Fig 59 - uploaded by Uwe Braun
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Phyllactinia guttata. A, B: Conidiophores; C-F: Conidia; G, H: Conidia with germ tubes. Scale bars = 10 µm.
Source publication
Schmidt, A. & Braun, U. 2020: Asexual morphs of powdery mildew species (Erysiphaceae)-new and supplementary morphological descriptions and illustrations. Schlechtendalia 37: 30-79. Descriptions of asexual morphs of powdery mildew species are provided, with a particular focus on characteristics of the conidiophores and conidial germination patterns....
Citations
... A recent taxonomic study on powdery mildew disease agents caused by Erysiphe species on Corylus hosts in the world includes six species; E. cornutae, E. corylacearum, E. coryli-americanae, E. corylicola, E. pseudocorylacearum, and E. syringae [20]. Beside them, P. guttata is a globally widespread powdery mildew agent on hazelnut, of no particular economic concern for hazelnut growers [4,7,19,31]. ...
Erysiphe corylacearum has recently been reported in northern Italy (Piedmont) and other European countries as the causal agent of a new emerging powdery mildew on hazelnut. This disease is much more dangerous than the common hazelnut powdery mildew caused by Phyllactinia guttata as it significantly reduces yield and quality of hazelnuts. This study aimed to perform morphological and molecular characterization of the fungal isolates from powdery mildew-infected plants in the Piedmont Italian region. Additionally, genetic diversity studies and pathogenicity tests were conducted. Thirty-six fungal isolates originating from symptomatic hazelnut plants exhibiting specific powdery mildew symptoms on the superior leaf side were identified morphologically as E. corylacearum. Single- and multilocus sequence typing of five loci (ITS, rpb2, CaM, GAPDH and GS) assigned all isolates as E. corylacearum. Multilocus and GAPDH phylogenetic studies resulted in the most efficient characterization of E. corylacearum. Studied fungal isolates were able to cause new emerging powdery mildew disease by fulfilling Koch’s postulates. The emergence of powdery mildew disease in Italy revealed the E. corylacearum subgrouping, population expansion, and high nucleotide similarity with other recently identified E. corylacearum hazelnut isolates. To contain this harmful disease and inhibit the fungus spread into new geographical zones, it will be necessary to implement more rigorous monitoring in neighboring hazelnut plantations near infected hazelnuts, use sustainable fungicides and search for new biocontrol agents.
... Some descriptions and illustrations have already been published in previous taxonomic treatments, such as Schmidt (1999), Schmidt & Scholler (2002, 2006, 2011, and Scholler et al. (2016). Schmidt & Braun (2020) published a first contribution to the conidial germination patterns of powdery mildew species aiming at providing supplementary descriptions for species with unknown or insufficiently known details of the germination of their conidia. The present publication represents the second part of this series. ...
... Schmidt & Braun (2020: 40, Fig. 14 (2020), turned out to be a synonym of E. capreae (Darsaraei et al. 2021). Schmidt & Braun (2020) discussed in detail the history of the exploration of the conidial germination patters of powdery mildews and emphasized the significance for the taxonomy of this fungal group and for diagnostic purposes (Neger 1902, Hirata 1955, Braun 1977, Zaracovitis 1965, Braun et al. 2002. Braun & Cook (2012: 15-22) outlined a comprehensive and detailed new system of conidial germination types, subtypes, and patterns, reflecting basic types linked with powdery mildew genera and sections, but also specific variations characteristic for individual species. ...
