First comprehensive phylogenetic analysis of the genus Erysiphe (Erysiphales, Erysiphaceae) I. The Microsphaera lineage

Phylogeny and taxonomy of the genera of Erysiphaceae, part 5: Erysiphe (the "Microsphaera lineage" part 1)

In this contribution, we offer the fifth installment of a series focusing on the phylogeny and taxonomy of powdery mildews. This paper is the second segment evaluating the genus Erysiphe. The first treatment of Erysiphe focused on phylogenetically basal species in the "Uncinula lineage." This research presents a phylogenetic-taxonomic assessment of species that form the group previously referred to as the "Microsphaera lineage." Given the size of the group, we split the treatment of this lineage of Erysiphe species into two parts based on their phylogenetic placement. Phylogenetic trees based on ITS+28S data are supplemented by sequences of additional markers (CAM, GADPH, GS, RPB2, and TUB). Included in the analysis of the Microsphaera lineage is the "Erysiphe aquilegiae complex" (group, clade, cluster), which encompasses sequences obtained from an assemblage of Erysiphe species with insufficient resolution in rDNA analyses. Attempts have been made to resolve this group at the species level by applying a multilocus approach. A detailed discussion of the "Erysiphe aquilegiae complex" is provided. Sequences are provided for the first time for several species, particularly North American species, such as Erysiphe aggregata, E. erineophila, E. parnassiae, and E. semitosta. Ex-type sequences for Microsphaera benzoin and M. magnusii have been retrieved. Alphitomorpha penicillata, Microsphaera vanbruntiana, and M. symphoricarpi are epitypified with ex-epitype sequences. The new species Erysiphe alnicola, E. deutziana, E. cornigena, E. lentaginis, and E. sambucina are described, the new combinations E. lauracearum, E. passiflorae, and E. sambucicola are introduced, and the new name E. santali is proposed.

Phylogeny and taxonomy of the genera of Erysiphaceae, part 4: Erysiphe (the "Uncinula lineage")

This is the fourth contribution within an ongoing series dedicated to the phylogeny and taxonomy of powdery mildews. This particular installment undertakes a comprehensive evaluation of a group previously referred to as the "Uncinula lineage" within Erysiphe. The genus Erysiphe is too large to be assessed in a single paper; thus, the treatment of Erysiphe is split into three parts, according to phylogenetic lineages. The first paper, presented here, discusses the most basal lineage of Erysiphe and its relationship to allied basal genera within tribe Erysipheae (i.e., Brasiliomyces and Salmonomyces). ITS+28S analyses are insufficient to resolve the basal assemblage of taxa within the Erysipheae. Therefore, phylogenetic multilocus examinations have been carried out to better understand the evolution of these taxa. The results of our analyses favor maintaining Brasiliomyces, Bulbomicroidium, and Salmonomyces as separate genera, at least for the interim, until further phylogenetic multilocus data are available for additional basal taxa within the Erysipheae. The current analyses also confirmed previous results that showed that the "Uncinula lineage" is not exclusively composed of Erysiphe species of sect. Uncinula but also includes some species that morphologically align with sect. Erysiphe, as well as species that had previously been assigned to Californiomyces and Typhulochaeta. Numerous sequences of Erysiphe species from the "Uncinula lineage" have been included in the present phylogenetic analyses and were confirmed by their position in well-supported species clades. Several species have been sequenced for the first time, including Erysiphe clintonii, E. couchii, E. geniculata, E. macrospora, and E. parvula. Ex-type sequences are provided for 16 taxa including E. nothofagi, E. trinae, and E. variabilis. Epitypes are designated and ex-epitype sequences are added for 18 taxa including Erysiphe carpophila, E. densa, and U. geniculata var. carpinicola. The new species Erysiphe canariensis is described, and the new names E. hosagoudarii and E. pseudoprunastri and the new combination E. ampelopsidis are introduced.

Mitochondrial characteristics of the powdery mildew genus Erysiphe revealed an extraordinary evolution in protein-coding genes

The genus Erysiphe was an obligate parasite causing powdery mildew disease on a wide range of higher plants. However, the knowledge of their mitogenome architecture for lifestyle adaptability was scarce. Here, we assembled the first complete mitogenome (190,559 bp in size) for rubber tree powdery mildew pathogen Erysiphe quercicola. Comparable analysis of the Erysiphe mitogenomes exhibited conserved gene content, genome organization and codon usage bias, but extensive dynamic intron gain/loss events were presented between Erysiphe species. The phylogeny of the Ascomycota species constructed in the phylogenetic analysis showed genetic divergences of the Erysiphe species. Compared with other distant saprophytic and plant pathogenic fungi, Erysiphe had a flat distribution of evolutionary pressures on fungal standard protein-coding genes (PCGs). The Erysiphe PCGs had the highest mean selection pressure. In particular, Erysiphe's cox1, nad1, cob and rps3 genes had the most elevated selection pressures among corresponding PCGs across fungal genera. Altogether, the investigations provided a novel insight into the potential evolutionary pattern of the genus Erysiphe to adapt obligate biotrophic lifestyle and promoted the understanding of the high plasticity and population evolution of fungal mitogenomes.

Phylogeny and taxonomy of the genera of Erysiphaceae, part 1: Golovinomyces

Powdery mildews are a monophyletic group of obligate plant pathogenic fungi in the family Erysiphaceae. Powdery mildews are economically important in that they cause damage to many agriculturally significant crops and plants in ecologically important habitats. In this contribution, we introduce a new series of publications focusing on the phylogeny and taxonomy of this group, with an emphasis on specimens collected from North America. The first part of the series focuses on the genus Golovinomyces and includes a section detailing the powdery mildew species concept. We conducted analyses of Golovinomyces spp. with available rDNA sequence data from GenBank and supplemented the data set with rDNA (ITS, 28S, IGS) as well as protein-coding (GAPDH) data from 94 North American collections. Many of the species evaluated are included in phylogenetic and morphological analyses for the first time, including the American species G. americanus, G. brunneopunctatus, G. californicus, G. greeneanus, G. hydrophyllacearum, and G. sparsus. A special emphasis was placed on acquiring ex-type or ex-epitype sequences or presenting reference sequences for phylogenetic-taxonomic purposes. Three new species, G. eurybiarum, G. galiorum, and G. malvacearum, are described, and the new combinations G. fuegianus, G. mutisiae, and G. reginae are introduced. Ex-holotype sequences of Erysiphe sparsa (≡ G. sparsus) reveal that it should be reduced to synonymy with G. ambrosiae, and ex-epitype sequences of G. valerianae reveal that it should be reduced to synonymy with G. orontii. Multiple epitypes are designated with ex-epitype sequences.

First Report of Erysiphe betae Causing Powdery Mildew on Chard (Beta vulgaris var. cicla) in Mexico

