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Mycosphaerella verrucosiafricana (CBS 118496). A. Leaf spot. B–C. Asci. D–E. Ascospores. F–G. Germinating ascospores. Scale bars: B = 3 μm, F = 8 μm.
Source publication
Species of Eucalyptus are widely planted as exotics in the tropics and Southern Hemisphere and to some extent in southern Europe, for timber and fibre production. Species of Mycosphaerella are commonly associated with leaves and twigs of Eucalyptus and can result in defoliation, dieback, and even tree death. In the present study, numerous isolates...
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Citations
... A Fungal DNA Kit (D3195) purchased from Omega-BioTek (Norcross, GA, USA) was used to extract DNA from three isolates of R. sphaeroidea. The 28S rRNA gene (LSU), internal transcribed spacer regions (ITS), calmodulin (cmdA), translation elongation factor 1-α (tef1-α), histone H3 (his3), glyceraldehyde-3-phosphate dehydrogenase (gapdh), and RNA polymerase II second largest subunit (rpb2) genes were amplified and sequenced with the primers LR5/LSU1Fd [36,37], ITS4/V9G [38,39], CAL-228F/CAL-737R [40], EF1- 728F/TEF-1R [41,42], CylH3F/CylH3R [43,44], GPD1/GPD2 [45], and RPB2-5f2/RPB2-7 [46,47], respectively. PCR was performed as previously described by Videira [16]. ...
Ramularia sphaeroidea was primarily identified based on the characteristics of its conidia and several sequences. The fungus causes severe leaf spot disease on hairy vetch (Vicia villosa var. glabrescens) in Yunnan Province in China. The growth, sporulation, fungicide efficacy, and host range of the pathogen were evaluated to aid in disease management. Different types of culture media and carbon and nitrogen sources were used to evaluate the growth of R. sphaeroidea. Oatmeal, maltose, and potassium nitrate agar had a higher amount of sporulation. Difenoconazole (10%) was the most effective fungicide against the leaf disease caused by R. sphaeroidea. In addition, foliar inoculation sprays were used to assess the host range of R. sphaeroidea in six different plant species, including alfalfa (Medicago sativa L.), sainfoin (Onobrychis viciifolia Scop.), erect milkvetch (Astragalus adsurgens Pall.), common vetch (Vicia sativa L.), red clover (Trifolium pratense L.), and white clover (Trifolium repens L.). R. sphaeroidea successfully infected these plants, indicating that it has a wider host range than hairy vetches.
... Während der Lagerung von sieben Tagen nahm der Anteil allerdings deutlich ab. Die Pilze Podoshaera und Mycosphaerella zählen zu den Pflanzenpathogenen (Crous et al. 2006;Baiswar et al. 2010), deren Anteil in den Proben ebenfalls einen Rückgang während der Lagerung im Vergleich zu den frisch gesammelten Pollenproben zeigt. Während ein prozentualer Rückgang der oben genannten Pilze zu beobachten war, konnte jedoch besonders bei zwei Pilz-bzw. ...
Honigbienen (Apis mellifera) sammeln zur Versorgung ihrer Brut neben Nektar auch Pollen von Pflanzen. Pollen liefern ein breites Spektrum an Nährstoffen, wie Proteine und Lipide, aber auch Kohlenhydrate, Vitamine und Enzyme. Aufgrund dieser Inhaltsstoffe ist Pollen auch für den Menschen attraktiv und wird als Nahrungsergänzungsmittel verwendet. Honigbienen sammeln jedoch nicht nur Pollen von Wildpflanzen, sondern auch von blühenden Kulturen, die in der Landwirtschaft angebaut werden. Dementsprechend können Kontaminationen von Pflanzenschutzmitteln in Blütenpollen und Bienenbrot gefunden werden. Um einen tieferen Einblick über das Auftreten und die Verteilung von Pestizidrückständen während einer ganzen Saison zu erhalten, wurden von April bis Juli 2018 insgesamt 102 täglich gesammelte Pollenproben mit Hilfe von Pollenfallen in einem Obstanbaugebiet in Süddeutschland gesammelt. Nahezu 90% der Pollenproben zeigten