Schmidt, A. & Braun, U. 2024: Asexual morphs of powdery mildew species (Erysiphaceae)-new and supplementary morphological descriptions and illustrations (part 2). Schlechtendalia 41: 43-59. The second contribution to descriptions of asexual morphs of powdery mildew species is provided, with a particular focus on characteristics of the conidial germination patterns. The concept followed the first contribution published in 2020. Descriptions and illustrations are based on collections made by the first author during long-term examinations of species of the Erysiphaceae. Voucher specimens are deposited at herbarium KR (Natural Science Museum, Karlsruhe, Germany). The conidial germination patterns of several powdery mildew species have been examined in detail for the first time, including Erysiphe lycopsidis, Euoidium pseudolongipes, Golovinomyces bolayi, G. macrocarpus, Podosphaera euphorbiae (on its type host Euphorbia peplus), P. macrospora, P. mors-uvae, P. phtheirospermi, and Sawadaea tulasnei. Salix ×multinervis and S. ×smithiana are new host records from Erysiphe capreae. Zusammenfassung: Schmidt, A. & Braun, U. 2024: Asexuelle Morphen von Mehltauarten (Erysiphaceae)-neue und ergänzende morphologische Beschreibungen und Abbildungen (Teil 2). Schlechtendalia 41: 43-59. Der zweite Beitrag mit Beschreibungen asexueller Morphen von Mehltau-Arten wird zur Verfügung gestellt, mit einem besonderen Schwerpunkt auf Merkmale der Keimungsmuster der Konidien. Das Konzept folgt dem ersten Teil, der 2020 publiziert wurde. Beschreibungen und Abbildungen basieren auf Kollektionen der Erstautorin, die sie im Rahmen langjähriger Untersuchungen von Arten der Erysiphaceae gefunden hat. Belegexemplare sind im Herbarium KR (Naturkundemuseum Karlsruhe, Germany) deponiert. Die Keimungsmuster einiger Mehltauarten wurden erstmalig im Detail untersucht, darunter Erysiphe lycopsidis, Euoidium pseudolongipes, Golovinomyces bolayi, G. macrocarpus, Podosphaera euphorbiae (on its type host Euphorbia peplus), P. macrospora, P. mors-uvae, P. phtheirospermi und Sawadaea tulasnei. Salix ×multinervis und S. ×smithiana sind neue Wirtsangaben für Erysiphe capreae.
... cruchetiana S. Blumer was accepted in Braun (1987) and Braun and Cook (2012). Recently, Schmidt and Braun (2020) examined the conidial germination pattern of Erysiphe species on Ononis hosts (O. spinosa L. and O. repens L.), observed differences to the germination pattern of E. pisi and recommended to reinstate E. cruchetiana as a species of its own. ...
... cruchetiana, we reinstate E. cruchetiana as a species of its own, confined to Ononis spp. This result and treatment are in agreement with the recommendation to consider E. cruchetiana as a separate species recently published by Schmidt & Braun (2020), who found differences in the conidial germination patterns between E. pisi and E. cruchetiana. ...
Fabaceae, one of the largest flowering plant families, comprises several subfamilies and genera. Fabaceous plant species host a large number of powdery mildew species belonging to the genus Erysiphe. The affiliation of these species to Erysiphe is readily possible, but they represent a morphologically and taxonomically complicated complex of closely related, morphologically similar species with overlapping traits. Precise morphological examinations along with phylogenetic analyses, including type collections and other representative samples, are needed to solve the complexity of Erysiphe spp. on legumes. In this study, we sequenced a number of collections of powdery mildews on Pisum, Lathyrus, Vicia and Ononis spp., with a special focus on specimens from Iran, to clarify species delimitations within the Erysiphe pisi complex and other Erysiphe species complexes on legumes. Sequences retrieved from powdery mildew on Pisum and Ononis fall into separate, well supported clades. Hence, the original status of E. cruchetiana as a species of its own on Ononis spp. is reinstated instead of E. pisi var. cruchetiana. Ten species, viz., E. astragali, E. bremeri, E. caulicola, E. cruchetiana, E. iranica, E. medicaginis, E. pisi, E. rayssiae, E. sesbaniae and E. trifoliorum were confirmed for Iran, redescribed and illustrated on the basis of Iranian collections. Erysiphe astragali, E. bremeri, E. coluteae and E. crispula form a genetically little differentiated clade in ITS/LSU analyses, which is referred to as E. astragali clade (complex), comparable to the E. trifoliorum clade (complex). Based on our results, E. coluteae and E. crispula are reduced to synonymy with E. astragali and E. sophorae is considered a synonym of E. bremeri. Sequences of the North American E. intermedia on Lupinus species form a small clade nested within the big E. astragali clade. DNA of the holotype of E. sesbaniae was sequenced for the first time in this study. To use the sequences obtained from some new collections as reference sequences for phylogenetic-taxonomic purposes, we propose, for the interim, reference sequences for E. bremeri, E. caulicola, E. cruchetiana, E. pisi and E. viciae-unijugae.
