The genus Bipolaris

Novel report of Bipolaris heliconiae causing frog-eye-like leaf spot on Dypsis lutescens in Indian Sub-Continent

Dypsis lutescens, commonly known as areca palm, is a highly valued ornamental species due to its aesthetic value. However, the foliage is vulnerable to various pathogens, particularly those responsible for fungal leaf spot diseases. In October 2023, a severe incidence (93 %) of destructive leaf spots was recorded on Dypsis lutescens at the University of Agricultural Sciences, GKVK, Bangalore, and surrounding areas. The leaf spot symptoms manifested as frog-eye-like lesions, leading to complete leaf desiccation and significantly reducing the palms ornamental value. The pathogen exhibited the highest radial growth (90.00 mm) and prominent sporulation on oat meal agar, whereas Richard's synthetic agar resulted in the lowest radial growth (38.00 mm) with no sporulation. Morphological and multilocus phylogenetic analyses confirmed the pathogen as Bipolaris heliconiae. Pathogenicity tests fulfilled Koch's postulates, confirming that Bipolaris heliconiae is the causative agent of leaf spot disease in Dypsis lutescens in India. This novel finding underscores the emergence of a new disease and highlights the urgent need for effective management strategies.

Phylogenetic analyses show the Select Agent Coniothyrium glycines represents a single species that has significant morphological and genetic variation

Soybean red leaf blotch (RLB), caused by the fungus Coniothyrium glycines, represents a foliar disease of soybean that is thus far restricted to Africa. The fungus is listed as a Select Agent by the Federal Select Agent Program because it could pose a severe threat to plant health were it to establish in the United States. Previous work uncovered tremendous molecular diversity at the internal transcribed spacer region, suggesting that there may be multiple species causing RLB. To determine whether multiple species cause RLB, we reconstructed the phylogeny of C. glycines and taxonomic allies using sequence data from four genes. We included 33 C. glycines isolates collected from six African countries and determined that all isolates form a well-supported, monophyletic lineage. Within this lineage there are at least six well-supported clades that largely correspond to geography, with one clade exclusively composed of isolates from Ethiopia, another exclusively composed of isolates from Uganda, and four composed of isolates from southern Africa. However, we did not detect any concordance for these clades between the four genes, indicating that all isolates included in this analysis are representative of a single species. Isolates in the Ethiopia clade are morphologically distinct from isolates in the other clades, as they produce larger sclerotia and smaller pycnida and more sclerotia in planta. Additionally, ancestral range estimations suggest that the C. glycines lineage emerged in southern Africa. These results show that there is significantly more genetic and morphological diversity than was initially suspected with this high-consequence fungal plant pathogen.

Maydisens, Sesterterpenoids with Anti-MDR Activity from Bipolaris maydis

Fourteen previously undescribed sesterterpenoids (1-14) were isolated from Bipolaris maydis. Their structures with absolute configurations were elucidated by NMR, HRESIMS, DP4+ calculations, ECD calculations, single-crystal X-ray diffraction analyses, and the modified Mosher's method. Compounds 1-5 possess an uncommon 5/11 bicyclic ring system identified from B. maydis for the first time. Compounds 6-14 have a 5/8/5 tricyclic ring system, and these compounds both possess carbonyl groups in ring A. Compound 10 showed significant reversal of paclitaxel resistance in cancer cells.

Combating wheat yellow mosaic virus through microbial interactions and hormone pathway modulations

BACKGROUND

The rhizosphere microbiome is critical for promoting plant growth and mitigating soil-borne pathogens. However, its role in fighting soil-borne virus-induced diseases, such as wheat yellow mosaic virus (WYMV) transmitted by Polymyxa graminis zoospores, remains largely underexplored. In this study, we hypothesized that during viral infections, plant microbiomes engage in critical interactions with plants, with key microbes playing vital roles in maintaining plant health. Our research aimed to identify microbial taxa that not only suppress the disease but also boost wheat yield by using a blend of techniques, including field surveys, yield assessments, high-throughput sequencing of plant and soil microbiomes, microbial isolation, hydroponic experiments, and transcriptome sequencing.

RESULTS

We found that, compared with roots and leaves, the rhizosphere microbiome showed a better performance in predicting wheat yield and the prevalence of P. graminis and WYMV across the three WYMV-impacted regions in China. Using machine learning, we found that healthy rhizospheres were marked with potentially beneficial microorganisms, such as Sphingomonas and Allorhizobium-Neorhizobium-Parararhizobium-Rhizobium, whereas diseased rhizospheres were associated with a higher prevalence of potential pathogens, such as Bipolaris and Fusicolla. Structural equation modeling showed that these biomarkers both directly and indirectly impacted wheat yield by modulating the rhizosphere microbiome and P. graminis abundance. Upon re-introduction of two key healthy rhizosphere biomarkers, Sphingomonas azotifigens and Rhizobium deserti, into the rhizosphere, wheat growth and health were enhanced. This was attributed to the up-regulation of auxin and cytokinin signaling pathways and the regulation of jasmonic acid and salicylic acid pathways during infections.

CONCLUSIONS

Overall, our study revealed the critical role of the rhizosphere microbiome in combating soil-borne viral diseases, with specific rhizosphere microbes playing key roles in this process. Video Abstract.

Characterization of Bipolaris bicolor germination: effects of a physical factor on fungal adaptability

Studies on physiological responses to stimuli from physical factors are essential for understanding the dynamics of the microorganisms and higly important for the management of plant diseases. Besides, the development of an epidemiological model for pathogen populations requires studying their physiological responses to physical stimuli. The objective of this study was to evaluate the germination dynamics of spores from six isolates of Bipolaris bicolor under effects of light at 25 °C. Suspensions of 1.6 × 105 conidia mL- 1 from the B. bicolor isolates were inoculated onto Petri dishes containing agar-water culture medium and incubated in a BOD chamber under two physical conditions: (a) constant darkness and (b) constant light for five hours. The study was conducted in a completely randomized design, with a 6 × 2 factorial arrangement (six B. bicolor isolates and two physical conditions) and five replications. The length of the germ tube was measured hourly. The constant darkness resulted in higher mean germ tube growth for the pathogen; however, differences in the final germination percentage were found among the isolates. The isolate F-24-02 exhibited the highest germination adaptability to constant darkness, presenting the longest germ tube length.

Recent advances in the population biology and management of maize foliar fungal pathogens Exserohilum turcicum, Cercospora zeina and Bipolaris maydis in Africa

Maize is the most widely cultivated and major security crop in sub-Saharan Africa. Three foliar diseases threaten maize production on the continent, namely northern leaf blight, gray leaf spot, and southern corn leaf blight. These are caused by the fungi Exserohilum turcicum, Cercospora zeina, and Bipolaris maydis, respectively. Yield losses of more than 10% can occur if these pathogens are diagnosed inaccurately or managed ineffectively. Here, we review recent advances in understanding the population biology and management of the three pathogens, which are present in Africa and thrive under similar environmental conditions during a single growing season. To effectively manage these pathogens, there is an increasing adoption of breeding for resistance at the small-scale level combined with cultural practices. Fungicide usage in African cropping systems is limited due to high costs and avoidance of chemical control. Currently, there is limited knowledge available on the population biology and genetics of these pathogens in Africa. The evolutionary potential of these pathogens to overcome host resistance has not been fully established. There is a need to conduct large-scale sampling of isolates to study their diversity and trace their migration patterns across the continent.

What are the 100 most cited fungal genera?

The global diversity of fungi has been estimated between 2 to 11 million species, of which only about 155 000 have been named. Most fungi are invisible to the unaided eye, but they represent a major component of biodiversity on our planet, and play essential ecological roles, supporting life as we know it. Although approximately 20 000 fungal genera are presently recognised, the ecology of most remains undetermined. Despite all this diversity, the mycological community actively researches some fungal genera more commonly than others. This poses an interesting question: why have some fungal genera impacted mycology and related fields more than others? To address this issue, we conducted a bibliometric analysis to identify the top 100 most cited fungal genera. A thorough database search of the Web of Science, Google Scholar, and PubMed was performed to establish which genera are most cited. The most cited 10 genera are Saccharomyces, Candida, Aspergillus, Fusarium, Penicillium, Trichoderma, Botrytis, Pichia, Cryptococcus and Alternaria. Case studies are presented for the 100 most cited genera with general background, notes on their ecology and economic significance and important research advances. This paper provides a historic overview of scientific research of these genera and the prospect for further research. Citation: Bhunjun CS, Chen YJ, Phukhamsakda C, Boekhout T, Groenewald JZ, McKenzie EHC, Francisco EC, Frisvad JC, Groenewald M, Hurdeal VG, Luangsa-ard J, Perrone G, Visagie CM, Bai FY, Błaszkowski J, Braun U, de Souza FA, de Queiroz MB, Dutta AK, Gonkhom D, Goto BT, Guarnaccia V, Hagen F, Houbraken J, Lachance MA, Li JJ, Luo KY, Magurno F, Mongkolsamrit S, Robert V, Roy N, Tibpromma S, Wanasinghe DN, Wang DQ, Wei DP, Zhao CL, Aiphuk W, Ajayi-Oyetunde O, Arantes TD, Araujo JC, Begerow D, Bakhshi M, Barbosa RN, Behrens FH, Bensch K, Bezerra JDP, Bilański P, Bradley CA, Bubner B, Burgess TI, Buyck B, Čadež N, Cai L, Calaça FJS, Campbell LJ, Chaverri P, Chen YY, Chethana KWT, Coetzee B, Costa MM, Chen Q, Custódio FA, Dai YC, Damm U, de Azevedo Santiago ALCM, De Miccolis Angelini RM, Dijksterhuis J, Dissanayake AJ, Doilom M, Dong W, Alvarez-Duarte E, Fischer M, Gajanayake AJ, Gené J, Gomdola D, Gomes AAM, Hausner G, He MQ, Hou L, Iturrieta-González I, Jami F, Jankowiak R, Jayawardena RS, Kandemir H, Kiss L, Kobmoo N, Kowalski T, Landi L, Lin CG, Liu JK, Liu XB, Loizides M, Luangharn T, Maharachchikumbura SSN, Makhathini Mkhwanazi GJ, Manawasinghe IS, Marin-Felix Y, McTaggart AR, Moreau PA, Morozova OV, Mostert L, Osiewacz HD, Pem D, Phookamsak R, Pollastro S, Pordel A, Poyntner C, Phillips AJL, Phonemany M, Promputtha I, Rathnayaka AR, Rodrigues AM, Romanazzi G, Rothmann L, Salgado-Salazar C, Sandoval-Denis M, Saupe SJ, Scholler M, Scott P, Shivas RG, Silar P, Souza-Motta CM, Silva-Filho AGS, Spies CFJ, Stchigel AM, Sterflinger K, Summerbell RC, Svetasheva TY, Takamatsu S, Theelen B, Theodoro RC, Thines M, Thongklang N, Torres R, Turchetti B, van den Brule T, Wang XW, Wartchow F, Welti S, Wijesinghe SN, Wu F, Xu R, Yang ZL, Yilmaz N, Yurkov A, Zhao L, Zhao RL, Zhou N, Hyde KD, Crous PW (2024). What are the 100 most cited fungal genera? Studies in Mycology 108: 1-411. doi: 10.3114/sim.2024.108.01.

