Pycnidial Conidiomata Research Articles

New nematicidal and antimicrobial secondary metabolites from a new species in the new genus, Pseudobambusicola thailandica.

During the course of a study on the functional biodiversity of the mycobiota inhabiting rainforests in Thailand, a fungal strain was isolated from a plant sample and shown to represent an undescribed species, as inferred from a combination of morphological and molecular phylogenetic methods. Molecular phylogenetic analyses, based on four DNA loci, revealed a phylogenetic tree with the newly generated sequences clustering in a separate branch, together with members of the Sulcatisporaceae (Pleosporales, Ascomycota). The Thai specimen morphologically resembled Neobambusicola strelitziae in having pycnidial conidiomata with phialidic conidiogenous cells that produce both fusoid-ellipsoid macroconidia and subcylindrical microconidia. However, the new fungus, for which the name Pseudobambusicola thailandica is proposed, differs from N. strelitziae in having conidiomata with well-defined necks, the presence of globose to subglobose thick-walled cells adjacent to conidiomata and the production of chlamydospores in culture. When cultures of P. thailandica, growing on water agar, were confronted with Caenorhabditis elegans nematodes, worms approaching the fungal mycelia were killed. This observation gave rise to a study of its secondary metabolites and six novel and two known compounds were isolated from submerged cultures of P. thailandica. The structures of metabolites 1–6, for which the trivial names thailanones A–F are proposed, were elucidated using a combination of spectral methods, including extensive 1 and 2D NMR analysis and high resolution mass spectrometry. Compounds 4 and 8 showed strong nematicidal and weak antifungal activity, whereas all other tested compounds showed moderate to weak nematicidal activity but no significant effects in the serial dilution assay against various fungi and bacteria. Compounds 1 and 8 also inhibited growth of the pathogenic basidiomycete Phellinus tremulae in a plate diffusion assay.

First Report of Dipsacus asperoides Leaf Spots Caused by Septoria scabiosicola in China

Dipsacus asperoides belonging to Dipsacaceae is herbaceous perennial plants. The roots of the plant have been used in traditional Chinese medicine to nourish liver and kidney, strengthen and modulate local metabolism for bones or muscles for thousands of years (Committee of China Pharmacopoeia, 2005). In a disease survey conducted in Gansu and Hubei in 2016, brown spots on the leaves were observed on D. asperoides. The leaf disease incidence is 45%-65%, and averaged 50-150 tiny spots on a leaf. The disease initially appears on the leaves as numerous small, circular or irregular dark brown spots, and later enlarged to 2-3 mm lesions with white centers and purple or dark brown broad margins. Pycnidial conidiomata is immersed or semi-immersed on white centers of the lesions, one to a few in each leaf spot, globose to subglobose, brown to dark brown, 75-87.5 µm×72.5-87.5 µm in diameter; ostiole single, initially 12.5(-13.5)-15µm wide, later becoming irregular and up to 40 µm wide；conidia hyaline, filiform, st...

Delonicicola siamensegen. & sp. nov. (Delonicicolaceaefam. nov., Delonicicolales ord. nov.), a Saprobic Species fromDelonix regiaSeed Pods

This paper introduces a new genus Delonicicola, to accommodate D. siamense sp. nov., which was found associated with Delonix regia seed pods, collected in Chiang Rai Province, Thailand. ITS sequence data confirmed a close relationship of Delonicicola with Liberomyces and Asteromella in Xylariomycetidae. Phylogenetic and molecular clock analyses of combined LSU, SSU and RPB2 sequence data provide evidence for a new family Delonicicolaceae and a new order Delonicicolales in Xylariomycetidae. Members of Delonicicolaceae are saprobes, endophytes or pathogens of angiosperms and it is characterized by pseudostromatal immersed, papillate ascomata, short pedicellate asci with a simple apex and 1-septate, hyaline ascospores. The asexual morph is coelomycetous with pycnidial conidiomata and allantoid, filiform or bacilloid, hyaline conidia.

Revision of Lophiotremataceae (Pleosporales, Dothideomycetes): Aquasubmersaceae, Cryptocoryneaceae, and Hermatomycetaceae fam. nov.

