Chiharu Nakashima

Species concepts in Cercospora: spotting the weeds among the roses.

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.

Phylogenetic lineages in Pseudocercospora

Pseudocercospora is a large cosmopolitan genus of plant pathogenic fungi that are commonly associated with leaf and fruit spots as well as blights on a wide range of plant hosts. They occur in arid as well as wet environments and in a wide range of climates including cool temperate, sub-tropical and tropical regions. Pseudocercospora is now treated as a genus in its own right, although formerly recognised as either an anamorphic state of Mycosphaerella or having mycosphaerella-like teleomorphs. The aim of this study was to sequence the partial 28S nuclear ribosomal RNA gene of a selected set of isolates to resolve phylogenetic generic limits within the Pseudocercospora complex. From these data, 14 clades are recognised, six of which cluster in Mycosphaerellaceae. Pseudocercospora s. str. represents a distinct clade, sister to Passalora eucalypti, and a clade representing the genera Scolecostigmina, Trochophora and Pallidocercospora gen. nov., taxa formerly accommodated in the Mycosphaerella heimii complex and characterised by smooth, pale brown conidia, as well as the formation of red crystals in agar media. Other clades in Mycosphaerellaceae include Sonderhenia, Microcyclosporella, and Paracercospora. Pseudocercosporella resides in a large clade along with Phloeospora, Miuraea, Cercospora and Septoria. Additional clades represent Dissoconiaceae, Teratosphaeriaceae, Cladosporiaceae, and the genera Xenostigmina, Strelitziana, Cyphellophora and Thedgonia. The genus Phaeomycocentrospora is introduced to accommodate Mycocentrospora cantuariensis, primarily distinguished from Pseudocercospora based on its hyaline hyphae, broad conidiogenous loci and hila. Host specificity was considered for 146 species of Pseudocercospora occurring on 115 host genera from 33 countries. Partial nucleotide sequence data for three gene loci, ITS, EF-1α, and ACT suggest that the majority of these species are host specific. Species identified on the basis of host, symptomatology and general morphology, within the same geographic region, frequently differed phylogenetically, indicating that the application of European and American names to Asian taxa, and vice versa, was often not warranted. Taxonomic novelties: New genera - Pallidocercospora Crous, Phaeomycocentrospora Crous, H.D. Shin & U. Braun; New species - Cercospora eucommiae Crous, U. Braun & H.D. Shin, Microcyclospora quercina Crous & Verkley, Pseudocercospora ampelopsis Crous, U. Braun & H.D. Shin, Pseudocercospora cercidicola Crous, U. Braun & C. Nakash., Pseudocercospora crispans G.C. Hunter & Crous, Pseudocercospora crocea Crous, U. Braun, G.C. Hunter & H.D. Shin, Pseudocercospora haiweiensis Crous & X. Zhou, Pseudocercospora humulicola Crous, U. Braun & H.D. Shin, Pseudocercospora marginalis G.C. Hunter, Crous, U. Braun & H.D. Shin, Pseudocercospora ocimi-basilici Crous, M.E. Palm & U. Braun, Pseudocercospora plectranthi G.C. Hunter, Crous, U. Braun & H.D. Shin, Pseudocercospora proteae Crous, Pseudocercospora pseudostigmina-platani Crous, U. Braun & H.D. Shin, Pseudocercospora pyracanthigena Crous, U. Braun & H.D. Shin, Pseudocercospora ravenalicola G.C. Hunter & Crous, Pseudocercospora rhamnellae G.C. Hunter, H.D. Shin, U. Braun & Crous, Pseudocercospora rhododendri-indici Crous, U. Braun & H.D. Shin, Pseudocercospora tibouchinigena Crous & U. Braun, Pseudocercospora xanthocercidis Crous, U. Braun & A. Wood, Pseudocercosporella koreana Crous, U. Braun & H.D. Shin; New combinations - Pallidocercospora acaciigena (Crous & M.J. Wingf.) Crous & M.J. Wingf., Pallidocercospora crystallina (Crous & M.J. Wingf.) Crous & M.J. Wingf., Pallidocercospora heimii (Crous) Crous, Pallidocercospora heimioides (Crous & M.J. Wingf.) Crous & M.J. Wingf., Pallidocercospora holualoana (Crous, Joanne E. Taylor & M.E. Palm) Crous, Pallidocercospora konae (Crous, Joanne E. Taylor & M.E. Palm) Crous, Pallidoocercospora irregulariramosa (Crous & M.J. Wingf.) Crous & M.J. Wingf., Phaeomycocentrospora cantuariensis (E.S. Salmon & Wormald) Crous, H.D. Shin & U. Braun, Pseudocercospora hakeae (U. Braun & Crous) U. Braun & Crous, Pseudocercospora leucadendri (Cooke) U. Braun & Crous, Pseudocercospora snelliana (Reichert) U. Braun, H.D. Shin, C. Nakash. & Crous, Pseudocercosporella chaenomelis (Y. Suto) C. Nakash., Crous, U. Braun & H.D. Shin; Typifications: Epitypifications - Pseudocercospora angolensis (T. Carvalho & O. Mendes) Crous & U. Braun, Pseudocercospora araliae (Henn.) Deighton, Pseudocercospora cercidis-chinensis H.D. Shin & U. Braun, Pseudocercospora corylopsidis (Togashi & Katsuki) C. Nakash. & Tak. Kobay., Pseudocercospora dovyalidis (Chupp & Doidge) Deighton, Pseudocercospora fukuokaensis (Chupp) X.J. Liu & Y.L. Guo, Pseudocercospora humuli (Hori) Y.L. Guo & X.J. Liu, Pseudocercospora kiggelariae (Syd.) Crous & U. Braun, Pseudocercospora lyoniae (Katsuki & Tak. Kobay.) Deighton, Pseudocercospora lythri H.D. Shin & U. Braun, Pseudocercospora sambucigena U. Braun, Crous & K. Schub., Pseudocercospora stephanandrae (Tak. Kobay. & H. Horie) C. Nakash. & Tak. Kobay., Pseudocercospora viburnigena U. Braun & Crous, Pseudocercosporella chaenomelis (Y. Suto) C. Nakash., Crous, U. Braun & H.D. Shin, Xenostigmina zilleri (A. Funk) Crous; Lectotypification - Pseudocercospora ocimicola (Petr. & Cif.) Deighton; Neotypifications - Pseudocercospora kiggelariae (Syd.) Crous & U. Braun, Pseudocercospora lonicericola (W. Yamam.) Deighton, Pseudocercospora zelkovae (Hori) X.J. Liu & Y.L. Guo.