The complete mitochondrial genomes of five critical phytopathogenic Bipolaris species: features, evolution, and phylogeny

In the present study, three mitogenomes from the Bipolaris genus (Bipolaris maydis, B. zeicola, and B. oryzae) were assembled and compared with the other two reported Bipolaris mitogenomes (B. oryzae and B. sorokiniana). The five mitogenomes were all circular DNA molecules, with lengths ranging from 106,403 bp to 135,790 bp. The mitogenomes of the five Bipolaris species mainly comprised the same set of 13 core protein-coding genes (PCGs), two rRNAs, and a certain number of tRNAs and unidentified open reading frames (ORFs). The PCG length, AT skew and GC skew showed large variability among the 13 PCGs in the five mitogenomes. Across the 13 core PCGs tested, nad6 had the least genetic distance among the 16 Pleosporales species we investigated, indicating that this gene was highly conserved. In addition, the Ka/Ks values for all 12 core PCGs (excluding rps3) were < 1, suggesting that these genes were subject to purifying selection. Comparative mitogenomic analyses indicate that introns were the main factor contributing to the size variation of Bipolaris mitogenomes. The introns of the cox1 gene experienced frequent gain/loss events in Pleosporales species. The gene arrangement and collinearity in the mitogenomes of the five Bipolaris species were almost highly conserved within the genus. Phylogenetic analysis based on combined mitochondrial gene datasets showed that the five Bipolaris species formed well-supported topologies. This study is the first report on the mitogenomes of B. maydis and B. zeicola, as well as the first comparison of mitogenomes among Bipolaris species. The findings of this study will further advance investigations into the population genetics, evolution, and genomics of Bipolaris species.

Seasonal variability of airborne mold concentrations as related to dust in a coastal urban area in the Eastern Mediterranean

Recent studies have demonstrated that the amount of specific airborne mold types and their concentrations increase during dust events. This study investigates the seasonal variation of airborne mold concentrations before, during, and after the dust transport in an eastern Mediterranean coastal area, Izmir city, Turkey. A total of 136 airborne mold samples were collected between September 2020 and May 2021. Two different culture media, namely Potato Dextrose Agar (PDA) and Malt-Extract Agar (MEA), were used for enumeration and genus-based identification of the airborne mold. In addition to culture media, the influences of air temperature, relative humidity, and particulate matter equal to or less than 10 µm (PM10) were also investigated seasonally. The HYSPLIT trajectory model and web-based simulation results were mainly used to determine dusty days. The mean total mold concentrations (TMC) on dusty days (543 Colony Forming Unit (CFU)/m3 on PDA and 668 CFU/m3 on MEA) were approximately 2-2.5 times higher than those on non-dusty days (288 CFU/m3 on PDA and 254 CFU/m3 on MEA) for both culture media. TMC levels showed seasonal variations (p < 0.001), indicating that meteorological parameters influenced mold concentrations and compositions. Some mold genera, including Cladosporium sp., Chrysosporium sp., Aspergillus sp., Bipolaris sp., Alternaria sp., and yeast, were found higher during dusty days than non-dusty days. Thus, dust event impacts levels and types of airborne molds and has implications for regions where long-range dust transport widely occurs.

Immune Mechanisms of Filamentous Fungal Keratitis

Filamentous fungal keratitis is a particularly serious eye infection that often results in ulceration, corneal perforation, and blindness. The cornea acts as a natural barrier against harmful agents due to the close connection of its epithelial cells. In addition, on its surface, there is a large number of substances with anti-inflammatory and bactericidal properties, such as secretory IgA and mucin glycoproteins, and antimicrobial peptides (AMPs), such as human β-defensin 2 (HBD-2) and LL-37, which are especially increased in filamentous fungal keratitis. The interaction between pathogenic fungi and the host's immune mechanisms is a complex process: pathogen-associated molecular pattern (PAMP) molecules (chitin, β-glucan, and mannan) found in the fungal cell wall are recognized by pattern recognition receptors (PRRs) (toll-like receptors {TLRs}, C-type lectin receptors {CLRs}, nucleotide-binding oligomerization domain-like receptors {NLRs}, and scavenger receptors {SR}) found in host defense cells, triggering the secretion of various types of cytokines, such as interleukins (IL), tumor necrosis factors (TNFs), and chemokines, which recruit macrophages and neutrophils to migrate to the site of infection and activate inflammatory responses. In addition, the interaction of hyphae and corneal epithelial cells can activate cluster of differentiation (CD) 4+ T cells, CD8+ T cells, and B cells and induce secretion of T-helper (Th)-type cytokines 2 (IL-4 and IL-13) and IgG.

Chromones from the endophytic fungus Bipolaris eleusines

Eight previously undescribed chromones eleusineketones A-H (1-8), as well as eight known compounds (9-16), were isolated from the endophytic fungus Bipolaris eleusines. These planar structures were created using an in-depth analysis of their spectral data, which included 1D, 2D, and HRESIMS data. Furthermore, the absolute configurations of compounds 1, 2, and 6 were determined by spectroscopic analysis and quantum chemical computational approaches, and compound 5 was determined by single-crystal X-ray diffraction analysis. The cytotoxic activity assay revealed that compounds 1 and 5 both inhibited MDA-MB-231 cells with IC50 values of 14.48 μM and 17.99 μM, respectively.

Exploring ascomycete diversity in Yunnan II: Introducing three novel species in the suborder Massarineae (Dothideomycetes, Pleosporales) from fern and grasses

This article presents the results of an ongoing inventory of Ascomycota in Yunnan, China, carried out as part of the research project series "Exploring ascomycete diversity in Yunnan". From over 100 samples collected from diverse host substrates, microfungi have been isolated, identified and are currently being documented. The primary objective of this research is to promote the discovery of novel taxa and explore the ascomycete diversity in the region, utilising a morphology-phylogeny approach. This article represents the second series of species descriptions for the project and introduces three undocumented species found in the families Bambusicolaceae, Dictyosporiaceae and Periconiaceae, belonging to the suborder Massarineae (Pleosporales, Dothideomycetes). These novel taxa exhibit typical morphological characteristics of Bambusicola, Periconia and Trichobotrys, leading to their designation as Bambusicolahongheensis, Periconiakunmingensis and Trichobotryssinensis. Comprehensive multigene phylogenetic analyses were conducted to validate the novelty of these species. The results revealed well-defined clades that are clearly distinct from other related species, providing robust support for their placement within their respective families. Notably, this study unveils the phylogenetic affinity of Trichobotrys within Dictyosporiaceae for the first time. Additionally, the synanamorphism for the genus Trichobotrys is also reported for the first time. Detailed descriptions, illustrations and updated phylogenies of the novel species are provided, and thus presenting a valuable resource for researchers and mycologists interested in the diversity of ascomycetes in Yunnan. By enhancing our understanding of the Ascomycota diversity in this region, this research contributes to the broader field of fungal taxonomy and their phylogenetic understanding.

Bipolaris fujianensis sp. nov., an Emerging Pathogen of Sapling Shoot Blight on Chinese Fir, and Its Sensitivity to Fungicides

Chinese fir is an extremely important economic tree species in southern China. In recent years, 74.5% of Chinese fir saplings suffered from shoot blight in Shunchang County, Nanping City, Fujian Province, China. Seventeen isolates were collected from rotten shoots, and their pathogenicity was confirmed following Koch's postulates. The five pathogenic isolates were identified as belonging to the genus Bipolaris based on morphological characteristics, including septate and geniculate conidiophores, smooth to slightly verruculose conidiogenous nodes, dematiaceous phragmospore conidia, oblong or fusiform conidia, and slightly protruding or truncate hilum on conidia, but the number of pseudosepta (3 to 11, mostly 5 to 8) and the size of conidia ([22.81 to 116.13] × [9.16 to 26.58] μm) are different from those of the known species of Bipolaris. A phylogenetic analysis based on ITS, GAPDH, and Tef1-α sequences determined that the five strains belong to a new species of Bipolaris, and the name Bipolaris fujianensis sp. nov. is proposed. The fungicide sensitivity of the pathogen strain Cfsb3 was further evaluated using eight fungicides. Flusilazole, difenoconazole, tebuconazole, and propiconazole exhibited high toxicity to Cfsb3, and the effective concentration inhibiting 50% (EC50) of mycelial growth was 0.08, 0.20, 0.34, and 0.36 μg/ml, respectively, for these four fungicides. Flusilazole, difenoconazole, and iprodione inhibited B. fujianensis by 100% on detached Chinese fir shoots at their recommended concentrations, but azoxystrobin and thiram were ineffective. In conclusion, this study reported an emerging pathogen of Chinese fir sapling shoot blight and proposed triazole and dicarboximide fungicides for disease control.