The family Lophiotremataceae (Pleosporales, Dothideomycetes) is taxonomically revised on the basis of morphological observations and phylogenetic analyses of sequences of nuclear rDNA SSU, ITS, and LSU regions and tef1 and rpb2 genes. A total of 208 sequences were generated from species of Lophiotremataceae and its relatives. According to phylogenetic analyses, Lophiotremataceae encompasses the genus Lophiotrema and five new genera: Atrocalyx, Crassimassarina, Cryptoclypeus, Galeaticarpa, and Pseudocryptoclypeus. These genera are characterised by ascomata with or without a slit-like ostiole and pycnidial conidiomata. Three new families, Aquasubmersaceae, Cryptocoryneaceae, and Hermatomycetaceae, are proposed. Two genera previously recognised as members of Lophiotremataceae, namely, Aquasubmersa having ascomata with a papillate ostiolar neck and pycnidial conidiomata and Hermatomyces possessing sporodochial conidiomata and dimorphic (lenticular and cylindrical) conidia, are included in Aquasubmersaceae and Hermatomycetaceae, respectively. Cryptocoryneum, characterised by the presence of stromatic sporodochia, cheiroid conidia, and conidial arms developed downward from the cap cells, is placed in Cryptocoryneaceae. Two new genera, Antealophiotrema and Pseudolophiotrema, are established, but their familial placements remain unresolved. Antealophiotrema bears ascomata morphologically similar to those of Lophiotrema, but is differentiated from the latter by having ascomata with a well-developed peridium and a monodictys-like asexual morph. Pseudolophiotrema is also similar to Lophiotrema, but can be distinguished by ascomata with a thin peridium. A total of three new families, seven new genera, eight new species, and two new combinations are described and illustrated.

Phylogenetic Analysis of the Synnema-Producing Genus Synnemapestaloides.

Synnemapestaloides rhododendri, the type species of the genus Synnemapestaloides, is a pathogen of Rhododendron brachycarpum. This fungus produces six-celled conidia with appendages at both end cells, and are generated by annellidic conidiogenous cells on the synnema. These conidial structures are similar to those of the genus Pestalotia. The monotypic genus Synnemapestaloides is currently classified in the family Amphisphaeriaceae solely based on conidial morphology. Here we demonstrate that Synnemapestaloides represents a distinct genus in the family Sporocadaceae (Amphisphaeriales) based on differences in the nucleotide sequences of the partial large subunit rDNA gene, the rDNA internal transcribed spacer, and the partial β-tubulin. The genus most closely related to Synnemapestaloides is Seimatosporium and the species most similar to Synnemapestaloides rhododendri is Seim. foliicola which produces short synnema-like conidiomata (sporodochia). These results demonstrate that Seim. foliicola should be transferred to Synnemapestaloides, and also demonstrate that Sporocadaceae can have synnematal in addition to pycnidial and acervular conidiomata.

They seldom occur alone

Species of Coleophoma have been reported as plant pathogenic, saprobic or endophytic on a wide host range. The genus is characterised by having pycnidial conidiomata, phialidic conidiogenous cells intermingled among paraphyses, and cylindrical conidia. Coleophoma has had a confusing taxonomic history with numerous synonyms, and its phylogeny has remained unresolved. The aim of the present study was to use a polyphasic approach incorporating morphology, ecology, and molecular data of the partial large subunit of nrDNA (LSU), the internal transcribed spacer region with intervening 5.8S nrDNA (ITS), partial β-tubulin (tub2), and translation elongation factor 1-alpha (tef1) gene sequences to resolve its taxonomy and phylogeny. Based on these results the genus was found to be polyphyletic, with taxa tentatively identified as Coleophoma clustering in Dothideomycetes and Leotiomycetes. Species corresponding to the concept of Coleophoma s.str. (Dermateaceae, Helotiales, Leotiomycetes) were found to form a distinct clade, with five new species. Furthermore, Coleophoma was found to be linked to the newly established sexual genus, Parafabraea, which is reduced to synonymy. Isolates occurring on Ilex aquifolium in the Netherlands also clustered in Dermateaceae, representing a novel genus, Davidhawksworthia. In the Dothideomycetes, several taxa clustered in Dothiora (Dothideaceae, Dothideales), which is shown to have Dothichiza and Hormonema-like asexual morphs, with four new species. Furthermore, Pseudocamaropycnis is introduced as a new genus (Mytilinidiaceae, Mytilinidiales), along with Briansuttonomyces (Didymellaceae, Pleosporales) and Dimorphosporicola (Pleosporaceae, Pleosporales).

