Colletotrichum species causing Glomerella leaf spot and apple bitter rot in the southeastern United States exhibit disparities in relative frequency, morphological phenotype, and QoI sensitivity.

Glomerella leaf spot (GLS), Glomerella fruit rot (GFR) and apple bitter rot (ABR), caused by Colletotrichum spp. are amongst the most devastating apple diseases in the southeastern United States. While several species have been identified as causal pathogens of GLS, GFR, and ABR, their relative frequency and fungicide sensitivity status in the southeastern U.S. is unknown. In total, 381 Colletotrichum isolates were obtained from symptomatic leaves and fruit from 18 conventionally managed apple orchards and two baseline populations in western North Carolina and Georgia in 2016 and 2017. Multilocus DNA sequence analysis revealed that C. chrysophilum was the predominant cause of GLS and GFR, and C. fioriniae was the causal agent of ABR. Baseline and commercial populations of Colletotrichum spp. were evaluated for sensitivity to pyraclostrobin and trifloxystrobin and no statistical differences in sensitivity between the two species were observed for conidial germination. However, EC50 values were significantly lower for C. fioriniae compared to C. chrysophilum for both fungicides regarding mycelial inhibition. Isolates recovered from commercial orchards revealed that 5 populations of C. chrysophilum and 1 population of C. fioriniae had reduced sensitivity to trifloxystrobin, and 1 C. fioriniae population had reduced sensitivity to pyraclostrobin via conidial germination assays. The cytb gene for 27 isolates of C. fioriniae, C. chrysophilum, and C. fructicola with different QoI sensitivities revealed the G143A mutation in a single isolate of C. chrysophilum with insensitivity to both fungicides. Results of these studies suggest that two Colletotrichum spp. predominantly cause GLS and ABR in the southeastern U.S. and that a reduction in sensitivity to some QoI fungicides may be responsible for control failures. This study also provides basis for monitoring shifts in QoI sensitivity in Colletotrichum spp. causing disease on apple in the southeastern U.S.

Testing the incremental effectiveness of pay-for-performance to improve implementation of a motivational interviewing brief intervention for substance use disorders in HIV settings: Results of a parallel cluster-randomized type 3 hybrid trial.

Background: Substance use disorders (SUDs) have a serious adverse impact on the physical and mental well-being of people with HIV. Previously, using a 39-site dual-randomized type 2 hybrid trial design, findings from the Substance Abuse Treatment to HIV Care Project supported the Implementation and Sustainment Facilitation (ISF) strategy to improve implementation and effectiveness of a motivational interviewing brief intervention (MIBI) for SUD within HIV service settings across the United States (US). Building on this trial, this parallel cluster-randomized type 3 hybrid trial aimed to test the incremental effectiveness of a pay-for-performance (P4P), a form of the "alter incentive/allowance structures" strategy. Methods: Twenty-six HIV service organizations, their staff participants (N=87), and their client participants (N=341) were cluster-randomized to one of two implementation conditions. The control condition included staff-focused training, feedback, and consultation (TFC) and team-focused implementation and sustainment (ISF). The experimental condition included TFC+ISF as well as P4P (TFC+ISF+P4P). P4P used financial incentives to reward MIBI implementation (US$10 per MIBI delivered) and MIBI implementation at or above a pre-defined level of quality (US$10 per demonstration). In addition to these outcomes, past 4-week changes/reductions in client participant's days of primary substance use and anxiety symptoms were examined. Results: The addition of P4P had a large and significant effect on the number of MIBIs implemented (d=1.30, p<.05) and reduction in anxiety (d=-1.54), but there was no impact on days of substance use. P4P had large effects on MIBI quality (d=1.24) and MIBI implementation effectiveness (d=1.28), but these were not significant (p<.10). Conclusions: P4P is a form of the "alter incentive/allowance structures" strategy. Its function is to reward the implementation of a clinical innovation. Rewarding implementation is consistent with the theory of implementation effectiveness, which suggests implementation climate (i.e., the extent to which implementation is expected, supported, and rewarded) is a key antecedent of implementation effectiveness (i.e., the consistency and quality of implementation). We found that P4P had a significant, positive impact on MIBI implementation in HIV service settings, but client-level outcomes were mixed. Future research should examine the effectiveness of the P4P strategy to improve implementation and sustainment of other evidence-based innovations. Trial registration: ClinicalTrials.gov: NCT04687917. Registered 12/18/2020.