Physiological and Biochemical Aspects of Silicon-Mediated Resistance in Maize against Maydis Leaf Blight

Maydis leaf blight (MLB), caused by the necrotrophic fungus Bipolaris maydis, has caused considerable yield losses in maize production. The hypothesis that maize plants with higher foliar silicon (Si) concentration can be more resistant against MLB was investigated in this study. This goal was achieved through an in-depth analysis of the photosynthetic apparatus (parameters of leaf gas exchange chlorophyll (Chl) a fluorescence and photosynthetic pigments) changes in activities of defense and antioxidative enzymes in leaves of maize plants with (+Si; 2 mM) and without (-Si; 0 mM) Si supplied, as well as challenged and not with B. maydis. The +Si plants showed reduced MLB symptoms (smaller lesions and lower disease severity) due to higher foliar Si concentration and less production of malondialdehyde, hydrogen peroxide, and radical anion superoxide compared to -Si plants. Higher values for leaf gas exchange (rate of net CO2 assimilation, stomatal conductance to water vapor, and transpiration rate) and Chl a fluorescence (variable-to-maximum Chl a fluorescence ratio, photochemical yield, and yield for dissipation by downregulation) parameters along with preserved pool of chlorophyll a+b and carotenoids were noticed for infected +Si plants compared to infected -Si plants. Activities of defense (chitinase, β-1,3-glucanase, phenylalanine ammonia-lyase, polyphenoloxidase, peroxidase, and lipoxygenase) and antioxidative (ascorbate peroxidase, catalase, superoxide dismutase, and glutathione reductase) enzymes were higher for infected +Si plants compared to infected -Si plants. Collectively, this study highlights the importance of using Si to boost maize resistance against MLB considering the more operative defense reactions and the robustness of the antioxidative metabolism of plants along with the preservation of their photosynthetic apparatus.

Genetic variations among the isolates of Bipolaris Maydis based on phenotypic and molecular markers

Abstract Maydis leaf blight, caused by Bipolaris maydis, is an important disease of maize crop in Khyber Pakhtunkhwa (KP) Pakistan. Fifteen isolates of the pathogen, collected across KP, were studied for variability based on phenotypic and molecular markers. Significant variability among the isolates was observed when assessed using phenotypic traits such as radial growth, spore concentration, fungicide sensitivity and virulence. The isolates were classified into six culture groups based on colour, texture and margins of the colony. Conidial morphology was also variable. These were either straight or slightly curved and light to dark brown in colour. Fungicide test showed significant variation in the degree of sensitivity against Carbendazim. Isolate Bm8 exhibited maximum radial growth on carbendazim spiked plates. Conversely, isolate Bm15 showed the lowest radial growth. Variations in virulence pattern of the isolates were evident when a susceptible maize variety Azam was inoculated with spores of B. maydis. Genetic variability amongst the isolates was also estimated by RAPD as well as sequencing of ITS region. The RAPD dendrogram grouped all the isolates into two major clusters. Average genetic distance ranged from 0.6% to 100%, indicating a diverse genetic gap among the isolates. Maximum genetic distance was found between isolates Bm9 and Bm10 as well as Bm2 and Bm8. Conversely, isolates Bm13 and Bm15 were at minimum genetic distance. Phylogenetic dendrogram based on sequencing of ITS region grouped all the isolates into a single major cluster. The clusters in both the dendrogram neither correlate to the geographical distribution nor to the morphological characteristics.

Evaluation of Bipolaris yamadae as a bioherbicidal agent against grass weeds in arable crops

BACKGROUND

Weeds are among the most damaging pests of agriculture, causing ≈10% worldwide reduction in crop productivity each year. Over-reliance on synthetic chemical herbicides has caused weeds around the world to evolve resistance. Bioherbicides may be an alternative. However, among their many constraints including strict environmental requirements, complicated mass-production and high product costs, limited pathogenicity and a narrow spectrum of activity are frequently encountered and are major barriers to commercialization.

RESULTS

We isolated a pathogenic fungus, HXDC-1-2, from diseased leaves of a gramineous weed, stiltgrass [Microstegium vimineum (Trin.) A. Camus], from the edge of farmland in Guizhou province, China. HXDC-1-2 was identified as the fungal species Bipolaris yamadae based on the morphological characteristics and ITS-GPDH-EF1α multiple primer analysis. Its potential as a bioherbicide was evaluated by determining its weed control efficacy and crop safety. The ED50 and ED90 values of HXDC-1-2 on Echinochloa crus-galli were 3.22 × 103 and 1.32 × 105 conidia mL-1 , respectively. Host range tests revealed that 20 gramineous weeds including Setaria viridis, Leptochloa chinensis, Eleusine indica, Pseudosorghum zollingeri, Leptochloa panicea, Bromus catharticus, E. crus-galli plants, were extremely susceptible whereas 77 crop species from 27 plant families including rice, wheat, barley, corn, soybean and cotton (excluding cowpea and sorghum) were unaffected.

CONCLUSION

Bipolaris yamadae strain HXDC-1-2 has great potential to be developed as a commercial broad-spectrum bioherbicidal agent for controlling grass weeds in arable crops. © 2023 Society of Chemical Industry.

Characterization of the Bipolaris maydis: symptoms and pathogenicity in popcorn genotypes (Zea mays L.)

Abstract Southern corn leaf blight (SCLB) is one of the most important corn leaf diseases. Appropriate management strategies and the use of resistant cultivars allow disease control. Therefore, knowing the aspects related to the pathogen and the response of hosts makes it possible to design efficient strategies for selecting genotypes resistant to this disease. In this sense, the objective was to carry out the Bipolaris maydis isolate characterization, evaluating the pathogenicity in different popcorn lines and the symptoms generated in the host after inoculation. The isolate characterization consisted of the macromorphological evaluation of the colonies and the micromorphological evaluation of the conidia in the PDA medium. An experiment was carried out in a greenhouse to evaluate the pathogenicity of the isolate, using 20 inbred lines of popcorn in a randomized block design with four replicates. Inoculation was carried out by spraying leaves, with a suspension containing 1.0 x 104 conidia.ml-1 of the CF/UENF 501 isolate of B. maydis. An incidence assessment and three assessments of disease symptom severity were performed, with seven days intervals between evaluations. The morphological characterization data of the isolate were analyzed using descriptive statistics, and for disease severity, the linear regression model was applied the first-degree model. The variance analysis was performed for the linear and angular coefficients obtained for each treatment. When a difference was found, the Scott-Knott clustering algorithm at 5% significance was applied. The isolate had gray-green colonies, a cottony appearance, and an irregular shape. The lines L353, L354, and L624 show more resistance at the beginning and throughout the evaluations. The high virulence of the CF/UENF 501 isolate made it possible to differentiate the lines in terms of disease intensity and the pattern of symptoms presented.

First complete mitogenome of Massarineae and its contribution to phylogenetic implications in Pleosporales

Endophytic fungi play an important role in the growth and development of traditional Chinese medicine plants. We isolated a strain of Acrocalymma vagum from the endophytic fungi of the traditional Chinese plants Paris. To accurately identify this endophytic fungal species of interest, we sequenced the mitochondrial genome of A. vagum, which is the first discovered mitochondrial genome in Massarineae. The A. vagum mitochondrial genome consists of a 35,079-bp closed circular DNA molecule containing 36 genes. Then, we compared the general sequence characteristics of A. vagum with those of Pleosporales, and the second structure of the 22 tRNAs was predicted. The phylogenetic relationship of A. vagum was constructed using two different data sets (protein-coding genes and amino acids). The phylogenetic tree shows that A. vagum is located at the root of Pleosporales. The analysis of introns shows that the number of introns increases with the increase in branch length. The results showed that monophyly was confirmed for all families in Pleosporales except for Pleosporaceae. A. vagum is an ancient species in the Pleosporales, and Pleosporaceae may require further revision. In Pleosporales, the number of introns is positively correlated with branch length, providing data for further study on the origin of introns.

Molecular phylogeny and morphology reveal two new graminicolous species, Curvularia aurantiasp. nov. and C. vidyodayana sp. nov. with new records of Curvularia spp. from Sri Lanka

Despite being a small island, Sri Lanka is rich in fungal diversity. Most of the fungi from Sri Lanka have been identified as pathogens of vegetables, fruits, and plantation crops to date. The pleosporalean genus Curvularia (Dothideomycetes) includes phytopathogenic, saprobic, endophytic, and human/animal opportunistic pathogenic fungal species. The majority of the plant-associated Curvularia species are known from poaceous hosts. During the current study, 22 geographical locations of the country were explored and collections were made from 10 different poaceous hosts. Morphology and molecular phylogeny based on three loci, including nuclear internal transcribed spacers 1 and 2 with 5.8S nrDNA (ITS), glyceraldehyde-3-phosphate dehydrogenase (gapdh), and translation elongation factor 1-α (tef1) supported the description of two new species of fungi described herein as C. aurantia sp. nov. and C. vidyodayana sp. nov. Moreover, novel host-fungal association records for C. chiangmaiensis, C. falsilunata, C. lonarensis, C. plantarum, and C. pseudobrachyspora are updated herein. In addition, five species within the genus Curvularia, viz., C. asiatica, C. geniculata, C. lunata, C. muehlenbeckiae, and C. verruculosa represent new records of fungi from Sri Lanka. Citation: Ferdinandez HS, Manamgoda DS, Udayanga D, Munasinghe MS, Castlebury LA (2023). Molecular phylogeny and morphology reveal two new graminicolous species, Curvularia aurantia sp. nov. and C. vidyodayana sp. nov. with new records of Curvularia spp. from Sri Lanka. Fungal Systematics and Evolution 12: 219-246. doi: 10.3114/fuse.2023.12.11.