Fungal Planet description sheets: 281-319.

Novel species of fungi described in the present study include the following from South Africa: Alanphillipsia aloeicola from Aloe sp., Arxiella dolichandrae from Dolichandra unguiscati, Ganoderma austroafricanum from Jacaranda mimosifolia, Phacidiella podocarpi and Phaeosphaeria podocarpi from Podocarpus latifolius, Phyllosticta mimusopisicola from Mimusops zeyheri and Sphaerulina pelargonii from Pelargonium sp. Furthermore, Barssia maroccana is described from Cedrus atlantica (Morocco), Codinaea pini from Pinus patula (Uganda), Crucellisporiopsis marquesiae from Marquesia acuminata (Zambia), Dinemasporium ipomoeae from Ipomoea pes-caprae (Vietnam), Diaporthe phragmitis from Phragmites australis (China), Marasmius vladimirii from leaf litter (India), Melanconium hedericola from Hedera helix (Spain), Pluteus albotomentosus and Pluteus extremiorientalis from a mixed forest (Russia), Rachicladosporium eucalypti from Eucalyptus globulus (Ethiopia), Sistotrema epiphyllum from dead leaves of Fagus sylvatica in a forest (The Netherlands), Stagonospora chrysopyla from Scirpus microcarpus (USA) and Trichomerium dioscoreae from Dioscorea sp. (Japan). Novel species from Australia include: Corynespora endiandrae from Endiandra introrsa, Gonatophragmium triuniae from Triunia youngiana, Penicillium coccotrypicola from Archontophoenix cunninghamiana and Phytophthora moyootj from soil. Novelties from Iran include Neocamarosporium chichastianum from soil and Seimatosporium pistaciae from Pistacia vera. Xenosonderhenia eucalypti and Zasmidium eucalyptigenum are newly described from Eucalyptus urophylla in Indonesia. Diaporthe acaciarum and Roussoella acacia are newly described from Acacia tortilis in Tanzania. New species from Italy include Comoclathris spartii from Spartium junceum and Phoma tamaricicola from Tamarix gallica. Novel genera include (Ascomycetes): Acremoniopsis from forest soil and Collarina from water sediments (Spain), Phellinocrescentia from a Phellinus sp. (French Guiana), Neobambusicola from Strelitzia nicolai (South Africa), Neocladophialophora from Quercus robur (Germany), Neophysalospora from Corymbia henryi (Mozambique) and Xenophaeosphaeria from Grewia sp. (Tanzania). Morphological and culture characteristics along with ITS DNA barcodes are provided for all taxa.

