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Species of Pseudocercospora are commonly associated with leaf and fruit spots on diverse plant hosts in sub-tropical and tropical regions. Pseudocercospora spp. have mycosphaerella-like sexual morphs, but represent a distinct genus in Mycosphaerellaceae (Mycosphaerellales, Dothideomycetes). The present study adds a further 29 novel species of Pseudocercospora from 413 host species representing 297 host genera occurring in 60 countries and designates four epitypes and one lectotype for established names. This study recognises 329 species names, with an additional 69 phylogenetic lineages remaining unnamed due to difficulty in being able to unambiguously apply existing names to those lineages. To help elucidate the taxonomy of these species, a phylogenetic tree was generated from multi-locus DNA sequence data of the internal transcribed spacers and intervening 5.8S nuclear nrRNA gene (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) gene sequences. Novel species described in this study include those from various countries as follows: Australia, Ps. acaciicola from leaf spots on Acacia sp., Ps. anopter from leaf spots on Anopterus glandulosus, Ps. asplenii from leaf spots on Asplenium dimorphum, Ps. australiensis from leaf spots on Eucalyptus gunnii, Ps. badjensis from leaf spots on Eucalyptus badjensis, Ps. erythrophloeicola from leaf spots on Erythrophleum chlorostachys, Ps. grevilleae from leaf spots on Grevillea sp., Ps. lophostemonigena from leaf spots on Lophostemon confertus, Ps. lophostemonis from leaf spots on Lophostemon lactifluus, Ps. paramacadamiae from leaf spots on Macadamia integrifolia, Ps. persooniae from leaf spots on Persoonia sp., Ps. pultenaeae from leaf spots on Pultenaea daphnoides, Ps. tristaniopsidis from leaf spots on Tristaniopsis collina, Ps. victoriae from leaf spots on Eucalyptus globoidea. Brazil, Ps. musigena from leaf spots on Musa sp. China, Ps. lonicerae-japonicae from leaf spots on Lonicera japonica, Ps. rubigena leaf spots on Rubus sp. France (Réunion), Ps. wingfieldii from leaf spots on Acacia heterophylla. Malaysia, Ps. musarum from leaf spots on Musa sp. Netherlands, Ps. rhododendri from leaf spots on Rhododendron sp. South Africa, Ps. balanitis from leaf spots on Balanites sp., Ps. dovyalidicola from leaf spots on Dovyalis zeyheri, Ps. encephalarticola from leaf spots on Encephalartos sp. South Korea, Ps. grewiana from leaf spots on Grewia biloba, Ps. parakaki from leaf spots on Diospyros kaki, Ps. pseudocydoniae from leaf spots on Chaenomeles lagenaria, Ps. paracydoniae from leaf spots on Chaenomeles speciosa. Thailand, Ps. acerigena from leaf spots on Acer sp., Ps. tectonigena from leaf spots on Tectona grandis. Epitypes are designated for Cercospora bonjeaneae-rectae, Cercospora halleriae, Ps. eucleae, and an epitype as well as a lectotype for Ps. macadamiae. Results obtained in the present study contribute to a better understanding of the host specificity and distribution in Pseudocercospora spp., many of which represent important pathogens of food or fibre crops, or organisms of quarantine concern. Citation: Groenewald JZ, Chen YY, Zhang Y, Roux J, Shin H-D, Shivas RG, Summerell BA, Braun U, Alfenas AC, Ujat AH, Nakashima C, Crous PW (2024). Species diversity in Pseudocercospora. Fungal Systematics and Evolution 13: 29-89. doi: 10.3114/fuse.2024.13.03.