nachweisbare Konzentrationen an Pestizidrückständen. Insgesamt konnten 29 Pestizide, mit mehr als die Hälfte an Fungiziden, gefolgt von Insektiziden und Herbiziden in den Proben nachgewiesen werden. Maximale Konzentrationen von bis zu 4500 ng/g konnten Ende April gemessen werden. Auch Proben die Anfang Mai und Ende Juni gesammelt wurden, wiesen hohe Pestizidkonzentrationen auf. Ein allgemeines Risikomanagement wurde durchgeführt, um das Risiko der nachgewiesenen Pestizidkonzentrationen für Honigbienen abzuschätzen. Die mikrobielle Qualität von Blütenpollen hängt stark von der botanischen und geografischen Herkunft, sowie den klimatischen Bedingungen und den Verarbeitungsschritten des Imkers nach der Ernte ab. Folgen nach der Ernte keine Verarbeitungsschritte wie Einfrieren oder Trocknung, kann das Wachstum von Mikroorganismen gefördert und die Pollenqualität durch negative Nebenwirkungen wie Fermentation oder Produktion von Mykotoxinen beeinflusst werden. Bakterien- und Pilzkolonien können sowohl durch kultivierungsabhängige Methoden wie Koloniezählung auf Platten als auch durch kultivierungsunabhängige Methoden wie der 16-rRNA-Amplikon Sequenzierung bestimmt werden. Nach der Hypothese, dass Lagerbedingungen die Zusammensetzung von Mikroorganismen in Blütenpollen beeinflussen, wurde frisch geernteter Blütenpollen im Juni 2018 und 2019 sieben Tage lang unter definierten Bedingungen (kalt, Raumtemperatur, warm) gelagert und durch Sequenzierung von 16S- und 18S-PCR-Amplikons analysiert. Die Bakteriengemeinschaft variierte geringfügig zwischen den untersuchten Standorten und zeigte keinen signifikanten Unterschied zwischen den Lagerbedingungen. Die Pilzgemeinschaft zeigte signifikante Unterschiede sowohl zwischen den untersuchten Standorten als auch zwischen den verschiedenen Lagerbedingungen. Die dominierenden Pilzgattungen in den Pollenproben waren Cladosporium, Aspergillus und Zygosaccharomyces. Während Cladosporium in frisch gesammeltem Pollen am dominantesten zu finden war und der prozentuale Anteil während der Lagerung abnahm, zeigten Aspergillus und Zygosaccharomyces eine signifikante Zunahme insbesondere unter warmen Lagerbedingungen. Auch andere, natürlich von Pflanzen produzierte Kontaminationen können negative Auswirkungen auf die menschliche Gesundheit haben. Pyrrolizidinalkaloide gehören zu einer Gruppe von sekundären Pflanzenstoffen, von denen mehr als 600 Strukturen in rund 3% aller blühenden Pflanzen weltweit bekannt sind. PA sind bekannt, sowohl akute Vergiftungen als auch chronische Schädigungen oder Krebs bei Tieren und Menschen auslösen zu können. Um das Wissen über PA-Kontaminationen in Blütenpollen zu erweitern und das Risiko der Konzentrationen abschätzen zu können, wurden im Juli 2019 an 57 Standorten in Baden-Württemberg Blütenpollen gesammelt und auf 42 verschiedene PA und deren N-Oxide untersucht. Insgesamt wurden in über 90% aller untersuchten Proben 22 verschiedene PAs nachgewiesen. Nur 5% der PA wurden als PA von Pflanzen der Senecio sp. identifiziert, während 95% der PA mit botanischem Hintergrund von Echium sp. und Eupatorium sp. identifiziert werden konnten. Die maximale Konzentration der Summe an PA pro Probe wurde mit 48400 ng/g bestimmt. Nach den berechneten Risikowerten des BfR stellten jedoch immerhin 42% der Proben ein erhöhtes Risiko für die menschliche Gesundheit dar.
... In this study, we showed that the relative fraction of Cladosporium decreases during storage, especially under warm conditions. The fungal genera Podosphaera and Mycosphaerella can be isolated from plant environments and are both known to be plant pathogens (Crous et al. 2006;Baiswar et al. 2010;Garibaldi et al. 2012). Both were identified in freshly collected pollen as well as in stored pollen, but their proportion generally decreased during storage. ...
