Fungal Samples Research Articles

The Mycobiota Diversity Associated with Mistletoe (Viscum album L.) in Poland

The spread of mistletoe, which mainly affects Scots pine in Europe’s managed forests, has become a serious ecological and economic problem, exacerbated by climate change and drought stress. Research into mistletoe-associated mycobiota provides crucial insights into the biology, ecology and distribution of these fungi and forms the basis for sustainable plant protection and effective management strategies. The aim of this study was to identify the fungal species associated with mistletoe (Viscum album L.) at 75 sites across Poland, with a focus on the northeastern regions of the country. The field work included a systematic and targeted search using the transect method, followed by laboratory analysis, during which fungal samples were prepared and examined under both light and scanning electron microscopes. The genetic analysis was carried out using ITS sequencing to confirm the presence of pathogen-specific fungi in the majority of V. album samples examined. The results showed four fungal species associated with the mycobiota of mistletoe: Sphaeropsis visci, Plenodomus visci, Cylindrodendrum hubeiense and Septoria krystynae. It is noteworthy that two of these species (P. visci and C. hubeiense) have not yet been detected in Poland. Based on these findings, the distribution areas of the identified fungal species were mapped accordingly.

Improving signal-to-noise ratio of Raman measurements based on ensemble learning approach.

Raman spectroscopy is an extensively explored vibrational spectroscopic technique to analyzethebiochemical composition and molecular structure of samples, which is often assumed to be non-destructive when carefully using proper laser power and exposure time. However, the inherentlyweak Raman signal and concurrent fluorescence interference often lead to Raman measurements withalow signal-to-noise ratio (SNR), especially for biological samples. Great efforts have been made to develop experimental approaches and/or numerical algorithms to improvetheSNR. In this study, we proposed an ensemble learning approach to recover and denoise Raman measurements withalow SNR. The proposed ensemble learning approach was evaluated on 986 pairs of Raman measurements, each pair of which consists of a low SNR Raman spectrum and a high SNR reference Raman spectrum from the exact same fungal sample but uses 200 timestheintegration time. Compared with conventional methods, the Raman measurementsrecoveredby the proposed ensemble learning approach are more identical to high SNR reference Raman measurements, with anaverage RMSE and MAE of only 1.337 × 10-2 and 1.066 × 10-2, respectively; thus, the proposed ensemble learning approach is expected to be a powerful tool for numerically improving the SNR of Raman measurements and further benefits rapid Raman acquisition from biological samples.

Highly Specific and Rapid Multiplex Identification of Candida Species Using Digital Microfluidics Integrated with a Semi-Nested Genoarray.

Candida species are the most common cause of fungal infections around the world, associated with superficial and even deep-seated infections. In clinical practice, there is great significance in identifying different Candida species because of their respective characteristics. However, current technologies have difficulty in onsite species identification due to long turnover time, high cost of reagents and instruments, or limited detection performance. We developed a semi-nested recombinase polymerase amplification (RPA) genoarray as well as an integrated system for highly specific identification of four Candida species with a simple design of primers, high detection sensitivity, fast turnover time, and good cost-effectiveness. The system constructed to perform the assay consists of a rapid sample processing module for nucleic acid release from fungal samples in 15 min and a digital microfluidic platform for precise and efficient detection reactions in 35 min. Therefore, our system could automatically identify specific Candida species, with a reagent consumption of only 2.5 μL of the RPA reaction mixture per target and no cross-reaction. Its detection sensitivity for four Candida species achieved 101-102 CFU/mL, which was 10-fold better than conventional RPA and even comparable to a common polymerase chain reaction. Evaluated by using cultured samples and 24 clinical samples, our system shows great applicability to onsite multiplex nucleic acid analysis.

