A common leaf spot disease occurring on Eucalyptus cladocalyx and E. lehmannii in the Western Cape Province of South Africa is known from literature to be caused by the fungus Coniothyrium ovatum, ...which is a pathogen native to several eucalypts in Australia. Recent
collections have shown that Australian material identified as C. ovatum is morphologically and phylogenetically distinct from the South African specimens, and that all these taxa would be better accommodated in the genus Teratosphaeria. South African specimens previously identified
as C. ovatum were found to represent two species that co-occur in the same leaves and even spots and are described here as T. juvenalis and T. verrucosa. Furthermore, a fresh collection of T. ovata from E. phoenicea in Australia, is distinguished morphologically
and phylogenetically from similar, newly described taxa such as T. veloci on E. miniata, and Readeriella dimorpha, which is also placed in Teratosphaeria. Although these leaf pathogens appear to be of minor economic importance, they are morphologically similar to
two serious eucalypt canker pathogens, namely T. gauchensis and T. zuluensis, which predominantly cause stem cankers, but could also be found occurring in leaf spots on their own, or in association with some of the other species treated here. Further research is, therefore, required
to develop molecular detection techniques for these taxa to enable researchers to rapidly distinguish the minor pathogens from the more serious quarantine pathogens that co-occur on leaves.
The Teratosphaeriaceae represents a recently established family that includes numerous saprobic, extremophilic, human opportunistic, and plant pathogenic fungi. Partial DNA sequence data of the 28S ...rRNA and RPB2 genes strongly support a separation of the Mycosphaerellaceae
from the Teratosphaeriaceae, and also provide support for the Extremaceae and Neodevriesiaceae, two novel families including many extremophilic fungi that occur on a diversity of substrates. In addition, a multi-locus DNA sequence dataset was generated (ITS, LSU, Btub,
Act, RPB2, EF-1α and Cal) to distinguish taxa in Mycosphaerella and Teratosphaeria associated with leaf disease of Eucalyptus, leading to the introduction of 23 novel genera, five species and 48 new combinations. Species are distinguished based on a polyphasic approach,
combining morphological, ecological and phylogenetic species concepts, named here as the Consolidated Species Concept (CSC). From the DNA sequence data generated, we show that each one of the five coding genes tested, reliably identify most of the species present in this dataset (except species
of Pseudocercospora). The ITS gene serves as a primary barcode locus as it is easily generated and has the most extensive dataset available, while either Btub, EF-1α or RPB2 provide a useful secondary barcode locus.
Cryptosporiopsis eucalypti
is a common follicolous pathogen of
Eucalyptus
species in tropical and temperate regions where these trees are grown in plantations. The taxonomy of
C. eucalypti
is ...confused by the fact that it is phylogenetically unrelated to the type species of
Cryptosporiopsis
(
Cryptosporiopsis nigra
=
C. scutellata
,
Helotiales
). The aim of this study was to resolve the taxonomic position of
C. eucalypti
based on morphology and phylogenetic inference. Thirty-two
Eucalyptus
leaf samples with symptoms typical of
C. eucalypti
infection were collected from 10 tropical and temperate countries across four continents. Cultures were established from single conidia, as well as from ascospores of a previously unreported teleomorph state. DNA sequences were obtained for the 28 S nrDNA, the internal transcribed spacers of the nrDNA operon, and beta-tubulin regions to determine generic and species-level relationships. DNA-sequence analysis showed that conidial and ascospore isolates of
C. eucalypti
have low intraspecific variation, although two collections from Australia and one from Uruguay represented two novel taxa. Based on the newly collected teleomorph stage, as well as the phylogenetic data,
C. eucalypti
is shown to represent a new genus closely related to
Plagiostoma
(
Gnomoniaceae
,
Diaporthales
) for which the names
Pseudoplagiostoma
gen. nov. and
Pseudoplagiostomaceae
fam. nov. (
Diaporthales
) are introduced. Two new species of
Cryptosporiopsis
(
Dermateaceae, Helotiales
) on
Eucalyptus
from Australia and California (USA) are also described.
