Endophytic species of Colletotrichum associated with cashew tree in northeastern Brazil.

Anthracnose caused by Colletotrichum is the most severe and widely occurring cashew disease in Brazil. Colletotrichum species are commonly found as pathogens, endophytes and occasionally as saprophytes in a wide range of hosts. The endophytic species associated with cashew trees are poorly studied. In this study, we report the Colletotrichum endophytic species associated with cashew trees in two locations in the state of Pernambuco, their prevalence in different plant organs (leaves, veins, branches and inflorescences), and compare the species in terms of pathogenicity and aggressiveness using different inoculation methods (wounded × unwounded). Six species of Colletotrichum were identified according to multilocus phylogenetic analyses, including Colletotrichum asianum, Colletotrichum chrysophilum, Colletotrichum karsti, Colletotrichum siamense, Colletotrichum theobromicola, and Colletotrichum tropicale. There were differences in the percentage of isolation in relation to the prevalence of colonized tissues and collection locations. C. tropicale was the prevalent species in both geographic areas and plant tissues collected, with no pattern of distribution of species between areas and plant tissues. All isolates were pathogenic in injured tissues of cashew plants. The best method to test the pathogenicity of Colletotrichum species was utilizing the combination of leaves + presence of wounds + conidial suspension, as it better represents the natural infection process. C. siamense was the most aggressive species.

Diversity of Colletotrichum species associated with torch ginger anthracnose.

Anthracnose caused by Colletotrichum species is one of the most important diseases of torch ginger. The disease leads to loss of aesthetic and commercial value of torch ginger stems. This study aimed to characterize Colletotrichum species associated with torch ginger anthracnose in the production areas of Pernambuco and Ceará. A total of 48 Colletotrichum isolates were identified using molecular techniques. Pathogenicity tests were performed on torch ginger with representative isolates. Phylogenetic analyses based on seven loci-DNA lyase (APN2), intergenic spacer between DNA lyase and the mating-type locus MAT1-2-1 (APN2/MAT-IGS), calmodulin (CAL), intergenic spacer between glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and a hypothetical protein (GAP2-IGS), glutamine synthetase (GS), and ß-tubulin (TUB2)-revealed that they belong to five known Colletotrichum species, namely, C. chrysophilum, C. fructicola, C. siamense, C. theobromicola, and C. tropicale, and three newly discovered species, described here as C. atlanticum, C. floscerae, and C. zingibericola. Of these, C. atlanticum was the most dominant. Pathogenicity assays showed that all isolates were pathogenic to torch ginger bracts. All species are reported for the first time associated with torch ginger in Brazil. The present study contributes to the current understanding of the diversity of Colletotrichum species associated with anthracnose on torch ginger and demonstrates the importance of accurate species identification for effective disease management strategies.

Phylogeographic and Phylogenomic Structure of the Quarantine Plant Pathogen Colletotrichum liriopes, Including New Reports in the United States.

Global agricultural trade has accelerated the emergence and re-emergence of new plant pathogens. In the United States, the fungal pathogen Colletotrichum liriopes is still considered a foreign quarantine pathogen that affects ornamental plants (i.e., Liriope spp.). Even though this species has been reported in East Asia on various asparagaceous hosts, its first and only report in the United States was in 2018. However, that study used only ITS nrDNA for identification, and no available culture or voucher specimen was maintained. The main objective of the present study was to determine the geographic and host distribution of specimens identified as C. liriopes. To accomplish this, new and existing isolates, sequences, and genomes obtained from various hosts and geographic locations (i.e., China, Colombia, Mexico, and the United States) were compared with the ex-type of C. liriopes. Multilocus phylogenetic (ITS, Tub2, GAPDH, CHS-1, and HIS3), phylogenomic, and splits tree analyses revealed that all the studied isolates/sequences form a well-supported clade with little intraspecific variation. Morphological characterizations support these findings. The minimum spanning network, low nucleotide diversity, and negative Tajima's D from both multilocus and genomic data suggest that there was a recent movement/invasion of a few East Asian genotypes to other countries where the ornamental plants are produced (e.g., South America) and subsequently to the importing countries, such as the United States. The study reveals that the geographic and host distribution of C. liriopes sensu stricto is expanded to the United States (i.e., at least Maryland, Mississippi, and Tennessee) and on various hosts in addition to Asparagaceae and Orchidaceae. The present study produces fundamental knowledge that can be used in efforts to reduce costs or losses from agricultural trade and to expand our understanding of pathogen movement.

