtilis. Study Limitations/Implications: The rhizobacteria identified in this study inhibited the mycelial growth of the phytoparasite. Therefore, further studies about these rhizobacteria should be carried out to determine the potential antibiosis that may cause the inhibitory effect. Findings/Conclusions: During the search for native beneficial rhizobacteria, two bacteria that exercise a biologically-effective control over Fusarium spp were identified in Culiacan: Bacillus velezensis and B. subtilis. This finding offers an opportunity in the agricultural biotechnology field to study beneficial native species that could provide an alternative to the use of chemicals.

Effectiveness of Chemical Fungicides for the in vitro Control of Fusarium spp. Causing Basal Rot in Onion in Sinaloa, Mexico.

Objective: Identificar la efectividad in vitro de cinco fungicidas químicos, y el porcentaje de inhibición de crecimiento micelial de F. falciforme, F. brachygibbosum y F. oxysporum en la producción de cebolla. Design/methodology/approach: Los aislamientos se sometieron a una prueba de sensibilidad in vitro de cinco fungicidas con concentraciones de 1, 10, 100 y 1000 ppm en medio de cultivo PDA. Se transfirieron discos de 0.5 cm de diámetro de los aislamientos al centro de caja Petri que contenían el medio de cultivo impregnado con los fungicidas. Se estableció un diseño completamente al azar con cinco tratamientos y un testigo, con tres repeticiones por concentración. Se midió el crecimiento micelial y se calculó el porcentaje de inhibición de crecimiento micelial. Results: Se observó diferencia en el porcentaje de inhibición del micelio entre los fungicidas y las especies siendo tubeconazole el más efectivo. Además, se encontró que, a mayor dosis de fungicida, el porcentaje de inhibición micelial disminuye. El fungicida más efectivo para F. falciforme y F. brachygibbosum fue boscalid y verango a bajas concentraciones, y tubeconazole y tiabendazol a altas concentraciones. Para F. oxysporum boscalid y verango fueron más efectivos a bajas concentraciones. Findings/conclusions: En general, F. oxysporum mostró una mayor sensibilidad a todos los fungicidas.

Antagonistic effect of symbiotic bacteria from entomopathogenic nematodes and Bacillus spp. against Panax ginseng root rot pathogens

Ginseng root rot is a destructive disease of Panax ginseng that seriously affects the yield and quality of P. ginseng. Based on the broad-spectrum suppression properties of entomopathogenic nematode (EPN) symbiotic bacteria, four symbiotic bacteria were selected: Xenorhabdus bovienii (Xbf), Xenorhabdus nematophila (Xna), Xenorhabdus nematophila Cxrd (Xnc) and Xenorhabdus budapestensis (Xbc). Meanwhile, six beneficial Bacillus strains (Bacillus velezensis S1A; Bacillus amyloliquefaciens H4C; Bacillus subtilis N5D; and Bacillus albus HYS, K8, and N2A) were tested. Their individual and combined effects (both in vitro and in P. ginseng slices) on fungi pathogenic to P. ginseng, Fusarium solani, Fusarium proliferatum and Fusarium oxysporum were evaluated. Xenorhabdus budapestensis had the highest suppression effects (up to 82%) on F. solani and F. oxysporum, and a 60% inhibition rate on F. proliferatum, significantly higher than Xnc, Xbf and Xna. Bacillus velezensis and B. subtilis had the strongest suppression rates on F. solani (40%). The combined effects of Xbc and B. subtilis K8 on F. solani and F. oxysporum were stronger than their individual effects. The P. ginseng slice experiment further confirmed the enhanced inhibition of Fusarium by mixing Xbc with B. subtilis K8. In conclusion, we used EPN symbiotic bacteria to suppress P. ginseng root rot and screened two EPN symbiotic bacteria that were highly effective against Fusarium spp. The combination of Bacillus strains with EPN symbiotic bacteria enhanced the suppression effect. Our results provide new biological materials and directions for biological control of P. ginseng root rot.

