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P W Crous - One of the best experts on this subject based on the ideXlab platform.
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application of the consolidated species concept to Cercospora spp from iran
Persoonia, 2015Co-Authors: Mounes Bakhshi, J Z Groenewald, Uwe Braun, Mahdi Arzanlou, A Babaiahari, P W CrousAbstract:The genus Cercospora includes many important plant pathogenic fungi associated with leaf spot diseases on a wide range of hosts. The mainland of Iran covers various climatic regions with a great biodiversity of vascular plants, and a correspondingly high diversity of cercosporoid fungi. However, most of the cercosporoid species found to date have been identified on the basis of morphological characteristics and there are no cultures that support these identifications. In this study the Consolidated Species Concept was applied to differentiate Cercospora species collected from Iran. A total of 161 Cercospora isolates recovered from 74 host species in northern Iran were studied by molecular phylogenetic analysis. Our results revealed a rich diversity of Cercospora species in northern Iran. Twenty species were identified based on sequence data of five genomic loci (ITS, TEF1-α, actin, calmodulin and histone H3), host, cultural and morphological data. Six novel species, viz. C. convolvulicola, C. conyzae-canadensis, C. cylindracea, C. iranica, C. pseudochenopodii and C. sorghicola, are introduced. The most common taxon was Cercospora cf. flagellaris, which remains an unresolved species complex with a wide host range. New hosts were recorded for previously known Cercospora species, including C. apii, C. armoraciae, C. beticola, C. cf. richardiicola, C. rumicis, Cercospora sp. G and C. zebrina.
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species concepts in Cercospora spotting the weeds among the roses
Studies in Mycology, 2013Co-Authors: J Z Groenewald, Chiharu Nakashima, Junji Nishikawa, Hyeondong Shin, J H Park, A N Jama, Marizeth Groenewald, Uwe Braun, P W CrousAbstract:Abstract The genus Cercospora contains numerous important plant pathogenic fungi from a diverse range of hosts. Most species of Cercospora are known only from their morphological characters in vivo . Although the genus contains more than 5 000 names, very few cultures and associated DNA sequence data are available. In this study, 360 Cercospora isolates, obtained from 161 host species, 49 host families and 39 countries, were used to compile a molecular phylogeny. Partial sequences were derived from the internal transcribed spacer regions and intervening 5.8S nrRNA, actin, calmodulin, histone H3 and translation elongation factor 1-alpha genes. The resulting phylogenetic clades were evaluated for application of existing species names and five novel species are introduced. Eleven species are epi-, lecto- or neotypified in this study. Although existing species names were available for several clades, it was not always possible to apply North American or European names to African or Asian strains and vice versa . Some species were found to be limited to a specific host genus, whereas others were isolated from a wide host range. No single locus was found to be the ideal DNA barcode gene for the genus, and species identification needs to be based on a combination of gene loci and morphological characters. Additional primers were developed to supplement those previously published for amplification of the loci used in this study. Taxonomic novelties: New species – Cercospora coniogrammes Crous & R.G. Shivas, Cercospora delaireae C. Nakash., Crous, U. Braun & H.D. Shin, Cercospora euphorbiae-sieboldianae C. Nakash., Crous, U. Braun & H.D. Shin, Cercospora pileicola C. Nakash., Crous, U. Braun & H.D. Shin, Cercospora vignigena C. Nakash., Crous, U. Braun & H.D. Shin. Typifications: epitypifications – Cercospora alchemillicola U. Braun & C.F. Hill, Cercospora althaeina Sacc., Cercospora armoraciae Sacc., Cercospora corchori Sawada, Cercospora mercurialis Pass., Cercospora olivascens Sacc., Cercospora violae Sacc.; neotypifications – Cercospora fagopyri N. Nakata & S. Takim., Cercospora sojina Hara.
