Search Results (80)

Culinary melon (Cucumis melo subsp. agrestis var. conomon) is widely cultivated throughout Thailand and represents an important agricultural crop. During 2023–2024, anthracnose, charcoal rot, and fruit rot caused by fungi were observed on postharvest culinary melon fruits in northern Thailand. This study aimed to isolate and identify fungal pathogens associated with these postharvest diseases in culinary melons, as well as to assess their pathogenicity. Eight fungal strains were isolated and identified through morphological characterization and multi-gene phylogenetic analysis. Colletotrichum chlorophyti and C. siamense were identified as the causal agents of anthracnose, Fusarium sulawesiense caused fruit rot, and Macrophomina phaseolina was responsible for charcoal rot. Pathogenicity tests were conducted, and the fungi were successfully re-isolated from the symptomatic lesions. Moreover, sensitivity tests for fungicides revealed that C. siamense was completely inhibited by copper oxychloride and copper hydroxide. Colletotrichum chlorophyti was inhibited by benalaxyl-M + mancozeb, copper hydroxide, and mancozeb. In the case of M. phaseolina, complete inhibition was observed with the use of benalaxyl-M + mancozeb, mancozeb, and propineb. Copper hydroxide successfully inhibited F. sulawesiense completely. To our knowledge, this study is the first to report C. siamense and C. chlorophyti as causes of anthracnose, F. sulawesiense as a cause of fruit rot, and M. phaseolina as a cause of charcoal rot in postharvest culinary melon fruits in Thailand. It also marks the first global report of C. siamense, M. phaseolina, and F. sulawesiense as causal agents of these respective diseases in culinary melon. Furthermore, the results of the fungicide sensitivity tests provide valuable information for developing effective management strategies to control these postharvest diseases in the future. Full article

Soilborne diseases cause losses of 45–70% in faba bean in Ethiopia. Studies were undertaken to define soilborne pathogens and their complexes in Ethiopia. First, the severity of root rot was assessed in 150 field sites across seven Ethiopian regions. Soil samples were collected, and the DNA of 29 pests and pathogens was quantified using a commercial quantitative PCR (qPCR) soil testing service. There was a very high incidence rate of Macrophomina phaseolina, as well as Pythium clades F and I. The other detected species in order of incidence included Fusarium redolens, Rhizoctonia solani, Aphanomyces euteiches, Phytophthora megasperma, Sclerotinia sclerotiorum and S. minor, and Verticillium dahliae, as well as low levels of Thielaviopsis basicola. Five anastomosis groups (AG) of R. solani, namely AG2.1, AG2.2, AG3, AG4, and AG5, were detected, of which AG2.2 and AG4 were most prevalent. We believe this is the first report of occurrence for Ethiopia of A. euteiches, Ph. megasperma, T. basicola, and the five AGs for R. solani. There were very high incidence rates of the foliar pathogens Botrytis cinerea, B. fabae, Didymella pinodes, and Phoma pinodella and of the nematode Pratylenchus thornei, followed by P. neglectus and P. penetrans. The root rot severity and distribution varied significantly across regions, as well as with soil types, soil pH, and soil drainage. Subsequently, metabarcoding of the soil DNA was undertaken using three primer pairs targeting fungi (ITS2), Fusarium species (TEF1 α), and Oomycetes (ITS1Oo). The ITS2 and TEF1α primers emphasized F. oxysporum as the most abundant soilborne fungal pathogen and highlighted F. ananatum, F. brachygibbosum, F. brevicaudatum, F. clavum, F. flagelliforme, F. keratoplasticum, F. napiforme, F. nelsonii, F. neocosmosporiellum, F. torulosum, and F. vanettenii as first reports of occurrence for Ethiopia. The ITS1Oo primer confirmed Pythium spp. as the most prevalent of all Oomycetes. Full article