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Septoria pistaciarum, a causal agent of Septoria leaf spot disease of pistachio, is a fungal pathogen that causes substantial losses in the cultivation, worldwide. This study describes the first pan-genome-based survey of this phytopathogen-comprising a total of 27 isolates, with 9 isolates each from 3 regional units of Greece (Pieria, Larissa and Fthiotida). The reference isolate (SPF8) assembled into a total of 43.1 Mb, with 38.6% contained within AT-rich regions of approximately 37.5% G:C. The genomes of the 27 isolates exhibited on average 42% gene-coding and 20% repetitive regions. The genomes of isolates from the southern Fthiotida region appeared to more diverged from each other than the other regions based on SNP-derived trees, and also contained isolates similar to both the Pieria and Larissa regions. In contrast, isolates of the Pieria and Larissa were less diverse and distinct from one another. Asexual reproduction appeared to be typical, with no MAT1-2 locus detected in any isolate. Genome-based prediction of infection mode indicated hemibiotrophic and saprotrophic adaptations, consistent with its long latent phase. Gene prediction and orthology clustering generated a pan-genome-wide gene set of 21,174 loci. A total of 59 ortholog groups were predicted to contain candidate effector proteins, with 36 (61%) of these either having homologs to known effectors from other species or could be assigned predicted functions from matches to conserved domains. Overall, effector prediction suggests that S. pistaciarum employs a combination of defensive effectors with roles in suppression of host defenses, and offensive effectors with a range of cytotoxic activities. Some effector-like ortholog groups presented as divergent versions of the same protein, suggesting region-specific adaptations may have occurred. These findings provide insights and future research directions in uncovering the pathogenesis and population dynamics of S. pistaciarum toward the efficient management of Septoria leaf spot of pistachio.

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Introduction: Sugarbeets account for 55 to 60% of U.S. sugar production. Cercospora leaf spot (CLS), primarily caused by the fungal pathogen Cercospora beticola, is a major foliar disease of sugarbeet. Since leaf tissue is a primary site of pathogen survival between growing seasons, this study evaluated management strategies to reduce this source of inoculum. Methods: Fall- and spring-applied treatments were evaluated over three years at two study sites. Treatments included standard plowing or tilling immediately post-harvest, as well as the following alternatives to tillage: a propane-fueled heat treatment either in the fall immediately pre-harvest or in the spring prior to planting, and a desiccant (saflufenacil) application seven days pre-harvest. After fall treatments, leaf samples were evaluated to determine C. beticola viability. The following season, inoculum pressure was measured by monitoring CLS severity in a susceptible beet variety planted into the same plots and by counting lesions on highly susceptible sentinel beets placed into the field at weekly intervals (fall treatments only). Results: No significant reductions in C. beticola survival or CLS were observed following fall-applied desiccant. The fall heat treatment, however, significantly reduced lesion sporulation (2019-20 and 2020-21, P < 0.0001; 2021-22, P < 0.05) and C. beticola isolation (2019-20, P < 0.05) in at-harvest samples. Fall heat treatments also significantly reduced detectable sporulation for up to 70- (2021-22, P < 0.01) or 90-days post-harvest (2020-21, P < 0.05). Reduced numbers of CLS lesions were observed on sentinel beets in heat-treated plots from May 26-June 2 (P < 0.05) and June 2-9 (P < 0.01) in 2019, as well as June 15-22 (P < 0.01) in 2020. Both fall- and spring-applied heat treatments also reduced the area under the disease progress curve for CLS assessed the season after treatments were applied (Michigan 2020 and 2021, P < 0.05; Minnesota 2019, P < 0.05; 2021, P < 0.0001). Discussion: Overall, heat treatments resulted in CLS reductions at levels comparable to standard tillage, with more consistent reductions across year and location. Based on these results, heat treatment of fresh or overwintered leaf tissue could be used as an integrated tillage-alternative practice to aid in CLS management.

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Brown spot needle blight (BSNB), caused by the fungal pathogen Lecanosticta acicola, is a well-known disease of Pinus spp. in several northern hemisphere countries. In the southern hemisphere, this disease has been reported only in Colombia and, apart from a single report of severe defoliation of Pinus radiata plantations in the early 1980s, has not caused serious damage in this country. An outbreak of a disease resembling BSNB on Mesoamerican Pinus spp. grown in Colombia has raised concern that L. acicola may have reemerged as a pathogen. DNA sequence-based analyses for the internal transcribed spacers, translation elongation factor 1-α and RNA polymerase II second largest subunit regions showed that the outbreaks were caused by L. pharomachri, a species distinct from, but closely related to, L. acicola. The discovery of L. pharomachri in Colombia is the first incidence of the pathogen causing a serious disease problem and the first occurrence on the hosts P. patula and P. maximinoi. A sexual state for L. pharomachri was discovered for the first time, and the description of the species has thus been emended.