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host range of Cercospora apii and c beticola and description of c apiicola a novel species from celery
Mycologia, 2006Co-Authors: Marizeth Groenewald, J Z Groenewald, Uwe Braun, P W CrousAbstract:The genus Cercospora is one of the largest and most heterogeneous genera of hyphomycetes. Cercospora species are distributed worldwide and cause Cercospora leaf spot on most of the major plant families. Numerous species described from diverse hosts and locations are morphologically indistinguishable from C. apii and subsequently are referred to as C. apii sensu lato. The importance and ecological role that different hosts play in taxon delimitation and recognition within this complex remains unclear. It has been shown that Cercospora leaf spot on celery and sugar beet are caused respectively by C. apii and C. beticola, both of which are part of the C. apii complex. During this study we characterized a new Cercospora species, C. apiicola, which was isolated from celery in Venezuela, Korea and Greece. The phylogenetic relationship between C. apiicola and other closely related Cercospora species was studied with five different gene areas. These analyses revealed that the C. apiicola isolates cluster together in a well defined clade. Both C. apii and C. beticola sensu stricto form well defined clades and are shown to have wider host ranges and to represent distinct species.
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distinct species exist within the Cercospora apii morphotype
Phytopathology, 2005Co-Authors: Marizeth Groenewald, J Z Groenewald, P W CrousAbstract:Groenewald, M., Groenewald, J. Z., and Crous, P. W. 2005. Distinct species exist within the Cercospora apii morphotype. Phytopathology 95:951-959. The genus Cercospora is one of the largest genera of hyphomycetes. Cercospora apii sensu lato is the oldest name for a large complex of morphologically indistinguishable Cercospora spp. occurring on a wide host range. There are currently 659 recognized Cercospora spp., and names of another 281 morphologically identical species are included in the synonymy of C. apii sensu lato. Two of the species that belong to the C. apii complex, C. apii and C. beticola, cause Cercospora leaf spot on Apium graveolens (celery) and Beta vulgaris (sugar beet), respectively. In
S J Pethybridge - One of the best experts on this subject based on the ideXlab platform.
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an improved pcr assay for species specific detection and quantification of Cercospora beticola
Canadian Journal of Plant Pathology-revue Canadienne De Phytopathologie, 2020Co-Authors: Noel L Knight, S J PethybridgeAbstract:Cercospora beticola causes Cercospora leaf spot (CLS) on sugar beet and table beet. Accurate identification of this pathogen is critical to disease diagnosis and effective research outcomes for imp...
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improving fungicide based management of Cercospora leaf spot in table beet in new york usa
Canadian Journal of Plant Pathology-revue Canadienne De Phytopathologie, 2019Co-Authors: S J Pethybridge, Linda E. Hanson, Niloofar Vaghefi, Sandeep Sharma, Zachariah R Hansen, Julie R KikkertAbstract:Cercospora leaf spot (CLS), caused by Cercospora beticola Sacc., is the dominant foliar disease affecting the profitability of table beet production in New York, USA. The disease is controlled prim...
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cryptic diversity pathogenicity and evolutionary species boundaries in Cercospora populations associated with Cercospora leaf spot of beta vulgaris
Fungal Biology, 2018Co-Authors: Niloofar Vaghefi, Linda E. Hanson, Julie R Kikkert, Gavriela Dena Carver, Lori B Koenick, Melvin D Bolton, Gary A Secor, S J PethybridgeAbstract:Abstract The taxonomy and evolutionary species boundaries in a global collection of Cercospora isolates from Beta vulgaris was investigated based on sequences of six loci. Species boundaries were assessed using concatenated multi-locus phylogenies, Generalized Mixed Yule Coalescent (GMYC), Poisson Tree Processes (PTP), and Bayes factor delimitation (BFD) framework. Cercospora beticola was confirmed as the primary cause of Cercospora leaf spot (CLS) on B. vulgaris . Cercospora apii , C. cf. flagellaris , Cercospora sp. G, and C. zebrina were also identified in association with CLS on B. vulgaris . Cercospora apii and C. cf. flagellaris were pathogenic to table beet but Cercospora sp. G and C. zebrina did not cause disease. Genealogical concordance phylogenetic species recognition, GMYC and PTP methods failed to differentiate C. apii and C. beticola as separate species. On the other hand, multi-species coalescent analysis based on BFD supported separation of C. apii and C. beticola into distinct species; and provided evidence of evolutionary independent lineages within C. beticola . Extensive intra- and intergenic recombination, incomplete lineage sorting and dominance of clonal reproduction complicate evolutionary species recognition in the genus Cercospora . The results warrant morphological and phylogenetic studies to disentangle cryptic speciation within C. beticola .