Co-Extraction of DNA and RNA from Candida albicans Using a Chemical Method in Conjunction with Silicon Carbide with Few Cells

Objective: The study aimed to optimize protocols for the joint extraction of deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) from 0.025 × 106 CFU of Candida albicans, targeting to overcome the challenges in the extraction of these genetic materials. Materials and methods: From this, treated silicon carbide (SiC) granules were added to fungal samples from methods 1, 2, and 3 obtained from aliquots of BHI or Sabouraud medium to cause cell lysis and enable the isolation of these macromolecules by phenol and chloroform. The concentration and integrity of the extracted nucleic acids were analyzed, respectively, by spectrophotometry using the A260/A280 ratios and 1% agarose gel electrophoresis. Results: Therefore, method 3 is the one that most comprises samples considered pure of both DNA and RNA, simultaneously. Furthermore, the presence of intact RNAs corresponding to the base pair size such as 5.8 S rRNA and tRNA was verified during electrophoresis, considering the particularities of RNA, which makes it very unstable and easily degraded. Conclusions: Thus, it results in a faster and simpler method in addition to obtain promising results using minimal amounts of biological sample and offering a valuable alternative for small laboratories to work with molecular biology.

Characterization and Differentiation of Candida auris on Dixon's Agar Using Raman Spectroscopy.

Candida auris, an emerging multidrug-resistant fungal pathogen, poses significant challenges in healthcare settings due to its high misidentification rate and resilience to treatments. Despite advancements in diagnostic tools, a gap remains in rapid, cost-effective identification methods that can differentiate C. auris from other Candida species, particularly on non-standard culture media. We used Raman spectroscopy to characterize C. auris grown on modified Dixon's agar (mDixon) and differentiated it from Candida albicans and Candida parapsilosis. Key Raman spectral markers at 1171 cm-1 and 1452 cm-1, linked to mannan and β-glucan composition, differentiated C. auris into two subgroups, A and B. Despite the spectral similarities of groups A and B with C. albicans and C. parapsilosis, respectively, all Candida species were distinguishable through principal component analysis (PCA). Additionally, this study is the first to demonstrate the distinct spectral signature of mDixon agar, achieved through spatially offset Raman spectroscopy (SORS), which enables accurate discrimination between the culture medium and fungal samples. The observed inter-individual variability within C. auris, coupled with the spectral overlap between C. auris subgroups and other Candida species, highlights a major challenge in differentiating closely related fungi due to their similar molecular composition. Enhancements in spectral resolution and further fluorescence minimization from the culture medium are needed to reliably detect the subtle biochemical differences within these species. Despite these challenges, the results underscore the potential of Raman spectroscopy as a real-time, non-destructive, and complementary tool for fungal pathogen identification.

Methodology comparison of environmental sediment fungal community analysis

Fungi play important roles in ecosystems. Analyzing fungal communities in environments has long been a challenge due to the large difference in compositions retrieved using different methods or sequencing regions, obscuring the true abundance and species information. Our study aimed to compare and determine more accurate approach for evaluating fungal populations in river sediment. To achieve this, different primer sets in the internal transcribed spacer (ITS) (ITS5/ITS1R, ITS1F/ITS2), 18S rRNA gene (0817F/1196R) for High-throughput sequencing (HTS), metagenomic shotgun sequencing (MS) directly from environmental samples, and HTS using ITS primers for the fungal samples collected from plate cultivation were used to characterize the fungal communities. We calculated diversity index and used FungalTraits to analyze methods preferences for fungal species. The study revealed that when analyzing the fungal species directly from environmental samples, amplification and sequencing of ITS region demonstrated more accuracy than MS and 18S rRNA gene sequencing methods, but displayed significant primer preference. Over 30 % fungal species from HTS after plate cultivation were not present in HTS from the environmental samples. NMDS analysis demonstrated significant disparities in species diversity among different methods, suggesting potential complementarity between them. Over 85% species identified by HTS using ITS primers belonged to filamentous fungi, while the MS mostly identified yeast (62%). Therefore, to get more accurate fungal community information in sediment, multiple methods were recommended by using cultivation, molecular biological methods dependent on PCR techniques like ITS1F/ITS2 primer for HTS and PCR independent method such as metagenomic shotgun sequencing techniques.