Trichoderma viride: An Eco-Friendly Biocontrol Solution Against Soil-Borne Pathogens in Vegetables Under Different Soil Conditions

The use of biological methods to control plant diseases has garnered attention due to their eco-friendly and economically viable nature. Trichoderma spp. are the most ubiquitous fungal saprophytes that can often grow as opportunistic symbionts, are eco-friendly, and are not reported to exert any environmental hazard. Soil-borne pathogens can significantly impact the yield of chilli and tomato crops. The study was conducted to explore the impact of various salts (NaCl, MgCl2, CaCl2, and KCl) and their concentrations (1%, 5%, 10%, and 15%) on the mycelial growth and sporulation of Trichoderma viride followed by its mass multiplication on diverse organic substrates like wheat seeds, wheat husks, mungbean seeds, maize seeds, rice seeds, pea seeds, sorghum seeds, banana peel, apple peel, pomegranate peel, citrus peel, tomato waste, chilli waste, spinach waste, cabbage waste, potato peel, onion peel, cucumber peel, carrot peel, used black tea leaves, used green tea leaves, poultry waste, and cow and goat dung. The study assessed the biocontrol potential of Trichoderma viride against important soil-borne pathogens in chilli (Pythium aphanidermatum, Phytophthora capsici, and Fusarium oxysporum) and tomato (Pythium aphanidermatum, Phytophthora infestans, and F. oxysporum) cropping in the pot and field experiments using saline and alkaline soils. Seed treatment with T. viride significantly enhanced the germination rates of both chilli and tomato crops, with sorghum being the most conducive substrate for mass-multiplying T. viride. The results revealed that lower salt concentrations minimally affected T. viride growth, while higher concentrations hampered both growth and sporulation. Optimal disease control and plant height were observed at a 20 mg concentration of T. viride, consequently applied in vivo using various application methods, i.e., seed treatment, root dip, irrigation, and mixed treatments (all the methods like seed treatment, root dip method, and irrigation method applied together) to manage soil-borne pathogens. Particularly, T. viride application through irrigation and mixed treatments demonstrated strong efficacy. These findings underscore the potential of T. viride application in saline and alkaline soils to manage soil-borne pathogens like Pythium, Phytophthora spp., and Fusarium spp. This study lays the foundation for the practical application of biocontrol agents, like T. viride, in Pakistani agricultural conditions. Moreover, there is a need for further exploration into the genetic mechanisms involved in disease inhibition and plant growth promotion, along with understanding the impact of T. viride on the metabolic pathways of host plants.

Characterization of Trichoderma spp. and their antagonistic activity against soilborne fungi associated with chickpea wilt in Sinaloa, Mexico

Chickpea wilt, caused by a complex of soilborne fungi (Fusarium spp. Macrophomina phaseolina, Rhizoctonia solani, Sclerotium rolfsii, and Sclerotinia sclerotiorum), is the most important disease of chickpeas (Cicer arietinum) in Mexico. The aims of this study were to characterize Trichoderma isolates using a combination of phenotypic and molecular approaches and to evaluate their antagonistic activity against soilborne fungi associated with chickpea wilt. A total of 30 Trichoderma isolates were obtained from rhizospheric soil samples collected from chickpea fields in different locations of Sinaloa, Mexico. Dual confrontation assays showed the potential antagonistic effect of Trichoderma isolates against F. languescens, M. phaseolina, R. solani, S. rolfsii, and S. sclerotiorum. Five Trichoderma isolates (FAVF335, FAVF340, FAVF345, FAVF349, and FAVF351) exhibited mycelial growth inhibition of the five pathogens that ranged from 56 to 71%. These isolates were characterized using cultural, morphological, and molecular studies and tested in vivo for their ability to control soilborne pathogens in two chickpea cultivars (Blanco Sinaloa-92 and P2245) under greenhouse conditions. Phylogenetic analysis based on a combined ITS, EF-1α, and rpb2 sequence dataset identified T. afroharzianum (FAVF345, FAVF349, and FAVF351) and T. longibrachiatum (FAVF335 and FAVF340). Coating of chickpea seeds with T. longibrachiatum (FAVF335 and FAVF340) significantly reduced the disease severity and improved the plant growth-promoting attributes.

Nickel-doped zinc tartrate (Ni@ZnT) nanocrystals: Synthesis, optical properties, and antimicrobial activity