The use of chemical pesticides has led to adverse effects on human health and the environment, prompting the exploration of alternative solutions. This study successfully biosynthesized iron oxide nanoparticles (Fe₃O₄ NPs) using chicken egg albumin, which served as reducing and capping agents, and evaluated their antifungal efficacy against Macrophomina phaseolina. The fungicidal potential of Fe₃O₄ NPs was assessed in vitro, demonstrating enhanced inhibition of M. phaseolina’s radial growth with increasing concentrations from 100 ppm to 300 ppm. Dielectric properties were also studied, revealing advantageous current conduction processes and conductive network development with temperature variation, which is particularly beneficial in the low-frequency range. At a fixed pH, dielectric studies showed increased mobile carrier movement and polarization with rising temperature at a fixed frequency. The photocatalytic activity of Fe₃O₄ NPs was assessed for the degradation of methylene blue (MB), an organic dye, under solar irradiation. In this study, Fe₃O₄ NPs photocatalysts achieved 89% (MB) degradation within 75 min. This research underscores the potential of using chicken egg albumin for the biosynthesis of Fe₃O₄ NPs. It offers a promising alternative for plant disease control and highlights their suitability for integration into eco-friendly plant protection strategies. Full article

Soil-borne diseases, including charcoal rot (Macrophomina phaseolina) and collar rot (Sclerotium rolfsii), threaten global soybean production. Four fungicide combinations were tested as seed treatments at three concentrations (1, 1.5, and 2 g or ml per kg of seed) under controlled conditions to address the challenges posed by these diseases. Under controlled conditions, the combination of thiophanate methyl + pyraclostrobin at a rate of 2 mL/kg of seed significantly alleviated disease symptoms caused by both pathogens. Additionally, it enhanced shoot and root weights by over 50% in plants affected by S. rolfsii. Field trials were conducted for two years at two distinct locations to assess the efficacy of three selected combination seed treatment fungicides against M. phaseolina and S. rolfsii. Both inoculated and uninoculated controls were included for the comparison. Among the fungicides, thiophanate-methyl + pyraclostrobin and trifloxystrobin + penflufen proved the most effective for suppressing both diseases under epiphytotic field conditions across the years and locations. This study also highlighted the benefits of these chemical combinations in enhancing agronomic traits, maintaining yield, and ensuring the economic viability of soybeans. Full article

Wood distillate (WD), also known as pyroligneous acid, is a liquid byproduct of charcoal production. It has antimicrobial and antifungal properties thanks to its combination of over 200 components, including organic acids, polyphenols, tannins and others. In this work, microcapsules containing WD coated with chitosan or chitosan and micronized biochar were developed, and their efficacy was tested against the soil-borne fungal pathogen Macrophomina phaseolina. The three products used fit into a circular economy model, and these bio-based microcapsules can be used to promote sustainable agricultural practices. The microencapsulation of WD was carried out via an ion-exchange gelation method, using sodium alginate as the polymer. WD microencapsulation and coating formation were successfully performed, resulting in microcapsules with a size between 600 and 700 µm when dried. Three types of WD microcapsules were produced: uncoated, chitosan-coated and chitosan–biochar-coated. Solubility tests were conducted by measuring the pH of each type of microcapsule in distilled water. It was observed that their solubilization trends were different depending on the type of microcapsules. In vitro growth of M. phaseolina on PDA plates was completely inhibited using WD concentrations of 3–5%. Furthermore, when WD microcapsules were added to a liquid culture medium, those coated with chitosan and biochar induced a significant reduction in M. phaseolina growth. Full article