Identification of entomopathogenic fungi from insect pests of mango and their efficacy against mango hoppers

Surveys were made in the Sindhudurg and Ratnagiri districts of the Konkan region of Maharashtra, India during 2017-2018 for the collection of mummified insect samples from different mango orchards in order to isolate entomopathogenic fungi. The collected mummified insect samples were brought to the laboratory and incubated on PDA plates. Those samples showing growth on PDA plates were sub-cultured until pure fungus growth was obtained. They were tested for their pathogenicity in the laboratory and 14 samples were found pathogenic to mango hoppers. They were sent to NFCCI, Agarkar Research Institute, Pune for identification. Out of the 14 entomopathogenic samples identified, 7 were from Genus Fusarium, 4 were mixed cultures of Fusarium and Aspergillus, and one sample each from Genus Trichoderma, Mucor and Nigrospora. Studies showed that Fusarium species were the most common entomopathogenic fungi associated with mango pests, especially mango hoppers. Laboratory evaluation of these samples showed that amongst different isolated entomogenus fungi, <i>Fusarium semitectum</i> sample 16(1) was more pathogenic to mango hoppers than other fungal samples. Field evaluation of this sample also proved its efficacy.

Detection of Ophidiomyces and Nannizziopsis spp. in the dermal lesions of free-roaming native snakes in Taiwan.

Chrysosporium-related fungi refers to an assemblage of fungi belonging to the Nannizziopsis, Ophidiomyces, and Paranannizziopsis genera. Chrysosporium-related fungi infection results in various skin lesions, such as necrosis and ulcers, in both captive and free-roaming reptiles. To update the prevalence of ophidiomycosis in Taiwan, which was first detected in 2019, we conducted a large-scale ecological survey of free-roaming native snakes with skin lesions in Taiwan. To the best of our knowledge, this is the first study on Chrysosporium-related fungi prevalence in Southeast Asia. Fungal samples collected from the skin lesions of snakes were cultured and subjected to morphological, histopathological, and molecular analyses. We examined 2382 free-roaming snakes representing 42 snake species; among them, 132 (5.54%) had skin lesions. Ten (0.42%) snakes, representing four species, tested positive for Ophidiomyces (five snakes, four species) or a possibly novel Nannizziopsis species (five snakes, three species). The infected snakes were generally healthy, with mild clinical signs. The low prevalence rate, mild clinical signs, and broad pathogen/host range suggest that Ophidiomyces and Nannizziopsis are endemic to Southeast Asia. The newly reported presence of Nannizziopsis in free-roaming snakes suggests the need for modifying the currently used surveillance strategy.

Degnala in Water Buffaloes: A Review on a Neglected Disease.

Degnala is one of the primary mycotoxicoses affecting buffaloes, with Fusarium spp. as the main causative agent. This disease is strongly associated with the feeding of rice straw to buffaloes and is considered endemic to regions where rice is cultivated. Cases are concentrated in winter when conditions favor fungal growth in inadequately stored straw. Degnala is characterized by necrosis and gangrene of the extremities, including the tail, lower limbs, ears, tongue, muzzle, and teats. The pelvic limbs are more affected than the thoracic limbs. A tortuous appearance of the tail is very common, and cracks or corneal loss of the hooves may occur, exposing the blades and even the bones. There is no diagnostic method for identifying the disease in animals other than clinical and epidemiological criteria, combined with fungal culture samples. There is no treatment that neutralizes the effects of the toxins; the current treatment is palliative and supportive, consisting of pentasulfate solution, anti-Degnala liquid, 2% nitroglycerin ointment, and broad-spectrum antibiotics for secondary infections. Additionally, the management of drying and proper storage of straw is essential for controlling this disease.

Near real-time quantification of microbial volatile organic compounds from mycoparasitic fungi: Potential for advanced monitoring and pest control