Chard (Beta vulgaris var. cicla; Chenopodiaceae) is a vegetable native to the Mediterranean, widely cultivated for its nutritional properties. In June 2020, an outbreak of powdery mildew was detected in a commercial crop of chard in San Martín Texmelucan, Puebla (19°14'37.1"N; 98°27'12.5"W), Mexico. The disease was present in 86% of the plants (n=400) and the pathogen was found to cover up to 95% of the surface of the leaves. Initially, small whitish patches were observed on both sides of the leaves. Subsequently, the patches grew rapidly to cover most of the leaf surface and premature senescence of infected leaves was observed. The signs of the pathogen were observed as abundant whitish masses of conidia. Microscopic analysis of the fungus showed amphigenous mycelia with lobed hyphal appressoria. Conidiophores (n=30) were simple and erect, 93133 × 7.58.5 μm. Foot cells (n=30) were cylindrical, predominately straight, and rarely somewhat curved at the base, 30.036.5 μm, followed by a longer cell and two shorter cells, and the conidium. Conidia (n=100) were hyaline, ellipsoid-ovoid, 3745 × 1416 μm. Germ tubes (n =30) were terminal, short (0.52.0 times the conidial width) and stout. Conidial appressoria (n=30) were mostly lobed, showing from 2-6 lobes. Chasmothecia were not found. The morphological characteristics observed correspond to previous descriptions of Erysiphe betae by Braun and Cook et al. (2012). A voucher specimen (accession no. UACH450) was deposited in the Department of Agricultural Parasitology Herbarium at the Chapingo Autonomous University. To confirm identification, DNA was extracted from the fungus, and the internal transcribed spacer (ITS) and the 28S gene region of rDNA from one sample were amplified by PCR, using the primers ITS1/ITS4 (White et al. 1990) and PM3 (Takamatsu and Kano 2001)/TW14 (Mori et al. 2000). The sequences obtained from our specimen were registered to the GenBank under the accession numbers ON157053 and ON157047 for ITS and LSU, respectively. Our sequences shared 100% identity for ITS (KX574674) and 99.8% for LSU (OM033348 and OM368494) with sequences of E. betae in BLAST'n search. Based on phylogenetic analysis using the Maximum Likelihood method including a published ITS + 28S dataset for Erysiphe species, the isolate UACH450 was grouped into a clade with E. betae. Takamatsu et al. (2015) found that E. betae, E. malvae and E. heraclei are phylogenetically indistinguishable (they form the E. heraclei species complex), nevertheless, E. malavae infects Lavatera and Malva (Malvaceae), E. heraclei predominately forms on hosts of Apiaceae and E. betae is commonly found on Beta and Chenopodium (Chenopodiaceae) (Braun and Cook 2012). Pathogenicity was verified by spraying a suspension of conidia (1107 conidia/ml) onto the leaves of six healthy chard plants and six plants were sprayed with sterile distilled water to serve as controls. All plants were maintained at temperatures from 28 2 °C and relative humidity of 802 %. All inoculated leaves developed powdery mildew symptoms after 14 days, whereas the control plants remained symptomless. The pathogenicity test was performed twice, observing the same results. The recovered pathogen showed the same morphological characteristics as the inoculated pathogen, thus fulfilling Koch's postulates. To our knowledge, this is the first report of Erysiphe betae causing powdery mildew on Beta vulgaris var. cicla in Mexico. This pathogen has been previously reported in Iraq (Amano, 1986) and Greece (Vakalounakis and Kavroulakis, 2017) on Beta vulgaris var. cicla. Also, Erysiphe betae has been reported in Mexico on Chenopodium and throughout the world on sugar beet (Farr and Rossman, 2022). This pathogen is a major issue as it can completely cover the leaves of the diseased plants, making them difficult to market.

Deciphering diversity at er loci for diversification of powdery mildew resistance in pea

Agricultural biotechnology aims to scrutinize the field crops which feed half of the world's population by improving their agronomic traits using various biotechnological tools. Pea- an important cash crop, rich in nutrients, but frequently infected with powdery mildew (fungal disease caused by Erysiphe pisi) that destroys the whole crop and causes economic loss for growers. We, therefore, targeted this research to find the pathogen-resistant pea lines and further decipher the diversity at er locus among resistant pea lines. Screening for resistant pea lines was done with Erysiphe pisi isolates (Genebank submission: KX455922.1) under the net house and greenhouse conditions. Molecular studies revealed that the Erysiphe resistant (er1) gene was present in 40 lines out of selected 50 pea lines and the mutational character was conferred up to 36 genotypes with 11 haplotype groups. The haplotype (gene) diversity (Hd) was found to be 0.5571 ± 0.099 SD and the nucleotide diversity (Pi) was 0.0160 ± 0.0042 SD Majority of resistant lines (67%) occurred in Hap-1, other remaining haplotypes (Hap 2-10) having 33% resistant lines, each showing characteristic nucleotide substitutions with respect to reference PsMLO1 gene; genotypes from these divergent haplotypes can be used in pea resistance breeding to avoid genetic homogeneity and genetic vulnerability.

<i>Erysiphe ruyongzhengiana </i>sp. nov., a new powdery mildew species on <i>Aristolochia debilis</i>, belonging to the <i>Erysiphe aquilegiae</i> clade

Powdery mildew was found on Aristolochia debilis (Aristolochiaceae) in Jiangsu Province and Shandong Province, China. This fungus is characterized by having long conidiophore foot-cells which are straight or curved at the base, and chasmothecia with numerous appendages. Phylogenetic analysis using internal transcribed spacer sequences showed that five sequences on A. debilis determined in this study and two sequences retrieved from Erysiphe sp. on A. debilis formed an independent cluster within the Erysiphe aquilegiae clade with 58% bootstrap support. This powdery mildew differs from allied species of the E. aquilegiae clade in producing longer conidia and conidiophores with longer foot-cells, which are often curved at the base. Morphological observations and molecular phylogenetic analysis revealed a new powdery mildew species, described as Erysiphe ruyongzhengiana.

Beyond Nuclear Ribosomal DNA Sequences: Evolution, Taxonomy, and Closest Known Saprobic Relatives of Powdery Mildew Fungi (Erysiphaceae) Inferred From Their First Comprehensive Genome-Scale Phylogenetic Analyses

Powdery mildew fungi (Erysiphaceae), common obligate biotrophic pathogens of many plants, including important agricultural and horticultural crops, represent a monophyletic lineage within the Ascomycota. Within the Erysiphaceae, molecular phylogenetic relationships and DNA-based species and genera delimitations were up to now mostly based on nuclear ribosomal DNA (nrDNA) phylogenies. This is the first comprehensive genome-scale phylogenetic analysis of this group using 751 single-copy orthologous sequences extracted from 24 selected powdery mildew genomes and 14 additional genomes from Helotiales, the fungal order that includes the Erysiphaceae. Representative genomes of all powdery mildew species with publicly available whole-genome sequencing (WGS) data that were of sufficient quality were included in the analyses. The 24 powdery mildew genomes included in the analysis represented 17 species belonging to eight out of 19 genera recognized within the Erysiphaceae. The epiphytic genera, all but one represented by multiple genomes, belonged each to distinct, well-supported lineages. Three hemiendophytic genera, each represented by a single genome, together formed the hemiendophytic lineage. Out of the 14 other taxa from the Helotiales, Arachnopeziza araneosa, a saprobic species, was the only taxon that grouped together with the 24 genome-sequenced powdery mildew fungi in a monophyletic clade. The close phylogenetic relationship between the Erysiphaceae and Arachnopeziza was revealed earlier by a phylogenomic study of the Leotiomycetes. Further analyses of powdery mildew and Arachnopeziza genomes may discover signatures of the evolutionary processes that have led to obligate biotrophy from a saprobic way of life. A separate phylogeny was produced using the 18S, 5.8S, and 28S nrDNA sequences of the same set of powdery mildew specimens and compared to the genome-scale phylogeny. The nrDNA phylogeny was largely congruent to the phylogeny produced using 751 orthologs. This part of the study has revealed multiple contamination and other quality issues in some powdery mildew genomes. We recommend that the presence of 28S, internal transcribed spacer (ITS), and 18S nrDNA sequences in powdery mildew WGS datasets that are identical to those determined by Sanger sequencing should be used to assess the quality of assemblies, in addition to the commonly used Benchmarking Universal Single-Copy Orthologs (BUSCO) values.

Identification of Causal Agent Inciting Powdery Mildew on Common Bean and Screening of Resistance Cultivars

Powdery mildew is one of the severe diseases on common bean in Southwestern China, but the identity of the pathogen inciting this disease is unclear. The objective of this study was to identify the causal agent of common bean powdery mildew and to screen resistant cultivars. The pathogen was identified through morphological identification, molecular phylogenetic analysis, and pathogenicity tests. Resistance of common bean cultivars was evaluated by artificial inoculation at the seedling stage. The common bean powdery mildew isolate CBPM1 was obtained after pathogen isolation and purification. Morphological identification confirmed that the isolate CBPM1 belonged to the Oidium subgenus Pseudoidium and germinated Pseudoidium-type germ tubes. Molecular phylogenetic analysis showed that the isolate CBPM1 and Erysiphe vignae isolates from different hosts were clustered into a distinct group. The pathogenicity and host range tests revealed that the isolate CBPM1 was strongly pathogenic to common bean, multiflora bean, lablab bean, cowpea, and mung bean, but not to soybean, adzuki bean, pea, faba bean, chickpea, lentil, pumpkin, and cucumber. In addition, 54 common bean cultivars were identified for resistance to powdery mildew, and 15 were resistant or segregant. Based on the morphological, molecular and pathogenic characteristics, the causal agent of common bean powdery mildew was identified as E. vignae. This is the first time E. vignae has been confirmed on common bean. Cultivars with different resistance levels were screened, and these cultivars could be used for disease control or the breeding of new resistant cultivars.