Regenerative agriculture aims to improve soil quality and restore soil biodiversity, re-establishing natural systems in agricultural areas. Among some strategies, it is important to reduce the use of chemical pesticides that affect the productive capacity of the soil and cause problems to the environment. Based on this necessity, we present a strategy of producing a single product with bioinsecticidal and biofungicidal effects by submerged co-cultivations and paired cultivations of Beauveria bassiana, Metarhizium anisopliae, and Trichoderma harzianum using different concentrations of glucose, sucrose, hydrolyzed animal protein (HAP), soybean meal hydrolysate plus organic phosphorus (SMH), and hydrolyzed feathers (HF) as renewable nutrients. The single cultivations and double and triple co-cultivations were carried out for 7 days at 28 °C in orbital agitation at 120 rpm. Most of the highest values of conidia were obtained in the treatments at the central point, in which (g L⁻¹) glucose (20), sucrose (10), HAP (7.5), SMH (2.5), and HF (2.5) were used. The fermented broths were applied to the backs of adult bugs (Euschistus heros), which mostly provided 66–88% mortality. Beauveria bassiana + Metarhizium anisopliae showed approximately 70% inhibition against Sclerotinia sclerotiorum and Macrophomina phaseolina. As a way forward, this product demonstrated integrated bioactivities as insecticide and fungicide and can be optimized to substitute chemical pesticides that have negative impacts on the environment. Full article

Strawberry crown and root rot diseases are caused by soil-borne pathogens including Macrophomina phaseolina (Mp) and Verticillium dahliae (Vd). The symptoms caused by these pathogens are very similar and difficult to distinguish, and traditional culture-based detection methods are laborious, time-consuming, and slow in providing results. In this work, we developed a duplex PCR-NALFIA assay using two pairs of species-specific primers labeled at the 5′ end with different molecules for the simultaneous identification of Mp and Vd. For the NALFIA assay, a lateral flow device (LFD) for the detection of two analytes was used. The method was developed by single and duplex PCR (Mp, Vd, Mp + Vd) using increasingly complex biological systems: (i) DNA from pure cultures of the pathogens; (ii) DNA from artificially inoculated cut melon stems; and (iii) DNA from artificially inoculated strawberry plants cv. Aromas. The duplex PCR protocol was effective in detecting the two pathogens within melon tissues and provided good results with strawberry crown tissues only when the DNA samples were purified by removing the PCR inhibitors. The amplicons were used for both agarose gel electrophoresis (AGE) and NALFIA assays and demonstrated the greater sensitivity of the NALFIA assay (10 pg) for simultaneous detection of the two pathogens. Full article

Background: Macrophomina phaseolina is an important phytopathogenic fungus affecting over 500 plant species worldwide. However, this fungus rarely causes disease in humans. Methods: We reported the first case of endophthalmitis due to M. phaseolina, describing microbiological diagnostic approaches. Also, we performed a systematic review of human infections by this plant pathogen in literature. We searched PubMed, Scopus, and Web of Science databases from inception to 31 December 2024. Results: Our case involved a male patient who presented with photophobia and pain in his right eye. His recent medical history revealed a superficial corneal injury caused by a metal burr three months prior, managed unsuccessfully by topical treatment and subsequent conjunctival flap surgery two months later. Ophthalmological and microbiological investigations, including microscopic examination, cultures, and DNA sequencing of ocular specimens, revealed M. phaseolina endophthalmitis. Despite intravenous and intravitreal antifungal therapy, the patient’s condition continued to worsen, eventually leading to enucleation. Regarding the literature review, we identified 12 additional cases of M. phaseolina human infections previously reported in literature. Overall, M. phaseolina was primarily associated with ocular infections (76.9% of cases), followed by skin infections and combined skin–joint infections. The majority of patients with M. phaseolina infection (63.6%) had no known immunosuppressive factors. Clinical outcomes were unfavorable in 46.15% of cases. Conclusions: M. phaseolina is an emerging cause of human infections, even in immunocompetent hosts, with a predilection for ocular infections. Further research is warranted to elucidate the pathogenesis of fungal infections caused by plant pathogens in humans. Full article