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In many parts of the world including the Great Lakes region of North America, Cercospora leaf spot (CLS), caused by the fungal pathogen Cercospora beticola, is a major foliar disease of sugar beet (Beta vulgaris). Management of CLS involves an integrated approach which includes the application of fungicides. To guide fungicide application timings, disease prediction models are widely used by sugar beet growers in North America. While these models have generally worked well, they have not included information about pathogen presence. Thus, incorporating spore production and dispersal could make them more effective. The current study used sentinel beets to assess the presence of C. beticola spores in the environment early in the 2017 and 2018 growing seasons. Weather variables including air temperature, relative humidity, rainfall, leaf wetness, wind speed, and solar radiation were collected. These data were used to identify environmental variables that correlated with spore levels during a time when CLS is not generally observed in commercial fields. C. beticola spores were detected during mid-April both years, which is much earlier than previously reported. A correlation was found between spore data and all the weather variables examined during at least one of the two years, except for air temperature. In both years, spore presence was significantly correlated with rainfall (P < 0.0001) as well as relative humidity (P < 0.0090). Rainfall was particularly intriguing, with an adjusted R2 of 0.3135 in 2017 and 0.1652 in 2018. Efforts are ongoing to investigate information on spore presence to improve prediction models and CLS management.

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Host preference of root endophytes of the three European tree species of Norway spruce (Picea abies), common ash (Fraxinus excelsior), and sycamore maple (Acer pseudoplatanus) were investigated in two forest stands near Zurich, Switzerland. The focus was placed on members of the Phialocephala fortinii s.l. (sensu lato)-Acephala applanata species complex (PAC), as well as other dark septate endopyhtes (DSE). PAC species were identified based on 13 microsatellite loci. Eleven PAC species were found, with Phialocephala helvetica, P. europaea being the most frequent. All but cryptic species 12 (CSP12) preferred Norway spruce as a host. Though very rare in general, CSP12 was most frequently isolated from maple roots. Regarding the abundant PAC species, P. helvetica and P. europaea, the preference of spruce as a host was least pronounced in P. europaea, as it was also often isolated from ash and maple. It is the first record of PAC found on common ash (Fraxinus excelsior). Cadophora orchidicola, a close relative of PAC, has frequently been isolated from ash. Various species of the Nectriaceae (Cylindrocarpon spp.) have often been isolated, particularly from maple roots. By comparison, Pezicula spp. (Cryptosporiopsis spp.) was found to be abundant on all three hosts. Phomopsis phaseoli exhibits a clear preference for spruce.

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Mycosphaerellaceae is a highly diverse fungal family containing a variety of pathogens affecting many economically important crops. Mitochondria play a crucial role in fungal metabolism and in the study of fungal evolution. This study aims to: (i) describe the mitochondrial genome of Pseudocercospora fijiensis, and (ii) compare it with closely related species (Sphaerulina musiva, S. populicola, P. musae and P. eumusae) available online, paying particular attention to the Sigatoka disease's complex causal agents. The mitochondrial genome of P. fijiensis is a circular molecule of 74,089 bp containing typical genes coding for the 14 proteins related to oxidative phosphorylation, 2 rRNA genes and a set of 38 tRNAs. P. fijiensis mitogenome has two truncated cox1 copies, and bicistronic transcription of nad2-nad3 and atp6-atp8 confirmed experimentally. Comparative analysis revealed high variability in size and gene order among selected Mycosphaerellaceae mitogenomes likely to be due to rearrangements caused by mobile intron invasion. Using fossil calibrated Bayesian phylogenies, we found later diversification times for Mycosphaerellaceae (66.6 MYA) and the Sigatoka disease complex causal agents, compared to previous strict molecular clock studies. An early divergent Pseudocercospora fijiensis split from the sister species P. musae + P. eumusae 13.31 MYA while their sister group, the sister species P. eumusae and P. musae, split from their shared common ancestor in the late Miocene 8.22 MYA. This newly dated phylogeny suggests that species belonging to the Sigatoka disease complex originated after wild relatives of domesticated bananas (section Eumusae; 27.9 MYA). During this time frame, mitochondrial genomes expanded significantly, possibly due to invasions of introns into different electron transport chain genes.