The antifungal properties of terpenoids from the endophytic fungus Bipolaris eleusines

A series of terpenoids (1-17), comprising six new compounds designated bipolariterpenes A-F (1-6) and eleven recognized compounds (7-17), were isolated from the wheat culture of the potato endophytic fungus Bipolaris eleusines. Their structures and stereochemistry were clarified by HRESIMS, NMR, DP4 + probability analyses, and computations for electronic circular dichroism (ECD). All compounds are made up of six meroterpenoids, four sesterterpenes and seven sesquiterpenes. Among them, four sesterterpenes (4, 5, 10, 11) were investigated for their antifungal, antibacterial and cytotoxic properties, and six meroterpenoids (1-3, 7-9) were evaluated for their antifungal properties. The compounds 7, 9, and 10 had substantial antifungal activity against Epidermophyton floccosum at a concentration of 100 µM. No antibacterial and cytotoxic activities were observed.

Biosynthesized silver nanoparticles enhanced wheat resistance to Bipolaris sorokiniana

Agronomic crops can benefit from the application of nanoscale materials in order to control phytopathogens and improve plant growth. Bipolaris sorokiniana, a soil- and seed-borne fungus, causes severe yield losses in wheat. In order to determine the physio-chemical changes in wheat under biotic stress of B. sorokiniana, the current study aimed to synthesis silver nanoparticles (AgNPs) using Allium sativum bulb extract. Herein, we applied the silver nanoparticles (AgNPs) as a foliar spray on two wheat varieties (Pakistan-2013, and NARC-2011) at the concentrations of 10, 20, 30, and 40 mg/L to suppress B. sorokiniana. Among all the applied concentrations of AgNPs, the 40 mg/L concentration demonstrated the most effective outcome in reduction of the intensity of spot blotch and improved the morphological, physiological, biochemical parameters, as well as antioxidant activity in wheat plant. Foliar application of AgNPs at 40 mg/L Pakistan-2013 and NARC-2011 wheat varieties significantly increased chlorophyll a 84.8% and 53.4%, chlorophyll b 28.9% and 84.3%, total chlorophyll content 294.3% and 241.2%, membrane stability index 7.5% and 6.1%, relative water contents 25.4% and 10.5%, proline content 320.5% and 609.9%, and soluble sugar content 120% and 259.4%, respectively, compared to control and diseased plant. This is the first study provides important insights into the role of phyto-mediated AgNPs in increasing resistant of wheat infected with B. sorokiniana. These findings offers valuable new insights that may be useful for reducing disease incidence in wheat fields.

Characterization of a Host-Specific Toxic Activity Produced by Bipolaris cookei, Causal Agent of Target Leaf Spot of Sorghum

Target leaf spot (TLS) of sorghum, caused by the necrotrophic fungus Bipolaris cookei, can cause severe yield loss in many parts of the world. We grew B. cookei in liquid culture and observed that the resulting culture filtrate (CF) was differentially toxic when infiltrated into the leaves of a population of 288 diverse sorghum lines. In this population, we found a significant correlation between high CF sensitivity and susceptibility to TLS. This suggests that the toxin produced in culture may play a role in the pathogenicity of B. cookei in the field. We demonstrated that the toxic activity is light sensitive and, surprisingly, insensitive to pronase, suggesting that it is not proteinaceous. We identified the two sorghum genetic loci most associated with the response to CF in this population. Screening seedlings with B. cookei CF could be a useful approach for prescreening germplasm for TLS resistance.

Differences in the Characteristics and Pathogenicity of Pyrenophora Species Associated with Seeds of Italian Ryegrass

Pyrenophora is a genus of pathogens that cause leaf damage and a common seedborne fungus of Italian ryegrass (Lolium multiflorum Lam.). To elucidate the main seedborne Pyrenophora species, 36 seed samples of Italian ryegrass were collected; in total, 113 strains, representing 12.3% of all isolated strains (921), were identified as Pyrenophora species using the identity of ITS sequences in NCBI and the similarity of morphological characteristics. P. dictyoides (97) was the most frequent species. By pure culture technique, 24 representative pure isolates were obtained for further study. Based on DNA analysis of multiple loci (ITS, LSU, GPDH, CHS-1, and RPB1) and morphological characters, eight Pyrenophora species were identified, P. avenicola, P. chaetomioides, P. dictyoides, P. lolii, P. nobleae, P. teres, P. triseptata, and P. tritici-repentis; among them, P. avenicola, P. tritici-repentis, and P. triseptata were newly reported on Italian ryegrass worldwide. Seed inoculation showed that P. dictyoides, P. lolii, and P. teres remarkably decreased the final germination percentages and germination indexes compared with control treatments (P ≤ 0.05); and plant inoculation showed that P. dictyoides, P. lolii, and P. nobleae could cause typical brown spot in vivo with a higher infection rate (P ≤ 0.05). In conclusion, pathogenicity tests showed that all Pyrenophora species could both inhibit seed germination and infect Italian ryegrass to different degrees; among them, P. dictyoides was the most important seedborne pathogen based on the combination of its isolation and infection rate, followed by P. lolii and P. nobleae. The data generated in this study are helpful for the accurate identification of Pyrenophora species and the development of seedborne disease management strategies.

Fungal diversity notes 1512-1610: taxonomic and phylogenetic contributions on genera and species of fungal taxa

This article is the 14th in the Fungal Diversity Notes series, wherein we report 98 taxa distributed in two phyla, seven classes, 26 orders and 50 families which are described and illustrated. Taxa in this study were collected from Australia, Brazil, Burkina Faso, Chile, China, Cyprus, Egypt, France, French Guiana, India, Indonesia, Italy, Laos, Mexico, Russia, Sri Lanka, Thailand, and Vietnam. There are 59 new taxa, 39 new hosts and new geographical distributions with one new combination. The 59 new species comprise Angustimassarina kunmingense, Asterina lopi, Asterina brigadeirensis, Bartalinia bidenticola, Bartalinia caryotae, Buellia pruinocalcarea, Coltricia insularis, Colletotrichum flexuosum, Colletotrichum thasutense, Coniochaeta caraganae, Coniothyrium yuccicola, Dematipyriforma aquatic, Dematipyriforma globispora, Dematipyriforma nilotica, Distoseptispora bambusicola, Fulvifomes jawadhuvensis, Fulvifomes malaiyanurensis, Fulvifomes thiruvannamalaiensis, Fusarium purpurea, Gerronema atrovirens, Gerronema flavum, Gerronema keralense, Gerronema kuruvense, Grammothele taiwanensis, Hongkongmyces changchunensis, Hypoxylon inaequale, Kirschsteiniothelia acutisporum, Kirschsteiniothelia crustaceum, Kirschsteiniothelia extensum, Kirschsteiniothelia septemseptatum, Kirschsteiniothelia spatiosum, Lecanora immersocalcarea, Lepiota subthailandica, Lindgomyces guizhouensis, Marthe asmius pallidoaurantiacus, Marasmius tangerinus, Neovaginatispora mangiferae, Pararamichloridium aquisubtropicum, Pestalotiopsis piraubensis, Phacidium chinaum, Phaeoisaria goiasensis, Phaeoseptum thailandicum, Pleurothecium aquisubtropicum, Pseudocercospora vernoniae, Pyrenophora verruculosa, Rhachomyces cruralis, Rhachomyces hyperommae, Rhachomyces magrinii, Rhachomyces platyprosophi, Rhizomarasmius cunninghamietorum, Skeletocutis cangshanensis, Skeletocutis subchrysella, Sporisorium anadelphiae-leptocomae, Tetraploa dashaoensis, Tomentella exiguelata, Tomentella fuscoaraneosa, Tricholomopsis lechatii, Vaginatispora flavispora and Wetmoreana blastidiocalcarea. The new combination is Torula sundara. The 39 new records on hosts and geographical distribution comprise Apiospora guiyangensis, Aplosporella artocarpi, Ascochyta medicaginicola, Astrocystis bambusicola, Athelia rolfsii, Bambusicola bambusae, Bipolaris luttrellii, Botryosphaeria dothidea, Chlorophyllum squamulosum, Colletotrichum aeschynomenes, Colletotrichum pandanicola, Coprinopsis cinerea, Corylicola italica, Curvularia alcornii, Curvularia senegalensis, Diaporthe foeniculina, Diaporthe longicolla, Diaporthe phaseolorum, Diatrypella quercina, Fusarium brachygibbosum, Helicoma aquaticum, Lepiota metulispora, Lepiota pongduadensis, Lepiota subvenenata, Melanconiella meridionalis, Monotosporella erecta, Nodulosphaeria digitalis, Palmiascoma gregariascomum, Periconia byssoides, Periconia cortaderiae, Pleopunctum ellipsoideum, Psilocybe keralensis, Scedosporium apiospermum, Scedosporium dehoogii, Scedosporium marina, Spegazzinia deightonii, Torula fici, Wiesneriomyces laurinus and Xylaria venosula. All these taxa are supported by morphological and multigene phylogenetic analyses. This article allows the researchers to publish fungal collections which are important for future studies. An updated, accurate and timely report of fungus-host and fungus-geography is important. We also provide an updated list of fungal taxa published in the previous fungal diversity notes. In this list, erroneous taxa and synonyms are marked and corrected accordingly.