The development and standardization of an effective inoculation technique are essential for reliable screening of crop genotypes. In this study, three inoculation methods—in vitro paper towel, in vitro agar, and soil inoculation in pots—were tested to evaluate the pathogenic potential of Macrophomina phaseolina, the causative agent of dry root rot (DRR). Since the pathogenicity of M. phaseolina is influenced by environmental factors, identifying a robust inoculation method is critical. Among the three techniques, the paper towel inoculation method resulted in the highest seedling mortality of 66.66% in cluster beans and 86.67% in cowpeas within just ten days, demonstrating its effectiveness. The agar inoculation technique, while successful, required 15 days to confirm pathogenicity, with seedling mortality rates of 63.33% for cowpeas and 53.33% for cluster beans. In contrast, the soil inoculation method showed comparatively lower mortality rates, with 36.66% for cluster beans and 26.67% for cowpeas. Based on these findings, the paper towel method emerged as the most efficient technique for inducing rapid pathogenicity in M. phaseolina in both cowpeas and cluster beans. Its suitability was further validated through the screening of released varieties of these crops compared against the soil inoculation method. Notably, genotypes that appeared moderately resistant under the soil inoculation method were found to range from susceptible to highly susceptible when evaluated using the paper towel technique. These results underscore the reliability of the paper towel method as a rapid and robust screening tool for identifying resistant genotypes of cowpea and cluster bean on a larger scale. Full article

Macrophomina phaseolina is a vital seed and soil-borne phytopathogen responsible for substantial crop yield losses. Although various methods exist for managing soil-borne pathogens, such as agronomic practices, chemical treatments, and varietal tolerance, biological control utilizing plant growth-promoting rhizobacteria (PGPR) or their secondary metabolites presents promising avenues. In this study, a screening of 150 isolates from the rhizosphere of Vigna radiata L. was conducted to identify strains capable of promoting host growth and controlling charcoal rot disease. Among the tested isolates, only 15 strains demonstrated the ability to produce plant growth-related metabolites, including indole acetic acid, hydrogen cyanide, ammonia, and lytic enzymes, and solubilize inorganic phosphate. Subsequently, these potent strains were evaluated for their antifungal activity against Macrophomina phaseolina in vitro. Three strains, namely MRP-7 (58% growth inhibition), MRP-12 (55% growth inhibition), and MRP-8 (44% growth inhibition), exhibited the highest percent growth inhibition (PGI.). Furthermore, a pot experiment demonstrated that the selected strains acted as effective growth promoters and ROS (reactive oxygen species) scavengers, and served as potential biocontrol agents, significantly reducing the incidence of charcoal rot disease and improving various agronomic attributes of the host plant. These findings highlight the potential of these strains to be utilized as biofertilizers and biocontrol agents for sustainable agricultural practices. Full article

Astragalus membranaceus is a famous traditional medicinal plant. However, drought and cadmium (Cd) pollution are the main abiotic stress factors that affect plant growth and yield and the ability to improve the host’s stress resistance through the use of beneficial endophytic fungi. To evaluate the tolerance of dark septate endophytes (DSE) to various abiotic stresses, 10 DSE strains [Microsphaeropsis cytisi (Mc), Alternaria alstroemeriae (Aa), Stagonosporopsis lupini (Sl), Neocamarosporium phragmitis (Np), Paraphoma chlamydocopiosa (Pc), Macrophomina phaseolina (Mp’), Papulaspora equi (Pe), Alternaria tellustris (At), Macrophomina pseudophaseolina (Mp), and Paraphoma radicina (Pr)] were investigated under different drought and Cd stressors in vitro by using solid-plate cultures and liquid-shaker cultures in the current study. The experiments involved using varying concentrations of PEG (0, 9, 18, and 27%) and Cd²⁺ (0, 25, 50, and 100 mg/L) to simulate different stress conditions on DSE. Additionally, the effect of DSE (Np and At) on the growth of A. membranaceus at different field water capacities (70% and 40%) and at different CdCl₂ concentrations (0, 5, 10, and 15 mg Cd/kg) in soil was studied. The results demonstrated that the colony growth rates of Aa, Np, Pc, Mp’, and Mp were the first to reach the maximum diameter at a PEG concentration of 18%. Aa, Np, and At remained growth-active at 100 mg Cd/L. In addition, Aa, Np, and At were selected for drought and Cd stress tests. The results of the drought-combined-with-Cd-stress solid culture indicated that the growth rate of Np was significantly superior to that of the other strains. In the liquid culture condition, the biomasses of Np and Aa were the highest, with biomasses of 1.39 g and 1.23 g under the concentration of 18% + 25 mg Cd/L, and At had the highest biomass of 1.71 g at 18% + 50 mg Cd/L concentration, respectively. The CAT and POD activities of Np reached their peak levels at concentrations of 27% + 50 mg Cd/L and 27% + 25 mg Cd/L, respectively. Compared to the control, these levels indicated increases of 416.97% and 573.12%, respectively. Aa, Np, and At positively influenced SOD activity. The glutathione (GSH) contents of Aa, Np, and At were increased under different combined stressors of drought and Cd. The structural-equation-modeling (SEM) analysis revealed that Aa positively influenced biomass and negatively affected Cd content, while Np and At positively influenced Cd content. Under the stress of 40% field-water capacity and the synergistic stress of 40% field-water capacity and 5 mg Cd/kg soil, Np and At significantly increased root weight of A. membranaceus. This study provides guidance for the establishment of agricultural planting systems and has good development and utilization value. Full article