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genetic structure of Cercospora beticola populations on beta vulgaris in new york and hawaii
Scientific Reports, 2017Co-Authors: Niloofar Vaghefi, Julie R Kikkert, Scot Nelson, S J PethybridgeAbstract:Cercospora leaf spot (CLS), caused by Cercospora beticola, is a major disease of Beta vulgaris worldwide. No sexual stage is known for C. beticola but in its asexual form it overwinters on infected plant debris as pseudostromata, and travels short distances by rain splash-dispersed conidiospores. Cercospora beticola infects a broad range of host species and may be seedborne. The relative contribution of these inoculum sources to CLS epidemics on table beet is not well understood. Pathogen isolates collected from table beet, Swiss chard and common lambsquarters in mixed-cropping farms and monoculture fields in New York and Hawaii, USA, were genotyped (n = 600) using 12 microsatellite markers. All isolates from CLS symptoms on lambsquarters were identified as C. chenopodii. Sympatric populations of C. beticola derived from Swiss chard and table beet were not genetically differentiated. Results suggested that local (within field) inoculum sources may be responsible for the initiation of CLS epidemics in mixed-cropping farms, whereas external sources of inoculum may be contributing to CLS epidemics in the monoculture fields in New York. New multiplex PCR assays were developed for mating-type determination for C. beticola. Implications of these findings for disease management are discussed.
J Z Groenewald - One of the best experts on this subject based on the ideXlab platform.
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application of the consolidated species concept to Cercospora spp from iran
Persoonia, 2015Co-Authors: Mounes Bakhshi, J Z Groenewald, Uwe Braun, Mahdi Arzanlou, A Babaiahari, P W CrousAbstract:The genus Cercospora includes many important plant pathogenic fungi associated with leaf spot diseases on a wide range of hosts. The mainland of Iran covers various climatic regions with a great biodiversity of vascular plants, and a correspondingly high diversity of cercosporoid fungi. However, most of the cercosporoid species found to date have been identified on the basis of morphological characteristics and there are no cultures that support these identifications. In this study the Consolidated Species Concept was applied to differentiate Cercospora species collected from Iran. A total of 161 Cercospora isolates recovered from 74 host species in northern Iran were studied by molecular phylogenetic analysis. Our results revealed a rich diversity of Cercospora species in northern Iran. Twenty species were identified based on sequence data of five genomic loci (ITS, TEF1-α, actin, calmodulin and histone H3), host, cultural and morphological data. Six novel species, viz. C. convolvulicola, C. conyzae-canadensis, C. cylindracea, C. iranica, C. pseudochenopodii and C. sorghicola, are introduced. The most common taxon was Cercospora cf. flagellaris, which remains an unresolved species complex with a wide host range. New hosts were recorded for previously known Cercospora species, including C. apii, C. armoraciae, C. beticola, C. cf. richardiicola, C. rumicis, Cercospora sp. G and C. zebrina.