A phylogenetic re-evaluation of Phyllosticta (Botryosphaeriales)

Phyllosticta is a geographically widespread genus of plant pathogenic fungi with a diverse host range. This study redefines Phyllosticta, and shows that it clusters sister to the Botryosphaeriaceae (Botryosphaeriales, Dothideomycetes), for which the older family name Phyllostictaceae is resurrected. In moving to a unit nomenclature for fungi, the generic name Phyllosticta was chosen over Guignardia in previous studies, an approach that we support here. We use a multigene DNA dataset of the ITS, LSU, ACT, TEF and GPDH gene regions to investigate 129 isolates of Phyllosticta, representing about 170 species names, many of which are shown to be synonyms of the ubiquitous endophyte P. capitalensis. Based on the data generated here, 12 new species are introduced, while epitype and neotype specimens are designated for a further seven species. One species of interest is P. citrimaxima associated with tan spot of Citrus maxima fruit in Thailand, which adds a fifth species to the citrus black spot complex. Previous morphological studies lumped many taxa under single names that represent complexes. In spite of this Phyllosticta is a species-rich genus, and many of these taxa need to be recollected in order to resolve their phylogeny and taxonomy. Taxonomic novelties: New species - Phyllosticta abieticola Wikee & Crous, P. aloeicola Wikee & Crous, P. citrimaxima Wikee, Crous, K.D. Hyde & McKenzie, P. leucothoicola Wikee, Motohashi & Crous, P. mangifera-indica Wikee, Crous, K.D. Hyde & McKenzie, P. neopyrolae Wikee, Motohashi, Crous, K.D. Hyde & McKenzie, P. pachysandricola Wikee, Motohashi & Crous, P. paxistimae Wikee & Crous, P. podocarpicola Wikee, Crous, K.D. Hyde & McKenzie, P. rhaphiolepidis Wikee, C. Nakash. & Crous, P. rubra Wikee & Crous, P. vacciniicola Wikee, Crous, K.D. Hyde & McKenzie; New combinations - P. foliorum (Sacc.) Wikee & Crous, P. philoprina (Berk. & M.A. Curtis) Wikee & Crous; Epitypifications (basionyms) - P. concentrica Sacc., P. cussoniae Cejp, P. owaniana G. Winter; Neotypifications (basionyms) - Phyllosticta cordylinophila P.A. Young, Physalospora gregaria var. foliorum Sacc., Sphaeropsis hypoglossi Mont., Sphaeropsis minima Berk. & M.A. Curtis.