Septoria-like pathogens causing leaf and fruit spot of pistachio.

Several species of Septoria are associated with leaf and fruit spot of pistachio (Pistacia vera), though their identity has always been confused, making identification problematic. The present study elucidates the taxonomy of the Septoria spp. associated with pistachio, and distinguishes four species associated with this host genus. Partial nucleotide sequence data for five gene loci, ITS, LSU, EF-1α, RPB2 and Btub were generated for a subset of isolates. Cylindroseptoria pistaciae, which is associated with leaf spots of Pistacia lentiscus in Spain, is characterised by pycnidial conidiomata that give rise to cylindrical, aseptate conidia. Two species of Septoria s. str. are also recognised on pistachio, S. pistaciarum, and S. pistaciae. The latter is part of the S. protearum species complex, and appears to be a wide host range pathogen occurring on hosts in several different plant families. Septoria pistacina, a major pathogen of pistachio in Turkey, is shown to belong to Pseudocercospora, and not Septoria as earlier suspected. Other than for its pycnidial conidiomata, it is a typical species of Pseudocercospora based on its smooth, pigmented conidiogenous cells and septate conidia. This phenomenon has also been observed in Pallidocercospora, and seriously questions the value of conidiomatal structure at generic level, which has traditionally been used to separate hyphomycetous from coelomycetous ascomycetes. Other than DNA barcodes to facilitate the molecular identification of these taxa occurring on pistachio, a key is also provided to distinguish species based on morphology.

Rediscovery of pycnidia inThamnolia vermicularis: implications for chemotype occurrence and distribution

AbstractThamnolia vermicularisis a globally widespread arctic-alpine lichen with two distinct chemotypes. The intermixing of these chemotypes at the local scale and lack of genetic variation between them is puzzling given the apparent absence of specialized reproductive structures. Apothecia and conidiomata were originally reported forThamnoliain the second half of the 19th century, but putative apothecia proved to be parasitic in origin. This study presents conclusive microscopic evidence for the existence of pycnidial conidiomata containing conidia on thalli ofThamnolia vermicularisfrom geographically widespread locations. Sequences of the internal transcribed spacer (ITS) region of ribosomal DNA from excised pycnidial conidiomata matched that of thallus tips from individualThamnoliathalli. Our examination of the historic literature found that the occurrence of pycnidial conidiomata was never disproved, but this information was lost from the post-1920s English-language literature. Our rediscovery of pycnidial conidiomata indicates thatThamnolia vermicularispossesses a reproductive strategy with the potential for long-distance dispersal of multitudes of mitotically produced conidia, providing a plausible explanation for the cosmopolitan distribution of the species and the low levels of genetic variation among populations. Reversible processes, for example alternative splicing, warrant consideration as explanations for chemotype intermixing.

The earliest records of internally stratified cyanobacterial and algal lichens from the Lower Devonian of the Welsh Borderland

Lichenization is assumed to be a very ancient mode of fungal nutrition, but fossil records are rare. Here we describe two fragments of exceptionally preserved, probably charred, lichen thalli with internal stratification. Cyanolichenomycites devonicus has a cyanobacterial and Chlorolichenomycites salopensis a unicellular, presumably green algal photobiont. Fruiting bodies are missing. Cyanolichenomycites devonicus forms asexual spores in a pycnidium. All specimens were examined with scanning electron microscopy techniques. The fossils were extracted by maceration. Extant lichens and free-living cyanobacteria were either experimentally charcoalified for comparison or conventionally prepared. Based on their septate hyphal structure, both specimens are tentatively interpreted as representatives of the Pezizomycotina (Ascomycota). Their presence in 415 million yr (Myr) old rocks from the Welsh Borderland predates existing Late Cretaceous records of pycnidial conidiomata by some 325 Myr and Triassic records of lichens with broadly similar organization by some 195 Myr. These fossils represent the oldest known record of lichens with symbionts and anatomy as typically found in morphologically advanced taxa today. The latter does not apply to Winfrenatia reticulata, the enigmatic crustose lichen fossil from the Lower Devonian, nor to presumed lichen-like organisms such as the Cambrian Farghera robusta or to the Lower Devonian Spongiophyton minutissimum.