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species concepts in Cercospora spotting the weeds among the roses
Studies in Mycology, 2013Co-Authors: J Z Groenewald, Chiharu Nakashima, Junji Nishikawa, Hyeondong Shin, J H Park, A N Jama, Marizeth Groenewald, Uwe Braun, P W CrousAbstract:Abstract The genus Cercospora contains numerous important plant pathogenic fungi from a diverse range of hosts. Most species of Cercospora are known only from their morphological characters in vivo . Although the genus contains more than 5 000 names, very few cultures and associated DNA sequence data are available. In this study, 360 Cercospora isolates, obtained from 161 host species, 49 host families and 39 countries, were used to compile a molecular phylogeny. Partial sequences were derived from the internal transcribed spacer regions and intervening 5.8S nrRNA, actin, calmodulin, histone H3 and translation elongation factor 1-alpha genes. The resulting phylogenetic clades were evaluated for application of existing species names and five novel species are introduced. Eleven species are epi-, lecto- or neotypified in this study. Although existing species names were available for several clades, it was not always possible to apply North American or European names to African or Asian strains and vice versa . Some species were found to be limited to a specific host genus, whereas others were isolated from a wide host range. No single locus was found to be the ideal DNA barcode gene for the genus, and species identification needs to be based on a combination of gene loci and morphological characters. Additional primers were developed to supplement those previously published for amplification of the loci used in this study. Taxonomic novelties: New species – Cercospora coniogrammes Crous & R.G. Shivas, Cercospora delaireae C. Nakash., Crous, U. Braun & H.D. Shin, Cercospora euphorbiae-sieboldianae C. Nakash., Crous, U. Braun & H.D. Shin, Cercospora pileicola C. Nakash., Crous, U. Braun & H.D. Shin, Cercospora vignigena C. Nakash., Crous, U. Braun & H.D. Shin. Typifications: epitypifications – Cercospora alchemillicola U. Braun & C.F. Hill, Cercospora althaeina Sacc., Cercospora armoraciae Sacc., Cercospora corchori Sawada, Cercospora mercurialis Pass., Cercospora olivascens Sacc., Cercospora violae Sacc.; neotypifications – Cercospora fagopyri N. Nakata & S. Takim., Cercospora sojina Hara.
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host range of Cercospora apii and c beticola and description of c apiicola a novel species from celery
Mycologia, 2006Co-Authors: Marizeth Groenewald, J Z Groenewald, Uwe Braun, P W CrousAbstract:The genus Cercospora is one of the largest and most heterogeneous genera of hyphomycetes. Cercospora species are distributed worldwide and cause Cercospora leaf spot on most of the major plant families. Numerous species described from diverse hosts and locations are morphologically indistinguishable from C. apii and subsequently are referred to as C. apii sensu lato. The importance and ecological role that different hosts play in taxon delimitation and recognition within this complex remains unclear. It has been shown that Cercospora leaf spot on celery and sugar beet are caused respectively by C. apii and C. beticola, both of which are part of the C. apii complex. During this study we characterized a new Cercospora species, C. apiicola, which was isolated from celery in Venezuela, Korea and Greece. The phylogenetic relationship between C. apiicola and other closely related Cercospora species was studied with five different gene areas. These analyses revealed that the C. apiicola isolates cluster together in a well defined clade. Both C. apii and C. beticola sensu stricto form well defined clades and are shown to have wider host ranges and to represent distinct species.
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distinct species exist within the Cercospora apii morphotype
Phytopathology, 2005Co-Authors: Marizeth Groenewald, J Z Groenewald, P W CrousAbstract:Groenewald, M., Groenewald, J. Z., and Crous, P. W. 2005. Distinct species exist within the Cercospora apii morphotype. Phytopathology 95:951-959. The genus Cercospora is one of the largest genera of hyphomycetes. Cercospora apii sensu lato is the oldest name for a large complex of morphologically indistinguishable Cercospora spp. occurring on a wide host range. There are currently 659 recognized Cercospora spp., and names of another 281 morphologically identical species are included in the synonymy of C. apii sensu lato. Two of the species that belong to the C. apii complex, C. apii and C. beticola, cause Cercospora leaf spot on Apium graveolens (celery) and Beta vulgaris (sugar beet), respectively. In
P S Teng - One of the best experts on this subject based on the ideXlab platform.