Managing spot blotch disease in wheat: Conventional to molecular aspects

Spot blotch (SB) caused by Bipolaris sorokiniana (teleomorph Cochliobolus sativus) is one of the devastating diseases of wheat in the warm and humid growing areas around the world. B. sorokiniana can infect leaves, stem, roots, rachis and seeds, and is able to produce toxins like helminthosporol and sorokinianin. No wheat variety is immune to SB; hence, an integrated disease management strategy is indispensable in disease prone areas. A range of fungicides, especially the triazole group, have shown good effects in reducing the disease, and crop-rotation, tillage and early sowing are among the favorable cultural management methods. Resistance is mostly quantitative, being governed by QTLs with minor effects, mapped on all the wheat chromosomes. Only four QTLs with major effects have been designated as Sb1 through Sb4. Despite, marker assisted breeding for SB resistance in wheat is scarce. Better understanding of wheat genome assemblies, functional genomics and cloning of resistance genes will further accelerate breeding for SB resistance in wheat.

Identification of Pathogens and Evaluation of Resistance and Genetic Diversity of Maize Inbred Lines to Stalk Rot in Heilongjiang Province, China

Maize stalk rot, caused by multiple pathogens, is a serious soilborne disease worldwide. Composition of pathogens causing maize stalk rot and resistance of maize inbred lines in Heilongjiang Province, China, are not well understood. In this study, 138 fungal isolates were collected from different maize-producing areas in Heilongjiang Province, which were identified as Fusarium graminearum (23.2%), F. subglutinans (18.9%), F. cerealis (18.9%), Bipolaris zeicola (13.0%), F. brachygibbosum (13.0%), F. temperatum (7.2%), and F. proliferatum (5.8%). Among them, F. graminearum (>20%) was the predominant species among the isolates causing maize stalk rot. B. zeicola had not previously been reported causing maize stalk rot in China. Resistance of 67 maize inbred lines to maize stalk rot was assessed, and 24 lines (35.8% of them) were highly resistant or resistant, indicating that approximately 65% of these lines were susceptible to maize stalk rot. Maize inbred lines were analyzed using simple sequence repeat markers and divided into five genetic groups with 12 pairs of primers. Additionally, analysis of molecular variance indicated that 44.2% of the genetic variation in disease resistance was distributed among populations. This study provides insight into the genetic diversity of inbred maize and may contribute useful information for breeding stalk rot disease-resistant hybrids, and facilitates development of effective strategies for managing this destructive disease complex.

Re-Evaluating Botryosphaeriales: Ancestral State Reconstructions of Selected Characters and Evolution of Nutritional Modes

Botryosphaeriales (Dothideomycetes, Ascomycota) occur in a wide range of habitats as endophytes, saprobes, and pathogens. The order Botryosphaeriales has not been subjected to evaluation since 2019 by Phillips and co-authors using phylogenetic and evolutionary analyses. Subsequently, many studies introduced novel taxa into the order and revised several families separately. In addition, no ancestral character studies have been conducted for this order. Therefore, in this study, we re-evaluated the character evolution and taxonomic placements of Botryosphaeriales species based on ancestral character evolution, divergence time estimation, and phylogenetic relationships, including all the novel taxa that have been introduced so far. Maximum likelihood, maximum parsimony, and Bayesian inference analyses were conducted on a combined LSU and ITS sequence alignment. Ancestral state reconstruction was carried out for conidial colour, septation, and nutritional mode. Divergence times estimates revealed that Botryosphaeriales originated around 109 Mya in the early epoch of the Cretaceous period. All six families in Botryosphaeriales evolved in the late epoch of the Cretaceous period (66-100 Mya), during which Angiosperms also appeared, rapidly diversified and became dominant on land. Families of Botryosphaeriales diversified during the Paleogene and Neogene periods in the Cenozoic era. The order comprises the families Aplosporellaceae, Botryosphaeriaceae, Melanopsaceae, Phyllostictaceae, Planistromellaceae and Saccharataceae. Furthermore, current study assessed two hypotheses; the first one being "All Botryosphaeriales species originated as endophytes and then switched into saprobes when their hosts died or into pathogens when their hosts were under stress"; the second hypothesis states that "There is a link between the conidial colour and nutritional mode in botryosphaerialean taxa". Ancestral state reconstruction and nutritional mode analyses revealed a pathogenic/saprobic nutritional mode as the ancestral character. However, we could not provide strong evidence for the first hypothesis mainly due to the significantly low number of studies reporting the endophytic botryosphaerialean taxa. Results also showed that hyaline and aseptate conidia were ancestral characters in Botryosphaeriales and supported the relationship between conidial pigmentation and the pathogenicity of Botryosphaeriales species.

First report of Bipolaris sorokiniana leaf spot disease on watermelon (Citrullus lanatus) in Florida

Watermelon is an important crop in Florida, representing $88.2 million in cash receipts in 2015 (USDA/NASS 2017). In April and May 2021, the UF/IFAS Plant Diagnostic Center in Gainesville, Florida received eight diseased watermelon leaf samples from Alachua, Gilcrest, Levy, and Suwannee counties in Florida. Lesions were round to oblong, light gray to tan with reddish brown margins and white to light gray center, and some were coalescing resulting in about 15% disease severity. Symptomatic leaf tissue (0.5 cm2) was surface sterilized in 0.6% sodium hypochlorite for one minute, rinsed with sterile tap water, plated onto water agar media plates, and incubated at 27°C under 12-h light/dark cycle for 7 days. Characteristic Bipolaris conidia with gray to black brownish cottony mycelial growth were consistently found growing from plated lesions. The pathogen was isolated from two of the eight samples using a 0.5 mm diameter sterile metal needle to transfer a single conidium onto DifcoTM Potato Dextrose Agar (PDA) plates. Three isolates were designated G21-562 from Levy and G21-599a and G21-599b from Alachua County. All three isolates produced curved or straight, cylindrical, obclavate, distoseptate brownish gray conidia with 3 to 8 septa, mostly tapering towards ends with dark brownish to black hilum, that ranged from averaged 62um x 25um (n=30, SD=8 for length and 3 for width). Conidiophores were brownish, septate, smooth, and straight, single or in small groups, simple or branched, and swollen at the upper tip. Internal transcribed spacer region (ITS) and partial glyceraldehyde-3-phosphate dehydrogenase (GPDH) gene sequences were amplified using primers ITS1/ITS4 and GPD-1/GPD-2 (Berbee et al. 1999). Reference sequences (Adhikari et al. 2020 and Manamgoda et al. 2014) were aligned using MUSCLE and trimmed to consistent length. Using concatenated sequence alignments of both loci, a maximum likelihood phylogenetic tree was constructed based on K2+G substitution model selected by BIC using Mega X (Kumar et al. 2018) with 1,000 bootstrap. The ITS and GPDG sequences of G21_599b, G21_599a and G21_562 (GenBank accessions OK614094 to 96, OP297398 to 400) showed 100% identity across 888 nucleotides across both loci to B. sorokiniana isolates CBS_110.14 and CBS_ 120.24 and were distinct from other reference isolates. To fulfill Koch's postulates, all three isolates were grown on PDA at 27°C and 12-h light/dark cycle. After a week, conidia were harvested in sterile water, and the conidial suspensions were adjusted to 105 conidia/ml using a hemocytometer. Each conidial suspension and Tween 20 water control was sprayed onto three seedlings of 'Sugar Baby' watermelon until runoff, and inoculated seedlings were sealed in a plastic bag for 24 hrs. The experiment was done in a greenhouse (20- 25°C) and repeated once. After a week of incubation, the same leaf lesion symptoms described above were observed on seedlings inoculated with conidia, whereas seedlings sprayed with the control were asymptomatic. Isolations from symptomatic tissue produced gray to black mycelia with conidia that were the same as described from field samples. To our knowledge, this is the first report of leaf spot on watermelon caused by B. sorokiniana. B. sorokiniana is a common pathogen of grasses and agronomic crops (Farr and Rossman 2020). The extent to which this emerging disease of Florida watermelon may negatively impact production is unknown and should be the subject of future observation and research.

A Variety of Fungal Species on the Green Frogs' Skin (Pelophylax esculentus complex) in South Banat

In the last several decades, amphibian populations have been declining worldwide. Many factors have been linked to global amphibian decline, including habitat destruction, pollution, introduced species, global environmental changes, and emerging infectious diseases. Recent studies of amphibian skin infections were mainly focused on the presence of chytridiomycosis, neglecting other members of the frogs' skin communities. The diversity pattern of fungal dwellers on the skin of green frogs (Pelophylax esculentus complex) was investigated. A total of 100 adults were sampled from three localities in South Banat (northern Serbia) over three consecutive years and detected fungal dwellers were identified using light microscopy and ITS and BenA gene sequencing. Structures belonging to fungi and fungus-like organisms including a variety of spores and different mycelia types were documented in the biofilm formed on amphibian skin, and are classified into 10 groups. In total, 42 fungal isolates were identified to species, section, or genus level. The difference in mycobiota composition between sampling points (localities and green frog taxa) was documented. The highest number of fungal structures and isolates was recorded on the hybrid taxon P. esculentus and locality Stevanove ravnice. Parental species showed a markedly lower diversity than the hybrid taxon and were more similar in diversity patterns and were placed in the same homogenous group. The locality Stevanove ravnice exhibited more pronounced differences in diversity pattern than the other two localities and was placed in a distinct and separate homogenous group. Among the fungal isolates, the highest isolation frequency was documented for Alternaria alternata, Aspergillus sp. sect. Nigri, Epicoccum nigrum, Fusarium proliferatum, and Trichoderma atroviride. Among the documented species, dematiaceous fungi, causative agents of chromomycosis in amphibians, were also recorded in this research with high isolation frequency. Also, some rare fungal species such as Quambalaria cyanescens and Pseudoteniolina globosa are documented for the first time in this research as microbial inhabitants of amphibian skin.