The appendaged coelomycete genus Seimatosporium (Sporocadaceae, Sordariomycetes) and some of its purported synonyms Allelochaeta, Diploceras and Vermisporium are re-evaluated. Based on DNA data for ...five loci (ITS, LSU, rpb2, tub2
and tef1), Seimatosporium is shown to be paraphyletic. The ex-type species of Allelochaeta, Discostromopsis and Vermisporium represent a distinct sister clade to which the oldest name Allelochaeta is applied. These genera were traditionally separated based
on a combination of conidial pigmentation, septation, and the nature of their conidial appendages. Allelochaeta is revealed to include taxa with both branched or solitary appendages, that could be cellular or continuous, with conidia being (2-)3(-5)-septate, hyaline, or
pigmented, concolourous or versicolourous. This suggests that these characters should be applied at species, and not at the generic level. Conidial pigmentation appears to have been lost or gained several times during the evolution of species within Allelochaeta. In total, 25 new species,
15 new combinations, and 10 new epitypifications are proposed.
Novel species of microfungi described in the present study include the following from Australia: Catenulostroma corymbiae from Corymbia, Devriesia stirlingiae from Stirlingia, Penidiella carpentariae ...from Carpentaria, Phaeococcomyces eucalypti
from Eucalyptus, Phialophora livistonae from Livistona, Phyllosticta aristolochiicola from Aristolochia, Clitopilus austroprunulus on sclerophyll forest litter of Eucalyptus regnans and Toxicocladosporium posoqueriae from Posoqueria.
Several species are also described from South Africa, namely: Ceramothyrium podocarpi from Podocarpus, Cercospora chrysanthemoides from Chrysanthemoides, Devriesia shakazului from Aloe, Penidiella drakensbergensis from Protea, Strelitziana
cliviae from Clivia and Zasmidium syzygii from Syzygium. Other species include Bipolaris microstegii from Microstegium and Synchaetomella acerina from Acer (USA), Brunneiapiospora austropalmicola from Rhopalostylis (New Zealand),
Calonectria pentaseptata from Eucalyptus and Macadamia (Vietnam), Ceramothyrium melastoma from Melastoma (Indonesia), Collembolispora aristata from stream foam (Czech Republic), Devriesia imbrexigena from glazed decorative tiles (Portugal),
Microcyclospora rhoicola from Rhus (Canada), Seiridium phylicae from Phylica (Tristan de Cunha, Inaccessible Island), Passalora lobeliaefistulosis from Lobelia (Brazil) and Zymoseptoria verkleyi from Poa (The Netherlands). Valsalnicola
represents a new ascomycete genus from Alnus (Austria) and Parapenidiella a new hyphomycete genus from Eucalyptus (Australia). Morphological and culture characteristics along with ITS DNA barcodes are also provided.
The genus Cladosporium is one of the largest genera of dematiaceous hyphomycetes, and is characterised by a coronate scar structure, conidia in acropetal chains and Davidiella teleomorphs. Based on ...morphology and DNA phylogeny, the species complexes of C. herbarum and C. sphaerospermum have been resolved, resulting in the elucidation of numerous new taxa. In the present study, more than 200 isolates belonging to the C. cladosporioides complex were examined and phylogenetically analysed on the basis of DNA sequences of the nuclear ribosomal RNA gene operon, including the internal transcribed spacer regions ITS1 and ITS2, the 5.8S nrDNA, as well as partial actin and translation elongation factor 1-α gene sequences. For the saprobic, widely distributed species Cladosporium cladosporioides, both a neotype and epitype are designated in order to specify a well established circumscription and concept of this species. Cladosporium tenuissimum and C. oxysporum, two saprobes abundant in the tropics, are epitypified and shown to be allied to, but distinct from C. cladosporioides. Twenty-two species are newly described on the basis of phylogenetic characters and cryptic morphological differences. The most important phenotypic characters for distinguishing species within the C. cladosporioides complex, which represents a monophyletic subclade within the genus, are shape, width, length, septation and surface ornamentation of conidia and conidiophores; length and branching patterns of conidial chains and hyphal shape, width and arrangement. Many of the treated species, e.g., C. acalyphae, C. angustisporum, C. australiense, C. basiinflatum, C. chalastosporoides, C. colocasiae, C. cucumerinum, C. exasperatum, C. exile, C. flabelliforme, C. gamsianum, and C. globisporum are currently known only from specific hosts, or have a restricted geographical distribution. A key to all species recognised within the C. cladosporioides complex is provided.