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impact of Cercospora leaf spot on root weight sugar yield and purity of beta vulgaris
Plant Disease, 1992Co-Authors: W W Shane, P S TengAbstract:The impact of Cercospora leaf spot, caused by Cercospora beticola, on the yield and quality of sugar beets (Beta vulgaris) was studied in one field trial in 1982 and two trials in 1983. Fungicides were applied to cultivars of various disease susceptibilities to obtain different levels of disease severity. Plants were rated for disease severity with a spot-percentage scale according to the number of lesions per leaf at intensities <3% and with standard area diagrams at intensities ≥3% (.)
Uwe Braun - One of the best experts on this subject based on the ideXlab platform.
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Additions and corrections to names published in Cercospora and Passalora
Mycotaxon, 2020Co-Authors: Uwe Braun, Pedro W. CrousAbstract:The new species Cercospora bothriochloae, C. phaseoli-lunati, C. smilacigena, Passalora brandenburgeri, PseudoCercospora lepidagathidis, P. sambucigena, P. xanthorhizae and Stenella hymenocallidis, the new names PseudoCercospora clematidigena, P. tinosporigena and Stenella deightoniana, and the new combinations Passalora cardiostegiae, P. lemnischea, PseudoCercospora forestierae and P. garryae are introduced. Additions and corrections to the nomenclature, taxonomy, typification, host range and distribution of fungi recorded in a checklist of Cercospora and Passalora names are also provided
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Taxonomy and phylogeny of Cercospora spp. from Northern Thailand
Phytotaxa, 2015Co-Authors: Jeerapa Nguanhom, Uwe Braun, Johannes Z. Groenewald, Ratchadawan Cheewangkoon, Chaiwat To-anun, Pedro W. CrousAbstract:The genus Cercospora represents a group of important plant pathogenic fungi with a wide geographic distribution, being commonly associated with leaf spots on a broad range of plant hosts. The goal of the present study was to conduct a morphological and molecular phylogenetic analysis of the Cercospora spp. occurring on various plants growing in Northern Thailand, an area with a tropical savannah climate, and a rich diversity of vascular plants. Sixty Cercospora isolates were collected from 29 host species (representing 16 plant families). Partial nucleotide sequence data for two gene loci (ITS and cmdA ), were generated for all isolates. Results from this study indicate that members of the genus Cercospora vary regarding host specificity, with some taxa having wide host ranges, and others being host-specific. Based on cultural, morphological and phylogenetic data, four new species of Cercospora could be identified: C. glycinicola (from Glycine max ), C. cyperacearum and C. cyperina (from Cyperus alternifolius ), and C. musigena (from Musa sp.). The most common Cercospora sp. found in Northern Thailand was C. cf. malloti , which occurred on a wide host range. Several collections could not be resolved to species level due to the lack of reference cultures and DNA data for morphologically similar species. Further collections from other countries are needed to help resolve the taxonomy of some species complexes occurring on various plant hosts in Thailand.
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application of the consolidated species concept to Cercospora spp from iran
Persoonia, 2015Co-Authors: Mounes Bakhshi, J Z Groenewald, Uwe Braun, Mahdi Arzanlou, A Babaiahari, P W CrousAbstract:The genus Cercospora includes many important plant pathogenic fungi associated with leaf spot diseases on a wide range of hosts. The mainland of Iran covers various climatic regions with a great biodiversity of vascular plants, and a correspondingly high diversity of cercosporoid fungi. However, most of the cercosporoid species found to date have been identified on the basis of morphological characteristics and there are no cultures that support these identifications. In this study the Consolidated Species Concept was applied to differentiate Cercospora species collected from Iran. A total of 161 Cercospora isolates recovered from 74 host species in northern Iran were studied by molecular phylogenetic analysis. Our results revealed a rich diversity of Cercospora species in northern Iran. Twenty species were identified based on sequence data of five genomic loci (ITS, TEF1-α, actin, calmodulin and histone H3), host, cultural and morphological data. Six novel species, viz. C. convolvulicola, C. conyzae-canadensis, C. cylindracea, C. iranica, C. pseudochenopodii and C. sorghicola, are introduced. The most common taxon was Cercospora cf. flagellaris, which remains an unresolved species complex with a wide host range. New hosts were recorded for previously known Cercospora species, including C. apii, C. armoraciae, C. beticola, C. cf. richardiicola, C. rumicis, Cercospora sp. G and C. zebrina.