A re-appraisal of Harknessia (Diaporthales), and the introduction of Harknessiaceae fam. nov.

Harknessiaceae is introduced as a new family in the ascomycete order Diaporthales to accommodate species of Harknessia with their Wuestneia-like teleomorphs. The family is distinguished by having pycnidial conidiomata with brown, furfuraceous margins, brown conidia with hyaline, tube-like basal appendages, longitudinal striations, and rhexolytic secession. Six species occurring on Eucalyptus are newly introduced, namely H. australiensis, H. ellipsoidea, H. pseudohawaiiensis, and H. ravenstreetina from Australia, H. kleinzeeina from South Africa, and H. viterboensis from Italy. Epitypes are designated for H. spermatoidea and H. weresubiae, both also occurring on Eucalyptus. Members of Harknessia are commonly associated with leaf spots, but also occur as saprobes and endophytes in leaves and twigs of various angiosperm hosts.

Acaroconium punctiforme gen. sp. nov., a new lichenicolous coelomycete on Acarospora species and Sarcogyne regularis

Abstract:The coelomycete Acaroconium punctiforme gen. sp. nov. is described from four members of the lichen-forming family Acarosporaceae, three species of Acarospora and Sarcogyne regularis. The new fungus is characterized by pycnidial conidiomata with a distinct ostiolar collar, enteroblastic conidiogenesis, and the production of simple brown conidia. The separation of the fungus from other somewhat similar pycnidial fungi growing on lichens and plant material is discussed.

Light and Transmission Electron Microscopic Studies on Conidiomata Developmental Morphology in Pestaloiopsis rhododendri

Investigations on the development of conidiomata in Pestalotiopsis rhododendri (Saccardo) Guba were done by using light and Transmission electron microscopes. Light microscopic studies showed the presence of non-ostiolate, pycnidial conidiomata in culture. Acervular conidiomata are produced normally by species of Pestalotiopsis on leaves. The other interesting observation during the study was the ultrastructure of the conidial wall in the coloured cells as well as the basal and apical hyaline cells with the appendages. Pestalotiopsis rhododendri resembles P. uvicola in the development of conidiomata. The first time report of the various stages of development of conidiomata in Pestalotiopsis rhododendri will be useful in fungal systematic studies.

First record of Colletogloeopsis zuluense comb. nov., causing a stem canker of Eucalyptus in China

Coniothyrium zuluense causes a serious canker disease of Eucalyptus in various parts of the world. Very little is known regarding the taxonomy of this asexual fungus, which was provided with a name based solely on morphological characteristics. In this study we consider the phylogenetic position of C. zuluense using DNA-based techniques. Distance analysis using 18S and ITS regions revealed extensive sequence divergence relative to the type species of Coniothyrium, C. palmarum and species of Paraconiothyrium. Coniothyrium zuluense was shown to be an anamorph species of Mycosphaerella, a genus that includes a wide range of Eucalyptus leaf and stem pathogens. Within Mycosphaerella it clustered with taxa having pigmented, verruculose, aseptate conidia that proliferate percurrently and sympodially from pigmented conidiogenous cells arranged in conidiomata that vary from being pycnidial to acervular. The genus Colletogloeopsis is emended to include species with pycnidial conidiomata, and the new combination Colletogloeopsis zuluense is proposed. This is also the first report of the pathogen from China where it is associated with stem cankers on Eucalyptus urophylla.

