Asexual Fungi Research Articles

Systematic revision of species of Atractilina and Spiropes hyperparasitic on Meliolales (Ascomycota) in the tropics.

Atractilina Dearn. & Barthol. and Spiropes Cif. are genera of asexual fungi that comprise species mainly hyperparasitic on black mildews (Meliolales, Ascomycota). Although a common group of anamorphic fungi, they have been described up to now only by morphology and their systematic position is unknown. The present study provides a morphological treatise of all known species of Atractilina and Spiropes hyperparasitic on Meliolales, including insights into their systematic position, based on DNA sequences generated here for the first time. The study was conducted, based on 33 herbarium specimens and 23 specimens recently collected in Benin and Panama. The obtained DNA sequence data (28S rDNA and ITS rDNA) of A.parasitica and of two species of Spiropes show systematic placements in the Dothideomycetes and Leotiomycetes, respectively. The sequence data of the two Spiropes spp. do not group together. Moreover, the anamorph-teleomorph connection between Atractilinaparasitica and Malacariameliolicola, a pseudothecioid fungus, is confirmed. Three species in the genus Spiropes are proposed as new to science, namely S.angylocalycis, S.carpolobiae and S.croissantiformis. Four species are reported for Benin for the first time, three species for Panama and one species for mainland America. Atractilina and Spiropes are currently two genera with highly heterogeneous species and they might have to be split in the future, once the taxonomic concepts are validated by morphology and molecular sequence data.

Ascomycota In the Shallow Ecoregion of Catarina, Caatinga, Brazil: Part 1

Objective: Inventories of fungi are essential, but they are rarely carried out, especially in areas of the Caatinga biome. It is therefore important to carry out surveys and mapping to make knowledge more accessible. In this context, the aim of this work was to organize and discuss the information and data related to the fungi of Raso da Catarina, cataloguing and presenting the first checklist of Ascomycota in an insufficiently researched locality, adding knowledge from scientific collections, publications, and field expeditions. Method: Literature searches were carried out on the Ascomycota of the Raso da Catarina Ecoregion; consultations of the Fungal Databases, U.S. National Fungus Collections, the EMBRAPA database (Fungi Reported on Plants in Brazil) and the Mycology Collections Portal; consultations of the speciesLink networks that integrate data from scientific collections; consultations of the Reflora Virtual Herbarium and the INCT-Herbário Virtual da Flora e dos Fungos. In addition to field expeditions in areas of the Raso da Catarina in the municipalities of Paulo Afonso, Jeremoabo and Glória. Results and conclusion: A total of 243 taxa comprising 75 asexual fungi, 85 lichenized sexual fungi and 73 non-lichenized sexual fungi, distributed in 148 genera, were catalogued. This work represents an initiative to systematize research carried out in Raso da Catarina, with the aim of adding knowledge to the estimate of Ascomycota species in the Caatinga. Originality/value: Work on fungi in areas of the Raso da Catarina is still incipient. Some data is scattered in a few publications and many taxa are in scientific collections without being published. This is therefore the first checklist of Ascomycota for the Ecoregion and provides relevant information.

Dinámica de crecimiento, esporulación y captura de hongos asexuales sobre Meloidogyne sp., in vitro

Root-knot nematodes are detrimental to agricultural crops and hard to control once established in the field. The objective of this research was to evaluate the growth, sporulation, and capture in vitro of asexual fungi against Meloidogyne sp. Molecular identification of the asexual fungi included in the study was performed by sequencing the ITS1 region of rDNA. The growth and sporulation of Arthrobotrys sp., Dactylellina sp. and Dactylaria sp. was evaluated in five culture media and two types of substrates (rice husks and ground corn). For the evaluation of attraction and capture of the nematodes, second stage juveniles of Meloidogyne sp. All the evaluated fungal isolates grew and sporulated in the culture media and substrates. The fungi Arthrobotrys sp. (C19-1-1) and Dactylellina sp. (C19-48) showed greater effectiveness in attracting and capturing Meloidogyne sp. The evaluated fungal isolates have the potential to colonize different culture media and substrates. In addition, they can form modified and specialized hyphae that control juvenile Meloidogyne sp. nematodes. Therefore, future studies should focus on evaluating fungal isolates against root-knot nematodes under field conditions.

Diversity of Genetic and Vegetative Compatibility Group of Colletotrichum coccodes Isolates from Chile Using Amplified Fragment Length Polymorphism Markers.