Peziza nivalis and relatives-spring fungi of wide distribution.

Several members of the genus Peziza sensu stricto occur at the edge of melting snow. These nivicolous species have been widely reported in the Northern Hemisphere and are also known from Australia and New Zealand. We have used 16 specimens from North America and Australia to study morphology and to perform DNA sequencing. In sequence analyses, we have used ITS1 and ITS2 (internal transcribed spacers), 28S, RPB2 (RNA polymerase II gene), and two genes new to these studies, GAPDH (glyceraldehyde-3-phosphate dehydrogenase) and HSP90 (heat shock protein 90). Although not all regions are available for all samples, we have recognized the following species: Peziza heimii, P. nivalis, and P. nivis. Phylogenetic analyses were done using ITS alone; combined ITS1-5.8S-ITS2, 28S, and RPB2; ITS, and 28S, RPB2, GAPDH, and HSP90. Even with this augmented set of genes and despite their widespread occurrence in North America, Europe, Australia, and New Zealand, we have not definitively distinguished species within this group. To assess these results, pairwise homoplasy index (PHI) analysis was employed. This showed evidence of recombination among the samples of P. nivalis and further supports the view of P. nivalis as a monophyletic cosmopolitan species. As part of this study, we also examined the variation in ITS copies in P. echinospora, for which a genome is available.

First Report of Powdery mildew Caused by Golovinomyces ambrosiae on Verbena × hybrida in the U.S.

Verbena × hybrida, also known as common garden verbena, has an important ornamental value for their wide range of flower colors and for attracting hummingbirds and butterflies. During the winter of 2021-2022 (December through February), more than 50% pot-grown verbena plants showed symptoms of powdery mildew in a field trial at a Syngenta Crop Protection research facility in Vero Beach, FL. Symptoms were characterized by the development of white, superficial mycelium on the adaxial side of leaves which, eventually, progressed to covering the whole surface of leaves, causing leaf discoloration, shoot distortion, and eventual plant death. Morphological characterization was carried out by observing powdery mildew colonies under the microscope. This powdery mildew forms dense patches of white mycelia, mainly on the adaxial leaf surfaces. The mycelium was a mat of hyphae with septa. Conidiophores were erect. The foot cells were straight, followed by one to three short cells bearing short chains of up to four conidia. The conidia were hyaline and ellipsoidal to doliiform in shape. Conidial germination is of the Eudoidium type. The conidia ranged from 25 to 32 µm long by 12 to 16 µm wide. The length to width ratio ranged between 1.6 and 2.3, but most were between 2.0 and 2.2. This is further verification of its identity as Golovinomyces ambrosiae and not Golovinomyces latisporus, because the length to width ratio of the latter species is consistently less than 2.0 (Qiu et al. 2020). Chasmothecia were not observed. Additionally, the ITS, GAPDH, and IGS regions were sequenced using the primer pairs ITS4/ITS5 (White et al. 1990), PMGAPDH1/PMGAPDH3R (Bradshaw et al. 2022a), and IGS-12a/NS1R (Carbone and Kohn 1999), respectively. The ITS region (GenBank number=PP924119) cannot distinguish between G. latisporus and G. ambrosiae and as such aligned 100% with both species on GenBank. However, the GAPDH and IGS regions can be used to distinguish G. ambrosiae from G. latisporus (Bradshaw et al. 2022b). The GAPDH (GenBank number=PP931995) and IGS (GenBank number=PP931996) regions aligned 100% with multiple G. ambrosiae sequences from GenBank including ON360708 and MK452567, respectively. The specimen was deposited in the Larry F. Grand Mycological Herbarium (NCSLG 24479). To confirm pathogenicity, 'Tuscany® Pink Picotee' and 'Quartz XP Violet with Eye' plugs were transplanted to 10-cm diameter pots containing ProMix potting mix and maintained in a greenhouse (± 26 °C). Inoculation was carried out 21 days after transplanting by touching infected leaves onto healthy leaves of 15 disease-free plants of each variety. Fifteen non-inoculated plants of each variety were used as controls. Typical powdery mildew symptoms and signs were first observed ten days after inoculation and the pathogen was more aggressive on 'Tuscany® Pink Picotee'. Symptoms were not observed on non-inoculated plants. The fungus was morphologically identical to the one originally recovered from infected plants in the field. There have been many reports of Golovinomyces spp. affecting Verbena spp. worldwide; however, this is the first report of G. ambrosiae causing powdery mildew on Verbena × hybrida in the U.S. (Braun and Cook, 2012, Choi et al., 2021; Bradshaw et al. 2024). Powdery mildews reduce plant quality and decreases the aesthetics value of infected plants, causing great losses to the ornamental industry. Correct identification of the causal agent is crucial to recommend appropriate control methods, as they may differ according to the pathogen species.