Microbial volatile organic compounds (MVOCs) are thought to play a key role in the interactions between mycoparasitic fungi, such as the biocontrol agent Trichoderma atroviride (T. atroviride), and their environment. However, the analysis of MVOC emissions from fungal samples is challenging because of low analyte concentrations, typically in the ppbV-range, and the complex chemical nature of biological samples. In a recent study using proton transfer reaction-time of flight-mass spectrometry (PTR-ToF-MS) to determine MVOC emissions from T. atroviride, many product ions were unspecific, as they could arise from a large number of possible analytes. The aim of the present study was to determine whether fast gas chromatography (fast-GC) coupled to PTR-ToF-MS could be used to overcome this issue and constitute a suitable on-line, near real-time method to identify and quantify fungal MVOC emissions in the ppbV-to-ppmV regime. Using gas standards of eleven MVOCs known to be emitted by T. atroviride such as 6-amyl-α-pyrone (6-PP), 2-pentylfuran, 1-octen-3-ol, 2-heptanone, 3-octanone, 2-methyl-1-propanol, 2-pentanone, 3-methyl-1-butanol, 3-methylbutanal, acetone and ethanol, we developed a fast-GC method with a total runtime of 180 s which significantly enhances the analytical specificity of PTR-ToF-MS compared to conventional PTR-ToF-MS without fast-GC separation. Limits of detection were on the order of 0.1–4 ppbV. The increased analytical specificity demonstrated notable benefits, especially for MVOCs having partially overlapping distributions of product ions when analyzed directly using PTR-ToF-MS.In order to demonstrate the applicability of the analytical method, we analysed T. atroviride samples in four biological replicates twice daily over a duration of five days. Using the fast-GC method, nine out of the eleven MVOC species considered in this study in the headspace of T. atroviride could be identified and quantified and their time evolution over the five-day incubation period determined. The measured volume mixing ratios (VMRs) ranged from single-digit ppbV (2-pentylfuran) up to few ppmV (6-PP and ethanol), with the other compounds in the 10-to-100-ppbV range (1-octen-3-ol, 2-heptanone, 2-methyl-1-propanol, 3-methyl-1-butanol, 3-methylbutanal and acetone).Our results suggest that fast-GC-PTR-ToF-MS is a method well-suited for the analysis of gas-phase samples of biological origin, including but not limited to (mycoparasitic) fungi, in a wide range of VMRs from sub-ppbV to few-ppmV.

Environmental Fungal Contamination Characterization of Three Inpatient Units Utilizing Optimized Detection Methods

Background: Environmental sampling and detection methods for fungi in healthcare settings are not well-established. We previously refined methods for fungal sampling and detection in a controlled laboratory environment and aimed to validate them in a real-world healthcare setting. Methods: We performed a microbiological analysis of air and surfaces in three inpatient units at a tertiary care center. Surface samples were obtained with foam sponges from 3 locations in patient rooms (Patient bedrails, bathroom floor, HVAC export) and 5 locations in units (HVAC exports 3x, clean linen storage, soiled linen storage). Air samples were taken with an active air sampler directly below HVAC exports. Sponges were processed using the stomacher technique. Samples underwent DNA extraction followed by qPCR with FungiQuant primers targeting the 18S rRNA gene. Amplicons from positive samples were sequenced (NextSeq 1000, 300bp PE) and SmartGene databases were used to interpret sequence data. For comparison to culture methods, samples were also plated onto Sabouraud and HardyCHROM Candida + auris medias. Fungal growth underwent DNA extraction, 18S PCR and Sanger sequencing for genus and species identification. Results: A total of 85 samples were obtained, from 15 patient rooms and three units resulting in 61 surface and 24 air samples. Patients in study rooms had a median age of 53, 9 (60%) were male, and no patients had an invasive fungal infection during their hospital encounter. 44 (53%) and 39 (46%) samples were positive for fungi via qPCR and culture, respectively. Of the 44 positive qPCR samples, microbiome analyses identified at least one fungi to the species, genus and family levels in 43 (98%), 28 (64%), 18 (41%) samples, respectively (Table 1). 114 total isolates were identified of which the most common were Mallassezia restricta (30 [26%]), Malassezia globose (29 [25%]), and Pennicillium paradoxum (4 [4%]). 39 genera were identified of which the most common were Mucor (19 [49%]) and Candida (8 [21%]). Of the 39 culture positive samples, 90 total isolates were recovered. The most common species were Paradendryphiella arenariae (19 [21%]), Aspergillus niger (12 [13%]) and Penicillium commune (12 [13%]). Conclusion: These results demonstrate the presence of diverse fungal species in both air and surface samples across inpatient units. Higher sensitivity was noted utilizing qPCR, however, identified genera and species were markedly different between qPCR and culture methods. Larger studies are needed to assess the efficacy of qPCR for fungal detection in the healthcare environment.