Analysis of plant pollen can provide valuable insights into the existing spectrum of microorganisms in the environment. When harvesting bee-collected pollen as a dietary supplement for human consumption, timely preservation of the freshly collected pollen is fundamental for product quality. Environmental microorganisms contained in freshly collected pollen can lead to spoilage by degradation of pollen components. In this study, freshly collected bee pollen was sampled at different locations and stored under various storage conditions to examine the hypothesis that storage conditions may have an effect on the composition of microorganisms in pollen samples. The samples were analyzed using 16S and 18S amplicon sequencing and characterized by palynological analysis. Interestingly, the bacterial communities between pollen samples from different locations varied only slightly, whereas for fungal community compositions, this effect was substantially increased. Further, we noticed that fungal communities in pollen are particularly sensitive to storage conditions. The fungal genera proportion Cladosporium and Mycosphaerella decreased, while Zygosaccharomyces and Aspergillus increased during storage. Aspergillus and Zygosaccharomyces fractions increased during storage at 30 °C, which could negatively impact the pollen quality if it is used as a dietary supplement.
... The source of the external fungi was the spores present on the raw material, and their relative abundance was high in each pile-fermentation. The high number of endophytes shows the broad range and diversity of the fungi in the raw materials of dark tea (Crous et al., 2006). Our findings provide deep insights in fungal community structure, which can be applied in piling stage-specific fungal inoculation that may improve the nutritional quality and aesthetic value of dark tea (Bressani et al., 2021) to overcome the challenge of malnutrition, which is a key point for one of the "Sustainable Development Goals (SDGs)" of UNO, to "Establish Good Health and Well-Being. ...
The fungi present during pile-fermentation of Sichuan dark tea play a pivotal role in the development of its aroma and physical characteristics. Samples of tea leaves were collected on days 0 (YC-raw material), 8 (W1-first turn), 16 (W2-second turn), 24 (W3-third turn), and 32 (W4-out of pile) during pile-fermentation. High-throughput sequencing revealed seven phyla, 22 classes, 41 orders, 85 families, 128 genera, and 184 species of fungi. During fermentation, the fungal diversity index declined from the W1 to W3 stages and then increased exponentially at the W4 stage. A bar plot and heatmap revealed that Aspergillus , Thermomyces , Candida , Debaryomyces , Rasamsonia , Rhizomucor , and Thermoascus were abundant during piling, of which Aspergillus was the most abundant. Cluster analysis revealed that the W4 stage of fermentation is critical for fungal growth, diversity, and the community structure in Sichuan dark tea. This study revealed the role of fungi during pile-fermentation in the development of the essence and physical characteristics of Sichuan dark tea. This study comes under one of the Sustainable Development Goals of United Nations Organization (UNO) to “Establish Good Health and Well-Being”.
... And its enzyme activities improve tea quality by producing the sweet substance xylitol, vitamins, and other organic acids in Fu brick tea (Xu et al., 2011). Uwebraunia is a kind of plant pathogenic fungi, which was a synonym of Dissoconium (Crous et al., 2006), but the genus have not been well described, and the understanding of its roles in pile-fermentation systems of primary dark tea is limited. ...
The application of novel, non-thermal technologies for the gentle preservation of foods is increasing. Some of the technologies, such as high hydrostatic pressure processing or pulsed electric fields, are already used in industrial scale. Others, such as cold plasma, ebeam, ultra high pressure homogenization or pulsed light, mainly exist in pilot scale and intensive research is performed in order to develop processes for the production of safe foods in industrial scale.
Conventional methods for food pasteurization or sterilization mainly rely on the thermal inactivation of microorganisms, in which microbial safety is usually only made possible by increasing the process intensity, with negative effects on the nutritional value and sensory properties. The aforementioned novel technologies aim to overcome these unwanted side effects by applying non-thermal inactivation mechanisms.
Although the basic inactivation mechanisms of these technologies have been described, further studies are performed in order to consider process combinations, matrix effects as well as structural and physiological effects on microbial cells. Furthermore, application concepts have been developed which require the selection of indicator microorganisms and treatment protocols for the validation and control of industrial scale processing.
The Research Topic aims to publish state of the art research about underlying inactivation mechanisms of microorganisms treated with novel decontamination technologies and their implication on the development of application and validation concepts.
... Teratosphaeria canker was known only from South Africa until the early 2000s (Van Zyl et al., 2002b). Surveys of Australian plantations and natural forests have also failed to detect similar symptoms or pathogens, although closely related species causing leaf spots have been identified (Andjic et al., 2010;Crous et al., 2006). For this reason, it was initially hy pothesized that the disease originated in South Africa, possibly as a result of a host shift (Slippers et al., 2005) from a closely related plant, probably one in the Myrtaceae (Wingfield et al., 1996). ...