Phyllosticta capitalensis, a widespread endophyte of plants

Phyllosticta capitalensis is an endophyte and weak plant pathogen with a worldwide distribution presently known from 70 plant families. This study isolated P. capitalensis from different host plants in northern Thailand, and determined their different life modes. Thirty strains of P. capitalensis were isolated as endophytes from 20 hosts. An additional 30 strains of P. capitalensis from other hosts and geographic locations were also obtained from established culture collections. Phylogenetic analysis using ITS, ACT and TEF gene data confirmed the identity of all isolates. Pathogenicity tests with five strains of P. capitalensis originating from different hosts were completed on their respective host plants. In all cases there was no infection of healthy leaves, indicating that this endophyte does not cause disease on healthy, unstressed host plants. That P. capitalensis is often isolated as an endophyte has important implications in fungal biology and plant health. Due to its endophytic nature, P. capitalensis is commonly found associated with lesions of plants, and often incorrectly identified as a species of quarantine importance, which again has implications for trade in agricultural and forestry production.

Cercosporoid fungi (Mycosphaerellaceae) 1. Species on other fungi, Pteridophyta and Gymnospermae

Cercosporoid fungi (former Cercospora s. lat.) represent one of the largest groups of hyphomycetes belonging to the Mycosphaerellaceae (Ascomycota). They include asexual morphs, asexual holomorphs or species with mycosphaerella-like sexual morphs. Most of them are leaf-spotting plant pathogens with special phytopathological relevance. The only monograph of Cercospora s. lat., published by Chupp (1954), is badly in need of revision. However, the treatment of this huge group of fungi can only be accomplished stepwise on the basis of treatments of cercosporoid fungi on particular host plant families. The present first part of this series comprises an introduction, a survey on currently recognised cercosporoid genera, a key to the genera concerned, a discussion of taxonomically relevant characters, and descriptions and illustrations of cercosporoid species on other fungi (mycophylic taxa), Pteridophyta and Gymnospermae, arranged in alphabetical order under the particular cercosporoid genera, which are supplemented by keys to the species concerned. The following taxonomic novelties are introduced: Passalora austroplenckiae comb. nov., P. backmanii comb. nov., P. condensata comb. nov., P. gymnocladi comb. nov., P. thalictri comb. nov., Pseudocercospora davalliicola sp. nov., P. chamaecyparidis comb. nov., P. cratevicola nom. nov., P. gleicheniae comb. nov., P. lygodiicola sp. nov., P. lygodiigena nom. nov., P. nephrolepidigena sp. nov., P. paraexosporioides sp. nov., P. pini-densiflorae var. montantiana comb. et stat. nov., P. pteridigena sp. nov., P. ptisanae sp. nov., P. sciadopityos sp. nov., P. subramanianii nom. nov., P. thujina comb. nov., and Zasmidium australiense comb. nov.

Cercosporoid fungi (Mycosphaerellaceae) 2. Species on monocots (Acoraceae to Xyridaceae, excluding Poaceae)

Cercosporoid fungi (formerly Cercospora s. lat.) represent one of the largest groups of hyphomycetes belonging to the Mycosphaerellaceae (Ascomycota). They include asexual morphs, asexual holomorphs, or species with mycosphaerella-like sexual morphs. Most of them are leaf-spotting plant pathogens with special phytopathological relevance. In the first part of a new monographic work, cercosporoid hyphomycetes occurring on other fungi (fungicolous species), on ferns (pteridophytes) and gymnosperms were treated. This second part deals with cercosporoid fungi on monocots (Liliopsida; Equisetopsida, Magnoliidae, Lilianae), which covers species occurring on host plants belonging to families arranged in alphabetical order from Acoraceae to Xyridaceae, excluding Poaceae (cereals and grasses) which requires a separate treatment. The species are described and illustrated in alphabetical order under the particular cercosporoid genera, supplemented by keys to the species concerned. A detailed introduction, a survey of currently recognised cercosporoid genera, a key to the genera concerned, and a discussion of taxonomically relevant characters were published in the first part of this series. Neopseudocercospora, an additional recently introduced cercosporoid genus, is briefly discussed. The following taxonomic novelties are introduced: Cercospora alpiniigena sp. nov., C. neomaricae sp. nov., Corynespora palmicola comb. nov., Exosporium miyakei comb. nov., E. petersii comb. nov., Neopseudocercospora zambiensis comb. nov., Passalora caladiicola comb. nov., P. streptopi comb. nov., P. togashiana comb. nov., P. tranzschelii var. chinensis var. nov., Pseudocercospora beaucarneae comb. nov., P. constrictoflexuosa comb. et stat. nov., P. curcumicola sp. nov., P. dispori comb. nov., P. smilacicola sp. nov., P. urariigena nom. nov., Zasmidium agavicola comb. nov., Z. cercestidis-afzelii comb. nov., Z. citri-griseum comb. nov., Z. cyrtopodii comb. nov., Z. gahnae comb. nov., Z. indicum comb. nov., Z. liriopes comb. nov., Z. mycovellosielloides sp. nov., Z. scleriae comb. nov., Z. smilacicola comb. nov., and Z. thaliae comb. nov.