Comparative Analysis of Imidazole and Urtica dioica Emulsions in the Management of Dermatophytic Infections

This study explores the epidemiological distribution and antifungal efficacy of treatments against common dermatophytic infections, which predominantly include species from the genera Trichophyton, Microsporum, and Epidermophyton. These infections are significant due to their prevalence and the challenge posed by recurrence and resistance. Between January and September 2022, 35 fungal samples were collected from a dermatological clinic and analyzed using various growth media. Our research focused on evaluating the antifungal effectiveness of a synthetic imidazole emulsion (CSI), an antibiotic, and a natural emulsion from Urtica dioica (CSP). Results revealed that CSI and antibiotic treatments were significantly more effective across all tested species compared to CSP, with CSI often showing superior or comparable efficacy to antibiotics. The findings underscore the robust antifungal properties of imidazole derivatives and suggest a potential limitation in the therapeutic utility of U. dioica extracts. The study highlights the need for continued exploration of innovative treatments and the development of effective management strategies for fungal infections, considering the variance in species prevalence and treatment response.

Comparative Analysis of Shelf Life and Fungal Spoilage of Different Brands of Bread Sold within Dutsin-Ma Metropolis

The study aimed to compare the shelf life and fungal spoilage of different brands of bread sold within Dutsin-Ma Metropolis. Nine brands of bread were purchased from different vendors within Dutsin-Ma metropolis and were transported in sterile polyethylene bags to the Microbiology Laboratory of Federal University Dutsin-Ma for analyses using standard procedures. The bread samples were stored at various storage conditions such as room temperature, sun exposure, and refrigerator, respectively, for a specified period of 7 days from day 1 to day 7, and samples were taken at each interval to measure the quality of the bread. At each interval, the shelf life of the bread was evaluated based on the color, texture, smell, and taste of the bread. Bread samples stored under ambient temperature had the highest contamination, while samples stored under the sun had less fungal growth and samples kept in a refrigerator showed no fungal growth at all. Analysis of different nine (9) brands of bread yielded fungal species such as Aspergillus niger, Rhizopus stolonifer, Fusarium and Penicillium species. Aspergillus niger was found to have the highest percentage occurrence (28%), while Fusarium spp and Trichophyton rubrum had the least percentage occurrence (8%). It is recommended that bakery processes should ensure proper hygiene during the manufacturing process to minimize microbial contamination, especially moulds. People are also advised to buy modern-produced breads for their consumption which is thought to have improved quality standards than the locally produced ones.

Determination of antifungal efficacy and phytotoxicity of a unique silica coated porous zinc oxide nanocomposite medium for slow-release agrochemicals.

In this study the antifungal efficacy and phytotoxicity of silica coated porous zinc oxide nanoparticle (SZNP) was analyzed as this nanocomposite was observed to be a suitable platform for slow release fungicides and has the promise to bring down the dosage of other agrochemicals as well. Loading and release kinetics of tricyclazole, a potent fungicide was analyzed by measuring surface area (SBET) using Brunauer-Emmett-Teller (BET) isotherm and LC-MS/MS respectively. The antifungal efficacy of ZnO nanoparticle (ZNP) and SZNP was investigated on two phytopathogenic fungi (Alternaria solani and Aspergillus niger). The morphological changes to the fungal structure due to ZNP and SZNP treatment were studied by field emission-scanning electron microscopy (FESEM). Nanoparticle mediated elevation of reactive oxygen species in fungal samples was detected by analyzing the level of superoxide dismutase, catalase, thiol content, lipid peroxidation and by 2,7-dichlorofluorescin diacetate (DCFH-DA) assay. The phytotoxicity of these two nanostructures was assessed in rice plants by measuring primary plant growth parameters. Further, the translocation of the nanocomposite in the same plant model system was examined by checking the presence of Fluorescein isothiocyanate (FITC) tagged SZNP within the plant tissue. ZNP had superior antifungal efficacy than SZNP and caused generation of more reactive oxygen species (ROS) in the fungal samples. Even then SZNP was preferred as an agrochemical delivery vehicle because unlike ZNP alone it was not toxic to plant system. Moreover, as silica in nano form is entomotoxic in nature and nano ZnO has antifungal property, both the cargo (agrochemical) and the carrier system (silica coated porous nano zinc oxide) will have a synergistic effect in crop protection.