Improved Bioherbicidal Efficacy of Bipolaris eleusines through Herbicide Addition on Weed Control in Paddy Rice

Bipolaris eleusines was mixed with herbicides to improve the control of barnyardgrass (Echinochloa crus-galli), a noxious weed in rice fields. The compatibility of B. eleusines with herbicides was evaluated for toxic effects on spore germination and mycelium growth in vitro tests, and varied effects were observed with different chemical products. Briefly, 25 g/L penoxsulam OD plus 10% bensulfuron-methyl WP were much more compatible with B. eleusines, and there was no inhibition of spore germination but the promotion of mycelium growth of B. eleusines at all treatment rates. Under greenhouse conditions, the coefficient of the specificity of B. eleusines conidial agent was determined as 3.91, closer to the herbicidal control of 2.89, showing it is highly specific between rice and barnyardgrass. Field experiments in 2011 and 2012 showed that B. eleusines conidial agent displayed good activity on barnyardgrass, monochoria [Monochoria vaginalis (Burm.f.) Presl. Ex Kunth.], and small-flower umbrella sedge (Cyperus difformis L.) and had no negative impact on the rice plant. It also reduced the loss of rice yield when compared with the non-treated control and could make this pathogen a conidial agent for commercial bioherbicidal development in the future.

Antimicrobial activity of the biologically synthesized zinc oxide nanoparticles against important rice pathogens

Global rice production is seriously affected by many abiotic and biotic factors. Among the aggressive rice pathogens, Xanthomonas oryzae pv. oryzae (X. o. pv. oryzae), Bipolaris oryzae (B. oryzae) and Sphaerulina oryzina (S. oryzina) cause bacterial leaf blight, brown leaf spot and narrow brown leaf spot diseases, respectively. The objective of this study was to evaluate the efficacy of biogenic zinc oxide nanoparticles (ZnO NPs) as antimicrobial agent to control rice pathogens. This is the first report of antifungal activity evaluation of ZnO NPs against B. oryzae and S. oryzina. A pre-characterized bacterial strain Escherichia sp. SINT7 was bio-prospected for synthesis of green ZnO NPs. The NPs were confirmed by a characteristic peak measured at 360.96 nm through UV-Vis spectroscopy. Further, the NPs were characterized to elucidate the surface capping molecules, crystallite structure and morphology by various spectroscopic and imaging techniques, which confirmed the spherical shape of NPs with size ranging from 13.07 to 22.25 nm. In vitro studies against X. o. pv. oryzae pathogen depicted the substantial antibacterial activity (up to 25.7 mm inhibition zone at 20 μg/ml NPs concentration). Similarly, ZnO NPs reduced the mycelial growth of B. oryzae and S. oryzina up to 72.68 and 95.78%, respectively at 50 μg/ml concentration on potato dextrose agar plates, while the mycelial biomass reduction was found to be 64.66 and 68. 49% for B. oryzae and S. oryzina, respectively on potato dextrose broth media as compared to control without the addition of NPs. The green ZnO NPs also significantly reduced the fungal spore germination and a disintegration of fungal hyphae for both fungal strains was observed under the microscope as a result of NPs treatment. Hence, it was concluded that biologically synthesized ZnO NPs are potential antimicrobials and could be compared in greenhouse pathogenicity assays with commercial pesticides to control rice pathogens.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12298-022-01251-y.

Filamentous Fungal Keratitis in Greece: A 16-Year Nationwide Multicenter Survey

In a multicenter, prospective study of filamentous fungal keratitis in Greece, predisposing factors, etiology, treatment practices, and outcome, were determined. Corneal scrapings were collected from patients with clinical suspicion of fungal keratitis, and demographic and clinical data were recorded. Fungal identification was based on morphology, molecular methods, and matrix assisted laser desorption ionization time-of-flight mass-spectrometry. A total of 35 cases were identified in a 16-year study period. Female to male ratio was 1:1.7 and median age 48 years. Corneal injury by plant material, and soft contact lens use were the main risk factors (42.8% and 31.4%, respectively). Trauma was the leading risk factor for men (68.1%), contact lens use (61.5%) for women. Fusarium species were isolated more frequently (n = 21, 61.8%). F. solani was mostly associated with trauma, F. verticillioides and F. proliferatum with soft contact lens use. Other fungi were: Purpureocillium lilacinum (14.7%), Alternaria (11.8%), Aspergillus (8.8%), and Phoma foliaceiphila, Beauveria bassiana and Curvularia spicifera, one case each. Amphotericin B and voriconazole MIC₅₀s against Fusarium were 2 mg/L and 4 mg/L respectively. Antifungal therapy consisted mainly of voriconazole locally or both locally and systemically, alone or in combination with liposomal AmB. Cure/improvement rate with antifungal therapy alone was 52%, keratoplasty was required in 40% of cases, and enucleation in 8%. In conclusion, filamentous fungal keratitis in Greece is rare, but with considerable morbidity. A large proportion of cases resulted in keratoplasty despite appropriate antifungal treatment.Kindly confirm the given name and family name are correctly identified for all authros.ConfirmedJournal instruction requires a city and country for affiliations; however, these are missing in affiliations 1, 3, 4, 5, 6, 13. Please verify if the provided city and country are correct and amend if necessary.All provided cities and countries are correct.

First Report of Brown Leaf Spot of Elymus nutans Caused by Bipolaris sorokiniana in Northwestern China

Elymus nutans is an important feed and forage resource in alpine region of northwestern China, and helps to maintain the ecological balance on Qinghai-Tibetan plateau (Fei et al. 2010). In September 2021, brown leaf spots were observed in Shandan Horse Farm (38.3061°N, 101.2453°E), Gansu province of China.Disease severity of leaves was estimated to be 38% based on a random sample of 100 leaves from each of 10 arbitrarily placed quadrats on the farm.The typical symptoms on leaves appeared as brown to dark brown spots with grayish white in the center, surrounded by a yellow halo. A total of twenty diseased leaves were collected from five different plants in the field. The lesions (about 5 mm) from these samples were initially soaked in 75% ethanol for 30 s followed by soaking in 1% NaClO solution for 1 min, repeatedly rinsed with sterilized water, air dried, and put on potato dextrose agar (PDA). After 7 days of incubation at 25°C in the dark, the same fungus was consistently isolated; the pure isolates were obtained by single-spore cultures (Cai et al. 2009). The colonies were irregular in shape and black in color with white margins. Conidia were spindle-shaped, dark brown, 5 to 9 septa (7 septa in general), and a size range of 21.74 to 78.97 × 7.95 to 21.12 µm (avg. 57.25 × 17.76 µm, n = 50),morphologically similar to B. sorokiniana reported on Avena nuda in China (Li et al. 2019). The ITS region of rDNA and partial glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene of the representative isolate PJC5 were amplified using the primers ITS1/ITS4 and gpd1/gpd2, respectively (Manamgoda et al. 2014). After sequencing sequences were deposited into GenBank with accession numbers OM419194 (ITS) and OM718009 (GAPDH). BLAST analysis showed 99% and 100% identity with the corresponding sequences (accession numbers MH855159.1 and HG779088.1) of known strain CBS 140.31 of B. sorokiniana (Manamgoda et al. 2014). For pathogenicity tests, ten 8-week-old healthy plants obtained by growing E. nutans in pots were spray-inoculated separately with a conidia suspension of 1 × 106 conidia/ml of isolate PJC5. Ten plants were also sprayed with sterilized distilled water as controls. Then all plants were individually covered with transparent polyethylene bags for three days to maintain high relative humidity and placed in greenhouse at 25°C. Seven days after inoculation, symptoms of leaf infection were similar to those observed in the field, while no symptoms appeared on leaves of control plants. The experiments were conducted three times and the pathogen was re-isolated from inoculated leaves and was confirmed as B. sorokiniana based on morphological and molecular analyses. B. sorokiniana has been reported to cause leaf spot of E. riparius in the United States (Roane et al. 2005) and E. breviaristatus (Zhuang, 2005) and A. nuda (Li et al. 2019) in China. To our knowledge, this is the first report of B. sorokiniana causing leaf spot on E. nutans in China. Identifying this pathogen provides a foundation to prevent this complex disease and to reduce economic loss.

First Report of Bipolaris oryzae on Typha latifolia and the Pathogenicity of Its Isolates on Different Rice Varieties

Rice ( Oryza sativa L.) is the staple food of more than half of the world population. However, its production is facing several biotic constraints. Among serious biotic factors that harm rice crops, the Helminthosporium disease has severe adverse impacts on rice yield, generating heavy losses of up to 90%. Four Bipolaris oryzae isolates were recovered for the first time from leaf lesions in the weed species Typha latifolia , and then subjected to pathogenicity tests on several rice varieties. The results indicated that Moroccan isolates of B. oryzae altered the leaf surface of five rice varieties tested. Among four isolates, Hor4 was the most pathogenic, showing high aggressiveness on the Cererrer and Elio varieties, with disease severity of 92.59%, followed by the Hor1, Hor2, and Hor3 isolates. The Arpa variety showed higher resistance to the Hor1 isolate, with a severity index of 35.18%. Through mycelial cutting or conidial suspension, B. oryzae isolated from T. latifolia was able to produce conidia on the leaves of this weed species.