Paraneoplastic Calmodulin Kinase-Like Vesicle-Associated Protein (CAMKV) Autoimmune Encephalitis.

OBJECTIVES: To report an autoimmune paraneoplastic encephalitis characterized by immunoglobulin G (IgG) antibody targeting synaptic protein calmodulin kinase-like vesicle-associated (CAMKV). METHODS: Serum and cerebrospinal fluid (CSF) samples harboring unclassified antibodies on murine brain-based indirect immunofluorescence assay (IFA) were screened by human protein microarray. In 5 patients with identical cerebral IFA staining, CAMKV was identified as top-ranking candidate antigen. Western blots, confocal microscopy, immune-absorption, and mass spectrometry were performed to substantiate CAMKV specificity. Recombinant CAMKV-specific assays (cell-based [fixed and live] and Western blot) provided additional confirmation. RESULTS: Of 5 CAMKV-IgG positive patients, 3 were women (median symptom-onset age was 59 years; range, 53-74). Encephalitis-onset was subacute (4) or acute (1) and manifested with: altered mental status (all), seizures (4), hyperkinetic movements (4), psychiatric features (3), memory loss (2), and insomnia (2). Paraclinical testing revealed CSF lymphocytic pleocytosis (all 4 tested), electrographic seizures (3 of 4 tested), and striking MRI abnormalities in all (mesial temporal lobe T2 hyperintensities [all patients], caudate head T2 hyperintensities [3], and cortical diffusion weighted hyperintensities [2]). None had post-gadolinium enhancement. Cancers were uterine adenocarcinoma (3 patients: poorly differentiated or neuroendocrine-differentiated in 2, both demonstrated CAMKV immunoreactivity), bladder urothelial carcinoma (1), and non-Hodgkin lymphoma (1). Two patients developed encephalitis following immune checkpoint inhibitor cancer therapy (atezolizumab [1], pembrolizumab [1]). All treated patients (4) demonstrated an initial response to immunotherapy (corticosteroids [4], IVIG [2]), though 3 died from cancer. INTERPRETATION: CAMKV-IgG is a biomarker of immunotherapy-responsive paraneoplastic encephalitis with temporal and extratemporal features and uterine cancer as a prominent oncologic association. ANN NEUROL 2024;96:21-33.

An In-Depth Evaluation of Powdery Mildew Hosts Reveals One of the World's Most Common and Widespread Groups of Fungal Plant Pathogens.

Powdery mildews are highly destructive fungal plant pathogens that have a significant economic impact on both agricultural and ecological systems worldwide. The intricate relationship between powdery mildews and their host plants has led to cospeciation. In this study, we conducted an extensive evaluation of powdery mildew hosts to provide an updated understanding of the host ranges and distributions of these fungi. The "United States National Fungus Collections Fungus-Host Dataset" is the primary source of information for our analyses. The analysis of the dataset demonstrated the worldwide prevalence of powdery mildews; the data contained over 72,000 reports of powdery mildews, representing ∼8.7% of all host-fungal records. We have updated the taxonomy and nomenclature of powdery mildews. In total, powdery mildews infect ∼10,125 host taxa belonging to 205 families of flowering plants, which accounts for 1,970 genera in 200 countries across six continents. Furthermore, we estimate that powdery mildews infect approximately 2.9% of described angiosperm species. Our study underscores the need for regular updates on powdery mildew host information due to the continuously evolving taxonomy and the discovery of new host taxa. Since 1986, we estimate an additional 1,866 host taxa, 353 genera, and 36 families have been reported. Additionally, the identification of powdery mildew hosts provides valuable insights into the coevolutionary dynamics between the fungi and their plant hosts. Overall, this updated list provides valuable insights into the taxonomy and geographic distribution of powdery mildew species, which builds upon the previous work of Amano in 1986. Discerning the geographic spread and host range of economically significant plant pathogens is vital for biosecurity measures and identifying the origins and expansion of potentially harmful pathogens.