New Records of Powdery Mildews from Taiwan: Erysiphe ipomoeae comb. nov., E. aff. betae on Buckwheat, and E. neolycopersici comb. nov. on Cardiospermum halicacabum

Erysiphe is the largest genus of powdery mildews (PMs), a group of obligate plant pathogenic fungi. Exploration of biodiversity generally relies on regional surveys and our aim is to investigate the PMs in Taiwan. Collections of the fungi on five plant species around agricultural environments were subjected to morphological and molecular characterization, using both internal transcribed spacer (ITS) and β-tubulin gene (TUB2) regions for the phylogenetic analyses. Erysipheipomoeae comb. nov., a species able to infect Ipomoea obscura and I. aquatica demonstrated by pathogenicity tests, has been neotypified. The two buckwheat species, Fagopyrum esculentum and F. tataricum, are found to be hosts of E. aff. betae. These results suggest that hosts in some plant families can be infected by more than one Erysiphe pathogen, e.g., Convolvulaceae by E. ipomoeae and E. convolvuli and Polygonaceae by E. polygoni and E. aff. betae, respectively. In addition, phylogenetic analyses of PMs on Cardiospermum halicacabum and tomato belonging to the E. aquilegiae complex are allocated under E. neolycopersici comb. nov. This extends the potential host range of E. aquilegiae complex to the plant family Sapindaceae. We conclude that awareness of the host associations of PMs can potentially benefit crop disease management.

War and Peas: Molecular Bases of Resistance to Powdery Mildew in Pea (Pisum sativum L.) and Other Legumes

Grain legumes, or pulses, have many beneficial properties that make them potentially attractive to agriculture. However, the large-scale cultivation of legumes faces a number of difficulties, in particular the vulnerability of the currently available cultivars to various diseases that significantly impair yields and seed quality. One of the most dangerous legume pathogens is powdery mildew (a common name for parasitic fungi of the order Erisyphales). This review examines the methods of controlling powdery mildew that are used in modern practice, including fungicides and biological agents. Special attention is paid to the plant genetic mechanisms of resistance, which are the most durable, universal and environmentally friendly. The most studied legume plant in this regard is the garden pea (Pisum sativum L.), which possesses naturally occurring resistance conferred by mutations in the gene MLO1 (Er1), for which we list here all the known resistant alleles, including er1-12 discovered by the authors of this review. Recent achievements in the genetics of resistance to powdery mildew in other legumes and prospects for the introduction of this resistance into other agriculturally important legume species are also discussed.

Phylogeny and taxonomy of Podosphaera filipendulae (Erysiphaceae) revisited

The phylogeny and taxonomy of Podosphaera filipendulae (including P. filipendulensis, syn. nov.) have been examined. Asian, European and North American collections were examined and the nucleotides sequences of their partial rDNA region were determined. In particular, the relationship between P. filipendulae and P. spiraeae was analysed. The results confirmed P. filipendulae and P. spiraeae as two separate, morphologically similar species. The phylogenetic analysis revealed a similar phylogeny to that of the host genera. Although ITS sequences retrieved from Asian, European and North American specimens of P. filipendulae on various Filipendula spp. are identical to sequences from P. macularis on hop, there is consistently one base substitution at the 5'-end of 28S rRNA gene between the species. This result provides evidence that the hop powdery mildew and P. filipendulae are biologically and morphologically clearly distinguished, and should be maintained as two separate species.

Examination of Gene Loss in the DNA Mismatch Repair Pathway and Its Mutational Consequences in a Fungal Phylum

The DNA mismatch repair (MMR) pathway corrects mismatched bases produced during DNA replication and is highly conserved across the tree of life, reflecting its fundamental importance for genome integrity. Loss of function in one or a few MMR genes can lead to increased mutation rates and microsatellite instability, as seen in some human cancers. Although loss of MMR genes has been documented in the context of human disease and in hypermutant strains of pathogens, examples of entire species and species lineages that have experienced substantial MMR gene loss are lacking. We examined the genomes of 1,107 species in the fungal phylum Ascomycota for the presence of 52 genes known to be involved in the MMR pathway of fungi. We found that the median ascomycete genome contained 49/52 MMR genes. In contrast, four closely related species of obligate plant parasites from the powdery mildew genera Erysiphe and Blumeria, have lost between five and 21 MMR genes, including MLH3, EXO1, and DPB11. The lost genes span MMR functions, include genes that are conserved in all other ascomycetes, and loss of function of any of these genes alone has been previously linked to increased mutation rate. Consistent with the hypothesis that loss of these genes impairs MMR pathway function, we found that powdery mildew genomes with higher levels of MMR gene loss exhibit increased numbers of mononucleotide runs, longer microsatellites, accelerated sequence evolution, elevated mutational bias in the A|T direction, and decreased GC content. These results identify a striking example of macroevolutionary loss of multiple MMR pathway genes in a eukaryotic lineage, even though the mutational outcomes of these losses appear to resemble those associated with detrimental MMR dysfunction in other organisms.

One Crop Disease, How Many Pathogens? Podosphaera xanthii and Erysiphe vignae sp. nov. Identified as the Two Species that Cause Powdery Mildew of Mungbean (Vigna radiata) and Black Gram (V. mungo) in Australia

Powdery mildew is a significant threat to mungbean (Vigna radiata) and black gram (V. mungo) production across Australia and overseas. Although they have been present in Australia for at least six decades and are easily recognized in the field, the precise identification of the pathogens causing this disease has remained unclear. Our goal was to identify the powdery mildew species infecting mungbean, black gram, and wild mungbean (V. radiata ssp. sublobata) in Australia. The internal transcribed spacer (ITS) and large subunit sequences of the ribosomal DNA and/or morphology of 57 Australian specimens were examined. Mungbean and black gram were infected by two species: Podosphaera xanthii and a newly recognized taxon, Erysiphe vignae sp. nov. Wild mungbean was infected only with P. xanthii. Mungbean and black gram powdery mildew ITS sequences from China, India, and Taiwan revealed the presence of only P. xanthii on these crops despite controversial reports of an Erysiphe species on both crops in India. Sequence analyses indicated that the closest relative of E. vignae is E. diffusa, which infects soybean (Glycine max) and other plants. E. vignae did not infect soybean in cross-inoculation tests. In turn, E. diffusa from soybean infected black gram and provoked hypersensitive response in mungbean. The recognition of a second species, E. vignae, as another causal agent of mungbean and black gram powdery mildew in Australia may complicate plant breeding efforts and control of the disease with fungicide applications.

Occurrence of Powdery Mildew Caused by Erysiphe buhrii on Dianthus chinensis in Inner Mongolia, China

Dianthus chinensis is widely cultivated for ornamental and medicinal use in China (Guo et al. 2017). The plant has been used in traditional Chinese medicine for the treatment of urinary problems such as strangury and diuresis (Han et al. 2015). In June and July 2020, powdery mildew-like signs and symptoms were seen on leaves of D. chinensis cultivated on the campus of Inner Mongolia Agricultural University, Hohhot city, Inner Mongolia Province, China. White powder-like masses occurred in irregular shaped lesions on both leaf surfaces and covered up to 50% of leaf area. Some infected leaves were deformed on their edges and some leaf senescence occurred. More than 40 % of plants (n = 180) exhibited these signs and symptoms. Conidiophores (n = 50) of the suspect fungus were unbranched and measured 70 to 140 µm long × 6 to 10 µm wide and had foot cells that were 25 to 48 µm long. Conidia (n = 50) were produced singly, elliptical to cylindrical shaped, 30 to 45 µm long × 12 to 19 µm wide, with length/width ratio of 2.0 to 3.2, and lacked fibrosin bodies. No chasmothecia were found. Based on these morphological characteristics, the fungus was tentatively identified as an Erysiphe sp. (Braun and Cook 2012). Fungal structures were isolated from diseased leaves and genomic DNA of the pathogen extracted utilizing the method described by Zhu et al. (2019). The internal transcribed spacer (ITS) region was amplified by PCR employing the primers PMITS1/PMITS2 (Cunnington et al. 2003) and the amplicon sequenced by Invitrogen (Shanghai, China). The sequence for the powdery mildew fungus (deposited into GenBank under Accession No. MW144997) showed 100 % identity (558/558 bp) with E. buhrii (Accession No. LC009898) that was reported on Dianthus sp. in Japan (Takamatsu et al. 2015). Pathogenicity tests were done by collecting fungal conidia from infected D. chinensis leaves and brushing them onto leaves of four healthy plants. Four uninoculated plants served as controls. Inoculated and uninoculated plants were placed in separate growth chambers maintained at 19 ℃, 65 % humidity, with a 16 h/8 h light/dark period. Nine-days post-inoculation, powdery mildew disease signs appeared on inoculated plants, whereas control plants remained asymptomatic. The same results were obtained for two repeated pathogenicity experiments. The powdery mildew fungus was identified and confirmed as E. buhrii based on morphological and molecular analysis. An Oidium sp. causing powdery mildew on D. chinensis previously was reported in Xinjiang Province, China (Zheng and Yu 1987). This, to the best of our knowledge, is the first report of powdery mildew caused by E. buhrii on D. chinensis in China (Farr and Rossman 2020). The sudden occurrence of this destructive powdery mildew disease on D. chinensis may adversely affect the health, ornamental value and medicinal uses of the plant in China. Identifying the cause of the disease will support efforts for its future control and management.