Taxonomic novelties:Cladosporium acalyphae Bensch, H.D. Shin, Crous & U. Braun, sp. nov., C. angustisporum Bensch, Summerell, Crous & U. Braun, sp. nov., C. asperulatum Bensch, Crous & U. Braun, sp. nov., C. australiense Bensch, Summerell, Crous & U. Braun, sp. nov., C. basiinflatum Bensch, Crous & U. Braun, sp. nov., C. chalastosporoides Bensch, Crous & U. Braun, sp. nov., C. exasperatum Bensch, Summerell, Crous & U. Braun, sp. nov., C. exile Bensch, Glawe, Crous & U. Braun, sp. nov., C. flabelliforme Bensch, Summerell, Crous & U. Braun, sp. nov., C. globisporum Bensch, Crous & U. Braun, sp. nov., C. hillianum Bensch, Crous & U. Braun, sp. nov., C. inversicolor Bensch, Crous & U. Braun, sp. nov., C. iranicum Bensch, Crous & U. Braun, sp. nov., C. paracladosporioides Bensch, Crous & U. Braun, sp. nov., C. perangustum Bensch, Crous & U. Braun, sp. nov., C. phyllactiniicola Bensch, Glawe, Crous & U. Braun, sp. nov., C. pseudocladosporioides Bensch, Crous & U. Braun, sp. nov., C. rectoides Bensch, H.D. Shin, Crous & U. Braun, sp. nov., C. scabrellum Bensch, Schroers, Crous & U. Braun, sp. nov., C. subuliforme Bensch, Crous & U. Braun, sp. nov., C. verrucocladosporioides Bensch, H.D. Shin, Crous & U. Braun, sp. nov., C. xylophilum Bensch, Shabunin, Crous & U. Braun, sp. nov.
Early detection of exotic pests is key to a timely response for enabling options for eradication and future management. It is widely recognised that engaging the public and industry in general ...surveillance significantly increases the chance of detecting newly arrived pests and pathogens. Once a new pest or pathogen is detected, Australia has guidelines to follow via the Emergency Plant Pest Response Deed and PLANTPLAN. This paper describes the detection of unusual symptoms in a Pinus radiata production nursery in New South Wales, Australia, and the subsequent response. The unusual symptoms were detected in early January 2021 by nursery staff and reported immediately to biosecurity authorities. The nursery was placed under quarantine as a precaution. Within five weeks, Fusarium commune was diagnosed from the samples, a known pathogen of conifers not previously recorded in Australia. Formal biosecurity processes were enacted immediately to determine whether the pathogen was an emergency plant pest and whether eradication was necessary and technically feasible. Quarantine and movement restrictions continued, such that no seedlings could leave the site other than for ongoing diagnosis and under biosecure protocols. Tracing was conducted to determine the distribution of the pathogen and a potential source, including ongoing sampling in production nurseries, diagnosis of planting media and seed, and diagnosis of root and soil eDNA samples collected in previous years. Fusarium commune was recovered at a very low frequency from two nurseries, primarily in association with healthy seedlings. Root and soil samples collected from nurseries and plantations between 2019 and 2020 tested negative for the presence of F. commune using F. commune-specific primers. Pathogenicity tests revealed that F. commune did not cause wilting or significant disease on tested seedlings. Overall, evidence suggested that F. commune did not pose a serious threat to the P. radiata industry. The Consultative Committee on Emergency Plant Pests determined that F. commune was not a significant pathogen and that no further action was warranted. The affected nursery was allowed to resume operations in mid-May 2021, in time for the winter planting season. Here we discuss the lessons from this response, including the benefits of a quick and timely response, cross-institutional collaboration, the potential threat to the forest industry, and the need to encourage greater general surveillance. These lessons can help in the event of an incursion of a serious pathogen such as F. circinatum (pine pitch canker).
Fungal pathogens of Proteaceae Crous, P W; Summerell, B A; Swart, L ...
Persoonia,
12/2011, Letnik:
27, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Species of Leucadendron, Leucospermum and Protea (Proteaceae) are in high demand for the international floriculture market due to their brightly coloured and textured flowers or bracts. Fungal ...pathogens, however, create a serious problem in cultivating flawless
blooms. The aim of the present study was to characterise several of these pathogens using morphology, culture characteristics, and DNA sequence data of the rRNA-ITS and LSU genes. In some cases additional genes such as TEF 1-α and CHS were also sequenced. Based on the results of this
study, several novel species and genera are described. Brunneosphaerella leaf blight is shown to be caused by three species, namely B. jonkershoekensis on Protea repens, B. nitidae sp. nov. on Protea nitida and B. protearum on a wide host range of Protea
spp. (South Africa). Coniothyrium-like species associated with Coniothyrium leaf spot are allocated to other genera, namely Curreya grandicipis on Protea grandiceps, and Microsphaeropsis proteae on P. nitida (South Africa). Diaporthe leucospermi is
described on Leucospermum sp. (Australia), and Diplodina microsperma newly reported on Protea sp. (New Zealand). Pyrenophora blight is caused by a novel species, Pyrenophora leucospermi, and not Drechslera biseptata or D. dematoidea as previously reported.