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Fifteen eremophilane sesquiterpenoids, including nine undescribed congeners, septeremophilane A-H, and chaetopenoid G, together with four conjugated unsaturated polyketide fatty acids, including an undescribed derivative, were isolated from cultures of the fungus Septoria rudbeckiae, a plant pathogenic fungus isolated from the halophyte Karelinia caspia. Septeremophilane A represents an unprecedented tetranor-eremophilane sesquiterpenoid with an α,ß-unsaturated δ-lactone unit bearing a hemiacetal group, while septeremophilane B-H possesses a trinor-eremophilane skeleton. Their structures and absolute configurations were established based on spectroscopic data (NMR and HRESIMS), quantum chemical calculations and electronic circular dichroism (ECD) experiments. All metabolites were tested for nitric oxide (NO) production inhibition in lipopolysaccharide (LPS)-activated BV-2 microglial cells, while dendryphiellin D, septeremophilane D, and septeremophilane E were found to display significant inhibition, with IC50 values of 11.9 ± 1.0, 8.5 ± 0.1, and 6.0 ± 0.2 µM, respectively.

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BACKGROUND: Two hyphomycetous species were collected from leaves of Smilax china (Liliales, Smilacaceae) and Cremastra appendiculata (Asparagales, Orchidaceae). ITS barcoding indicated that they belong to the genus Zasmidium. NEW INFORMATION: Morphological data in combination with molecular phylogenetic analyses based on ITS, LSU and rpb2 confirmed that our Chinese strains represented a new species, Zasmidium liboense and a new record of Z. citri-griseum.

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Pseudocercospora fuligena is a fungus that causes black leaf mold, an important disease of tomato in tropical and subtropical regions of the world. Despite its economic importance, genomic resources for this pathogen are scarce and no reference genome was available thus far. Here, we report a 50.6-Mb genome assembly for P. fuligena, consisting of 348 contigs with an N50 value of 0.407 Mb. In total, 13,764 protein-coding genes were predicted with an estimated BUSCO completeness of 98%. Among the predicted genes there were 179 candidate effectors, 445 carbohydrate-active enzymes, and 30 secondary metabolite gene clusters. The resources presented in this study will allow genome-wide comparative analyses and population genomic studies of this pathogen, ultimately improving management strategies for black leaf mold of tomato.

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A worldwide survey of cercosporoid ascomycete species on hosts of the genus Diospyros (persimmon) with key to the species based on characters in vivo is provided. Special emphasis is placed on species of the genus Pseudocercospora, which are in part also phylogenetically analysed, using a multilocus approach. Species of the latter genus proved to be very diverse, with a remarkable degree of cryptic speciation. Seven new species are described (Pseudocercospora diospyri-japonicae, P. diospyriphila, P. ershadii, P. kakiicola, P. kobayashiana, and P. tesselata), and two new names are introduced [P. kakiigena (≡ Cylindrosporium kaki, non Pseudocercospora kaki), and Zasmidium diospyri-hispidae (≡ Passalora diospyri, non Zasmidium diospyri)]. Six taxa are lectotypified (Cercospora atra, C. diospyri, C. diospyri var. ferruginea, C. flexuosa, C. fuliginosa, C. kaki), and Pseudocercospora kaki is epitypified.

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We report the first secondary metabolite, 8,8'-bijuglone, obtained from pure cultures of the slow growing Douglas fir- (Pseudotsuga menziesii var. menziesii) foliage-associated fungus Zasmidium pseudotsugae. The quinone was characterized using extensive LC/MS and NMR-based spectroscopic methods. 8,8'-Bijuglone exhibited moderate antibiotic activity against Gram-positive pathogens and weak cytotoxic activity in the NCI-60 cell line panel and in our in-house human colon carcinoma (HCT-116) cell line. An analysis of the fungal genome sequence to assess its metabolic potential was implemented using the bioinformatic tool antiSMASH. In total, 36 putative biosynthetic gene clusters were found with a majority encoding for polyketides (17), followed by non-ribosomal peptides (14), terpenes (2), ribosomal peptides (1), and compounds with mixed biosynthetic origin (2). This study demonstrates that foliage associated fungi of conifers produce antimicrobial metabolites and suggests this guild of fungi may present a rich source of novel molecules.