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.

Avirulent Isolates of Penicillium chrysogenum to Control the Blue Mold of Apple Caused by P. expansum.

Blue mold is an economically significant postharvest disease of pome fruit that is primarily caused by Penicillium expansum. To manage this disease and sustain product quality, novel decay intervention strategies are needed that also maintain long-term efficacy. Biocontrol organisms and natural products are promising tools for managing postharvest diseases. Here, two Penicillium chrysogenum isolates, 404 and 413, were investigated as potential biocontrol agents against P. expansum in apple. Notably, 404 and 413 were non-pathogenic in apple, yet they grew vigorously in vitro when compared to the highly aggressive P. expansum R19 and Pe21 isolates. Whole-genome sequencing and species-specific barcoding identified both strains as P. chrysogenum. Each P. chrysogenum strain was inoculated in apple with the subsequent co-inoculation of R19 or Pe21 simultaneously, 3, or 7 days after prior inoculation with 404 or 413. The co-inoculation of these isolates showed reduced decay incidence and severity, with the most significant reduction from the longer establishment of P. chrysogenum. In vitro growth showed no antagonism between species, further suggesting competitive niche colonization as the mode of action for decay reduction. Both P. chrysogenum isolates had incomplete patulin gene clusters but tolerated patulin treatment. Finally, hygromycin resistance was observed for both P. chrysogenum isolates, yet they are not multiresistant to apple postharvest fungicides. Overall, we demonstrate the translative potential of P. chrysogenum to serve as an effective biocontrol agent against blue mold decay in apples, pending practical optimization and formulation.

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.

Extensive intragenomic variation in the internal transcribed spacer region of fungi.

Fungi are among the most biodiverse organisms in the world. Accurate species identification is imperative for studies on fungal ecology and evolution. The internal transcribed spacer (ITS) rDNA region has been widely accepted as the universal barcode for fungi. However, several recent studies have uncovered intragenomic sequence variation within the ITS in multiple fungal species. Here, we mined the genome of 2414 fungal species to determine the prevalence of intragenomic variation and found that the genomes of 641 species, about one-quarter of the 2414 species examined, contained multiple ITS copies. Of those 641 species, 419 (∼65%) contained variation among copies revealing that intragenomic variation is common in fungi. We proceeded to show how these copies could result in the erroneous description of hundreds of fungal species and skew studies evaluating environmental DNA (eDNA) especially when making diversity estimates. Additionally, many genomes were found to be contaminated, especially those of unculturable fungi.

Phylogeny and taxonomy of the genera of Erysiphaceae, part 3: Cystotheca.

This contribution is part of a series devoted to the phylogeny and taxonomy of powdery mildews, with an emphasis on North American taxa. An overview of Cystotheca species is given, including references to ex-type sequences or, if unavailable, proposals for representative reference sequences for phylogenetic-taxonomic purposes. The new species C. mexicana is described, based on Mexican collections on Quercus glaucoides × Quercus microphylla and Quercus liebmannii × Q. microphylla. Cystotheca lanestris is reported for the first time worldwide on Quercus laceyi (Collected in Mexico) and on Q. toumeyi (collected in Arizona, USA). Cystotheca lanestris on Q. agrifolia and on Q. cerris is reported for the first time in Mexico. Epitypes with ex-epitype sequences are designated for Cystotheca wrightii, Lanomyces tjibodensis (= C. tjibodensis), Sphaerotheca kusanoi, and S. lanestris (C. lanestris).