Fusicladium proteae is described on Protea sp. (South Africa), Pestalotiopsis protearum on Leucospermum cuneiforme (Zimbabwe), Ramularia vizellae and R.stellenboschensis on Protea spp. (South Africa), and Teratosphaeria capensis
on Protea spp. (Portugal, South Africa). Aureobasidium leaf spot is shown to be caused by two species, namely A. proteae comb. nov. on Protea spp. (South Africa), and A. leucospermi sp. nov. on Leucospermum spp. (Indonesia, Portugal, South Africa). Novel
genera and species elucidated in this study include Gordonomyces mucovaginatus and Pseudopassalora gouriqua (hyphomycetes), and Xenoconiothyrium catenata (coelomycete), all on Protea spp. (South Africa).
Many fungi are pathogenic on plants and cause significant damage in agriculture and forestry. They are also part of the natural ecosystem and may play a role in regulating plant numbers/density. ...Morphological identification and analysis of plant pathogenic fungi, while important, is often hampered by the scarcity of discriminatory taxonomic characters and the endophytic or inconspicuous nature of these fungi. Molecular (DNA sequence) data for plant pathogenic fungi have emerged as key information for diagnostic and classification studies, although hampered in part by non-standard laboratory practices and analytical methods. To facilitate current and future research, this study provides phylogenetic synopses for 25 groups of plant pathogenic fungi in the Ascomycota, Basidiomycota, Mucormycotina (Fungi), and Oomycota, using recent molecular data, up-to-date names, and the latest taxonomic insights. Lineage-specific laboratory protocols together with advice on their application, as well as general observations, are also provided. We hope to maintain updated backbone trees of these fungal lineages over time and to publish them jointly as new data emerge. Researchers of plant pathogenic fungi not covered by the present study are invited to join this future effort.
Bipolaris, Botryosphaeriaceae, Botryosphaeria, Botrytis, Choanephora, Colletotrichum, Curvularia, Diaporthe, Diplodia, Dothiorella, Fusarium, Gilbertella, Lasiodiplodia, Mucor, Neofusicoccum, Pestalotiopsis, Phyllosticta, Phytophthora, Puccinia, Pyrenophora, Pythium, Rhizopus, Stagonosporopsis, Ustilago and Verticillium
are dealt with in this paper.
To assess the variability among histopathologists in diagnosing and grading cervical intraepithelial neoplasia eight experienced histopathologists based at different hospitals examined the same set ...of 100 consecutive colposcopic cervical biopsy specimens and assigned them into one of six diagnostic categories. These were normal squamous epithelium, non-neoplastic squamous proliferations, cervical intraepithelial neoplasia grades I, II, and III, and other. The histopathologists were given currently accepted criteria for diagnosing and grading cervical intraepithelial neoplasia and asked to mark their degree of confidence about their decision on a visual linear analogue scale provided. The degree of agreement between the histopathologists was characterised by kappa statistics, which showed an overall poor agreement (unweighted kappa 0.358). Agreement between observers was excellent for invasive lesions, moderately good for cervical intraepithelial neoplasia grade III, and poor for cervical intraepithelial neoplasia grades I and II (unweighted kappa 0.832, 0.496, 0.172, and 0.175, respectively); the kappa value for all grades of cervical intraepithelial neoplasia taken together was 0.660. The most important source of disagreement lay in the distinction of reactive squamous proliferations from cervical intraepithelial neoplasia grade I. The histopathologists were confident in diagnosing cervical intraepithelial neoplasia grade III and invasive carcinoma (other) but not as confident in diagnosing cervical intraepithelial neoplasia grades I and II and glandular atypia (other). Experienced histopathologists show considerable interobserver variability in grading cervical intraepithelial neoplasia and more importantly in distinguishing between reactive squamous proliferations and cervical intraepithelial neoplasia grade I. It is suggested that the three grade division of cervical intraepithelial neoplasia should be abandoned and a borderline category introduced that entails follow up without treatment.
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