A ridge-based detection algorithm with filament overlap identification for 2D mycelium network analysis

Many terrestrial ecosystems engage mycorrhizal symbiotic associations, potentially to enhance nutrition, increase resistance to soil-borne pests and diseases, and improve resilience and soil structure. Mycorrhizal fungi create dynamic networked structures through branching and anastomosis that connect multiple plants and consent to transport resources underground from nutrient-rich patches to demanding plants. Controlled laboratory experiments are fundamental to improving our knowledge of mycelium network growth dynamics and further understanding its role in preserving ecological niches. We propose a method for highly automated analysis of the mycelium network structure and other morphological properties, such as hyphal length, hyphal density, and number of crossing and branches, in 2D microscopy images of fungal samples. Available tools for automated network analyses suffer from overestimating network connectivity since filament crossings are not considered. In particular, we propose a) a ridge-based mycelium detection algorithm and b) a geometrical-based approach to identify overlapping filaments crossing each other. The algorithmic solution is evaluated on a total of 135 real mycelium sample images over different validation steps, originating from different datasets and having different characteristics, including background, contrast, image acquisition system, fungal species, and clearness (e.g., level of transparency, homogeneity, dirtiness of the medium) of the sample. Results show that 1) the proposed detection method can be used to measure the length of mycelium in an image, replacing manual tracing and allowing for less laborious analysis ρ̂c=0.96, 2) the filament detection is on par with state-of-the-art techniques F1=0.88−0.94 with a more intuitive parameterization, and 3) the proposed algorithm correctly identifies filament crossings F1=0.89 in most common cases, yielding a reduction in the overestimation of network connectivity. The latter feature consents to applying the proposed fully automated solution to complex and irregular fungal structures, advancing mycelium detection and reconstruction performance accuracy with respect to the state-of-the-art.

Phylogenetic and Morphological Evidence for Three New Species of Diaporthales (Ascomycota) from Fujian Province, China.

Members of the fungal order Diaporthales are sac fungi that include plant pathogens (the notorious chestnut blight fungus), as well as saprobes and endophytes, and are capable of colonizing a wide variety of substrates in different ecosystems, habitats, and hosts worldwide. However, many Diaporthales species remain unidentified, and various inconsistencies within its taxonomic category remain to be resolved. Here, we aimed to identify and classify new species of Diaporthales by using combined morphological and molecular characterization and coupling this information to expand our current phylogenetic understanding of this order. Fungal samples were obtained from dead branches and diseasedleaves of Camellia (Theaceae) and Castanopsis (Fagaceae) in Fujian Province, China. Based on morphological characteristics and molecular phylogenetic analyses derived from the combined nucleotide sequences of loci of the internal transcribed spacer regions with the intervening 5.8S nrRNA gene (ITS), the 28S large subunit of nuclear ribosomal RNA gene (LSU), the translation elongation factor 1-α gene (tef1), the partial beta-tubulin gene (tub2), and partial RNA polymerase II second-largest subunit gene (rpb2), three new species of Diaporthales were identified and characterized. They are as follows: Chrysofolia camelliae sp. nov., Dendrostoma castanopsidis sp. nov., and Pseudoplagiostoma wuyishanense sp. nov. They are described and illustrated. This study extends our understanding of species diversity within the Diaporthales.

First Report of Powdery Mildew on Berchemia floribunda Caused by Erysiphe berchemiae in China.