Genetic time traveling: sequencing old herbarium specimens, including the oldest herbarium specimen sequenced from kingdom Fungi, reveals the population structure of an agriculturally significant rust.

Sequencing herbarium specimens can be instrumental in answering ecological, evolutionary, and taxonomic inquiries. We developed a protocol for sequencing herbarium specimens of rust fungi (Pucciniales) and proceeded to sequence specimens ranging from 4 to 211 yr old from five different genera. We then obtained sequences from an economically important biological control agent, Puccinia suaveolens, to highlight the potential of sequencing herbarium specimens in an ecological sense and to evaluate the following hypotheses: (1) The population structure of a plant pathogen changes over time, and (2) introduced pathogens are more diverse in their native range. Our efforts resulted in sequences from 87 herbarium specimens that revealed a high level of diversity with a population structure that exhibited spatial-temporal patterns. The specimens sequenced from Europe showed more diversity than the ones from North America, uncovering an invasion pattern likely related to its European native host in North America. Additionally, to the best of our knowledge, the specimen from France collected in c. 1811 is the oldest herbarium specimen sequenced from kingdom Fungi. In conclusion, sequencing old herbarium specimens is an important tool that can be extrapolated to better understand plant-microbe evolution and to evaluate old type specimens to solidify the taxonomy of plant pathogenic fungi.

Testing the incremental effectiveness of pay-for-performance to improve implementation of a motivational interviewing brief intervention for substance use disorders in HIV settings: Results of a cluster-randomized type 3 hybrid trial.

Background: Substance use disorders (SUDs) have a serious adverse impact on people living with HIV. Previously, using a 39-site dual-randomized type 2 hybrid trial design, findings from the Substance Abuse Treatment to HIV Care Project supported the Implementation and Sustainment Facilitation (ISF) strategy to improve implementation and effectiveness of a motivational interviewing brief intervention (MIBI) for SUD within HIV service settings across the United States (US). Building on this trial, this cluster-randomized type 3 hybrid trial aimed to test the incremental effectiveness of a pay-for-performance (P4P), a form of the "alter incentive/allowance structures" strategy. Methods: Twenty-six HIV service organizations, their staff participants (N=87), and their client participants (N=341) were cluster-randomized to one of two implementation conditions. The control condition included staff-focused training, feedback, and consultation (TFC) and team-focused implementation and sustainment (ISF). The experimental condition included TFC+ISF as well as P4P (TFC+ISF+P4P). P4P used financial incentives to reward MIBI implementation (US$10 per MIBI delivered) and MIBI implementation at or above a pre-defined level of quality (US$10 per demonstration). In addition to these outcomes, past 4-week changes/reductions in client participant's days of primary substance use and anxiety symptoms were examined. Results: The addition of P4P had a large and significant effect on the number of MIBIs implemented (d=1.30, p<.05) and reduction in anxiety (d=-1.54), but there was no impact on days of substance use. P4P had large effects on MIBI quality (d=1.24) and MIBI implementation effectiveness (d=1.28), but these were not significant (p<.10). Conclusions: P4P is a form of the "alter incentive/allowance structures" strategy Its function is to reward the implementation of a clinical innovation. Rewarding implementation is consistent with the theory of implementation effectiveness, which suggests implementation climate (i.e., the extent to which implementation is expected, supported, and rewarded) is a key antecedent of implementation effectiveness (i.e., the consistency and quality of implementation). We found that P4P had a significant, positive impact on MIBI implementation in HIV service settings, but client-level outcomes were mixed. Future research should examine the cost-effectiveness of this strategy, as well as to examine the effectiveness of P4P to improve the implementation of other evidence-based innovations. Trial registration: ClinicalTrials.gov: NCT04687917. Registered 12/18/2020.

Comparative Penicillium spp. Transcriptomics: Conserved Pathways and Processes Revealed in Ungerminated Conidia and during Postharvest Apple Fruit Decay.