Phaeohyphomycotic Soft Tissue Infections Caused by the Coelomycetous Fungus Microsphaeropsis arundinis

Microsphaeropsis arundinis is an anamorphic fungal plant inhabitant belonging to the form class Coelomycetes. We describe two cases of M. arundinis soft tissue infections in immunosuppressed patients. This organism has not previously been described as causing disease in humans. It was identified on the basis of its typical ostiolate pycnidial conidiomata, ampulliform conidiogenous cells, and small, smooth-walled, brown, cylindrical conidia.

First report of Uredo crepidis-japonicae and Septoria crepidis on Crepis japonica in Brazil

Crepis japonica Benth is a herbaceous plant native from China and Japan which was recently introduced into Brazil, where it is disseminating rapidly and already has become an important weed in nurseries (Plantas Daninhas do Brasil, 3 ed., pg.146, 2000). In July 2000 a leaf rust was observed on C. japonica growing in a citrus (Citrus sp.) nursery situated in Vicosa, Minas Gerais State, Brazil. The fungus was identified as Uredo crepidis-japonicae Lindroth which has been reported only from Australia, Continental China, Formosa (Taiwan) and Japan (Rept. Tottori Mycol. Inst., n.08, pg.1, 1980). Irregularly oval shaped leaf lesions were dark-brown due to the presence of a powdery mass of uredospores (Figure 1A). Severely infected leaves were clorotic. Morphological features for this fungus were: uredia, 0.3 to 0.5 mm diam; uredospores spherical, 14 to 20 μm diam, pale brown, with 3 to 4 germ pores, and walls 1μm thick. U. crepidis-japonicae is the uredial stage of Puccinia crepidisjaponicae Dietel, but no teliospores were found in the material examined (VIC 22136). However, size and shape of uredospore alone suffices for distinguishing this species from other rust fungi on Crepis spp. (Table 1). In January 2001 another foliar disease on young and old leaves was also observed on C. japonica, at a different site in Vicosa. The inciting agent was identified as Septoria crepidis Vestrerg. (Syll. Fung., XIV, pg. 974, 1899) known from USA, Europe and Asia. Lesions were necrotic, irregular, pale-brown, 1 to 8mm diam. The fungus had immersed, globose pycnidial conidiomata (Figure 1B), 60 to 70 μm diam, pale-brown, ostiolate, conidiophores were absent; conidia were hyaline, filiform, multiseptate, 25 to 35 μm x 1.0 to 1.5 μm (VIC 22137). These are the first reports of occurrence of these fungi in Brazil. Both fungi were probably introduced into Brazil TABLE 1 Morphological characteristics of uredospores of rust fungi (Puccinia spp.) with uredial stage on Crepis spp.

ECOLOGY OF FOLIICOLOUS LICHENS AT THE ‘ BOTARRAMA ’ TRAIL (COSTA RICA), A NEOTROPICAL RAINFOREST. IV. SPECIES ASSOCIATIONS, THEIR SALIENT FEATURES AND THEIR DEPENDENCE ON ENVIRONMENTAL VARIABLES

A community ecology approach using an association of species test and a principal component analysis resulted in the recognition of two major and two minor foliicolous lichen communities in a neotropical rainforest. The major communities are governed by microclimatic factors, one characteristic of the shady understorey and the other confined to light gaps. The minor communities are due to subtle phorophyte preferences towards palm and dicot leaves. The shady understorey community is dominated by the families Arthoniaceae , Opegraphaceae , Trichotheliaceae and Pilocarpaceae , which predominantly have Phycopeltis as their phycobiont, thin thalli, abundant sexual reproduction, small ascospores produced in high numbers, and pycnidial conidiomata. The light-gap community is mainly composed of the families Gomphillaceae and Ectolechiaceae , with Trebouxia as their phycobiont, thickly crystalline or whitish, dispersed thalli, frequent asexual reproduction, large ascospores produced in low numbers, and specialized campylidia and hyphophores as conidiomata. Phycobiont, thallus structure, and the mode of reproduction are considered as adaptations to different microsites, whereas the shape and size of ascospores and conidia seem to be of less importance. The foliicolous lichen communities reflect the spatial and temporal structure of the forest, in particular the continuity of the shady understorey in comparison to the discontinuity of the light gaps. While the formation of the shady understorey community follows more deterministic patterns, the light-gap community exhibits high stochasticity.