The genus Berchemia (family Rhamnaceae), a group of climbing plants, is mainly distributed in Asia, Africa, and South America. Berchemia plants are widely used in traditional medicine in some Asian countries (Inoshiri et al. 1987). For example, in Japan, B. racemosa (synonym B. floribunda) is used for the treatment of gallstones, liver diseases, neuralgia, and stomach cramps, and in China, B. floribunda is used for the treatment of rheumatism and lumbago. In August 2022, typical powdery mildew symptoms were observed on wild B. floribunda plants in Huaxi District, Guiyang, Guizhou Province, China. The incidence was approximately 60% among 100 B. floribunda plants observed outdoors. White colonies almost entirely covered on both adaxial and abaxial surfaces of all leaves on symptomatic plants. Infected leaves appeared curled or chlorotic, infection occasionally leading to defoliation. To describe the pathogen morphologically, fungal samples were collected from two individual B. floribunda plants and microscopically characterized. In these samples, hyphae were flexuous to straight, branched, septate, 3-6 μm wide, with lobed hyphal appressoria. Conidiophores were erect, flexuous to straight, and 50-160 µm long (n = 30). Foot cells were subcylindrical to slightly curved-sinuous at the base, 20-40 µm long (n = 30), followed by 2-3 shorter cells. Conidia formed singly, occasionally 2-3 in a chain. Conidia were ellipsoid to ovoid, 20-42 × 12-18 µm (n = 50), without fibrosin bodies. Chasmothecia were not found. For molecular identification, the ribosomal DNA internal transcribed spacers (ITSs) of the two fungal samples were amplified and sequenced using the ITS1/ITS4 primer pair (White et al. 1990). The obtained 649-bp ITS sequences (GenBank accession nos. OR414364 and OR414365, respectively) shared 100% identity, and they showed 99.52% identity with the ITS sequence (GenBank accession no. LC009934) of Erysiphe berchemiae. Phylogenetic analysis grouped OR414364 and OR414365 in a clade with LC009934. Based on morphological and molecular characteristics, the powdery mildew fungus from B. floribunda was identified as E. berchemiae (Braun and Cook 2012). The voucher specimen (accession no. GZNU-BFEE/0820/2022) were deposited at the School of Life Sciences, Guizhou Normal University. Pathogenicity was assessed by gently pressing naturally diseased leaves of B. floribunda onto leaves of three healthy potted 1-year-old B. floribunda plants. Three non-inoculated healthy plants were used as controls. The plants were incubated in a greenhouse at 25 ± 2°C, 80% relative humidity. Similar powdery mildew symptoms were observed on the inoculated plants 9 days after inoculation, whereas the control plants remained symptomless. The reisolated fungus from inoculated leaves was morphologically identical to that observed on the original diseased leaves, and the ITS sequence of the reisolated fungus shared 100% identity with OR414364 and OR414365, fulfilling Koch's postulates. E. berchemiae has previously been described as a powdery mildew pathogen on B. yunnanensis (Chen et al. 1987) and B. kulingensis (Chen 1993) in China and B. racemosa (synonym B. floribunda) in Japan (Braun and Cook 2012; Takamatsu et al. 2015), but this is the first report of E. berchemiae causing disease of B. floribunda in China. This work suggests that E. berchemiae is an important pathogen of Berchemia plants, at least for some species in the genus Berchemia.

First Report of Powdery Mildew on Quercus fabri and Q. robur Caused by Erysiphe quercicola in China.