... Based on the ITS and EF1α genes, T. gauchensis groups closest to T. majorizuluensis, T. foliensis and T. stellenbos chiana (Quaedvlieg et al., 2014;Silva et al., 2015) (Fig. 3). With the exception of T. stellenboschiana, discovered in Stellenbosch, South Africa, these leaf pathogens were all described from east ern Australia (Andjic et al., 2010;Crous et al., 2009bCrous et al., , 2006Summerell et al., 2006). It seems unlikely that two species causing the same disease symptoms are not each other's closest relatives (Gezahgne et al., 2005;Old et al., 2003). ...
Background
Teratosphaeria gauchensis and T. zuluensis are closely related fungi that cause Teratosphaeria (previously Coniothyrium) stem canker disease on Eucalyptus species propagated in plantations for commercial purposes. This disease is present in many countries where Eucalyptus trees are planted, and continues to spread with international trade of infected plant germplasm.
Taxonomy
Fungi, Ascomycota, Pezizomycotina, Dothideomycetes, Dothideomycetidae, Capnodiales, Teratosphaeriaceae, Teratosphaeria
Identification
The causal agents form dark masses of pycnidia that are visible on the surface of distinct stem cankers that typically form on young green stem tissues. Accurate diagnosis of the causal agents requires DNA sequence data.
Host range
Nine species of Eucalyptus are known to be affected. Of these, E. grandis, and its hybrids, which include some of the most important planting stock globally, appear particularly vulnerable.
Disease symptoms
Small necrotic lesions develop on young green stem tissue. These lesions coalesce forming larges cankers that exude gum. Epicormic shoots develop below the girdling canker and, in severe cases, trees die.
Useful websites
Mycobank, http://www.mycobank.org; Publications of the Forestry and Agricultural Biotechnology Institute (FABI), http://www.fabinet.up.ac.za/index.php/journals.
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... Conidiophores in fascicles of 8-20, simple, erect, straight Notes: The Cercospora apii species complex has not yet been fully resolved even though multigene analyses (Groenewald et al. 2013) are available. Here we applied the broad species concept for morphologically indistinguishable specimens (Crous and Braun 2003). Bomarea species have hitherto not been recorded as hosts for cercosporoid fungi (Crous and Braun 2003;Farr and Rossman 2017). ...
... Here we applied the broad species concept for morphologically indistinguishable specimens (Crous and Braun 2003). Bomarea species have hitherto not been recorded as hosts for cercosporoid fungi (Crous and Braun 2003;Farr and Rossman 2017). ...
... Whether they primarily grow on living or dead leaves is not always clear, but their specific hypophyllous colonies may indicate primary growth on living leaves rather than dead leaves in the litter. Another fungus associated with living leaves, Cercospora melastomatis Pat., was transferred to Sporidesmium (Crous and Braun 2003). Hughes (1983) felt that foliicolous Sporidesmium species should be segregated from the species growing on woody substrates and transferred two foliicolous species from Sporidesmium to Janetia, whereas Goh and Hyde (1996) did not consider the substrate important and applied a broad genus concept, which again was challenged based on morphology alone by Mena-Portales et al. (2016). ...
Foliicolous fungi were collected on living plants of mycologically rarely explored plant families in the montane Quercus-Chusquea forest of western Panama. Five new species of the genera Periconiella, Pseudocercospora, Sporidesmium, and Zasmidium are morphologically described from living leaves of Myrsine coriacea (Primulaceae) and Clusia stenophylla (Clusiaceae). A species of Bomarea (B. caldasii, Alstroemeriaceae) is recorded as host for a cercosporoid fungus (Cercospora apii s.lat.) for the first time.
... However, there is little data available to support this hypothesis. Recent studies based on molecular data indicate that some species of Mycosphaerella have narrow host ranges, while others have wider host ranges Crous et al. 2006Crous et al. , 2009d. Host-specific Mycosphaerella species may jump from a dying host to a nonhost and produce progeny that then may infect another favorable host . ...