Eudarluca caricis, the teleomorph of the mycoparasite Sphaerellopsis filum, on blackberry rust Phragmidium violaceum

Eudarluca caricis, the teleomorph of Sphaerellopsis filum, was found on blackberry rust (Phragmidium violaceum) in south west England and its morphology is described. Cultures derived from ascospores produced pycnidial conidiomata and conidia typical of S. filum, confirming the connection between the meiotic and mitotic stages of the fungus. Microconidia were also found in the cultures derived from ascospores. Conidiomata developed on the majority of uredinial pustules of P. violaceum 10 d after inoculating detached, uredinia-bearing blackbery leaves with the conidia from the cultures derived from ascospores.

Rhizopycnis vagum gen. et sp. nov., a new coelomycetous fungus from roots of melons and sugarcane

A new coelomycete, Rhizopycnis vagum, is described that has been isolated from the roots of melons in Texas, Guatemala and Honduras as well as from the roots of sugarcane in Taiwan. This fungus is a contributing factor in vine decline of melons grown in the Rio Grande Valley of Texas. This asexually reproducing fungus is characterized by large, black pycnidial conidiomata, enteroblastic conidiogenesis, and conidia that are hyaline to brown with 13 septa. The similarities of this fungus to Stagonospora and other coelomycetes are discussed. The ITS region of the rDNA of the holotype culture and additional isolates of R. vagum were sequenced and used to confirm that a fungus with similar characteristics from sugarcane roots in Taiwan was conspecific.

Medium‐ and Light‐dependence of Growth and Conidiomata Production in Phaeocytosporella zeae Pathogenic to Maize

AbstractCulture appearance, mycelium growth and pycnidial conidiomata formation in Phaeocytosporella zeae cultivated on potato dextrose agar (PDA), Leonian agar and carnation leaf agar (CLA) during permanent dark (25 C) or a 12‐h photoperiod (24/18°C) are described. Different media and light conditions significantly affected fungus growth and the occurrence of conidiomata.Dark conditions favoured more mycelium growth of the fungus than alternating light and dark. Moreover, fungus growth was more rapid on PDA and CLA media than on Leonian agar. Carnation leaf agar and a 12‐h photoperiod provided excellent conditions for the promotion of rapid conidiomata formation in a number of P. zeae isolates.

Phomopsis asparagi . [Descriptions of Fungi and Bacteria

Abstract A description is provided for Phomopsis asparagi . Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Asparagus officinalis, A. plumosus, A. verticillatus . DISEASE: Stem blight of Asparagus species. The first symptom is a discolouration of the stem tissue followed by the appearance of brown, elliptical lesions. As infection progresses the affected areas become shrivelled and turn into well defined spots surrounded by dark brown margins. The centre of these spots become ashy-white with numerous immersed pycnidial conidiomata which later become erumpent. As disease advances the growth of the lateral branches is frequently arrested. All parts of the plant except the berries are susceptible to infection. In severe cases needles turn yellow, the plants are partially or completely defoliated and finally wither (16, 12; 55, 2446; 67, 1628). GEOGRAPHICAL DISTRIBUTION: Africa (Ethiopia), Asia (India, China-Shanghai, Malaysia, Pakistan, Siberia, Taiwan); Europe (France, Germany, Italy, Spain, Yugoslavia); North America (Eastern U.S.A., Alabama, Arkansas, New Jersey). TRANSMISSION: Through plant debris in soil (67, 4258; Kheswalla, 1936). Infection occurs rapidly through wounds. It has been found that conidia are discharged from pycnidial conidiomata by immersion in water, spraying with water and saturated high humidity. Longevity of conidial ooze was affected by spore cone., and undiluted spore ooze retained 41% germination after desiccation for 1 month (67, 4259). Survival of conidia in soil is affected by temperature and moisture. It has been reported that all conidia were destroyed after exposure to 35°C for 2 d; only 14% remained viable after 30 d at 10°C. At 28°C, conidia survived longer in dry than in wet soil. The fungus survived on infected stems buried in the soil during ploughing or in the ground for 3-4 months. On diseased stems at soil surface the pathogen survived > 6 months (67, 4258).