... Since the teleomorphic stage of Erysiphe platani was not observed, we compared it with Phyllactinia guttata according to anamorphic morphological characters. Conidiophores and conidia of Erysiphe platani are much shorter and thicker in comparison with Phyllactinia guttata, which has very long and filiform, 5-8 µm wide conidiophores, conidia clavate to somewhat spathulate, 57-88 × 16-28 µm (Schmidt, Braun, 2020). ...
As a result of mycological research on the territory of Zaamin National Nature Park, a new powdery mildew for mycobiota of Uzbekistan-Erysiphe platani was found. This species was collected on Platanus orientalis. A brief description and photographs of Erysiphe platani are provided.
... Chasmothecia were not observed. The morphology of the fungi was consistent with those of Erysiphe pisi (Schmidt and Braun 2020). A voucher specimen (accession no. ...
During February of 2022, symptoms of powdery mildew were found on 14% of 179 samples of mexican palo verde plants (Parkinsonia aculeata) in Ahome, Sinaloa, Mexico. White fungal colonies were observed on both sides of infected leaves. Hyphal appressoria were slightly to multilobed. Conidiophores were erect and cylindrical. Foot-cells were cylindrical, straight to somewhat curved measuring 16.5–41 × 5.5–8.5 μm, followed by 1–2 shorter cells. Conidia were ellipsoid-cylindrical, measuring 26–41 × 12–18 μm. Chasmothecia were not observed. The morphology of the fungi was consistent with those of Erysiphe pisi (Schmidt and Braun 2020). A voucher specimen (accession no. FAVF651) was deposited at the Faculty of Agriculture of the Autonomous University of Sinaloa (Mexico). The internal transcribed spacer (ITS) region, and part of the 28 S (LSU) region were amplified using the primers PM5/ITS4 and NL1/TW14 (Mori et al. 2000), respectively. The sequences were deposited in GenBank under accession numbers ON314580 and ON314806. Sequences comparisons in the GenBank showed 99% identity with sequences of E. pisi (ITS; LC009890) and E. trifoliorum (LSU; MT380914). A concatenated phylogenetic analysis using Maximum Likelihood confirmed the identity of isolate FAVF651 as E. pisi. Pathogenicity was demonstrated by gently dusting conidia from infected leaves onto leaves of 20 healthy mexican palo verde plants. Ten non-inoculated plants served as controls. Inoculated and non-inoculated plants were separated and maintained in a greenhouse at 25–35 ºC. After 12 days, all inoculated plants developed the same powdery mildew symptoms observed in natural infections, but none of the control. Erysiphe pisi was recovered from inoculated plants, thus fulfilling Koch’s postulates. Erysiphe sp. has been recorded on P. aculeata in Florida and California, USA (Farr and Rossman 2022); however, this is the first report of E. pisi causing powdery mildew on P. aculeata in Mexico and worldwide.
... cumminsiana" on Charthamus tenuis, Filago eriocephala, and Senecio vernalis from Israel recorded by Voytyuk et al. (2004Voytyuk et al. ( , 2006 is unclear. The first record of this species from Germany on Lapsana communis was published by Schmidt and Braun (2020 fig. 1). ...