Essential oils (EOs) are natural products widely used in sustainable agrochemistry, not only because they are biodegradable and safe but also because they are regarded as alternatives to chemical fungicides against fungal species that attack crops. Allelopathy, another field of study, falls within the most recent and sustainable strategies applied to weed suppression to replace synthetic herbicides. Therefore, this study reports the chemical composition and allelopathic and antifungal effects of the EOs extracted from Calyptranthes concinna dried leaves (Cc-EO) and its pure major constituent elemicin. Their antifungal activities were evaluated by the disk diffusion method (DDM) at doses between 0.05 mg/mL and 0.4 mg/mL of Cc-EO and elemicin. The allelopathic effect was evaluated by studying the inhibition of germination and the growth of Lactuca sativa seeds. The chemical composition of Cc-EO was determined by GC-MS and GC-FID analyses. The major constituents of Cc-EO were elemicin (60.5%), α-cadinol (9.0%) and caryophyllene oxide (8.3%). Cc-EO and elemicin were assayed in vitro against 17 fungi of agronomic interest (Aspergillus niger, A. flavus, A. nomius, Penicillium digitatum, P. expansum, Sclerotinia sclerotiorum, S. rolfsii, S. minor, Fusarium graminearum, Myrothecium verrucaria, Corynespora cassiicola, Erwinia psidii, Colletotrichum musae, Alternaria carthami, Rhizoctonia solani, Rhizopus stolonifer and Macrophomina phaseolina). The concentration of Cc-EO (0.4 mg/mL) inhibited 100% of the mycelium growth of seven strains, equal to the fungicide fluazinam, which was used as a positive control. Elemicin showed antifungal activity against all fungi at all concentrations under investigation (above 50%). A strong allelopathic effect was recorded for Cc-EO and elemicin at the dose of 0.28 mg/mL, with the almost total inhibition of germination. This study revealed, for the first time, the strong and remarkable fungicidal and allelopathic effects of Cc-EO and elemicin, an important finding for the agrochemical field. Full article

Zinc oxide nanoparticles (ZnO NPs) exhibit diverse applications, including antimicrobial, UV-blocking, and catalytic properties, due to their unique structure and properties. This study focused on the characterization of zinc oxide nanoparticles (ZnO NPs) synthesized from Juglans regia leaves and their application in mitigating the impact of simultaneous infection by Meloidogyne arenaria (root-knot nematode) and Macrophomina phaseolina (root-rot fungus) in cowpea plants. The characterization of ZnO NPs was carried out through various analytical techniques, including UV–visible spectrophotometry, Powder-XRD analysis, FT-IR spectroscopy, and SEM-EDX analysis. The study confirmed the successful synthesis of ZnO NPs with a hexagonal wurtzite structure and exceptional purity. Under in vitro conditions, ZnO NPs exhibited significant nematicidal and antifungal activities. The mortality of M. arenaria juveniles increased with rising ZnO NP concentrations, and a similar trend was observed in the inhibition of M. phaseolina mycelial growth. SEM studies revealed physical damage to nematodes and structural distortions in fungal hyphae due to ZnO NP treatment. In infected cowpea plants, ZnO NPs significantly improved plant growth parameters, including plant length, fresh mass, and dry mass, especially at higher concentrations. Leghemoglobin content and the number of root nodules also increased after ZnO NP treatment. Additionally, ZnO NPs reduced gall formation and egg mass production by M. arenaria nematodes and effectively inhibited the growth of M. phaseolina in the roots. Furthermore, histochemical analyses demonstrated a reduction in oxidative stress, as indicated by decreased levels of reactive oxygen species (ROS) and lipid peroxidation in ZnO NP-treated plants. These findings highlight the potential of green-synthesized ZnO NPs as an eco-friendly and effective solution to manage disease complex in cowpea caused by simultaneous nematode and fungal infections. Full article