Taxonomy and phylogeny of the Erysiphe lonicerae complex (Helotiales, Erysiphaceae) on Lonicera spp

The phylogeny and taxonomy of powdery mildews, belonging to the genus Erysiphe, on Lonicera species throughout the world are examined and discussed. Phylogenetic analyses revealed that sequences retrieved from Erysiphe lonicerae, a widespread powdery mildew species distributed in the Northern Hemisphere on a wide range of Lonicera spp., constitutes a complex of two separate species, viz., E. lonicerae (s. str.) and Erysiphe ehrenbergii comb. nov. Erysiphe lonicerae occurs on Lonicera spp. belonging to Lonicera subgen. Lonicera (= subgen. Caprifolium and subgen. Periclymenum), as well as L. japonica. Erysiphe ehrenbergii comb. nov. occurs on Lonicera spp. of Lonicera subgen. Chamaecerasus. Phylogenetic and morphological analyses have also revealed that Microsphaera caprifoliacearum (≡ Erysiphe caprifoliacearum) should be reduced to synonymy with E. lonicerae (s. str.). Additionally, Erysiphe lonicerina sp. nov. on Lonicera japonica in Japan is described and the new name Erysiphe flexibilis, based on Microsphaera lonicerae var. flexuosa, is introduced. The phylogeny of Erysiphe ehrenbergii and E. lonicerae as well as other Erysiphe species on honeysuckle is discussed, and a survey of all species, including a key to the species concerned, is provided. Citation: Bradshaw M, Braun U, Götz M, Takamatsu S (2020). Taxonomy and phylogeny of the Erysiphe lonicerae complex (Helotiales, Erysiphaceae) on Lonicera spp. Fungal Systematics and Evolution 7: 49-65. doi: 10.3114/fuse.2021.07.03.

Two new records of powdery mildews (Erysiphaceae) from Japan: Erysiphe actinidiicola sp. nov. and Erysiphe sp. on Limonium tetragonum

Erysiphe actinidiicola on Actinidia polygama is described based on morphological and molecular data. Erysiphe actinidiicola is distinguished from E. actinidiae var. actinidiae by having irregularly to dichotomously branched chasmothecial appendages, larger chasmothecia sizes and numbers of asci per chasmothecium. Molecular analyses indicated that this species forms a clade separated from E. actinidiae var. actinidiae. An epitype is proposed for E. actinidiae var. actinidiae with ex-epitype sequences. A powdery mildew found on Limonium tetragonum is tentatively described as Erysiphe sp. This species is distinguished from E. limonii, a powdery mildew on Limonium spp., based on the DNA sequence differences in the 28S rDNA and internal transcribed spacer region as well as the morphological differences in the length of the conidiophores. This is the first record of powdery mildew on L. tetragonum in the world.

First report of Erysiphe corylacearum, agent of powdery mildew, on hazelnut (Corylus avellana) in Romania

Romania has an area dedicated to hazelnut (Corylus avellana L.), covering 890 hectares as of 2019. During October 2020, powdery mildew symptoms were observed on the upper side of leaves of hazelnut 'Tonda di Giffoni' in two commercial orchards in Dudeștii Vechi, Romania (Fig. 1). The disease was present on 70% of the trees in planting, with at least 5 leaves per tree having powdery mildew. Micromorphological examination revealed amphigenous, hyaline, branched, septate mycelial patches of 2.3 to 3.6 μm in diameter. Conidiophores measured 24-60 × 5-6 (average: 45 × 6) μm and consisted of erect, cylindrical to flexuous foot cells, followed by 1-2 shorter cells. Ellipsoid, ovoid to doliform conidia were produced singly and they measured 19-35 × 16-24 (average: 28 × 19) μm. Chasmothecia were spherical, 75 to 107 (average: 88) μm in diameter. Nine to thirteen straight, sometimes flexuous, appendages measured 54 to 92 (average: 66) μm in length and they had five times dichotomous branched apices with curved tips (Fig. 2). Each chasmothecium contained three to five ellipsoid, ovoid to subglobose asci measuring 41-58 × 29-55 μm (average 52 × 43) μm. The asci contained four to eight ascospores measuring 13-24 × 11-15 (average 18 × 14) μm. Morphological identification was confirmed by sequencing the ITS-region of rDNA using two isolates from leaves, stored as frozen mycelium at -20°C. PCR was performed with Erysiphales-specific primer pair PMITS1/PMITS2 (Cunnington et al. 2003). The obtained sequences were deposited in GenBank (Accession n° MW423075, MW423076). Blast analysis of both sequences had 100% identity to ITS rDNA sequences of Erysiphe corylacearum from Azerbaijan (Abasova et al. 2018; Accession n° LC270863), Turkey (Sezer et al. 2017; KY082910), Switzerland (Beenken et al. 2020; MN82272), Iran (Arzanlou et al. 2018; MH047243), Italy (Mezzalama et al. 2020; MW045425) and 99% identity from Georgia (Meparishvili et al. 2019; MK157199). The sequences had a lower percent identity (83%) to Phyllactinia guttata (Accession n° AB080558) (Fig. 3). Pathogenicity was verified on one-year-old plants of C. avellana 'Tonda di Giffoni', which were artificially inoculated with a conidial suspension from infected leaves (n = 25). Inoculated plants were incubated at 20 to 28°C with 70 to 80% relative humidity. White mycelium appeared on the upper surface of the leaves at 8 to 10 days after inoculation. No symptoms were found on control plants sprayed with sterile water. The fungus present on inoculated leaves was morphologically identical to the original isolates from diseased trees from the field. E. corylacearum is native to East Asia and was previously reported in Japan on wild species of Corylus (Takamatsu et al. 2015; Accession n° LC009928). The pathogen most likely spread into Europe from east to west of Europe (Heluta et al. 2019), through the Caucasus, starting from Turkey, Azerbaijan, Georgia, and Iran. P. guttata was considered the only causal agent of powdery mildew on hazelnut in most countries, including Romania (Brown 1995). Compared to P. guttata, which generally develops a mycelium on the underside of leaves, E. corylacearum grows with a white mycelium on the upper side of the leaves. Recently, E. corylacearum on C. avellana was reported also in Ukraine (Heluta et al. 2019), from which it could have moved to Romania. Crop protection strategies for hazelnut should be revised according to the new pathogen occurrence.

First records of powdery mildew fungi (Erysiphales) on medicinal plants in Taiwan

BACKGROUND

Production of medicinal plants in Taiwan is not only hampered by international market competition, but also lack of knowledge of their pathogens, such as powdery mildew fungi (Erysiphales, Ascomycota). Records of these fungi in Taiwan originate from few researchers for the last one hundred years and are still incomplete. Since powdery mildews in tropical/subtropical environments rarely develop the sexual stages with morphologically diagnostic characteristics, internal transcribed spacer sequences (ITS) of the ribosomal RNA genes obtained from the asexual stages have become important modern tools for species identification.

RESULTS

Powdery mildews on medicinal plants from educational and ornamental plantations in Taiwan were identified based on the anamorph morphology and ITS sequences. Four powdery mildews on medicinal plants are new records for Taiwan, Arthrocladiella mougeotii on Lycium chinense, Erysiphe glycines on Pueraria lobata, Erysiphe lespedezae on Bauhinia sp., Desmodium caudatum, and Uraria crinita, and E. lonicerae on Lonicera japonica. Eryngium foetidum is a new host for Erysiphe heraclei hitherto known on other host plants in Taiwan. Eryngium foetidum and Uraria crinita are new host plants for powdery mildews worldwide. Only specific field collection of the pathogens yielded the new records, not checking plant specimens in a phanerogam herbarium. The pathogens did not cause death of the host plants, but appeared to enhance stress by infection of mature leaves.

CONCLUSIONS

Taxonomic study of powdery mildews in Taiwan results into new host records of economically important medicinal plants in Taiwan with potential consequences for plant production and quarantine and also shows that host records are quite incomplete worldwide. Although ITS sequences were useful for species identification, the lack of data for several species on the same host genus on the one hand and the low variation between closely related species on the other indicate the need for further study.