Elucidating the Colletotrichum spp. diversity responsible for papaya anthracnose in Brazil.

Papaya (Carica papaya L.) is among the most important tropical fruits produced in Brazil and is grown in nearly every state. However, several diseases can affect papaya production. Anthracnose stands out among these diseases due to high postharvest yield losses. Previous studies identified Colletotrichum magna (invalid name) and Colletotrichum gloeosporioides causing anthracnose of papaya in Brazil, but species identification was inadequate due to reliance on nuclear ribosomal internal transcribed space (nrITS) and glutamine synthetase (GS) sequences. Thus, the diversity of Colletotrichum spp. causing papaya anthracnose in Brazil may be underestimated. The present study aims to identify the Colletotrichum species associated with papaya anthracnose in Brazil based on broad geographical sampling and multilocus phylogenetic analysis, as well as to assess the prevalence and aggressiveness of the species found. Here, we report C. chrysophilum, C. fructicola, C. gloeosporioides, C. karsti, C. okinawense, C. plurivorum, C. queenslandicum, C. siamense, C. theobromicola, Colletotrichum truncatum causing papaya anthracnose in Brazil. We are also synonymizing Colletotrichum corchorum-capsularis under C. truncatum. Colletotrichum okinawense was the most prevalent species in general and in most sampled locations, and with C. truncatum represents the most aggressive species.

Molecular reassessment of diaporthalean fungi associated with strawberry, including the leaf blight fungus, Paraphomopsis obscurans gen. et comb. nov. (Melanconiellaceae).

Phytopathogenic fungi in the order Diaporthales (Sordariomycetes) cause diseases on numerous economically important crops worldwide. In this study, we reassessed the diaporthalean species associated with prominent diseases of strawberry, namely leaf blight, leaf blotch, root rot and petiole blight, based on molecular data and morphological characters using fresh and herbarium collections. Combined analyses of four nuclear loci, 28S ribosomal DNA/large subunit rDNA (LSU), ribosomal internal transcribed spacers 1 and 2 with 5.8S ribosomal DNA (ITS), partial sequences of second largest subunit of RNA polymerase II (RPB2) and translation elongation factor 1-α (TEF1), were used to reconstruct a phylogeny for these pathogens. Results confirmed that the leaf blight pathogen formerly known as Phomopsis obscurans belongs in the family Melanconiellaceae and not with Diaporthe (syn. Phomopsis) or any other known genus in the order. A new genus Paraphomopsis is introduced herein with a new combination, Paraphomopsis obscurans, to accommodate the leaf blight fungus. Gnomoniopsis fragariae comb. nov. (Gnomoniaceae), is introduced to accommodate Gnomoniopsis fructicola, the cause of leaf blotch of strawberry. Both of the fungi causing leaf blight and leaf blotch were epitypified. Fresh collections and new molecular data were incorporated for Paragnomonia fragariae (Sydowiellaceae), which causes petiole blight and root rot of strawberry and is distinct from the above taxa. An updated multilocus phylogeny for the Diaporthales is provided with representatives of currently known families.

Comparative genome analyses suggest a hemibiotrophic lifestyle and virulence differences for the beech bark disease fungal pathogens Neonectria faginata and Neonectria coccinea.