Molecular diversity, haplotype distribution and genetic variation flow of Bipolaris sorokiniana fungus causing spot blotch disease in different wheat-growing zones

Bipolaris sorokiniana (BS) is an economically important fungal pathogen causing spot blotch of wheat (Trtiticum aestivum) and found in all wheat-growing zones of India. Very scanty and fragmentary information is available on its genetic diversity. The current research is the first detailed report on the geographic distribution and evolution of BS population in five geographically distinct wheat-growing zones (North Western Plain Zone (NWPZ), North Eastern Plain zone (NEPZ), North Hill Zone (NHZ), Southern Hill Zone (SHZ) and Peninsular Zone (PZ)) of India, studied by performing nucleotide sequence comparison of internal transcribed spacer region of 528 isolates. A moderate to low levels of haplotypic diversity was noticed in different wheat-growing zones. Phylogenetic analysis suggests that B. sorokiniana exist in two distinct lineages as all isolates under study were grouped in two different clades and found analogous to the findings of haplotypic and TCS network analysis. The genetic parameters revealed the existence of 40 haplotypes with three major haplotypes (H-1, H-2 and H-3) which showed star-like structure network surrounded by several single haplotypes, revealing high frequency of the mutations (Eta = 2 - 158) in total analyzed population. H-1 was observed as a predominant haplotype and prevalent in all the five zones. Moderate level of genetic differentiation was found between NHZ and other zones like NWPZ (F_st = 0.332) and SHZ (F_st = 0.382) and PZ (F_st = 0.299), whereas it was low between NEPZ and PZ (F_st = 0.034). Higher transfer rate of genetic variation was noticed between NEPZ and PZ (N_m = 7.06), while it was found minimum between NHZ and SHZ (N_m = 0.40). Moreover, negative score of neutrality statistics (Tajima's D and Fu's FS test) for NWPZ population suggested recent population expansion. However, positive score for both the neutrality tests observed in NEPZ indicated the dominance of balancing selection in structuring their population. Recombination events were observed in the NWPZ and NHZ population, while it was absent in SHZ, NEPZ and PZ population. Thus, the lack of any specific genetic population structure in all the zones indicates for the expansion history only from one common source population, i.e. NWPZ, a mega zone of wheat production in India. Overall, it seems that the predominance of individual haplotypes with a moderate level of genetic variation and human-mediated movement of contaminated seed and dispersal of inoculum, mutations and recombination as prime evolutionary processes play essential role in defining the genetic structure of BS population.

Multi-Gene Phylogenetic Approach for Identification and Diversity Analysis of Bipolaris maydis and Curvularia lunata Isolates Causing Foliar Blight of Zea mays

Bipolaris species are known to be important plant pathogens that commonly cause leaf spot, root rot, and seedling blight in a wide range of hosts worldwide. In 2017, complex symptomatic cases of maydis leaf blight (caused by Bipolaris maydis) and maize leaf spot (caused by Curvularia lunata) have become increasingly significant in the main maize-growing regions of India. A total of 186 samples of maydis leaf blight and 129 maize leaf spot samples were collected, in 2017, from 20 sampling sites in the main maize-growing regions of India to explore the diversity and identity of this pathogenic causal agent. A total of 77 Bipolaris maydis isolates and 74 Curvularia lunata isolates were screened based on morphological and molecular characterization and phylogenetic analysis based on ribosomal markers-nuclear ribosomal DNA (rDNA) internal transcribed spacer (ITS) region, 28S nuclear ribosomal large subunit rRNA gene (LSU), D1/D2 domain of large-subunit (LSU) ribosomal DNA (rDNA), and protein-coding gene-glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Due to a dearth of molecular data from ex-type cultures, the use of few gene regions for species resolution, and overlapping morphological features, species recognition in Bipolaris has proven difficult. The present study used the multi-gene phylogenetic approach for proper identification and diversity of geographically distributed B. maydis and C. lunata isolates in Indian settings and provides useful insight into and explanation of its quantitative findings.

Whole-genome sequence analysis of Bipolaris sorokiniana infecting wheat in India and characterization of ToxA gene in different isolates as pathogenicity determinants

Spot blotch disease of wheat caused by Bipolaris sorokiniana Boerma (Sacc.) is an emerging problem in South Asian countries. Whole genome of a highly virulent isolate of B. sorokiniana BS112 (BHU, Uttar Pradesh; Accession no. GCA_004329375.1) was sequenced using a hybrid assembly approach. Secreted proteins, virulence gene(s), pathogenicity-related gene(s) were identified and the role of ToxA gene present in this genome, in the development of disease was recognized. ToxA gene (535 bp) was analyzed and identified in the genome of B. sorokiniana (BS112) which revealed 100% homology with the ToxA gene of Pyrenophora tritici repentis (Accession no. MH017419). Furthermore, ToxA gene was amplified, sequenced and validated in 39 isolates of B. sorokiniana which confirmed the presence of ToxA gene in all the isolates taken for this study. All ToxA sequences were submitted in NCBI database (MN601358-MN601396). As ToxA gene interacts with Tsn1 gene of host, 13 wheat genotypes were evaluated out of which 5 genotypes (38.4%) were found to be Tsn1 positive with more severe necrotic lesions compared to Tsn1-negative wheat genotypes. In vitro expression analysis of ToxA gene in the pathogen B. sorokiniana using qPCR revealed maximum upregulation (14.67 fold) at 1st day after inoculation (DAI) in the medium. Furthermore, in planta expression analysis of ToxA gene in Tsn1-positive and Tsn1-negative genotypes, revealed maximum expression (7.89-fold) in Tsn1-positive genotype, Agra local at 5th DAI compared to Tsn1-negative genotype Chiriya 7 showing minimum expression (0.048-fold) at 5th DAI. In planta ToxA-Tsn1 interaction studies suggested that spot blotch disease is more severe in Tsn1-positive genotypes, which will be helpful in better understanding and management of spot blotch disease of wheat.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-022-03213-3.

Fungal Diversity in Barley Under Different Storage Conditions

The diversity of fungi in barley in simulated storage environments was analyzed. Barley was stored at different temperatures (15, 25, 35°C) and relative humidity (55, 65, 75, 85 RH) for 180 and 360 days. Alpha diversity, beta diversity, species composition, and species differences were analyzed using Illumina HiSeq technology. The fungal communities in all barley samples before and after storage belonged to 3 phyla, 18 classes, 39 orders, 71 families, 103 genera, and 152 species. The relative abundance of the dominant phylum Ascomycota was 77.98–99.19%. The relative abundance of Basidiomycota was 0.77–21.96%. At the genus level, the dominant genera of fungi in barley initially included Fusarium, Aspergillus, Microdochium, Alternaria, and Epicoccum. After 360 days of storage, the dominant genera became Epicoccum, Alternaria, Bipolar, Cladosporium, Fusarium, and Aspergillus. According to Venn diagrams and principal coordinates analysis, the fungal community diversity in barley initially was much higher than in barley stored at different temperatures and humidity. The application of PLS-DA could accurately distinguish between barley stored for 180 and 360 days. Some high-temperature and high-humidity environments accelerated storage. The dominant genera differed in different storage conditions and constantly changed with increasing storage duration. Epicoccum was one of the dominant genera after longer storage periods. This study provides theoretical support for optimizing safe storage conditions in barley.

Comparative study of antifungal activity of two preparations of green silver nanoparticles from Portulaca oleracea extract

The green silver nanoparticles (green AgNPs) exhibit an exceptional antimicrobial property against different microbes, including bacteria and fungi. The current study aimed to compare the antifungal activities of both the crude aqueous extract of Portulaca oleracea or different preparations of green AgNPs biosynthesized by mixing that aqueous extract with silver nitrate (AgNO3). Two preparations of the green AgNPs were synthesized either by mixing the aqueous extract of P. oleracea with silver nitrate (AgNO3) (normal AgNPs) or either irradiation of the AgNPs, previously prepared, under 60Co γ-ray using chitosan (gamma-irradiated AgNPs). Characterization of different AgNPs were tested by Zeta potential analyzer, Ultraviolet (UV) Visible Spectroscopy, and Fourier-Transform Infrared (FTIR) spectrometry. Three different plant pathogenic fungi were tested, Curvularia spicifera, Macrophomina phaseolina, and Bipolaris sp. The antifungal activities were evaluated by Transmission Electron Microscope (TEM) for either the crude aqueous extract of P. oleracea at three doses (25%, 50%, and 100%) or the newly biosynthesized AgNPs, normal or gamma-irradiated. With a few exceptions, the comparative analysis revealed that the irradiated green AgNPs at all three concentrations showed a relatively stronger antifungal effect than the normal AgNPs against all the three selected fungal strains. UV-visible spectroscopy of both preparations showed surface plasmon resonance at 421 nm. TEM results showed that both AgNPs were aggregated and characterized by a unique spherical shape, however, the gamma-irradiated AgNPs were smaller than the non-irradiated AgNPs (0.007-0.026 µM vs. 0.009-0.086 µM). TEM photographs of the fungal strains treated with the two AgNPs preparations showed flaccid structures, condensed hyphae, and shrunken surface compared with control cells. The data suggested that the biosynthesized P. oleracea AgNPs have antifungal properties against C. spicifera, M. phaseolina, and Bipolaris sp. These AgNPs may be considered a fungicide to protect different plants against phytopathogenic fungi.