Persimmon (Diospyros kaki) fruit production is severely affected by circular leaf spot worldwide. Mycosphaerella nawae causes circular leaf spot of persimmon (CLSP) and can result in leaf spot, defoliation, early fruit maturation, and subsequent softening and abscission. The morphology and phylogenetic position of M. nawae within the family Mycosphaerellaceae is, therefore, of utmost importance given its impact on persimmon production. Based on previous morphological and molecular studies, the phylogenetic position of the anamorphic genera associated with M. nawae remain in confusion. In the present study, 15 isolates of M. nawae were collected from the tissue of living leaves exhibiting leaf spot symptoms. A subsample of three isolates was characterized phylogenetically and morphologically. Isolates were compared based on DNA sequence data for the internal transcribed spacer region (ITS1- 5.8S ITS2), part of the 28S nrDNA including domains D1-D3 (LSU), actin (Act), translation elongation factor 1-alpha (EF-1α), and RNA polymerase II second largest subunit (rpb2). The anamorph and teleomorph structures, ascospore germination patterns, as well as host specificity were used to describe the isolates. The phylogenetic and morphological analyses revealed that M. nawae requires a new holomorphic genus within Mycosphaerellaceae, described herein as Plurivorosphaerella gen. nov. A host specificity test revealed that Plurivorosphaerella nawae comb. nov. (M. nawae) can superficially colonize but not infect, apple, peach, cherry, and plum.
Keywords: circular leaf spot, Mycosphaerella, Devonomyces endophyticus, Plurivorosphaerella gen. nov., phylogenetic analyses
... And its enzyme activities improve tea quality by producing the sweet substance xylitol, vitamins, and other organic acids in Fu brick tea (Xu et al., 2011). Uwebraunia is a kind of plant pathogenic fungi, which was a synonym of Dissoconium (Crous et al., 2006), but the genus have not been well described, and the understanding of its roles in pile-fermentation systems of primary dark tea is limited. ...
Primary dark tea is used as raw material for compressed dark tea, such as Fu brick tea, Hei brick tea, Hua brick tea, and Qianliang tea. Pile-fermentation is the key process for the formation of the characteristic properties of primary dark tea, during which the microorganism plays an important role. In this study, the changes of major chemical compounds, enzyme activities, microbial diversity, and their correlations were explored during the pile-fermentation process. Our chemical and enzymatic analysis showed that the contents of the major compounds were decreased, while the activities of polyphenol oxidase, cellulase, and pectinase were increased during this process, except peroxidase activity that could not be generated from microbial communities in primary dark tea. The genera Cyberlindnera, Aspergillus, Uwebraunia, and Unclassified Pleosporales of fungus and Klebsiella, Lactobacillus of bacteria were predominant in the early stage of the process, but only Cyberlindnera and Klebsiella were still dominated in the late stage and maintained a relatively constant until the end of the process. The amino acid was identified as the important abiotic factor in shaping the microbial community structure of primary dark tea ecosystem. Network analysis revealed that the microbial taxa were grouped into five modules and seven keystone taxa were identified. Most of the dominant genera were mainly distributed into module III, which indicated that this module was important for the pile-fermentation process of primary dark tea. In addition, bidirectional orthogonal partial least squares (O2PLS) analysis revealed that the fungi made more contributions to the formation of the characteristic properties of primary dark tea than bacteria during the pile-fermentation process. Furthermore, 10 microbial genera including Cyberlindnera, Aspergillus, Eurotium, Uwebraunia, Debaryomyces, Lophiostoma, Peltaster, Klebsiella, Aurantimonas, and Methylobacterium were identified as core functional genera for the pile-fermentation of primary dark tea. This study provides useful information for improving our understanding on the formation mechanism of the characteristic properties of primary dark tea during the pile-fermentation process.
... further limit identification and phylogenetic studies of these species (Crous et al., 2007b). Identification difficulties can also be attributed to the occurrence of various species in a single lesion, thus causing problems with identification based solely on morphology (Crous et al., 2006;Crous, 2009). As some species are morphologically similar and require specific molecular techniques for identification (Hunter et al., 2011;Pérez et al., 2014), the collection of cultures is necessary to identify these species using DNA analysis or ascospore germination patterns. ...
Mycosphaerella leaf disease (MLD) is a dangerous disease for eucalypt plantations; however little information is available regarding its control using fungicides in South America. In this study, we evaluated MLD control, and growth in young stands of Eucalyptus dunnii clones (C18 and C25). After two applications of azoxystrobin + cyproconazole (0.3 L/ha-1 and 0.45 L/ha-1), with a spraying volume of 200 L/ha -1, and trifloxystrobin + tebuconazole (0.5 L/ha-1 and 0.75 L/ha -1), with a spraying volume of 100 L/ha-1, mean severity reduction for apical branches of C18 was 74%. For middle branches, application of trifloxystrobin + tebuconazole at 0.5 L/ha-1 reduced severity by 27% in C18. While fungicide applications did not affect growth in height or root collar diameter, our results suggest that the application of fungicide can deter disease progression throughout the plant. Therefore, the monitoring of disease outbreaks is crucial to enable effective, early application.