Fungal diversity notes 1387-1511: taxonomic and phylogenetic contributions on genera and species of fungal taxa

This article is the 13th contribution in the Fungal Diversity Notes series, wherein 125 taxa from four phyla, ten classes, 31 orders, 69 families, 92 genera and three genera incertae sedis are treated, demonstrating worldwide and geographic distribution. Fungal taxa described and illustrated in the present study include three new genera, 69 new species, one new combination, one reference specimen and 51 new records on new hosts and new geographical distributions. Three new genera, Cylindrotorula (Torulaceae), Scolecoleotia (Leotiales genus incertae sedis) and Xenovaginatispora (Lindomycetaceae) are introduced based on distinct phylogenetic lineages and unique morphologies. Newly described species are Aspergillus lannaensis, Cercophora dulciaquae, Cladophialophora aquatica, Coprinellus punjabensis, Cortinarius alutarius, C. mammillatus, C. quercoflocculosus, Coryneum fagi, Cruentomycena uttarakhandina, Cryptocoryneum rosae, Cyathus uniperidiolus, Cylindrotorula indica, Diaporthe chamaeropicola, Didymella azollae, Diplodia alanphillipsii, Dothiora coronicola, Efibula rodriguezarmasiae, Erysiphe salicicola, Fusarium queenslandicum, Geastrum gorgonicum, G. hansagiense, Helicosporium sexualis, Helminthosporium chiangraiensis, Hongkongmyces kokensis, Hydrophilomyces hydraenae, Hygrocybe boertmannii, Hyphoderma australosetigerum, Hyphodontia yunnanensis, Khaleijomyces umikazeana, Laboulbenia divisa, Laboulbenia triarthronis, Laccaria populina, Lactarius pallidozonarius, Lepidosphaeria strobelii, Longipedicellata megafusiformis, Lophiotrema lincangensis, Marasmius benghalensis, M. jinfoshanensis, M. subtropicus, Mariannaea camelliae, Melanographium smilaxii, Microbotryum polycnemoides, Mimeomyces digitatus, Minutisphaera thailandensis, Mortierella solitaria, Mucor harpali, Nigrograna jinghongensis, Odontia huanrenensis, O. parvispina, Paraconiothyrium ajrekarii, Parafuscosporella niloticus, Phaeocytostroma yomensis, Phaeoisaria synnematicus, Phanerochaete hainanensis, Pleopunctum thailandicum, Pleurotheciella dimorphospora, Pseudochaetosphaeronema chiangraiense, Pseudodactylaria albicolonia, Rhexoacrodictys nigrospora, Russula paravioleipes, Scolecoleotia eriocamporesi, Seriascoma honghense, Synandromyces makranczyi, Thyridaria aureobrunnea, Torula lancangjiangensis, Tubeufia longihelicospora, Wicklowia fusiformispora, Xenovaginatispora phichaiensis and Xylaria apiospora. One new combination, Pseudobactrodesmium stilboideus is proposed. A reference specimen of Comoclathris permunda is designated. New host or distribution records are provided for Acrocalymma fici, Aliquandostipite khaoyaiensis, Camarosporidiella laburni, Canalisporium caribense, Chaetoscutula juniperi, Chlorophyllum demangei, C. globosum, C. hortense, Cladophialophora abundans, Dendryphion hydei, Diaporthe foeniculina, D. pseudophoenicicola, D. pyracanthae, Dictyosporium pandanicola, Dyfrolomyces distoseptatus, Ernakulamia tanakae, Eutypa flavovirens, E. lata, Favolus septatus, Fusarium atrovinosum, F. clavum, Helicosporium luteosporum, Hermatomyces nabanheensis, Hermatomyces sphaericoides, Longipedicellata aquatica, Lophiostoma caudata, L. clematidis-vitalbae, Lophiotrema hydei, L. neoarundinaria, Marasmiellus palmivorus, Megacapitula villosa, Micropsalliota globocystis, M. gracilis, Montagnula thailandica, Neohelicosporium irregulare, N. parisporum, Paradictyoarthrinium diffractum, Phaeoisaria aquatica, Poaceascoma taiwanense, Saproamanita manicata, Spegazzinia camelliae, Submersispora variabilis, Thyronectria caudata, T. mackenziei, Tubeufia chiangmaiensis, T. roseohelicospora, Vaginatispora nypae, Wicklowia submersa, Xanthagaricus necopinatus and Xylaria haemorrhoidalis. The data presented herein are based on morphological examination of fresh specimens, coupled with analysis of phylogenetic sequence data to better integrate taxa into appropriate taxonomic ranks and infer their evolutionary relationships.

First Report of Powdery Mildew Caused by Erysiphe berberidis on Berberis fortunei in China

Berberis fortune (Lindl.) is commonly used in Chinese traditional medicine (Liu et al. 2020). In April 2020, white powdery colonies covering up to 100% of both upper leaf surfaces and calyces were observed on this species growing on Anhui Agricultural University campus (31°51'51″N; 117°15'31″E) in Hefei City, Anhui Province, China. Sporulating mycelia were white and effuse. Conidiophores were erect, with straight, cylindrical foot cells, 20 to 26 × 9 to 12 μm (average: 24 × 11 µm) (n = 30), followed by one to three shorter cells, and producing conidia in chains. Conidia were ellipsoid-ovoid, subcylindrical, and measured 27 to 36 × 12 to 16.5 µm (average: 32.4 × 14.1 µm) (n = 50). For accurate identification, DNA was extracted from the mycelia, which were collected by scraping symptomatic leaves. The internal transcribed spacer (ITS) was amplified and sequenced using primers ITS1/ITS4. The 623-bp ITS (GenBank accession no. MT449013) showed 99% identity with those of Erysiphe berberidis LC010057 (Takamatsu et al. 2015), KY661153 and KY660920. Based on morphological characteristics and phylogenetic analysis, the powdery mildew fungus on B. fortunei was identified as E. berberidis (Glawe, D. A. 2003). Ten leaves on an asymptomatic B. fortunei were inoculated by gently pressing diseased leaves against the surface of healthy leaves. Ten non-inoculated plants served as controls. All plants were maintained in a greenhouse at 22 to 25°C and >80% relative humidity. Inoculated plants developed powdery mildew colonies after 14 days, whereas uninoculated plants remained healthy. Morphological and molecular characters of the powdery mildew fungus on artificially inoculated plants were identical to those on naturally infected B. fortune. Previously in Siberia, Russia, powdery mildew on woody plants has been reported to be caused by E. berberidis (Tomoshevich M. A. 2019). However, this is the first report of powdery mildew caused by E. berberidis on B. fortunei in China. Its identification will establish a foundation for controlling the disease in China.

Powdery Mildew Caused by Erysiphe sedi on Crassula capitella in China

Crassula capitella Thunb. is a succulent used ornamentally in gardens and landscapes. In August 2019, severe powdery mildew infection was observed on C. capitella in a plant nursery, 1000m2 in area, in Xining (36°42'44.39" N, 101°44'50.50″E, alt. 2330 m), China. Approximately 35% of the leaves on a plant were symptomatic, and 80% of the plants were affected. The disease seriously reduced the ornamental value. A voucher specimen was deposited in the Herbarium of Plant Pathology at Qinghai University under accession no. QHU2019150. The pathogen formed superficial mycelia on leaves and stems producing conspicuous white colonies followed by necrosis of the leaf tissues and defoliation. Mycelia were amphigenous, white, effuse or in patches, persistent with lobed appressoria. The pathogen produced conidia singly on 2- to 3-celled conidiophores occurring on the ectophytic hyphae. Conidia were subcylindrical, measured 22 to 41 × 10 to 16 (n = 50) µm, and were produced singly on the tip of conidiophores. Conidiophores were erect and up to 110 µm long, foot-cells straight, cylindrical and 22 to 53 × 8 to 10 (n = 50) µm, followed by one to three shorter cells. Chasmothecia were not found. The fungus was identified as Erysiphe sedi based on morphology (Braun and Cook 2012). To confirm the identification, the ITS region was amplified. The ITS5/P3 and PM5/ITS4 primers were used to amplify the ITS region by nested PCR, and the cloned fragments were sequenced (Takamatsu and Kano 2001). The aligned ITS region sequences were deposited in GenBank (accession no. MT178769). A BLAST search analysis of the two sequences revealed 99.84% identity with E. sedi infecting Sedum aizoon in Russia (LC010045). A phylogenetic tree was constructed in MEGA6 with 15 ITS sequences using the neighbor-joining method with the Kimura 2-parameter substitution model. The sequence retrieved from powdery mildew on Crassula capitella in China clustered together with the sequences obtained from E. sedi on Sedum spp. with nearly 100 % concordance, placing it in the Erysiphe aquilegiae complex as defined by Takamatsu et al. (2015) and recently critically discussed by Shin et al. (2019). This complex comprises numerous Erysiphe spp. insufficiently resolved, especially when based only on ITS data. However, for the time being we follow Götz et al. (2019) and recognize E. sedi as a species of its own and identify the Chinese collection on Crassula capitella as E. sedi because of the morphological agreement and concordant ITS data. Pathogenicity tests were completed by gently pressing infected leaves onto five healthy leaves of C. capitella, Inoculated and non-inoculated plants were maintained separately in different rooms of a greenhouse at 22 to 25°C. Inoculated plants developed signs and symptoms after 12 days, whereas control plants remained symptomless. The morphology of the fungus on inoculated leaves was identical to that originally observed on diseased plants. To our knowledge, this is the first report of powdery mildew caused by Erysiphe sedi on C. capitella in China and worldwide, although E. sedi is reported to infect many Crassulaceous or Crassulaceae hosts (Cho et al. 2012, Götz et al. 2019).