Neonectria faginata and Neonectria coccinea are the causal agents of the insect-fungus disease complex known as beech bark disease (BBD), known to cause mortality in beech forest stands in North America and Europe. These fungal species have been the focus of extensive ecological and disease management studies, yet less progress has been made toward generating genomic resources for both micro- and macro-evolutionary studies. Here, we report a 42.1 and 42.7 mb highly contiguous genome assemblies of N. faginata and N. coccinea, respectively, obtained using Illumina technology. These species share similar gene number counts (12,941 and 12,991) and percentages of predicted genes with assigned functional categories (64 and 65%). Approximately 32% of the predicted proteomes of both species are homologous to proteins involved in pathogenicity, yet N. coccinea shows a higher number of predicted mitogen-activated protein kinase genes, virulence determinants possibly contributing to differences in disease severity between N. faginata and N. coccinea. A wide range of genes encoding for carbohydrate-active enzymes capable of degradation of complex plant polysaccharides and a small number of predicted secretory effector proteins, secondary metabolite biosynthesis clusters and cytochrome oxidase P450 genes were also found. This arsenal of enzymes and effectors correlates with, and reflects, the hemibiotrophic lifestyle of these two fungal pathogens. Phylogenomic analysis and timetree estimations indicated that the N. faginata and N. coccinea species divergence may have occurred at ∼4.1 million years ago. Differences were also observed in the annotated mitochondrial genomes as they were found to be 81.7 kb (N. faginata) and 43.2 kb (N. coccinea) in size. The mitochondrial DNA expansion observed in N. faginata is attributed to the invasion of introns into diverse intra- and intergenic locations. These first draft genomes of N. faginata and N. coccinea serve as valuable tools to increase our understanding of basic genetics, evolutionary mechanisms and molecular physiology of these two nectriaceous plant pathogenic species.

Names of Phytopathogenic Fungi: A Practical Guide.

Using the correct name for phytopathogenic fungi and oomycetes is essential for communicating knowledge about species and their biology, control, and quarantine as well as for trade and research purposes. However, many plant pathogenic fungi are pleomorphic, meaning they produce different asexual (anamorph) and sexual (teleomorph) morphs in their life cycles. Therefore, more than one name has been applied to different morphs of the same species, which has confused users. The onset of DNA technologies makes it possible to connect different morphs of the same species, resulting in a move to a more natural classification system for fungi in which a single name for a genus and species can now be used. This move to a single nomenclature, coupled with the advent of molecular systematics and the introduction of polythetic taxonomic approaches, has been the main driving force for a reclassification of fungi, including pathogens. Nonetheless, finding the correct name for species remains challenging. In this article we outline a series of steps or considerations to greatly simplify this process and provide links to various online databases and resources to aid in determining the correct name. Additionally, a list of accurate names is provided for the most common genera and species of phytopathogenic fungi.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Diaporthe Seed Decay of Soybean [Glycine max (L.) Merr.] Is Endemic in the United States, But New Fungi Are Involved.

Diaporthe seed decay can compromise seed quality in soybean [Glycine max (L.) Merr.] in the warm and humid production areas of the United States during crop maturation. In the current study, 45 isolates of Diaporthe were recovered from seed sampled from soybean fields affected by Diaporthe-associated diseases in eight U.S. states in 2017. The isolates obtained belonged to 10 species of Diaporthe based on morphology and phylogenetic analyses of the internal transcribed spacer, partial translation elongation factor 1-α, and ß-tubulin gene sequences. The associated species included D. aspalathi, D. caulivora, D. kongii, D. longicolla, D. sojae, D. ueckerae, D. unshiuensis, and three novel fungi, D. bacilloides, D. flavescens, and D. insulistroma. One isolate each of the 10 species was examined for pathogenicity on seed of cultivar Sava under controlled conditions. Seven days postinoculation, significant differences in the percentages of decayed seeds and seedling necrosis were observed among the isolates and the noninoculated control (P < 0.0001). While the isolates of D. bacilloides, D. longicolla, and D. ueckerae caused a significantly greater percentage of decayed seeds (P < 0.0001), the isolate of D. aspalathi caused the greatest seedling necrosis (P < 0.0001). The observation of new fungi causing Diaporthe seed decay suggests the need for a more comprehensive survey in U.S. soybean producing areas since members of the genus Diaporthe appear to form a complex that causes seed decay.

Competing sexual and asexual generic names in Pucciniomycotina and Ustilaginomycotina (Basidiomycota) and recommendations for use.