The second contribution to a new series devoted to the phylogeny and taxonomy of powdery mildews is presented. An overview of Neoerysiphe species is given, including references to ex-type sequences or, if unavailable, representative reference sequences for phylogenetic-taxonomic purposes are provided. The new species N. stachydis is described, and Striatoidium jaborosae is reduced to synonymy with Neoerysiphe macquii. Epitypes with ex-epitype sequences are designated for Alphitomorpha ballotae, A. labiatarum, Erysiphe galii, E. chelones, and E. galeopsidis. Based on phylogenetic analyses, it has been demonstrated that Neoerysiphe cumminsiana is confined to its type host, Roldana hartwegii (= Senecio seemannii), and other North and South American parasites on Asteraceae hosts, previously assigned to this species, pertain to N. macquii. The first record of N. macquii from Europe (Germany) on cultivated Bidens aurea was confirmed by sequencing. Sequence analysis of type material of N. rubiae reveals that this species should be excluded from Neoerysiphe; however, the true affinity of this taxon is not yet clear.
... However, all other features, including the number of appendages and dimensions of asci and ascospores, aligned with the species description. Based on German material, Schmidt and Braun (2020) described the asexual morph of E. azaleae in detail, including peculiarities of the conidial germination. = Trichocladia vaccinii f. andromedae Jacz., Karm Opred Grib Vyp 2 Muchn-rosj griby (Leningrad):297. ...
The genus Rhododendron comprises over 1000 evergreen and deciduous species. In the Pacific Northwest Coast region of North America (PNWC), powdery mildews infecting deciduous Rhododendron spp. are well documented but less so on evergreen Rhododendron spp. Infections of both groups of hosts historically have been attributed to Erysiphe azaleae or E. vaccinii. No formal characterizations of powdery mildew fungi infecting either deciduous or evergreen Rhododendron spp. in the PNWC have been completed. The objectives of this study were to identify the powdery mildew pathogens infecting evergreen Rhododendron spp. in the PNWC and to assess the phylo-genetic position of these fungi within the Erysiphaceae. To ascertain valid taxonomic conclusions, and to determine whether potential introductions of exotic Rhododendron powdery mildews in North America have occurred, it was necessary to put the new North American phylogenetic data into a worldwide context. Therefore, available phylogenetic data from all Erysiphe spp. on Rhododendron have been included in our analyses. Based on analyses of numerous new internal transcribed spacer (ITS) and 28S rDNA sequences and already available sequences deposited in GenBank retrieved from evergreen and deciduous Rhododendron spp., the following Erysiphe spp. could be phylogenetically confirmed (all belonging to Erysiphe sect. Microsphaera): Erysiphe azaleae nom. cons. (Oidium ericinum could be verified as a synonym), E. digitata (holotype sequenced), E. izuensis, and E. vaccinii. Erysiphe azaleae and E. vaccinii are epitypified with sequenced specimens, and an ex-neotype sequence has been obtained for Oidium ericinum. Erysiphe rhododendri (Erysiphe sect. Erysiphe), only known from two collections in India (Himalayan region), was not available for phylogentic analyses. ARTICLE HISTORY
... Braun and Cook, 2012). Taxonomy of this genus date backs to Vassilkov who published Arthrocladiella for Arthrocladia Golovin (refer to Braun and Cook 2012). Arthrocladiella mougeotii is the only species that infects various species of Lycium in Solanaceae (Glawe et al. 2004, Braun and Cook. 2012, Wang et al. 2015, Özer et al. 2016, Kiss et al. 2018, Schmidt and Braun. 2020, Zhu et al. 2020). Occurrence of this species has been confirmed on Lycium species worldwide such as Russia, Europe, China, Japan, New Zealand, USA, Turkey, Israel (Braun and Cook 2012). As we are aware, there is no report of the occurrence of this fungus outside of the Solanaceae family. ...
Arthrocladiella is a monotypic member of family Erysiphaceae ( Ascomycota, Helotiales ), which has only been reported from Lycium spp. (Solanaceae). Morphological data supplemented with rDNA ITS sequence confirmed that the Arthrocladiella mougeotii infects Lycium sp. in Iran. Moreover, Arthrocladiella is reported as a new genus for Iranian Mycobiota.