Australia: A Continent Without Native Powdery Mildews? The First Comprehensive Catalog Indicates Recent Introductions and Multiple Host Range Expansion Events, and Leads to the Re-discovery of Salmonomyces as a New Lineage of the Erysiphales

In contrast to Eurasia and North America, powdery mildews (Ascomycota, Erysiphales) are understudied in Australia. There are over 900 species known globally, with fewer than currently 60 recorded from Australia. Some of the Australian records are doubtful as the identifications were presumptive, being based on host plant-pathogen lists from overseas. The goal of this study was to provide the first comprehensive catalog of all powdery mildew species present in Australia. The project resulted in (i) an up-to-date list of all the taxa that have been identified in Australia based on published DNA barcode sequences prior to this study; (ii) the precise identification of 117 specimens freshly collected from across the country; and (iii) the precise identification of 30 herbarium specimens collected between 1975 and 2013. This study confirmed 42 species representing 10 genera, including two genera and 13 species recorded for the first time in Australia. In Eurasia and North America, the number of powdery mildew species is much higher. Phylogenetic analyses of powdery mildews collected from Acalypha spp. resulted in the transfer of Erysiphe acalyphae to Salmonomyces, a resurrected genus. Salmonomyces acalyphae comb. nov. represents a newly discovered lineage of the Erysiphales. Another taxonomic change is the transfer of Oidium ixodiae to Golovinomyces. Powdery mildew infections have been confirmed on 13 native Australian plant species in the genera Acacia, Acalypha, Cephalotus, Convolvulus, Eucalyptus, Hardenbergia, Ixodia, Jagera, Senecio, and Trema. Most of the causal agents were polyphagous species that infect many other host plants both overseas and in Australia. All powdery mildews infecting native plants in Australia were phylogenetically closely related to species known overseas. The data indicate that Australia is a continent without native powdery mildews, and most, if not all, species have been introduced since the European colonization of the continent.

Fungal Planet description sheets: 1042-1111

Novel species of fungi described in this study include those from various countries as follows: Antarctica, Cladosporium arenosum from marine sediment sand. Argentina, Kosmimatamyces alatophylus (incl. Kosmimatamyces gen. nov.) from soil. Australia, Aspergillus banksianus, Aspergillus kumbius, Aspergillus luteorubrus, Aspergillus malvicolor and Aspergillus nanangensis from soil, Erysiphe medicaginis from leaves of Medicago polymorpha, Hymenotorrendiella communis on leaf litter of Eucalyptus bicostata, Lactifluus albopicri and Lactifluus austropiperatus on soil, Macalpinomyces collinsiae on Eriachne benthamii, Marasmius vagus on soil, Microdochium dawsoniorum from leaves of Sporobolus natalensis, Neopestalotiopsis nebuloides from leaves of Sporobolus elongatus, Pestalotiopsis etonensis from leaves of Sporobolus jacquemontii, Phytophthora personensis from soil associated with dying Grevillea mccutcheonii.Brazil, Aspergillus oxumiae from soil, Calvatia baixaverdensis on soil, Geastrum calycicoriaceum on leaf litter, Greeneria kielmeyerae on leaf spots of Kielmeyera coriacea. Chile, Phytophthora aysenensis on collar rot and stem of Aristotelia chilensis.Croatia, Mollisia gibbospora on fallen branch of Fagus sylvatica.Czech Republic, Neosetophoma hnaniceana from Buxus sempervirens.Ecuador, Exophiala frigidotolerans from soil. Estonia, Elaphomyces bucholtzii in soil. France, Venturia paralias from leaves of Euphorbia paralias.India, Cortinarius balteatoindicus and Cortinarius ulkhagarhiensis on leaf litter. Indonesia, Hymenotorrendiella indonesiana on Eucalyptus urophylla leaf litter. Italy, Penicillium taurinense from indoor chestnut mill. Malaysia, Hemileucoglossum kelabitense on soil, Satchmopsis pini on dead needles of Pinus tecunumanii.Poland, Lecanicillium praecognitum on insects’ frass. Portugal, Neodevriesia aestuarina from saline water. Republic of Korea, Gongronella namwonensis from freshwater. Russia, Candida pellucida from Exomias pellucidus, Heterocephalacria septentrionalis as endophyte from Cladonia rangiferina, Vishniacozyma phoenicis from dates fruit, Volvariella paludosa from swamp. Slovenia, Mallocybe crassivelata on soil. South Africa, Beltraniella podocarpi, Hamatocanthoscypha podocarpi, Coleophoma podocarpi and Nothoseiridium podocarpi (incl. Nothoseiridium gen. nov.) from leaves of Podocarpus latifolius, Gyrothrix encephalarti from leaves of Encephalartos sp., Paraphyton cutaneum from skin of human patient, Phacidiella alsophilae from leaves of Alsophila capensis, and Satchmopsis metrosideri on leaf litter of Metrosideros excelsa.Spain, Cladophialophora cabanerensis from soil, Cortinarius paezii on soil, Cylindrium magnoliae from leaves of Magnolia grandiflora, Trichophoma cylindrospora (incl. Trichophoma gen. nov.) from plant debris, Tuber alcaracense in calcareus soil, Tuber buendiae in calcareus soil. Thailand, Annulohypoxylon spougei on corticated wood, Poaceascoma filiforme from leaves of unknown Poaceae.UK, Dendrostoma luteum on branch lesions of Castanea sativa, Ypsilina buttingtonensis from heartwood of Quercus sp. Ukraine, Myrmecridium phragmiticola from leaves of Phragmites australis.USA, Absidia pararepens from air, Juncomyces californiensis (incl. Juncomyces gen. nov.) from leaves of Juncus effusus, Montagnula cylindrospora from a human skin sample, Muriphila oklahomaensis (incl. Muriphila gen. nov.) on outside wall of alcohol distillery, Neofabraea eucalyptorum from leaves of Eucalyptus macrandra, Diabolocovidia claustri (incl. Diabolocovidia gen. nov.) from leaves of Serenoa repens, Paecilomyces penicilliformis from air, Pseudopezicula betulae from leaves of leaf spots of Populus tremuloides. Vietnam, Diaporthe durionigena on branches of Durio zibethinus and Roridomyces pseudoirritans on rotten wood. Morphological and culture characteristics are supported by DNA barcodes.

Phylogeny and taxonomy of powdery mildew on Viburnum species

The phylogeny and taxonomy of powdery mildew on Viburnum species is evaluated and discussed. Morphological and phylogenetic analyses revealed two new species and demonstrated that Erysiphe hedwigii and E. viburni should be reduced to synonymy and are referred to herein as E. viburni. The two new species, E. viburniphila and E. pseudoviburni, previously hidden under E. viburni (including E. hedwigii), is described on the basis of European, North American, and East Asian powdery mildew collections on Viburnum edule, V. tinus, V. odoratissimum var. awabuki, and V. sieboldii. The sexual morph of E. viburniphila is similar to that of E. viburni; however, morphological differences exist in their asexual morphs. Analyses of sequences from the internal transcribed spacer (ITS) and 28S genomic regions of Erysiphe species obtained on Viburnum species (and other closely allied Eryisphe species) throughout the world reveled that E. viburniphila and E. pseudoviburni are in two different monophyletic groups that are separate from all other Erysiphe species. Erysiphe hedwigii and E. viburni on Viburnum species have often been recognized as separate species based on morphological differences in the size of their chasmothecia and the number of chasmothecial appendages. Taxonomic conclusions based on these morphological distinctions within these species are unreliable (these characters are rather variable and often have overlapping ranges). The present phylogenetic analyses suggest that E. hedwigii has to be reduced to synonymy with E. viburni. To fix the application of the species names E. hedwigii and E. viburni, epitypes have been designated for these taxa with ex-epitype sequences. Additionally, the Asian species E. miranda is phylogenetically confirmed as a species of its own, described in detail and discussed.