This work used the sol-gel method to synthesize nickel-doped zinc tartrate nanocrystals (Ni@ZnT NCs) to study their optical properties and antimicrobial activities. Using the Scanning electron microscopy study, these NCs show irregular-shaped morphology. Their crystalline nature and average crystalline size of 45 ​nm were studied by X-ray diffraction. Using an Energy-Dispersive X-ray confirmed the presence of zinc (Zn), nickel (Ni), carbon (C), hydrogen (H), and oxygen (O) elements. FTIR analysis was used to identify several functional groups like O–H stretching (3461.6 ​cm−1), CO stretching mode (2367.55 ​cm−1), and stretching vibrations of Ni–Zn–O (below 800 ​cm−1). The thermal stability was confirmed by thermogravimetric analysis. UV–Vis spectroscopy studied the optical properties; an absorption peak represents the Zn–Ni transition at about 336 ​nm and a band gap of 3.86 ​eV and was also used to calculate the refractive index and extinction coefficient at 280 ​nm. For ZnT and Ni@ZnT NCs, the maximum absorption λ was found to be 295 ​nm and 278 ​nm. The antibacterial activity of ZnT and Ni@ZnT NCs was evaluated against Bacillus subtilis and Escherichia coli; for these strains, the NCs (15.3 ​mm and 15.6 ​mm) showed a somewhat larger zone of inhibition than ZnT (13.6 ​mm and 12.3 ​mm). The study also evaluated the antifungal activity of these materials against some fungal strains, such as Penicillium chrysogenum, Aspergillus niger, Candida albicans, and Fusarium spp, the zone of inhibition varied from 12 to 13.6 ​mm, and there was a significant difference between the two materials. Therefore, this work successfully synthesized Ni@ZnT NCs and studied their optical properties and antimicrobial activity.

Bio-inhibitive corrosion effect of carica papaya leaf extract on cold-rolled mild steel in 0.1 M HCl solution

Plant extracts are prone to microbial growth that can lead to microbial-induced corrosion (MIC), a major setback for their performance and stability as corrosion inhibitors. Hence, this work aims to identify the microbes that may cause the ineffectiveness of carica papaya leaf extract (CPLE) as a bio-corrosion inhibitor of cold-rolled mild steel in 0.1 M HCl solution for 48 days at 28℃. Cold-rolled mild steel coupons were immersed in 100 ml of 0.1 M hydrochloric (HCl) acid solution containing 1 g, 2 g, 3 g, 4 g, and 5 g of carica papaya leaf extract (CPLE) for 48 days at 28℃. The gravimetric method was used to determine the coupons' corrosion rate (CR), surface coverage, and inhibition efficiency (IE%) of the CPLE. The functional groups in the CPLE were identified using Fourier Transform Infrared Spectroscopy (FTIR), and the surface appearance of the coupons after immersion was examined using an atomic force microscope (AFM). Gravimetric data showed the coupons dipped in a 0.1 M HCl solution containing 3 g/100 ml of the inhibitor exhibited the highest inhibition efficiency of 87.73%, surface coverage of 0.88, and lowest corrosion rate of 0.00255 mm/day or 0.93 mm/yr, after 48 days at 28℃. In FTIR, transmittance peaks occurred at 1558 cm−1 for amines (-NH) in alkaloid scissoring, 1452 cm−1 for aromatic -C = C in flavonoids, 2932 cm−1 for aliphatic methylene (-CH2) and aldehyde (RCOH) stretching, 1035 and 1077 cm−1 for aromatic-OR in tannin, and 3280 cm−1 for out-of-plane bending of hydroxyl (-OH) in phenolics. Vitamin C (522,940 μg/g), flavonoids (860 μg/g), saponins (637.9 μg/g), terpenoid (48.4 μg/g), phenol (120%μg/g), alkaloid (4.18 μg/g), tannin (59.84%), and glycosides (9.04%) make up the extract's average phytochemical content. AFM presents pits and ridges on the mild steel coupons immersed in 0.1 M HCl solution without the extract. Those immersed in the solutions with varying concentrations of the extract had a passive layer of the CPLE adhering to the surfaces of the coupons thereby preventing the coupon’s direct contact with the acid solution and weight loss. However, over time, microbial growth decreased the efficiency of CPLE due to metabolites. Microbial tests show creamy, irregular and raised bacterial total colony-forming units per gram (Tcfu/g) as 4.6 × 105 Tcfu/g and 1.9 × 107 Tcfu/g in 2 runs. Also, a mixture of white and fluffy appearance and spore formation of fungi population of 4.8 × 105 Tcfu/g and 3.2 × 107 Tcfu/g in 2 Runs made up of Penicillium spp, Coccidioides immitis, Aspergillus flavus, and Fusarium spp, with hyphae, were seen in the solutions containing CPLE.

Fusarium species associated with Bakanae Disease of Rice in Bangladesh.