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Species of Septoria are commonly associated with leaf spot diseases of a broad range of plant hosts worldwide. During our investigation of fungi associated with leaf spot diseases in northern and northwestern Iran, several Septoria isolates were recovered from symptomatic leaves on different herbaceous and woody plants in the Asteraceae, Betulaceae, and Salicaceae families. These isolates were studied by applying a polyphasic approach including morphological and cultural data and a multigene phylogeny using a combined data set of partial sequences of the 28S nuc rRNA gene (large subunit [28S]), internal transcribed spacer regions and intervening 5.8S nuc rRNA gene (ITS) of the nuc rDNA operon, actin (actA), translation elongation factor 1-α (tef1), calmodulin (cmdA), ß-tubulin (tub2), and DNA-directed RNA polymerase II second largest subunit (rpb2). Four novel species are proposed, namely, Septoria eclipticola on Eclipta prostrata, Septoria firouraghina on Cirsium arvense, Septoria guilanensis on Populus deltoides, and Septoria taleshana on Alnus subcordata. All species are illustrated, and their morphology and phylogenetic relationships with other Septoria species are discussed.

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Cercospora is a well-studied and important genus of plant pathogenic species responsible for leaf spots on a broad range of plant hosts. The lack of useful morphological traits and the high degree of variation therein complicate species identifications in Cercospora. Recent studies have revealed multi-gene DNA sequence data to be highly informative for species identification in Cercospora. During the present study, Cercospora isolates obtained from Crownvetch (Securigera varia) in Iran and Romania were subjected to an eight-gene (ITS, tef1, actA, cmdA, his3, tub2, rpb2 and gapdh) analysis. By applying a polyphasic approach including morphological characteristics, host data, and molecular analyses, these isolates were identified as C. rautensis. To our knowledge, this is the first record of C. rautensis from Iran (Asia). In addition, an epitype is designated here for C. rautensis.

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Although the genus Pseudocercospora has a worldwide distribution, it is especially diverse in tropical and subtropical countries. Species of this genus are associated with a wide range of plant species, including several economically relevant hosts. Preliminary studies of cercosporoid fungi from Brazil allocated most taxa to Cercospora, but with the progressive refinement of the taxonomy of cercosporoid fungi, many species were relocated to or described in Pseudocercospora. Initially, species identification relied mostly on morphological features, and thus no cultures were preserved for later phylogenetic comparisons. In this study, a total of 27 Pseudocercospora spp. were collected, cultured, and subjected to a multigene analysis. Four genomic regions (LSU, ITS, tef1 and actA) were amplified and sequenced. A multigene Bayesian analysis was performed on the combined ITS, actA and tef1 sequence alignment. Our results based on DNA phylogeny, integrated with ecology, morphology and cultural characteristics revealed a rich diversity of Pseudocercospora species in Brazil. Twelve taxa were newly described, namely P. aeschynomenicola, P. diplusodonii, P. emmotunicola, P. manihotii, P. perae, P. planaltinensis, P. pothomorphes, P. sennae-multijugae, P. solani-pseudocapsicicola, P. vassobiae, P. wulffiae and P. xylopiae. Additionally, eight epitype specimens were designated, three species newly reported, and several new host records linked to known Pseudocercospora spp.

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The genus Ramularia includes numerous phytopathogenic species, several of which are economically important. Ramularia eucalypti is currently the only species of this genus known to infect Eucalyptus by causing severe leaf-spotting symptoms on this host. However, several isolates identified as R. eucalypti based on morphology and on nrDNA sequence data of the ITS region have recently been isolated from other plant hosts, from environmental samples and also from human clinical specimens. Identification of closely related species based on morphology is often difficult and the ITS region has previously been shown to be unreliable for species level identification in several genera. In this study we aimed to resolve this species-complex by applying a polyphasic approach involving morphology, multi-gene phylogeny and matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS). Six partial genes (ITS, ACT, TEF1-α, HIS3, GAPDH and RPB2) were amplified and sequenced for a total of 44 isolates representing R. eucalypti s.lat. and closely related species. A multi-gene Bayesian phylogenetic analysis and parsimony analysis were performed, and both the resulting trees showed significant support for separation of seven species in R. eucalypti s.lat., including two previously described (R. eucalypti and R. miae), four novel species here described (R. haroldporteri, R. glennii, R. mali and R. plurivora) and one undescribed Ramularia species (sterile). Additionally, Mycosphaerella nyssicola is newly combined in Ramularia as R. nyssicola. Main mass spectra (MSPs) of several R. eucalypti s.lat. strains were generated using MALDI-TOF MS and were compared through a Principal Component Analysis (PCA) dendogram. The PCA dendrogram supported three clades containing R. plurivora, R. glenni/R. mali and R. eucalypti/R. miae. Although the dendrogram separation of species differed from the phylogenetic analysis, the clinically relevant strains were successfully identified by MALDI-TOF MS.