Fungal diversity notes 1151–1276: taxonomic and phylogenetic contributions on genera and species of fungal taxa

Fungal diversity notes is one of the important journal series of fungal taxonomy that provide detailed descriptions and illustrations of new fungal taxa, as well as providing new information of fungal taxa worldwide. This article is the 11th contribution to the fungal diversity notes series, in which 126 taxa distributed in two phyla, six classes, 24 orders and 55 families are described and illustrated. Taxa in this study were mainly collected from Italy by Erio Camporesi and also collected from China, India and Thailand, as well as in some other European, North American and South American countries. Taxa described in the present study include two new families, 12 new genera, 82 new species, five new combinations and 25 new records on new hosts and new geographical distributions as well as sexual-asexual reports. The two new families are Eriomycetaceae (Dothideomycetes, family incertae sedis) and Fasciatisporaceae (Xylariales, Sordariomycetes). The twelve new genera comprise Bhagirathimyces (Phaeosphaeriaceae), Camporesiomyces (Tubeufiaceae), Eriocamporesia (Cryphonectriaceae), Eriomyces (Eriomycetaceae), Neomonodictys (Pleurotheciaceae), Paraloratospora (Phaeosphaeriaceae), Paramonodictys (Parabambusicolaceae), Pseudoconlarium (Diaporthomycetidae, genus incertae sedis), Pseudomurilentithecium (Lentitheciaceae), Setoapiospora (Muyocopronaceae), Srinivasanomyces (Vibrisseaceae) and Xenoanthostomella (Xylariales, genera incertae sedis). The 82 new species comprise Acremonium chiangraiense, Adustochaete nivea, Angustimassarina camporesii, Bhagirathimyces himalayensis, Brunneoclavispora camporesii, Camarosporidiella camporesii, Camporesiomyces mali, Camposporium appendiculatum, Camposporium multiseptatum, Camposporium septatum, Canalisporium aquaticium, Clonostachys eriocamporesiana, Clonostachys eriocamporesii, Colletotrichum hederiicola, Coniochaeta vineae, Conioscypha verrucosa, Cortinarius ainsworthii, Cortinarius aurae, Cortinarius britannicus, Cortinarius heatherae, Cortinarius scoticus, Cortinarius subsaniosus, Cytospora fusispora, Cytospora rosigena, Diaporthe camporesii, Diaporthe nigra, Diatrypella yunnanensis, Dictyosporium muriformis, Didymella camporesii, Diutina bernali, Diutina sipiczkii, Eriocamporesia aurantia, Eriomyces heveae, Ernakulamia tanakae, Falciformispora uttaraditensis, Fasciatispora cocoes, Foliophoma camporesii, Fuscostagonospora camporesii, Helvella subtinta, Kalmusia erioi, Keissleriella camporesiana, Keissleriella camporesii, Lanspora cylindrospora, Loratospora arezzoensis, Mariannaea atlantica, Melanographium phoenicis, Montagnula camporesii, Neodidymelliopsis camporesii, Neokalmusia kunmingensis, Neoleptosporella camporesiana, Neomonodictys muriformis, Neomyrmecridium guizhouense, Neosetophoma camporesii, Paraloratospora camporesii, Paramonodictys solitarius, Periconia palmicola, Plenodomus triseptatus, Pseudocamarosporium camporesii, Pseudocercospora maetaengensis, Pseudochaetosphaeronema kunmingense, Pseudoconlarium punctiforme, Pseudodactylaria camporesiana, Pseudomurilentithecium camporesii, Pseudotetraploa rajmachiensis, Pseudotruncatella camporesii, Rhexocercosporidium senecionis, Rhytidhysteron camporesii, Rhytidhysteron erioi, Septoriella camporesii, Setoapiospora thailandica, Srinivasanomyces kangrensis, Tetraploa dwibahubeeja, Tetraploa pseudoaristata, Tetraploa thrayabahubeeja, Torula camporesii, Tremateia camporesii, Tremateia lamiacearum, Uzbekistanica pruni, Verruconis mangrovei, Wilcoxina verruculosa, Xenoanthostomella chromolaenae and Xenodidymella camporesii. The five new combinations are Camporesiomyces patagoniensis, Camporesiomyces vaccinia, Camposporium lycopodiellae, Paraloratospora gahniae and Rhexocercosporidium microsporum. The 22 new records on host and geographical distribution comprise Arthrinium marii, Ascochyta medicaginicola, Ascochyta pisi, Astrocystis bambusicola, Camposporium pellucidum, Dendryphiella phitsanulokensis, Diaporthe foeniculina, Didymella macrostoma, Diplodia mutila, Diplodia seriata, Heterosphaeria patella, Hysterobrevium constrictum, Neodidymelliopsis ranunculi, Neovaginatispora fuckelii, Nothophoma quercina, Occultibambusa bambusae, Phaeosphaeria chinensis, Pseudopestalotiopsis theae, Pyxine berteriana, Tetraploa sasicola, Torula gaodangensis and Wojnowiciella dactylidis. In addition, the sexual morphs of Dissoconium eucalypti and Phaeosphaeriopsis pseudoagavacearum are reported from Laurus nobilis and Yucca gloriosa in Italy, respectively. The holomorph of Diaporthe cynaroidis is also reported for the first time.

Erysiphedeutziicola sp. nov. (Erysiphaceae, Ascomycota), a powdery mildew species found on Deutziaparviflora (Hydrangeaceae) with unusual appendages

A powdery mildew (Erysiphales) has recently been collected on leaves of an ornamental shrub Deutziaparviflora in Baihua Mountain, Beijing, China. Microscopic examination of the chasmothecia suggested a species belonging to Erysiphesect.Erysiphe, above all due to mycelioid chasmothecial appendages, although circinate apices of the appendages were rather in favour of Erysiphesect.Uncinula, which is a fairly rare combination of appendage characteristics in Erysiphe. Phylogenetic analyses of ITS and 28S rDNA sequences demonstrated that the two examined powdery mildew collections on D.parviflora clustered together as an independent lineage within Erysiphe with 100% bootstrap support, representing a species of its own, which is phylogenetically allied to, but clearly distinct from Erysiphedeutziae and, in addition, morphologically quite different from all known Erysiphe species on hosts belonging to the Hydrangeaceae. The new species on D.parviflora is described as Erysiphedeutziicola.

Development of Genomic Resources for the Powdery Mildew, Erysiphe pulchra

Powdery mildews (PMs) are important plant pathogens causing widespread damage. Here, we report the first draft genome of Erysiphe pulchra, the causative agent of PM of flowering dogwood, Cornus florida. The assembled genome was 63.5 Mbp and resulted in formation of 19,442 contigs (N50 = 11,686 bp) that contained an estimated 6,860 genes with a genome coverage of 62×. We found 102 candidate secreted effector proteins (CSEPs) in E. pulchra similar to E. necator genes that are potentially involved in disease development. This draft genome is an initial step for understanding the evolutionary history of the PMs and will also provide insight into evolutionary strategies that led to the wide host expansion and environmental adaptations so effectively employed by the PM lineages.

Further Support of Conspecificity of Oak and Mango Powdery Mildew and First Report of Erysiphe quercicola and Erysiphe alphitoides on Mango in Mainland Europe

Mango leaves and inflorescences infected by powdery mildew in southern Spain were analyzed using multigene sequencing (ITS + 4 single-copy coding genes) to identify the causal agent. Erysiphe quercicola was detected in 97% out of 140 samples, collected in six different orchards in the Malaga region. Among these, a small proportion also yielded E. alphitoides (8% of all samples) and E. alphitoides was found alone in 3% of samples. A phylogenetic approach was completed by cross inoculations between oak and mango, which led to typical symptoms, supporting the conspecificity of oak and mango powdery mildews. To our knowledge, this is the first report of E. quercicola and E. alphitoides causing powdery mildew on mango trees in mainland Spain, and thus mainland Europe, based on unequivocal phylogenetic and biological evidence. Our study thus confirmed the broad host range of both E. quercicola and E. alphitoides. These results have practical implications in terms of the demonstrated ability for host range expansion in powdery mildews. They also open interesting prospects to the elucidation of molecular mechanisms underlying the ability to infect single versus multiple and unrelated host plants since these two closely related powdery mildew species belong to a small clade with both generalist and specialist powdery mildews.