Colletotrichum coccodes (Wallr.) Hughes is an asexual fungus with five vegetative compatibility groups. It was postulated that C. coccodes was isolated at the center of origin of potato at one time, and due to the movement of potato around the globe, the fungus was established on each continent but became bottlenecked and genetically unable to form stable heterokaryons via vegetative compatibility grouping (VCG) studies. The objectives of this study were (i) to determine if the VCGs around the world are related to the VCGs in Chile, (ii) to determine the diversity of C. coccodes populations in Chile, and (iii) to find any evidence for a cryptic sexual life cycle for this fungus. Worldwide C. coccodes populations have been found to be genetically correlated and belong to one or more C. coccodes-identified VCGs. The most distributed VCG in Chile was VCG2, which is the most common VCG in North America. We hypothesize that one or more VCGs had spread from Chile to the rest of the world. Precautions and further studies should be investigated by using other molecular markers and gene sequencing.

A fungal plant pathogen discovered in the Devonian Rhynie Chert

Fungi are integral to well-functioning ecosystems, and their broader impact on Earth systems is widely acknowledged. Fossil evidence from the Rhynie Chert (Scotland, UK) shows that Fungi were already diverse in terrestrial ecosystems over 407-million-years-ago, yet evidence for the occurrence of Dikarya (the subkingdom of Fungi that includes the phyla Ascomycota and Basidiomycota) in this site is scant. Here we describe a particularly well-preserved asexual fungus from the Rhynie Chert which we examined using brightfield and confocal microscopy. We document Potteromyces asteroxylicola gen. et sp. nov. that we attribute to Ascomycota incertae sedis (Dikarya). The fungus forms a stroma-like structure with conidiophores arising in tufts outside the cuticle on aerial axes and leaf-like appendages of the lycopsid plant Asteroxylon mackiei. It causes a reaction in the plant that gives rise to dome-shaped surface projections. This suite of features in the fungus together with the plant reaction tissues provides evidence of it being a plant pathogenic fungus. The fungus evidently belongs to an extinct lineage of ascomycetes that could serve as a minimum node age calibration point for the Ascomycota as a whole, or even the Dikarya crown group, along with some other Ascomycota previously documented in the Rhynie Chert.

Safagamyces marinus gen. et sp. nov. (Halosphaeriaceae, Sordariomycetes) from Red Sea mangroves, Egypt

Safagamyces marinus gen. et sp. nov. was recorded from decaying stem of Phragmites australis inside Safaga mangrove is described and illustrated in this article. Phylogenetic analyses of SSU and LSU rDNA sequences dataset placed the new fungus as a distinct branch basal to a node that contains the three asexual marine genera: Cirrenalia, Cucurbitinus and Pseudolignincola in the family Halosphaeriaceae. The fungus is characterized by straight or slightly curved, branched, smooth, 2-6 septate conidia and the sympodial conidial proliferation. Conidial cells increase in size and pigmentation from hyaline at the base to dark-brown at the apex. The new taxon is compared with other asexual fungi in Halosphaeriaceae.

Vesiculophora diversiseptata gen. & sp. nov. and Anapleurothecium clavatum & Podosporium simile spp. nov. from the Brazilian Amazon

Three asexual fungi are described and illustrated from the Brazilian Amazon:Vesiculophora diversiseptata as a new genus and species; and Anapleurothecium clavatum and Podosporium simile as new species. Vesiculophora diversiseptata is characterized by its conidiophores becoming scorpioid after successive subacroauxic extensions and monoblastic conidiogenous cells that produce heteroseptate, brown phragmoconidia; A. clavatum is distinguished by its ellipsoidal to clavate, 3-euseptate, brown conidia; and P. simile is characterized by its synnematous conidiomata with monotretic conidiogenous cells and brown, 3–11-eusepatate, mainly obclavate, verrucose conidia. Additionally, Pleurothecium leptospermi is transferred to Anapleurothecium.