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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.

RESUMEN

Septoria is a large genus of asexual morphs of Ascomycota causing leaf spot diseases of many cultivated and wild plants. Host specificity has long been a decisive criterium in species delimitation in Septoria, mainly because of the paucity of useful morphological characters and the high level of variation therein. This study aimed at improving the species delimitation of Septoria by adopting a polyphasic approach, including multilocus DNA sequencing and morphological analyses on the natural substrate and in culture. To this end 365 cultures preserved in CBS, Utrecht, The Netherlands, among which many new isolates obtained from fresh field specimens were sequenced. Herbarium material including many types was also studied. Full descriptions of the morphology in planta and in vitro are provided for 57 species. DNA sequences were generated for seven loci, viz. nuclear ITS and (partial) LSU ribosomal RNA genes, RPB2, actin, calmodulin, Btub, and EF. The robust phylogeny inferred showed that the septoria-like fungi are distributed over three main clades, establishing the genera Septoria s. str., Sphaerulina, and Caryophylloseptoria gen. nov. Nine new combinations and one species, Sphaerulina tirolensis sp. nov. were proposed. It is demonstrated that some species have wider host ranges than expected, including hosts from more than one family. Septoria protearum, previously only associated with Proteaceae was found to be also associated with host plants from six additional families of phanerogams and cryptogams. To our knowledge this is the first study to provide DNA-based evidence that multiple family-associations occur for a single species in Septoria. The distribution of host families over the phylogenetic tree showed a highly dispersed pattern for 10 host plant families, providing new insight into the evolution of these fungi. It is concluded that trans-family host jumping is a major force driving the evolution of Septoria and Sphaerulina. TAXONOMIC NOVELTIES: New genus - Caryophylloseptoria Verkley, Quaedvlieg & Crous; New species - Sphaerulina tirolensis Verkley, Quaedvlieg & Crous; New combinations - Caryophylloseptoria lychnidis (Desm.) Verkley, Quaedvlieg & Crous, Caryophylloseptoria silenes (Westend.) Verkley, Quaedvlieg & Crous, Caryophylloseptoria spergulae (Westend.) Verkley, Quaedvlieg & Crous, Sphaerulina aceris (Lib.) Verkley, Quaedvlieg & Crous, Sphaerulina cornicola (DC.: Fr.) Verkley, Quaedvlieg & Crous, Sphaerulina gei (Roberge ex Desm.) Verkley, Quaedvlieg & Crous, Sphaerulina hyperici (Roberge ex Desm.) Verkley, Quaedvlieg & Crous, Sphaerulina frondicola (Fr.) Verkley, Quaedvlieg & Crous, Sphaerulina socia (Pass.) Quaedvlieg, Verkley & Crous; Epitypifications (basionyms) - Ascochyta lysimachiae Lib., Septoria astragali Roberge ex Desm., Septoria cerastii Roberge ex Desm., Septoria clematidis Roberge ex Desm., Septoria cruciatae Roberge ex Desm., Septoria spergulae Westend., Septoria epilobii Westend., Septoria galeopsidis Westend., Septoria gei Roberge ex Desm., Septoria hyperici Roberge ex Desm., Septoria rubi Westend., Septoria senecionis Westend., Septoria urticae Roberge ex Desm.