Trunk canker poses a major threat to the production of Chinese hickory tree (Carya cathayensis Sarg.), which is primarily determined by Botryosphaeriaceae. In our previous work, we identified Botryosphaeria dothidea as the predominant pathogen of this disease. However, it is still unclear about corresponding gene families and mechanisms associated with B. dothidea’s pathogenicity on Chinese hickory tree. Here, we present a comparative analysis of high-quality genome assemblies of Botryosphaeria dothidea and other isolated pathogens, showing highly syntenic relationships between B. dothidea and its closely related species and the conservative evolution of the Botryosphaeriaceae family. Higher GC contents were found in the genomes of B. dothidea and three other isolated pathogens (Botryshaeria cortices, Botryshaeria fabicerciana, and Botryshaeria qingyuanensis) compared to Macrophomina phaseolina, Neofusicoccum parvum, Diplodia corticola, and Lasiodiplodia theobromae. An investigation of genes specific to or expanded in B. dothidea revealed that one secreted glucanase, one orsellinic acid biosynthesis enzyme, and two MFS transporters positively regulated B. dothidea’s pathogenicity. We also observed an overrepresentation of viral integrase like gene and heterokaryon incompatibility proteins in the B. dothidea’s genome. In addition, we observed one LRR-domain-containing protein and two Sec-domain-containing proteins (Sec_1 and Sec_7) that underwent positive selection. This study will help to understand B. dothidea’s pathogenicity and potential influence on the infection of Chinese hickory, which will help in the development of disease control and ensure the security of Chinese hickory production. Full article

The biosynthesis of silver nanoparticles (AgNPs) using plant extracts has become a safe replacement for conventional chemical synthesis methods to fight plant pathogens. In this study, the antifungal activity of biosynthesized AgNPs was evaluated both in vitro and under greenhouse conditions against root rot fungi of common beans (Phaseolus vulgaris L.), including Macrophomina phaseolina, Pythium graminicola, Rhizoctonia solani, and Sclerotium rolfsii. Among the eleven biosynthesized AgNPs, those synthesized using Alhagi graecorum plant extract displayed the highest efficacy in suppressing those fungi. The findings showed that using AgNPs made with A. graecorum at a concentration of 100 μg/mL greatly slowed down the growth of mycelium for R. solani, P. graminicola, S. rolfsii, and M. phaseolina by 92.60%, 94.44%, 75.93%, and 79.63%, respectively. Additionally, the minimum inhibitory concentration (75 μg/mL) of AgNPs synthesized by A. graecorum was very effective against all of these fungi, lowering the pre-emergence damping-off, post-emergence damping-off, and disease percent and severity in vitro and greenhouse conditions. Additionally, the treatment with AgNPs led to increased root length, shoot length, fresh weight, dry weight, and vigor index of bean seedlings compared to the control group. The synthesis of nanoparticles using A. graecorum was confirmed using various physicochemical techniques, including UV spectroscopy, Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS) analysis. Collectively, the findings of this study highlight the potential of AgNPs as an effective and environmentally sustainable approach for controlling root rot fungi in beans. Full article