Bakanae disease has become a serious threat for sustainable rice production in Asian countries including Bangladesh. Fusarium species are important seedborne pathogens that cause bakanae disease of rice. Typical bakanae symptomatic samples were collected through a series of sampling conducted in several districts of Bangladesh for 4 consecutive years from 2019 - 2022. The pathogens were confirmed using morphological characteristics, DNA sequences, and phylogenetic analyses of two genes, namely, translation elongation factor 1-alpha (TEF1-α), and RNA polymerase subunit II (RPB2). A total of 121 Fusarium isolates were recovered from diseased rice samples at different geographical locations. From the phylogenetics analyses of TEF1-α and RPB2 gene sequences coupled with morphological characterization revealed that the collected isolates belonged to five species viz. F. fujikuroi (75.2% isolation frequency), F. incarnatum (17.35%), F. commune (4.95%), F. verticillioides (1.65%), and F. proliferatum (0.82%). Phylogenetic analysis also showed that 28 representative strains were attributed to five species. Finally, four Fusarium spp. F. fujikuroi, F. commune, F. verticillioides and F. proliferatum were found to be pathogenic under virulence assays of the isolates. The pathogenicity test results demonstrated that F. fujikuroi caused typical symptoms of bakanae, leaf elongation and chlorosis, whereas F. proliferatum and F. verticillioides only caused stunting of seedlings and F. commune caused wilt and root rot. F. incarnatum was found to be associated with bakanae disease of rice, however their pathogenicity could not be established. This study provides insight into the diversity and pathogenicity of Fusarium populations associated with bakanae disease in Bangladesh, which will help in formulating effective strategies and policies for better control of the bakanae disease.

Genome-Wide Transcriptional Response of Avocado to Fusarium sp. Infection.

The avocado crop is relevant for its economic importance and because of its unique evolutionary history. However, there is a lack of information regarding the molecular processes during the defense response against fungal pathogens. Therefore, using a genome-wide approach in this work, we investigated the transcriptional response of the Mexican horticultural race of avocado (Persea americana var. drymifolia), including miRNAs profile and their possible targets. For that, we established an avocado-Fusarium hydroponic pathosystem and studied the response for 21 days. To guarantee robustness in the analysis, first, we improved the avocado genome assembly available for this variety, resulting in 822.49 Mbp in length with 36,200 gene models. Then, using an RNA-seq approach, we identified 13,778 genes differentially expressed in response to the Fusarium infection. According to their expression profile across time, these genes can be clustered into six groups, each associated with specific biological processes. Regarding non-coding RNAs, 8 of the 57 mature miRNAs identified in the avocado genome are responsive to infection caused by Fusarium, and the analysis revealed a total of 569 target genes whose transcript could be post-transcriptionally regulated. This study represents the first research in avocados to comprehensively explore the role of miRNAs in orchestrating defense responses against Fusarium spp. Also, this work provides valuable data about the genes involved in the intricate response of the avocado during fungal infection.

Efficacy of antibiotics and bactericides against Xanthomonas axonopodis pv. citri causing bacterial canker disease of acid lime (Citrus aurantifolia)

Diseases are the major constraints for citrus production which impede the fruit yield and quality. Citrus suffers from a number of diseases caused by fungi, bacteria, viruses and viriods. Among these diseases, canker caused by Xanthomonas axonopodis pv. citri, foot rot or gummosis caused by Phytophthora spp., twig blight caused by Diplodia natalensis and Fusarium spp. Three antibiotics and three bactericides viz., Streptocycline, Kasugamycin 5% + Copper oxychloride 45% WP, Kasugamycin, Bacterimycin, Copper oxychloride 50% WP, Copper hydroxide 53.8% W/W were evaluated for their effectiveness in controlling the growth of Xanthomonas axonopodis pv. citri at the Department of Plant Pathology, College of Agriculture, Ummendganj-Kota, (Agricultural University, Kota) Rajasthan. Inhibition was highest in case of copper oxychloride 50% WP (34.20 mm) followed by bronopol 27% (28.90 mm) and streptocycline 90% W/W (12.48 mm) at 500 ppm concentration and no inhibition zone was found in kasugamycin. All the antibiotics/bactericides inhibited bacterial growth at higher concentrations.