RESUMEN

Septoria represents a genus of plant pathogenic fungi with a wide geographic distribution, commonly associated with leaf spots and stem cankers of a broad range of plant hosts. A major aim of this study was to resolve the phylogenetic generic limits of Septoria, Stagonospora, and other related genera such as Sphaerulina, Phaeosphaeria and Phaeoseptoria using sequences of the the partial 28S nuclear ribosomal RNA and RPB2 genes of a large set of isolates. Based on these results Septoria is shown to be a distinct genus in the Mycosphaerellaceae, which has mycosphaerella-like sexual morphs. Several septoria-like species are now accommodated in Sphaerulina, a genus previously linked to this complex. Phaeosphaeria (based on P. oryzae) is shown to be congeneric with Phaeoseptoria (based on P. papayae), which is reduced to synonymy under the former. Depazea nodorum (causal agent of nodorum blotch of cereals) and Septoria avenae (causal agent of avenae blotch of barley and rye) are placed in a new genus, Parastagonospora, which is shown to be distinct from Stagonospora (based on S. paludosa) and Phaeosphaeria. Partial nucleotide sequence data for five gene loci, ITS, LSU, EF-1α, RPB2 and Btub were generated for all of these isolates. A total of 47 clades or genera were resolved, leading to the introduction of 14 new genera, 36 new species, and 19 new combinations. TAXONOMIC NOVELTIES: New genera - Acicuseptoria Quaedvlieg, Verkley & Crous, Cylindroseptoria Quaedvlieg, Verkley & Crous, Kirstenboschia Quaedvlieg, Verkley & Crous, Neoseptoria Quaedvlieg, Verkley & Crous, Neostagonospora Quaedvlieg, Verkley & Crous, Parastagonospora Quaedvlieg, Verkley & Crous, Polyphialoseptoria Quaedvlieg, R.W. Barreto, Verkley & Crous, Ruptoseptoria Quaedvlieg, Verkley & Crous, Septorioides Quaedvlieg, Verkley & Crous, Setoseptoria Quaedvlieg, Verkley & Crous, Stromatoseptoria Quaedvlieg, Verkley & Crous, Vrystaatia Quaedvlieg, W.J. Swart, Verkley & Crous, Xenobotryosphaeria Quaedvlieg, Verkley & Crous, Xenoseptoria Quaedvlieg, H.D. Shin, Verkley & Crous. New species - Acicuseptoria rumicis Quaedvlieg, Verkley & Crous, Caryophylloseptoria pseudolychnidis Quaedvlieg, H.D. Shin, Verkley & Crous, Coniothyrium sidae Quaedvlieg, Verkley, R.W. Barreto & Crous, Corynespora leucadendri Quaedvlieg, Verkley & Crous, Cylindroseptoria ceratoniae Quaedvlieg, Verkley & Crous, Cylindroseptoria pistaciae Quaedvlieg, Verkley & Crous, Kirstenboschia diospyri Quaedvlieg, Verkley & Crous, Neoseptoria caricis Quaedvlieg, Verkley & Crous, Neostagonospora caricis Quaedvlieg, Verkley & Crous, Neostagonospora elegiae Quaedvlieg, Verkley & Crous, Paraphoma dioscoreae Quaedvlieg, H.D. Shin, Verkley & Crous, Parastagonospora caricis Quaedvlieg, Verkley & Crous, Parastagonospora poae Quaedvlieg, Verkley & Crous, Phlyctema vincetoxici Quaedvlieg, Verkley & Crous, Polyphialoseptoria tabebuiae-serratifoliae Quaedvlieg, Alfenas & Crous, Polyphialoseptoria terminaliae Quaedvlieg, R.W. Barreto, Verkley & Crous, Pseudoseptoria collariana Quaedvlieg, Verkley & Crous, Pseudoseptoria obscura Quaedvlieg, Verkley & Crous, Sclerostagonospora phragmiticola Quaedvlieg, Verkley & Crous, Septoria cretae Quaedvlieg, Verkley & Crous, Septoria glycinicola Quaedvlieg, H.D. Shin, Verkley & Crous, Septoria oenanthicola Quaedvlieg, H.D. Shin, Verkley & Crous, Septoria pseudonapelli Quaedvlieg, H.D. Shin, Verkley & Crous, Setophoma chromolaenae Quaedvlieg, Verkley, R.W. Barreto & Crous, Setoseptoria phragmitis Quaedvlieg, Verkley & Crous, Sphaerulina amelanchier Quaedvlieg, Verkley & Crous, Sphaerulina pseudovirgaureae Quaedvlieg, Verkley & Crous, Sphaerulina viciae Quaedvlieg, H.D. Shin, Verkley & Crous, Stagonospora duoseptata Quaedvlieg, Verkley & Crous, Stagonospora perfecta Quaedvlieg, Verkley & Crous, Stagonospora pseudocaricis Quaedvlieg, Verkley, Gardiennet & Crous, Stagonospora pseudovitensis Quaedvlieg, Verkley & Crous, Stagonospora uniseptata Quaedvlieg, Verkley & Crous, Vrystaatia aloeicola Quaedvlieg, Verkley, W.J. Swart & Crous, Xenobotryosphaeria calamagrostidis Quaedvlieg, Verkley & Crous, Xenoseptoria neosaccardoi Quaedvlieg, H.D. Shin, Verkley & Crous. New combinations - Parastagonospora avenae (A.B. Frank) Quaedvlieg, Verkley & Crous, Parastagonospora nodorum (Berk.) Quaedvlieg, Verkley & Crous, Phaeosphaeria papayae (Speg.) Quaedvlieg, Verkley & Crous, Pseudocercospora domingensis (Petr. & Cif.) Quaedvlieg, Verkley & Crous, Ruptoseptoria unedonis (Roberge ex Desm.) Quaedvlieg, Verkley & Crous, Septorioides pini-thunbergii (S. Kaneko) Quaedvlieg, Verkley & Crous, Sphaerulina abeliceae (Hiray.) Quaedvlieg, Verkley & Crous, Sphaerulina azaleae (Voglino) Quaedvlieg, Verkley & Crous, Sphaerulina berberidis (Niessl) Quaedvlieg, Verkley & Crous, Sphaerulina betulae (Pass.) Quaedvlieg, Verkley & Crous, Sphaerulina cercidis (Fr.) Quaedvlieg, Verkley & Crous, Sphaerulina menispermi (Thüm.) Quaedvlieg, Verkley & Crous, Sphaerulina musiva (Peck) Quaedvlieg, Verkley & Crous, Sphaerulina oxyacanthae (Kunze & J.C. Schmidt) Quaedvlieg, Verkley & Crous, Sphaerulina patriniae (Miura) Quaedvlieg, Verkley & Crous, Sphaerulina populicola (Peck) Quaedvlieg, Verkley & Crous, Sphaerulina quercicola (Desm.) Quaedvlieg, Verkley & Crous, Sphaerulina rhabdoclinis (Butin) Quaedvlieg, Verkley & Crous, Stromatoseptoria castaneicola (Desm.) Quaedvlieg, Verkley & Crous. Typifications: Epitypifications - Phaeosphaeria oryzae I. Miyake, Phaeoseptoria papayae Speg.; Neotypification - Hendersonia paludosa Sacc. & Speg.