Species of the common discomycete genus Bisporella reassigned to at least four genera

ABSTRACT Bisporella as typically conceived is a genus of noticeable, bright yellow inoperculate discomycetes. This interpretation of the genus, however, is at odds with Bisporella pallescens, the current name of the type species of the genus; furthermore, the genus has been interpreted as including the unusual species Bisporella resinicola. By comparing morphological and molecular traits of species traditionally included in Bisporella, we show that the genus is polyphyletic, with many “typical” members of the genus belonging instead in Calycina in Pezizellaceae. Bisporella pallescens is conclusively linked with its asexual morph, Bispora antennata, and the genus Bisporella is abandoned as a later synonym of the monotypic genus Bispora (previously applied only to asexual fungi) and placed as sister to Hymenoscyphus in Helotiaceae. Bisporella resinicola is shown to represent an independent monotypic genus, Eustilbum, which so far is placed incertae sedis in Helotiales. Finally, “Bisporella” subpallida, like Bispora, belongs to Helotiaceae but is instead related to “Phaeohelotium” epiphyllum.

Curvicladiellapaphiopedili sp. nov. (Hypocreales, Nectriaceae), a new species of orchid (Paphiopedilum sp.) from Guizhou, China.

BackgroundAn asexual fungus, collected from diseased leaves of Paphiopedilum sp. from Guizhou Province, China, and based on the phylogenetic analyses and morphological characters, it was identified as a new species in Curvicladiella. The genus Curvicladiella are recorded for the first time for China.New informationThe morphology of Curvicladiellapaphiopedili sp. nov. is characterised by penicillate conidiophores with a stipe, dull, tapering towards the apex, the curved stipe extension and cylindrical conidia. In the phylogenetic analyses of combined cmdA, his3, ITS, LSU, tef1 and tub2 sequence data, this taxon was clustered as sister to Curvicladiellacignea within Nectriaceae.

Cladorrhinum yunnanense sp. nov. from China

A new asexual fungus, Cladorrhinum yunnanense, isolated from unidentified fallen leaves of a broadleaf tree in Yunnan, China, is described by morphological characters and phylogenetic analyses of DNA sequence data from three loci (ITS, LSU and TUB).

Differential Physiological Prerequisites and Gene Expression Profiles of Conidial Anastomosis Tube and Germ Tube Formation in Colletotrichum gloeosporioides

The conidia of a hemibiotrophic fungus, Colletotrichum gloeosporioides, can conventionally form a germ tube (GT) and develop into a fungal colony. Under certain conditions, they tend to get connected through a conidial anastomosis tube (CAT) to share the nutrients. CAT fusion is believed to be responsible for the generation of genetic variations in few asexual fungi, which appears problematic for effective fungal disease management. The physiological and molecular requirements underlying the GT formation versus CAT fusion remained underexplored. In the present study, we have deciphered the physiological prerequisites for GT formation versus CAT fusion in C. gloeosporioides. GT formation occurred at a high frequency in the presence of nutrients, while CAT fusion was found to be higher in the absence of nutrients. Younger conidia were found to form GT efficiently, while older conidia preferentially formed CAT. Whole transcriptome analysis of GT and CAT revealed highly differential gene expression profiles, wherein 11,050 and 9786 genes were differentially expressed during GT formation and CAT fusion, respectively. A total of 1567 effector candidates were identified; out of them, 102 and 100 were uniquely expressed during GT formation and CAT fusion, respectively. Genes coding for cell wall degrading enzymes, germination, hyphal growth, host-fungus interaction, and virulence were highly upregulated during GT formation. Meanwhile, genes involved in stress response, cell wall remodeling, membrane transport, cytoskeleton, cell cycle, and cell rescue were highly upregulated during CAT fusion. To conclude, the GT formation and CAT fusion were found to be mutually exclusive processes, requiring differential physiological conditions and sets of DEGs in C. gloeosporioides. This study will help in understanding the basic CAT biology in emerging fungal model species of the genus Colletotrichum.

Establishment of conidial fusion in the asexual fungus Verticillium dahliae as a useful system for the study of non-sexual genetic interactions

Cell-to-cell fusion is a fundamental biological process across the tree of life. In filamentous fungi, somatic fusion (or anastomosis) is required for the normal development of their syncytial hyphal networks, and it can initiate non-sexual genetic exchange processes, such as horizontal genetic transfer and the parasexual cycle. Although these could be important drivers of the evolution of asexual fungi, this remains a largely unexplored possibility due to the lack of suitable resources for their study in these puzzling organisms. We thus aimed at the characterization of cell fusion in the important asexual fungus Verticillium dahliae via Conidial Anastomosis Tubes (CATs), which can be useful for the analysis of parasexuality. We optimized appropriate procedures for their highly reproducible quantification and live-cell imaging, which were used to characterize their physiology and cell biology, and to start elucidating their underlying genetic machinery. Formation of CATs was shown to depend on growth conditions and require functional Fus3 and Slt2 MAP kinases, as well as the NADPH oxidase NoxA, whereas the GPCR Ste2 and the mating-type protein MAT1-2-1 were dispensable. We show that nuclei and other organelles can migrate through CATs, which often leads to the formation of transient dikaryons. Their nuclei have possible windows of opportunity for genetic interaction before degradation of one by a presumably homeostatic mechanism. We establish here CAT-mediated fusion in V. dahliae as an experimentally convenient system for the cytological analysis of fungal non-sexual genetic interactions. We expect that it will facilitate the dissection of sexual alternatives in asexual fungi.