Quercus (Fagaceae) is a genus of ecologically and economically important shrub and tree species (Yin et al. 2018). In April 2022, powdery mildew symptoms were observed on Quercus fabri and Quercus robur leaves on Longwen hill, Guizhou Normal University, Guiyang, China. The incidence was 30% (Q. fabri, n = 50) and 20% (Q. robur, n = 30), respectively. Powdery mildew fungi from these two Quercus species shared similar morphological characteristics. Mycelia occurred on adaxial and abaxial leaf surfaces, forming small to large patches; hyphae were hyaline, 3-7 µm wide; hyphal appressoria were lobed to multilobed, solitary; conidiophores were erect, straight, 36-80 µm long (n = 30); foot cells were followed by 1-2 shorter cells; conidia formed singly, obovoid to ellipsoid, 24-38 × 12-27 µm (n = 50), without fibrosin bodies; no chasmothecia were observed. Based on these characteristics, powdery mildew fungi on both Q. fabri and Q. robur were identified as Erysiphe quercicola (Takamatsu et al. 2007). To confirm the identification, ribosomal DNA internal transcribed spacer (ITS) sequences of two fungal samples from Q. fabri and Q. robur were separately amplified and sequenced using primer pair ITS1/ITS4 (White et al. 1990). The obtained ITS sequences (GenBank accession nos. QR414372 and QR414373, respectively) shared 100% identity, and 99.38-99.84% identity with diverse ITS sequences of E. quercicola (Takamatsu et al. 2015). In a phylogenetic tree based on ITS sequences of Erysiphe species (Takamatsu et al. 2007), QR414372 and QR414373 were grouped in a clade with ITS sequences of E. quercicola. To fulfil Koch's postulates, leaves of three healthy potted Q. fabri plants and three healthy potted Q. robur plants were inoculated by gently pressing diseased Q. fabri and Q. robur leaves onto healthy leaves. Non-inoculated healthy Q. fabri and Q. robur plants served as controls. All plants were incubated in a greenhouse at 25 ± 2°C with 80% relative humidity. Typical powdery mildew symptoms were observed on all inoculated plants 15 days after inoculation, whereas no symptoms were observed on control plants. Fungi separately reisolated from inoculated Q. fabri and Q. robur were morphologically identical to those on their originally diseased plants, and ITS sequences of reisolated fungi shared 100% identity with QR414372 and QR414373. E. quercicola has previously been reported to infect Quercus species, including Q. robur in Australia, Q. crispula, Q. phillyraeoides and Q. serrata in Japan, and Q. phillyraeoides in Korea (Lee et al. 2011). In China, Q. fabri and Q. robur may be infected by E. alphitoides and E. hypophylla, respectively (Zheng et al. 1987). To our knowledge, this is the first report of powdery mildew caused by E. quercicola on Q. fabri and Q. robur in China. This work provides a foundation to protect Quercus plants against this fungal pathogen.

Oschib1 gene encoding a GH18 chitinase confers resistance against sheath blight disease of rice caused by Rhizoctonia solani AG1-IA.

Sheath blight disease of rice caused by Rhizoctonia solani AG1-IA, is a major fungal disease responsible for huge loss to grain yield and quality. The major limitation of achieving persistent and reliable resistance against R. solani is the governance of disease resistance trait by many genes. Therefore, functional characterization of new genes involved in sheath blight resistance is necessary to understand the mechanism of resistance as well as evolving effective strategies to manage the disease through host-plant resistance. In this study, we performed RNA sequencing of six diverse rice genotypes (TN1, BPT5204, Vandana, N22, Tetep, and Pankaj) from sheath and leaf tissue of control and fungal infected samples. The approach for identification of candidate resistant genes led to identification of 352 differentially expressed genes commonly present in all the six genotypes. 23 genes were analyzed for RT-qPCR expression which helped identification of Oschib1 showing differences in expression level in a time-course manner between susceptible and resistant genotypes. The Oschib1 encoding classIII chitinase was cloned from resistant variety Tetep and over-expressed in susceptible variety Taipei 309. The over-expression lines showed resistance against R. solani, as analyzed by detached leaf and whole plant assays. Interestingly, the resistance response was correlated with the level of transgene expression suggesting that the enzyme functions in a dose dependent manner. We report here the classIIIb chitinase from chromosome10 of rice showing anti-R. solani activity to combat the dreaded sheath blight disease.

A new pathogenic polypore on urban trees: The first record of Rigidoporus ulmarius (Rigidoporaceae, Hymenochaetales) in Hungary

AbstractThe Giant Elm Bracket (Rigidoporus ulmarius) is a widely-distributed necrotrophic polypore species that causes white heart rot in deciduous trees. Despite its recognition as one of the largest species known for forming basidiomata, this perennial polypore had not been documented in Hungary. However, in recent years, two specimens macroscopically resembling this species were collected on old horse chestnut (Aesculus hippocastanum) trees from two different places in Hungary by amateur mycologists. In this study, subsequent morphological and molecular-genetic analyses of these fungal samples confirmed their identity as R. ulmarius. This study represents the first documented occurrence of this plant pathogenic polypore species in Hungary.