Blue mold, caused by Penicillium spp., is an impactful postharvest disease resulting in significant economic losses due to reduced pome fruit quality and mycotoxin contamination. Using two Penicillium species with different levels of aggressiveness, transcriptomics were implemented in order to identify genes expressed during apple fruit decay and loci expressed in ungerminated conidia. Total RNA was isolated from ungerminated conidia and decayed apple fruit infected with P. expansum R19 or P. polonicum RS1. There were 2442 differentially expressed genes (DEGs) between the R19 and RS1 in apple. Comparisons within species between apple and conidia revealed 4404 DEGs for R19 and 2935 for RS1, respectively. Gene ontology (GO) analysis revealed differential regulation in fungal transport and metabolism genes during decay, suggesting a flux in nutrient acquisition and detoxification strategies. In R19, the oxidoreductase GO category comprised 20% of all DEG groups in apple verses conidia. Ungerminated conidia from both species showed DEGs encoding the glyoxylate shunt and beta-oxidation, specifying the earliest metabolic requirements for germination. This is the first study to identify pre-loaded transcripts in conidia from blue mold fungi, reveal unique genes between species expressed during apple decay, and show the expression dynamics of known fungal virulence factors. These findings will enable development of targeted approaches for blue mold abatement strategies.

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.

Phylogeny and taxonomy of the genera of Erysiphaceae, part 2: Neoerysiphe.

The second contribution to a new series devoted to the phylogeny and taxonomy of powdery mildews is presented. An overview of Neoerysiphe species is given, including references to ex-type sequences or, if unavailable, representative reference sequences for phylogenetic-taxonomic purposes are provided. The new species N. stachydis is described, and Striatoidium jaborosae is reduced to synonymy with Neoerysiphe macquii. Epitypes with ex-epitype sequences are designated for Alphitomorpha ballotae, A. labiatarum, Erysiphe galii, E. chelones, and E. galeopsidis. Based on phylogenetic analyses, it has been demonstrated that Neoerysiphe cumminsiana is confined to its type host, Roldana hartwegii (= Senecio seemannii), and other North and South American parasites on Asteraceae hosts, previously assigned to this species, pertain to N. macquii. The first record of N. macquii from Europe (Germany) on cultivated Bidens aurea was confirmed by sequencing. Sequence analysis of type material of N. rubiae reveals that this species should be excluded from Neoerysiphe; however, the true affinity of this taxon is not yet clear.

Phylogeny and taxonomy of Erysiphe spp. on Rhododendron, with a special emphasis on North American species.

The genus Rhododendron comprises over 1000 evergreen and deciduous species. In the Pacific Northwest Coast region of North America (PNWC), powdery mildews infecting deciduous Rhododendron spp. are well documented but less so on evergreen Rhododendron spp. Infections of both groups of hosts historically have been attributed to Erysiphe azaleae or E. vaccinii. No formal characterizations of powdery mildew fungi infecting either deciduous or evergreen Rhododendron spp. in the PNWC have been completed. The objectives of this study were to identify the powdery mildew pathogens infecting evergreen Rhododendron spp. in the PNWC and to assess the phylogenetic position of these fungi within the Erysiphaceae. To ascertain valid taxonomic conclusions, and to determine whether potential introductions of exotic Rhododendron powdery mildews in North America have occurred, it was necessary to put the new North American phylogenetic data into a worldwide context. Therefore, available phylogenetic data from all Erysiphe spp. on Rhododendron have been included in our analyses.Based on analyses of numerous new internal transcribed spacer (ITS) and 28S rDNA sequences and already available sequences deposited in GenBank retrieved from evergreen and deciduous Rhododendron spp., the following Erysiphe spp. could be phylogenetically confirmed (all belonging to Erysiphe sect. Microsphaera): Erysiphe azaleae nom. cons. (Oidium ericinum could be verified as a synonym), E. digitata (holotype sequenced), E. izuensis, and E. vaccinii. Erysiphe azaleae and E. vaccinii are epitypified with sequenced specimens, and an ex-neotype sequence has been obtained for Oidium ericinum. Erysiphe rhododendri (Erysiphe sect. Erysiphe), only known from two collections in India (Himalayan region), was not available for phylogentic analyses.

More than a Virulence Factor: Patulin Is a Non-Host-Specific Toxin that Inhibits Postharvest Phytopathogens and Requires Efflux for Penicillium Tolerance.