Occurrence of Anemophilous Fungi in the Special Collection of the Agricultural Sciences Center Library of the Federal University of Paraíba

Objectives: The work objective was to verify the occurrence of anemophilous fungi present in the air and on the surface of books in the special and rare collection of the CCA/UFPB Library. To the isolation of anemophilous fungi present in the air, there used a direct exposure method, in which plates were exposed for 20 min. Methods: To the isolation of anemophilous fungi present in the air, there used a direct exposure method, in which plates were exposed for 20 min. The fungi collection from the surfaces of the books, it was performed through rubbing sterile swabs along the entire length of the cover and placed in a test tube with a saline solution. Then, it sowed the samples in Petri dishes containing culture medium. The plates with samples of fungi from the air and the surface of the books, it was incubated in an oven at 28 oC. After the growth of the colonies, the identification was based on macro and micromorphological analyzes. Results: There obtained a total of 688 isolates of anemophilous fungi belonging to 14 taxa. Most belong to the group of asexual fungi. The most frequent taxa were Penicillium (61.5%), sterile mycelia (23.5%), and Cladosporium (7.6%). Conclusion: The Library presented an important presence of several fungal genera in its spaces, favoring the biodeterioration of historical documents, besides being able to compromise the health of employees and visitors.

Evaluation of Formulated Anti-dermatophyte Creams from Ethanol Extract of Mitracarpus villosus Leaves

Microsporium, Trichophyton, and Epidermophyton are asexual fungi usually called dermatophytes. They are known to cause a kind of skin diseases called dermatophytosis. There have been reported cases of resistance by the dermatophytes with prolonged usage of synthetic antifungals on the skin. The aim of this study was to formulate herbal antifungal cream containing extract of Mitracarpus villosus as an anti-dermatophytic preparation and evaluate its physicochemical properties, stability and efficacy of the product. The formulated creams containing 0.5, 1 and 2% w/w of extract were subjected to stability tests using temperature variation method at -10, 4, 30, 37 and 45oC. Freeze-thaw test, Centrifuge test, pH and exposure to UV light test were also carried out using standard method. Efficacy of the cream formulations were determined using Wistar rats as experimental animals.
 The percentage yield of the extract was (2.1%). Percentage ethanol phytochemical composition indicated that for alkaloid it is 1.06±0.04%, saponins (0.96±0.07%), flavonoids (0.06±0.02%) and tannins (0.04±0.01%). The emulsion produced was an oil-in-water emulsion and had a white colour with pH of 7.02, spread of emulsion, rubbing-in effect and stability to centrifugation was very high. The antifungal results showed the activity against the dermatophytes to be in the increasing order Epidermophyton floccosum (9 mm) <Microsporum audounii (12 mm) <Trichophyton mentagrophtes (13 mm) <M. furfur (12 mm).Temperature stability and Centrifuge testing indicated that the formulations were stable. Light testing indicated no change in the colour of the products. Animal studies evaluation of the formulations of the cream indicated that their efficacy against the dermatophytes is concentration dependent and is in the increasing order M. audounii (34 µm) = E. floccosum (34 µm) <T. mentagrophyte (35 µm) <M. furfur (45 µm) which shows that 2% Mitracarpus villosus cream was statistically significant (P<0.05) against all the test microorganisms.

Corynespora sinensis sp. nov. from Jiangxi, China

A new asexual fungus, Corynespora sinensis, is described and illustrated. It was found on dead branches of unidentified plants in Jiangxi Province, China, and is characterized by its smooth ellipsoid, obclavate, or fusiform 3(–4) distoseptate conidia produced in simple chains of 2. A synopsis of Corynespora species described since 2010 is provided.