... Most collections (without chasmothecia) were shown to belong to N. nevoi (hyphal appressoria lobed, foot-cells of the conidiophores characteristically short, 20-50 × 9-15 µm, basal septae of conidiophores foot-cells often conspicuously constricted, conidia with striate surfaces [as shown by scanning electron microscopy]). The occurrence of N. nevoi on L. communis has also been confirmed by sequence analyses and affirmed in the first report of this species on this host from Germany (Schmidt and Braun, 2020). There were even some collections with chasmothecia, originally identified as "Golovinomyces cichoracearum", which turned out to be Po. ...
The Golovinomyces cichoracearum complex is morphologically highly variable and causes powdery mildew on a wide range of Compositae, including Hieracium spp. and Lapsana communis. A comprehensive phylogenetic analysis of Golovinomyces, published in 2013, revealed that G. cichoracearum s. str. was confined to Scorzonera and Tragopogon spp. as hosts (Compositae, tribe Lactuceae, subtribe Scorzonerinae). To clarify the phylogeny and taxonomy of Golovinomyces on Hieracium spp. (Compositae, tribe Lactuceae, subtribe Hieraciinae), which is common in Asia and Europe, morphology and phylogenetic analyses of ITS + 28S rDNA sequences were conducted for 57 powdery mildew specimens of Hieracium spp. and Lapsana communis. Golovinomyces on Hieracium spp. in Asia and Europe, previously referred to as G. cichoracearum, is a previously undescribed, cryptic species, which is described here as Golovinomyces hieraciorum sp. nov.. Since a sequence retrieved from a powdery mildew on Lapsana communis in Switzerland clustered in sister position to the G. hieraciorum clade, numerous German specimens identified as G. cichoracearum were included in the present examinations. All the re-examined collections of “G. cichoracearum” on L. communis were misidentified, and were shown to belong to Neoërysiphe nevoi or Podosphaera ergerontis-canadensis.
... Only P. xanthii and the plurivorous species G. bolayi, G. orontii, G. tabaci (G. orontii s.l.) infect all economically important cucurbit species worldwide (Pirondi et al. 2015b(Pirondi et al. , 2016Lebeda et al. 2016;Braun et al. 2019;Qiu et al. 2020a); however, Golovinomyces species identification on cucurbits has been challenging because anamorph morphology and DNA sequence data strongly overlap among closely related species (Schmidt and Braun 2020;Pirondi et al. 2015a). ...
Powdery mildew is one of the most severe diseases affecting Cucurbitaceae. We identify the members of Erysiphaceae infecting cucurbits in three producing regions in Mexico. We determined that Golovinomyces ambrosiae (Schwein.) U. Braun & R.T.A. Cook, Neoerysiphe sechii R. Gregorio-Cipriano & D. González, and Podosphaera xanthii (Castagne) U. Braun & Shishkoff infected cultivated and wild cucurbits species or subspecies. Leaf samples showing symptoms and signs of powdery mildew were collected from the northwestern, central western, and eastern regions of Mexico between 2017 and 2020. Species associated with the disease were identified based on morphology and internal transcribed spacer rDNA sequences. All powdery mildew specimens presented only the anamorph. Podosphaera xanthii was the predominant species; it was found in 84.76% of the samples and in 13 out of 14 species or subspecies of cucurbits. Neoerysiphe sechii was found in 15.24% of the samples and in only four cucurbit species from the central western and eastern regions of Mexico. Golovinomyces ambrosiae was documented for the first time in a Cucurbitaceae species (Sicyos deppei G.Don) from central west Mexico. Three new hosts were registered for N. sechii (Cucurbita ficifolia Bouché, Echinopepon milleflorus Naudin, and Sicyos laciniatus L.) and eight for P. xanthii (Cucurbita argyrosperma C.Huber, Cucurbita argyrosperma subsp. sororia (L.H.Bailey) Merrick & D.M.Bates, C. ficifolia, Cucurbita okeechobeensis subsp. martinezii (L.H.Bailey) T.C.Andres & G.P.Nabhan ex T.W.Walte, Cucurbita radicans Naudin, Sechium edule (Jacq.) Sw., S. laciniatus, and S. deppei).