RESUMEN

Several species of Septoria are associated with leaf and fruit spot of pistachio (Pistacia vera), though their identity has always been confused, making identification problematic. The present study elucidates the taxonomy of the Septoria spp. associated with pistachio, and distinguishes four species associated with this host genus. Partial nucleotide sequence data for five gene loci, ITS, LSU, EF-1α, RPB2 and Btub were generated for a subset of isolates. Cylindroseptoria pistaciae, which is associated with leaf spots of Pistacia lentiscus in Spain, is characterised by pycnidial conidiomata that give rise to cylindrical, aseptate conidia. Two species of Septoria s. str. are also recognised on pistachio, S. pistaciarum, and S. pistaciae. The latter is part of the S. protearum species complex, and appears to be a wide host range pathogen occurring on hosts in several different plant families. Septoria pistacina, a major pathogen of pistachio in Turkey, is shown to belong to Pseudocercospora, and not Septoria as earlier suspected. Other than for its pycnidial conidiomata, it is a typical species of Pseudocercospora based on its smooth, pigmented conidiogenous cells and septate conidia. This phenomenon has also been observed in Pallidocercospora, and seriously questions the value of conidiomatal structure at generic level, which has traditionally been used to separate hyphomycetous from coelomycetous ascomycetes. Other than DNA barcodes to facilitate the molecular identification of these taxa occurring on pistachio, a key is also provided to distinguish species based on morphology.