Blodgettia sinensis sp. nov. from Lushan Mountain, China

A new asexual fungus Blodgettia sinensis is described and illustrated from a specimen collected on dead branches of an unidentified broadleaf tree in Lushan Mountain, China. The fungus differs from other described Blodgettia species in its ellipsoidal, brown, 3(–6)-euseptate conidia with rounded apices.

A research article on Trichoderma spp: An effective biocontrol agent for management of plant diseases and enhance the sustainability

Trichoderma spp. are free living asexual fungi that are present in all types of agricultural soils, root ecosystem and also in decaying wood. The fungus is also a decomposer of cellulosic waste materials and antagonistic activity showed that it is parasitic on many soil-borne and foliage pathogens viz., bacteria, fungus, virus, nematodes and higher parasitic plants and effectively control collar rot, root rot, foot rot, stem rot, sheath blight, gray mold, damping off, mildew and other disease like nematode causing problems etc. The traditional method (chemical-based pesticides) control plant diseases very effectively and suppress plant pathogens but these are not eco-friendly. Continuous use of agro-chemical and pesticides caused the resistance in pathogens towards these chemicals. It not only develops resistance among pathogens but also causes environmental pollution, this hazardous chemical pollutes water body and pollute our food chain too. It is harming fish and other aquatic lives, beneficial insects like honeybee, predator insects and other non-targeted organisms like plant growth promoting rhizobacteria-fungus (PGPR & PGPF). For overcome with these unsafe methods researchers are searching some other alternative methods that are significantly eco-friendly. Biological control agents, plants extract, crop rotation with potential crop/varieties, repellent plant, natural enemies, PGPR and PGPF are some of the most effective control measure in which, Trichoderma is the most versatile fungus genus that can control and manage phytopathogenic diseases and so increase plant growth. So, this review was summarised that Trichoderma spp. act as effective bio-agent can control many plant pathogenic fungus like Fusarium, Phytophthora, Pythium, Colletotrichum, Fulvia, Rhizoctonia, Rhizopus, Alternaria, Verticillium, and Sclerotinia etc.

Multigene phylogeny and taxonomy of Dendryphion hydeiand Torula hydeispp. nov. from herbaceous litter in northern Thailand.

During our studies on asexual fungi colonizing herbaceous litter in northern Thailand, we discovered two new fungal species, viz. Dendryphion hydei and Torula hydei spp. nov. The latter are examined, and their morphological characters are described as well as their DNA sequences from ribosomal and protein coding genes are analysed to infer their phylogenetic relationships with extant fungi. Torula hydei is different from other similar Torula species in having tiny and catenate conidia. Dendryphion hydei can be distinguished from other similar Dendryphion species in having large conidiophores and subhyaline to pale olivaceous brown, 2-4(-5)-septate conidia. Multigene phylogenetic analyses of a combined LSU, SSU, TEF1-α, RPB2 and ITS DNA sequence dataset generated from maximum likelihood and Bayesian inference analyses indicate that T. hydei forms a distinct lineage and basal to T. fici. Dendryphion hydei forms a distinct lineage and basal to D. europaeum, D. comosum, D. aquaticum and D. fluminicola within Torulaceae (Pleosporales, Dothideomycetes).

Fusarium oxysporum f. sp. phaseoli genetic variability assessed by new developed microsatellites.

Fusarium oxysporum f. sp. phaseoli (Fop) J.B. Kendrich & W.C. Snyder is the causal agent of Fusarium wilt of common bean (Phaseolus vulgaris L.). The objective of this study was to develop microsatellite markers (SSRs) to characterize the genetic diversity of Fop. Two libraries enriched with SSRs were developed and a total of 40 pairs of SSRs were characterized. Out of these, 15 SSRs were polymorphic for 42 Fop isolates. The number of alleles varied from two to ten, with an average of four alleles per locus and an average PIC (Polymorphic Information Content) of 0.38. The genetic diversity assessed by microsatellites for Fop was low, as expected for an asexual fungus, and not associated with geographic origin, but they were able to detect enough genetic variability among isolates in order to differentiate them. Microsatellites are a robust tool widely used for genetic fingerprinting and population structure analyses. SSRs for Fop may be an efficient tool for a better understanding of the ecology, epidemiology and evolution of this pathogen.

Assemblage and diversity of asexual fungi in 10 terrestrial damp leaf litters: Comparison of two incubation techniques

Assemblage and diversity of asexual fungi in 10 terrestrial damp leaf litters: Comparison of two incubation techniques