Innovative Use of Hermetia illucens Frass Extract as Priming to Promote Tomato and Wheat Growth and Protection

ABSTRACTFrass deriving from Hermetia illucens was explored as a new sustainable tool to induce biostimulation and/or antifungal activity in Solanum lycopersicum L. var Cerasiforme and Triticum durum Desf. var Simeto against the soil‐borne pathogens Fusarium spp. Phytotoxicity and in vitro antagonism assessments (mycelial growth inhibition of about 40%) allowed to define the optimal dilution of 10% of pasteurised‐frass extract (pFE) to employ for seed priming. Germination tests on water agar demonstrated the priming effectiveness for wheat, but not for tomato, as the analysed parameters were not positively affected. The pFE was used also in combination with the known biocontrol agent Trichoderma harzianum T22 (T22), demonstrating that they could work together to obtain a good growth promotion and protective effect in wheat. Indeed, the priming with pFE significantly reduced the disease incidence of almost 60% or 80%, compared to the infected control, if used alone or combined with T22, respectively. The ability of frass extract to control F. sporotrichioides in wheat was attributed to both enzymatic and non‐enzymatic responses, due to observed differences in total phenolic content (TPC) and superoxide dismutase activity (SOD) in seedlings derived from treated seeds, compared to untreated control. Our findings highlight the great potential of H. illucens frass as a sustainable, green, and circular economy‐based tool in agricultural systems.

Study of Fungal Organisms Associated with Smoked and Dried Fish Sold in Awka Markets, Anambra State

Fungal contamination of fish is considered as the major cause of spoilage and it constitutes a significant public health problem. This study was carried out to determine the fungal organisms associated with smoked and dried fish samples: Scomber scombrus (Mackerel), Sardinella longiceps (Sardine), Oreochromis niloticus (Tilapia), Clarias gariepinus (catfish), Gadus morhua (Stock fish), Ethmalosa fimbriata (Bonga fish), and Citharinus citharus (Mangala) sold in Awka markets, Anambra State, Nigeria. A total of fifty (50) (25 smoked and 25 dried) fishes were obtained from three markets in Awka and examined microbiologically for viable fungal infestation using Potato Dextrose Agar (PDA) media. A total of 121 fungal organisms were isolated from 25 smoked and 25 dried fish samples and identified. The isolated fungi were Mucor spp, Aspergillus niger, Aspergillus flavus, Penicillium spp, Fusarium spp and Rhizopus spp. It was observed that all the fish samples harboured multiple fungal organisms. Aspergillus niger was the fungus with the highest mean fungal count of 9.00±5.568, followed by Mucor spp (8.00±1.732), while Aspergillus flavus was the lowest (3.67±1.528). In the dried fish samples, Gardus morhua (stock fish) had the highest infestation with fungi (1.08±1.083), while in smoked fish, Clarias gariepinus (catfish) had the highest infestation. The high level of fungal contamination can be attributed to poor handling of fish and the environment. Considering the danger to public health, food and safety authorities should intensify their monitoring efforts towards controlling fish contamination, and fish sellers should also be sensitized on hygienic fish handling techniques.

Effect of Temperature, Relative Humidity, and Incubation Time on the Mycotoxin Production by Fusarium spp. Responsible for Dry Rot in Potato Tubers.

Potato is the fourth most consumed crop in the world. More than half of the crop is stored for three to nine months at cold temperatures (3-10 °C) for the fresh and seed market. One of the main causes of fresh potato waste in the retail supply chain is the processing of fungal and bacterial rots during storage. Dry rot is a fungal disease that mainly affects the potato crop during storage and is responsible for 1% of tuber losses in the UK. It is produced by Fusarium spp., such as Fusarium sambucinum and F. oxysporum, which can lead to the accumulation of mycotoxins in the potato tuber. Little is known about the impact of environmental factors on the accumulation of mycotoxins in potato tubers. Understanding the ecophysiology of these fungi is key to mitigating their occurrence under commercial storage conditions. Therefore, this work aimed to elucidate the effect of three different temperatures (5, 10, and 15 °C) and two different water activities (aw; 0.97, 0.99) on the ecophysiology and mycotoxin accumulation of F. sambucinum and F. oxysporum in a potato-based semi-synthetic medium. The mycotoxin accumulation was then studied in vivo, in potato tubers cultivated under organic farming conditions, stored for 40 days at 8.5 °C. Results showed that higher temperatures and aw enhanced fungal growth, lag time, and mycotoxin accumulation in vitro. Growth rate was 2 and 3.6 times higher when the temperature increased from 5 to 10 and 15 °C, respectively. Six different mycotoxins (T-2, HT-2, diacetoxyscirpenol, 15-acetoxyscirpenol, neosolaniol, and beauvericin) were detected in vitro and in vivo. T-2 was the most abundant mycotoxin detected in vitro, observing 106 ng of T-2/g media after 21 days of incubation at 10 °C and 0.99 aw. Due to the long period of time that potato tubers spend in storage, the fluctuations of environmental factors, such as temperature and relative humidity, could promote the development of fungal rot, as well as mycotoxin accumulation. This could result in important food and economic losses for the potato market and a threat to food safety.