Mycotoxin contamination is a leading cause of food spoilage and waste on a global scale. Patulin, a mycotoxin produced by Penicillium spp. during postharvest pome fruit decay, causes acute and chronic effects in humans, withstands pasteurization, and is not eliminated by fermentation. While much is known about the impact of patulin on human health, there are significant knowledge gaps concerning the effect of patulin during postharvest fruit-pathogen interactions. Application of patulin on six apple cultivars reproduced some blue mold symptoms that were cultivar-independent and dose-dependent. Identical symptoms were also observed in pear and mandarin orange. Six Penicillium isolates exposed to exogenous patulin exhibited delayed germination after 24 h, yet all produced viable colonies in 7 days. However, four common postharvest phytopathogenic fungi were completely inhibited by patulin during conidial germination and growth, suggesting the toxin is important for Penicillium to dominate the postharvest niche. Using clorgyline, a broad-spectrum efflux pump inhibitor, we demonstrated that efflux plays a role in Penicillium auto-resistance to patulin during conidial germination. The work presented here contributes new knowledge of patulin auto-resistance, its mode of action, and inhibitory role in fungal-fungal interactions. Our findings provide a solid foundation to develop toxin and decay mitigation approaches.

Phylogeny and taxonomy of Erysiphe berberidis (s. lat.) revisited.

Phylogenetic and morphological analyses have been conducted on powdery mildew specimens on different Berberis and Mahonia spp. from Asia, Europe and North America. The present study showed that collections of Erysiphe berberidis exhibit a high degree of morphological plasticity of the sexual morph, in contrast to their morphologically, rather uniform, asexual morph. In phylogenetic tree, all sequences cluster in a large strongly supported clade, without any indication and support for further differentiation into cryptic species. There are three morphological types within E. berberidis s. lat. that contain consistent differences. Until future multi-locus analyses will be available, we prefer to treat these 'morphological types' as varieties. These include Erysiphe berberidis var. berberidis, E. berberidis var. asiatica, and E. berberidis var. dimorpha comb. nov. (≡ Microsphaera berberidis var. dimorpha, M. berberidicola, and M. multappendicis). To fix the application of species name E. berberidis, an appropriate epitype was designated, with an ITS sequences.

Phylogeny and taxonomy of powdery mildew caused by Erysiphe species on Lupinus hosts.

The genus Lupinus (Fabaceae) consists of over 250 plant species located throughout the world. Powdery mildew, caused by Erysiphe species, is a common disease infecting these ecologically, ornamentally, and agriculturally important plants. In the present work, we conducted phylogenetic and taxonomic analyses on Erysiphe species colonizing hosts of the leguminous genus Lupinus, using sequences from the internal transcribed spacer (ITS) and 28S genomic regions. Powdery mildews of the genus Erysiphe on Fabaceae are taxonomically intricate and challenging. Therefore, it is necessary to phylogenetically analyze the DNA retrieved from powdery mildew on lupines in a broad context that includes common and allied powdery mildew species that occur on a range of leguminous plants such as Erysiphe astragali, E. baeumleri, E. pisi, and E. trifoliorum. A new species Erysiphe lupini, found in the USA on Lupinus lepidus, L. polyphyllus, and Lupinus sp., is described. Additionally, Erysiphe intermedia (≡ Microsphaera trifolii var. intermedia) has been confirmed as a North American lupine powdery mildew that is a sister species to E. astragali on Astragalus spp. European Erysiphe collections on lupines were often referred to as E. intermedia, but our analyses have shown that they pertain to E. trifoliorum. The E. trifoliorum clade is composed of several species (i.e. E. baeumleri, E. euonymi, E. hyperici, and E. trifoliorum), that cannot be sufficiently resolved based solely on ITS+28S sequences. Morphological and biological differences between the species are discussed and provide evidence that the species concerned should be maintained. Finally, a sequence obtained from a powdery mildew collected in Portugal on the native Lupinus micranthus pertained to the Erysiphe guarinonii clade. This collection is tentatively treated as Erysiphe sp. To fix the application of the species names E. astragali, E. baeumleri (including its synonym E. marchica), and E. intermedia, epitypes have been designated with ex-epitype sequences.