A Genetic Resource for Rice Improvement: Introgression Library of Agronomic Traits for All AA Genome Oryza Species

Rice improvement depends on the availability of genetic variation, and AA genome Oryza species are the natural reservoir of favorable alleles that are useful for rice breeding. To systematically evaluate and utilize potentially valuable traits of new QTLs or genes for the Asian cultivated rice improvement from all AA genome Oryza species, 6,372 agronomic trait introgression lines (ILs) from BC2 to BC6 were screened and raised based on the variations in agronomic traits by crossing 170 accessions of 7 AA genome species and 160 upland rice accessions of O. sativa as the donor parents, with three elite cultivars of O. sativa, Dianjingyou 1 (a japonica variety), Yundao 1 (a japonica variety), and RD23 (an indica variety) as the recurrent parents, respectively. The agronomic traits, such as spreading panicle, erect panicle, dense panicle, lax panicle, awn, prostrate growth, plant height, pericarp color, kernel color, glabrous hull, grain size, 1,000-grain weight, drought resistance and aerobic adaption, and blast resistance, were derived from more than one species. Further, 1,401 agronomic trait ILs in the Dianjingyou 1 background were genotyped using 168 SSR markers distributed on the whole genome. A total of twenty-two novel allelic variations were identified to be highly related to the traits of grain length (GL) and grain width (GW), respectively. In addition, allelic variations for the same locus were detected from the different donor species, which suggest that these QTLs or genes were conserved and the different haplotypes of a QTL (gene) were valuable resources for broadening the genetic basis in Asian cultivated rice. Thus, this agronomic trait introgression library from multiple species and accessions provided a powerful resource for future rice improvement and genetic dissection of agronomic traits.

A fungal Bipolaris bicolor strain as a potential bioherbicide for goosegrass (Eleusine indica) control

BACKGROUND

Tea, one of the most important commercial crops on earth, is strongly affected by weeds on productivity and quality. Bioherbicides are shedding new light on weed control in tea gardens in an economical and safe manner.

RESULTS

A pathogenic strain SYNJC-2-2 was isolated from diseased leaves of a noxious weed, goosegrass (Eleusine indica), from a tea garden in Zhejiang Province, China. It was identified as the fungal species Bipolaris bicolor based on the morphological characteristics and phylogenetic analysis. The potential of the B. bicolor strain SYNJC-2-2 as a bioherbicide was assessed by determining its efficacy to control weeds and selectivity to crops, its infection process and the influence of environmental conditions on conidial production and germination. The ED₉₀ (effective dose of conidia resulting in 90 disease index) of SYNJC-2-2 on goosegrass was 2 × 10⁴ conidia mL^-1 . Additionally, three Poaceae weeds, Setaria viridis, Microstegium vimineum and Pennisetum alopecuroides, were also extremely susceptible to SYNJC-2-2. SYNJC-2-2 was safe to 14 out of 17 crop species in nine families, especially tea plants. Conidial germination, hyphal growth and appressorial formation occurred within 3 to 6 h on goosegrass leaves. Hyphae invaded leaf tissues mainly through epidermal cell junctions and cracks, causing cell death and necrotic lesions within 2 days on inoculated leaves and killing goosegrass plants within 7 days. Furthermore, SYNJC-2-2 has a strong adaptability to environmental variables and high conidial production capacity on goosegrass juice agar media.

CONCLUSION

Bipolaris bicolor strain SYNJC-2-2 has the potential to be developed as a bioherbicide for controlling goosegrass, especially in tea gardens.

The fungal root endophyte Serendipita vermifera displays inter-kingdom synergistic beneficial effects with the microbiota in Arabidopsis thaliana and barley

Plant root-associated bacteria can confer protection against pathogen infection. By contrast, the beneficial effects of root endophytic fungi and their synergistic interactions with bacteria remain poorly defined. We demonstrate that the combined action of a fungal root endophyte from a widespread taxon with core bacterial microbiota members provides synergistic protection against an aggressive soil-borne pathogen in Arabidopsis thaliana and barley. We additionally reveal early inter-kingdom growth promotion benefits which are host and microbiota composition dependent. Using RNA-sequencing, we show that these beneficial activities are not associated with extensive host transcriptional reprogramming but rather with the modulation of expression of microbial effectors and carbohydrate-active enzymes.

Current Insight into Traditional and Modern Methods in Fungal Diversity Estimates

Fungi are an important and diverse component in various ecosystems. The methods to identify different fungi are an important step in any mycological study. Classical methods of fungal identification, which rely mainly on morphological characteristics and modern use of DNA based molecular techniques, have proven to be very helpful to explore their taxonomic identity. In the present compilation, we provide detailed information on estimates of fungi provided by different mycologistsover time. Along with this, a comprehensive analysis of the importance of classical and molecular methods is also presented. In orderto understand the utility of genus and species specific markers in fungal identification, a polyphasic approach to investigate various fungi is also presented in this paper. An account of the study of various fungi based on culture-based and cultureindependent methods is also provided here to understand the development and significance of both approaches. The available information on classical and modern methods compiled in this study revealed that the DNA based molecular studies are still scant, and more studies are required to achieve the accurate estimation of fungi present on earth.

In silico analyses of maleidride biosynthetic gene clusters

Maleidrides are a family of structurally related fungal natural products, many of which possess diverse, potent bioactivities. Previous identification of several maleidride biosynthetic gene clusters, and subsequent experimental work, has determined the 'core' set of genes required to construct the characteristic medium-sized alicyclic ring with maleic anhydride moieties. Through genome mining, this work has used these core genes to discover ten entirely novel putative maleidride biosynthetic gene clusters, amongst both publicly available genomes, and encoded within the genome of the previously un-sequenced epiheveadride producer Wicklowia aquatica CBS 125634. We have undertaken phylogenetic analyses and comparative bioinformatics on all known and putative maleidride biosynthetic gene clusters to gain further insights regarding these unique biosynthetic pathways.

First report of Curvularia intermedia Boedijn causing leaf blight disease on Microstegium vimineum in China

Stiltgrass [Microstegium vimineum (Trin.) A. Camus], is an annual C4 grass of Asiatic origin whose native range includes India, Pakistan, Nepal, China, Korea, and Japan (Cole et al 2004). In China, it is mainly distributed south of the Yangtze River, and is one of the most important weeds in autumn-maturing dryland crops, orchards, tea gardens, and plantations. With its high shade tolerance, M. vimineum also invades forest understories and crowds out the local vegetation (Warren et al. 2011). From June to August 2019, a leaf disease was observed causing severe defoliation of stiltgrass on the roadside of Sun Yat-sen Mausoleum in Nanjing City, Jiangsu Province, China (32.045964°N, 118.840064°E). Yellow or yellow-brown necrotic spots were observed on leaf tips and margins of the lower canopy, which later expanded to the entire leaf and progressed up the plant. Disease incidence was approximately 75-85% in August. Thirty symptomatic leaves were collected, and tissue samples (5 × 5 mm) were surface disinfected with 75% ethanol for 30 s, 0.02% NaClO for 30 s, 75% ethanol for 30 s, and washed twice with sterile water. Disinfected tissues were placed on potato dextrose agar (PDA) and incubated at 28°C for 5 days. Twenty-seven morphologically similar isolates were obtained from the leaves and purified by single-spore culturing for further study. Colonies on PDA were 70 to 85 mm in diameter after 4 to 5 days, initially white becoming gray-green with flocculent aerial mycelia. Conidiophores were solitary or clustered, 85 to 139 µm long × 5 to 8 µm wide (n = 50), and conidia were obclavate to ellipsoid or spindle shaped, brown, and measured 28 to 37 µm long × 13 to 18 µm wide (n = 50) with three false dissepiments. All characteristics were consistent with the morphology of Curvularia intermedia Boedijn (Sivanesan 1987). The rDNA internal transcribed spacer (ITS), glyceraldehyde-3-phosphate dehydrogenase (GPDH) and translation elongation factor (TEF) of a representative isolate (JSNJ-2019) were amplified using primers ITS1/ITS4, GPD1/GPD2 and EF1-983F/EF1-2218R (Manamgoda et al. 2014). The ITS sequence of JSNJ-2019 (GenBank: MZ613310) showed 99.83% (582/583bp) identity with C. intermedia (GenBank: MF370184 and GU073102); the GPDH sequence (GenBank: MZ701795) showed 99.66% (581/583bp) identity with C. intermedia (GenBank: LT715828) and the TEF sequence (Genbank: OM282974) showed 99.77% (864/866bp) identity with C. intermedia (GenBank: MF370186). Phylogenetic analysis based on the TEF sequences using Maximum-Likelihood and Bayesian methods placed JSNJ-2019 in the same clade with reference strain C. intermedia B19. The isolate was deposited in China Centre for Type Culture Collection (CCTCC) (Isolate code: CCTCC AF 2022041). For the pathogenicity assay, ten healthy M. vimineum plants grown in plastic pots (five to six leaf stage) were sprayed with 20ml conidial suspension (5×104 spores /ml); another ten healthy plants sprayed with sterile water served as controls. All inoculated and control plants were covered with transparent polyethylene bags immediately and were maintained in a greenhouse at 28±1℃. The transparent polyethylene bags were removed after 24 hours. The pathogenicity test was repeated three times. Five days post-inoculation, inoculated plants showed leaf blight symptoms as observed in the field, whereas no disease symptoms was observed on control plants. Reisolations were performed from inoculated plants, and the reisolated pathogen was confirmed as C. intermedia inter based on morphological and PCR assay (Konstantinova et al. 2002). No pathogens were isolated from control plants. Host range tests showed, C. intermedia JSNJ-2019 was pathogenic on corn, wheat, sorghum, barnyardgrass, crabgrass, green foxtail, Chinese sprangletop, cynodon, cogongrass, goosegrass, purslane and bedstraw and non-pathogenic on barley, rice, oat, cotton, bean, peanuts, rapeseed, tobacco and tea. These findings suggest C. intermedia could be used as a biocontrol agent against invasive M. vimineum and farmland weeds. However, application of C. intermedia as a bioherbicide should be limited to insensitive crop growing areas.

Bipolarithizole A, an antifungal phenylthiazole-sativene merosesquiterpenoid from the potato endophytic fungus Bipolaris eleusines

Bipolarithizole A (1) is a phenylthiazole-sativene sesquiterpenoid hybrid isolated from the fungus Bipolaris eleusines. It shows anti-pathogenic fungi activity against Rhizoctonia solani with an MIC value of 16 μg mL−1.