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species concepts in Cercospora spotting the weeds among the roses
Studies in Mycology, 2013Co-Authors: J Z Groenewald, Chiharu Nakashima, Junji Nishikawa, Hyeondong Shin, J H Park, A N Jama, Marizeth Groenewald, Uwe Braun, P W CrousAbstract:Abstract The genus Cercospora contains numerous important plant pathogenic fungi from a diverse range of hosts. Most species of Cercospora are known only from their morphological characters in vivo . Although the genus contains more than 5 000 names, very few cultures and associated DNA sequence data are available. In this study, 360 Cercospora isolates, obtained from 161 host species, 49 host families and 39 countries, were used to compile a molecular phylogeny. Partial sequences were derived from the internal transcribed spacer regions and intervening 5.8S nrRNA, actin, calmodulin, histone H3 and translation elongation factor 1-alpha genes. The resulting phylogenetic clades were evaluated for application of existing species names and five novel species are introduced. Eleven species are epi-, lecto- or neotypified in this study. Although existing species names were available for several clades, it was not always possible to apply North American or European names to African or Asian strains and vice versa . Some species were found to be limited to a specific host genus, whereas others were isolated from a wide host range. No single locus was found to be the ideal DNA barcode gene for the genus, and species identification needs to be based on a combination of gene loci and morphological characters. Additional primers were developed to supplement those previously published for amplification of the loci used in this study. Taxonomic novelties: New species – Cercospora coniogrammes Crous & R.G. Shivas, Cercospora delaireae C. Nakash., Crous, U. Braun & H.D. Shin, Cercospora euphorbiae-sieboldianae C. Nakash., Crous, U. Braun & H.D. Shin, Cercospora pileicola C. Nakash., Crous, U. Braun & H.D. Shin, Cercospora vignigena C. Nakash., Crous, U. Braun & H.D. Shin. Typifications: epitypifications – Cercospora alchemillicola U. Braun & C.F. Hill, Cercospora althaeina Sacc., Cercospora armoraciae Sacc., Cercospora corchori Sawada, Cercospora mercurialis Pass., Cercospora olivascens Sacc., Cercospora violae Sacc.; neotypifications – Cercospora fagopyri N. Nakata & S. Takim., Cercospora sojina Hara.
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Taxonomic notes on some species of the Cercospora complex (V)
2013Co-Authors: Uwe BraunAbstract:Abstract: Braun, U. 1999: Taxonomic notes on some species of the Cercospora complex (V). Schlechtendalia 2 : 1-28. 32 species of the genus Cercospora s.lat. have been re-examined, reassessed, and placed in Mycovellosiella, Passalora, Phaeoramularia, and PseudoCercospora . The species concerned are described, illustrated, and the nomenclature of some of these taxa is discussed. Furthermore, a second collection of PseudoCercospora lippiae-albae on a new host species is recorded. Zusammenfassung: Braun, U. 1999: Taxonomic notes on some species of the Cercospora complex (V). Schlechtendalia 2 : 1-28. 32 Arten der Gattung Cercospora s.lat. sind untersucht, neu bewertet und in die Gattungen Mycovellosiella, Passalora, Phaeoramularia und PseudoCercospora uberfuhrt worden. Diese Arten werden beschrieben und abgebildet, und die Nomenklatur einiger Taxa wird diskutiert. Weiterhin wird uber eine zweite Kollektion von PseudoCercospora lippiae-albae auf einer neuen Wirtsart berichtet.