Mycosphaerellaceae – Chaos or clarity?

The Mycosphaerellaceae represent thousands of fungal species that are associated with diseases on a wide range of plant hosts. Understanding and stabilising the taxonomy of genera and species of Mycosphaerellaceae is therefore of the utmost importance given their impact on agriculture, horticulture and forestry. Based on previous molecular studies, several phylogenetic and morphologically distinct genera within the Mycosphaerellaceae have been delimited. In this study a multigene phylogenetic analysis (LSU, ITS and rpb2) was performed based on 415 isolates representing 297 taxa and incorporating ex-type strains where available. The main aim of this study was to resolve the phylogenetic relationships among the genera currently recognised within the family, and to clarify the position of the cercosporoid fungi among them. Based on these results many well-known genera are shown to be paraphyletic, with several synapomorphic characters that have evolved more than once within the family. As a consequence, several old generic names including Cercosporidium, Fulvia, Mycovellosiella, Phaeoramularia and Raghnildiana are resurrected, and 32 additional genera are described as new. Based on phylogenetic data 120 genera are now accepted within the family, but many currently accepted cercosporoid genera still remain unresolved pending fresh collections and DNA data. The present study provides a phylogenetic framework for future taxonomic work within the Mycosphaerellaceae.

Cercosporoid fungi (Mycosphaerellaceae) 3. Species on monocots (Poaceae, true grasses).

The third part of a series of monographic treatments of cercosporoid fungi (formerly Cercospora s. lat., Mycosphaerellaceae, Ascomycota) continues with a treatment of taxa on monocots (Liliopsida; Equisetopsida, Magnoliidae, Lilianae), covering asexual and holomorph species with mycosphaerella-like sexual morphs on true grasses (Poaceae), which were excluded from the second part. The species concerned are keyed out, alphabetically listed, described, illustrated and supplemented by references to previously published descriptions, illustrations, and exsiccatae. A key to the recognised genera and a discussion of taxonomically relevant characters was published in the first part of this series. Several species are lecto- or neotypified. The following taxonomic novelties are introduced: Cercospora barretoana comb. nov., C. cymbopogonicola nom. nov., Cladosporium elymi comb. nov., Passalora agrostidicola sp. nov., P. brachyelytri comb. nov., and P. dichanthii-annulati comb. nov.

Species diversity of Pseudocercospora from Far East Asia

This study reflects on the monophyly of, and species diversity within, the genus Pseudocercospora in Far East Asia. Morphological characteristics and phylogenetic analyses of Pseudocercospora species were based on type specimens and ex-type cultures, which were collected from Japan and Taiwan. A phylogenetic tree was generated from multi-locus DNA sequence data of the internal transcribed spacer regions of the nrDNA cistron (ITS), partial actin (actA), and partial translation elongation factor 1-alpha (tef1), as well as the partial DNA-directed RNA polymerase II second largest subunit (rpb2). Based on these results, Pseudocercospora amelanchieris on Amelanchier and Ps. iwakiensis on Ilex were newly described from Japan, and a further 22 types (incl. two neo-, five lecto-, and 15 epitypes), were designated. The genus Pseudocercospora as presently circumscribed was found to be monophyletic, while the secondary barcodes, actA, tef1, and rpb2 were shown to be well suited to delimitate species within the genus.