Can Oak Powdery Mildew Severity be Explained by Indirect Effects of Climate on the Composition of the Erysiphe Pathogenic Complex?

Coinfection by several pathogens is increasingly recognized as an important feature in the epidemiology and evolution of plant fungal pathogens. Oak mildew is induced by two closely related Erysiphe invasive species (Erysiphe alphitoides and E. quercicola) which differ in their mode of overwintering. We investigated how climate influences the co-occurrence of the two species in oak young stands and whether this is important for the disease epidemiology. We studied the frequency of flag-shoots (i.e., shoots developing from infected buds, usually associated with E. quercicola) in 95 oak regenerations over a 6-year period. Additionally, in 2012 and 2013, the oak mildew severity and the two Erysiphe spp. relative frequencies were determined in both spring and autumn in 51 regenerations and 43 1-year-old plantations of oaks. Both the frequency of flag-shoots and the proportion of Erysiphe lesions with E. quercicola presence were related to climate. We showed that survival of E. quercicola was improved after mild winters, with increase of both the flag-shoot frequency and the proportion of Erysiphe lesions with E. quercicola presence in spring. However, disease severity was not related to any complementarity effect between the two Erysiphe spp. causing oak powdery mildew. By contrast, increased E. alphitoides prevalence in spring was associated with higher oak mildew severity in autumn. Our results point out the critical role of between-season transmission and primary inoculum to explain disease dynamics which could be significant in a climate-warming context.

A new putative alphapartitivirus recovered from the powdery mildew fungus Erysiphe palczewskii

Two double-stranded RNAs (dsRNA) likely representing the genome of a novel alphapartitivirus which we provisionally named Erysiphe palczewskii alphapartitivirus 1 (EpV1) were recovered from the powdery mildew fungus E. palczewskii infecting Sophora japonica in Jingzhou, Hubei province of China. The two dsRNAs, 1955 (dsRNA1) and 1917 (dsRNA2) bp in size, respectively, each contains a single open reading frame (ORF) encoding a 585- and 528-aa protein, respectively. The 585-aa protein contains a conserved RNA-dependent RNA polymerase (RdRp) domain and shows significant homology to RdRps of approved or putative partitiviruses, particularly those belonging to the genus Alphapartitivirus. However, it shares an aa sequence identity lower than 80% with its closest relative, the RdRp of the putative alphapartitivirus Grapevine partitivirus, and lower than 60% with the RdRps of other partitiviruses. In a phylogenetic tree constructed with RdRp aa sequences of selected partitiviruses, the putative virus EpV1 clustered with Grapevine partitivirus and formed a well-supported monophyletic clade with known or putative alphapartitiviruses.

Reprint of "Sequence and phylogenetic analyses of novel totivirus-like double-stranded RNAs from field-collected powdery mildew fungi"

The identification of mycoviruses contributes greatly to understanding of the diversity and evolutionary aspects of viruses. Powdery mildew fungi are important and widely studied obligate phytopathogenic agents, but there has been no report on mycoviruses infecting these fungi. In this study, we used a deep sequencing approach to analyze the double-stranded RNA (dsRNA) segments isolated from field-collected samples of powdery mildew fungus-infected red clover plants in Japan. Database searches identified the presence of at least ten totivirus (genus Totivirus)-like sequences, termed red clover powdery mildew-associated totiviruses (RPaTVs). The majority of these sequences shared moderate amino acid sequence identity with each other (<44%) and with other known totiviruses (<59%). Nine of these identified sequences (RPaTV1a, 1b and 2-8) resembled the genome of the prototype totivirus, Saccharomyces cerevisiae virus-L-A (ScV-L-A) in that they contained two overlapping open reading frames (ORFs) encoding a putative coat protein (CP) and an RNA dependent RNA polymerase (RdRp), while one sequence (RPaTV9) showed similarity to another totivirus, Ustilago maydis virus H1 (UmV-H1) that encodes a single polyprotein (CP-RdRp fusion). Similar to yeast totiviruses, each ScV-L-A-like RPaTV contains a -1 ribosomal frameshift site downstream of a predicted pseudoknot structure in the overlapping region of these ORFs, suggesting that the RdRp is translated as a CP-RdRp fusion. Moreover, several ScV-L-A-like sequences were also found by searches of the transcriptome shotgun assembly (TSA) libraries from rust fungi, plants and insects. Phylogenetic analyses show that nine ScV-L-A-like RPaTVs along with ScV-L-A-like sequences derived from TSA libraries are clustered with most established members of the genus Totivirus, while one RPaTV forms a new distinct clade with UmV-H1, possibly establishing an additional genus in the family. Taken together, our results indicate the presence of diverse, novel totiviruses in the powdery mildew fungus populations infecting red clover plants in the field.

Early evolution of endoparasitic group in powdery mildews: molecular phylogeny suggests missing link between Phyllactinia and Leveillula

Of the 17 genera of the Erysiphaceae, only four genera (viz. Leveillula, Phyllactinia, Pleochaeta and Queirozia) exhibit (partly) endoparasitism. To investigate early evolution of this endoparasitic nature, we performed molecular phylogenetic analyses of powdery mildews belonging to the tribe Phyllactinieae collected in North and South America. The most ancestral taxa in the tribe Phyllactinieae belong to the Pleochaeta/Queirozia group, from which the genus Phyllactinia was derived. Finally, the truly endoparasitic genus Leveillula emerged from a part of Phyllactinia The present study showed clear evolutional polarity in the powdery mildews concerned (that is, partly endoparasitic group evolved from ectoparasitic group) and then a truly endoparasitic group emerged from a partly endoparasitic group. In addition, a group with distinctly dimorphic conidia proved to be basal in the Phyllactinieae, and a group without distinctly dimorphic conidia was derived from that group. The present analyses clearly showed that Leveillula derived from a part of the "Basal Phyllactinia group". However, all sister taxa to Leveillula were distributed in North and South America. Because the putative geographic origin of Leveillula is assumed to be Central and Western Asia or the Mediterranean region, we postulate a missing link during the evolution of Leveillula from Phyllactinia Based on the present phylogenetic studies and the new rules of the International Code of Nomenclature for algae, fungi, and plants (McNeill et al. 2012), the following new species and taxonomic re-allocations are proposed: Phyllactinia bougainvilleae sp. nov., Ph. caricae comb. nov., Ph. caricicola comb. nov., Ph. durantae comb. nov., Ph. leveilluloides sp. nov., Ph. obclavata comb. nov., and Ph. papayae comb. nov.

Sequence and phylogenetic analyses of novel totivirus-like double-stranded RNAs from field-collected powdery mildew fungi

The identification of mycoviruses contributes greatly to understanding of the diversity and evolutionary aspects of viruses. Powdery mildew fungi are important and widely studied obligate phytopathogenic agents, but there has been no report on mycoviruses infecting these fungi. In this study, we used a deep sequencing approach to analyze the double-stranded RNA (dsRNA) segments isolated from field-collected samples of powdery mildew fungus-infected red clover plants in Japan. Database searches identified the presence of at least ten totivirus (genus Totivirus)-like sequences, termed red clover powdery mildew-associated totiviruses (RPaTVs). The majority of these sequences shared moderate amino acid sequence identity with each other (<44%) and with other known totiviruses (<59%). Nine of these identified sequences (RPaTV1a, 1b and 2-8) resembled the genome of the prototype totivirus, Saccharomyces cerevisiae virus-L-A (ScV-L-A) in that they contained two overlapping open reading frames (ORFs) encoding a putative coat protein (CP) and an RNA dependent RNA polymerase (RdRp), while one sequence (RPaTV9) showed similarity to another totivirus, Ustilago maydis virus H1 (UmV-H1) that encodes a single polyprotein (CP-RdRp fusion). Similar to yeast totiviruses, each ScV-L-A-like RPaTV contains a -1 ribosomal frameshift site downstream of a predicted pseudoknot structure in the overlapping region of these ORFs, suggesting that the RdRp is translated as a CP-RdRp fusion. Moreover, several ScV-L-A-like sequences were also found by searches of the transcriptome shotgun assembly (TSA) libraries from rust fungi, plants and insects. Phylogenetic analyses show that nine ScV-L-A-like RPaTVs along with ScV-L-A-like sequences derived from TSA libraries are clustered with most established members of the genus Totivirus, while one RPaTV forms a new distinct clade with UmV-H1, possibly establishing an additional genus in the family. Taken together, our results indicate the presence of diverse, novel totiviruses in the powdery mildew fungus populations infecting red clover plants in the field.