With the change to one scientific name for pleomorphic fungi, generic names typified by sexual and asexual morphs have been evaluated to recommend which name to use when two names represent the same genus and thus compete for use. In this paper, generic names in Pucciniomycotina and Ustilaginomycotina are evaluated based on their type species to determine which names are synonyms. Twenty-one sets of sexually and asexually typified names in Pucciniomycotina and eight sets in Ustilaginomycotina were determined to be congeneric and compete for use. Recommendations are made as to which generic name to use. In most cases the principle of priority is followed. However, eight generic names in the Pucciniomycotina, and none in Ustilaginomycotina, are recommended for protection: Classicula over Naiadella, Gymnosporangium over Roestelia, Helicobasidium over Thanatophytum and Tuberculina, Melampsorella over Peridermium, Milesina over Milesia, Phragmidium over Aregma, Sporobolomyces over Blastoderma and Rhodomyces, and Uromyces over Uredo. In addition, eight new combinations are made: Blastospora juruensis, B. subneurophyla, Cronartium bethelii, C. kurilense, C. sahoanum, C. yamabense, Milesina polypodii, and Prospodium crusculum combs. nov.

Rust fungi on Panicum.

Rusts are economically important diseases of switchgrass (Panicum virgatum) and other Paniceae grasses. Phylogenetic analyses based on sequences of the nuc rDNA 5.8S internal transcribed spacer 2 region (ITS2), partial 28S region, and intergenic spacer region (IGS) of nuc rDNA showed that species of rust fungi infecting switchgrass are closely related within Puccinia. Variation among rbcLa sequences for the associated hosts sampled concurred with the original identifications. Five species infecting switchgrass were recognized: Puccinia graminicola (≡ Uromyces graminicola), P. pammelii (= P. panici), and the proposed new species P. amari, P. novopanici, and P. pascua. These species were distinct from P. emaculata, the species previously considered the principal rust pathogen infecting switchgrass but that was found exclusively on witchgrass (Panicum capillare) in this study. Rust fungi on switchgrass previously identified as P. emaculata were identified as the morphologically similar species P. amari, P. novopanici, and P. pammelii. The morphological species Puccinia graminicola was found to comprise three species, P. graminicola and the proposed new species P. pascua on switchgrass and P. cumminsii on Panicum sp.

Overlooked competing asexual and sexually typified generic names of Ascomycota with recommendations for their use or protection.

With the change to one scientific name for fungal species, numerous papers have been published with recommendations for use or protection of competing generic names in major groups of ascomycetes. Although genera in each group of fungi were carefully considered, some competing generic names were overlooked. This paper makes recommendations for additional competing genera not considered in previous papers. Chairs of relevant Working Groups of the ICTF were consulted in the development of these recommendations. A number of generic names need protection, specifically Amarenographium over Amarenomyces, Amniculicola over Anguillospora, Balansia over Ephelis, Claviceps over Sphacelia, Drepanopeziza over Gloeosporidiella and Gloeosporium, Golovinomyces over Euoidium, Holwaya over Crinium, Hypocrella over Aschersonia, Labridella over Griphosphaerioma, Metacapnodium over Antennularia, and Neonectria over Cylindrocarpon and Heliscus. The following new combinations are made: Amniculicola longissima, Atichia maunauluana, Diaporthe columnaris, D. liquidambaris, D. longiparaphysata, D. palmicola, D. tersa, Elsinoë bucidae, E.caricae, E. choisyae, E. paeoniae, E. psidii, E. zorniae, Eupelte shoemakeri, Godronia myrtilli, G. raduloides, Sarcinella mirabilis, S. pulchra, Schizothyrium jamaicense, and Trichothallus niger. Finally, one new species name, Diaporthe azadirachte, is introduced to validate an earlier name, and the conservation of Discula with a new type, D. destructiva, is recommended.

New combinations of plant-associated fungi resulting from the change to one name for fungi.

In advancing to one scientific name for each fungus species, a number of name changes are required especially for plant-associated fungi. These include species names that are not in the correct genus. For example, the generic name Elsinoë is used for fungi causing scab diseases but a number of these species were described in the asexually typified genus Sphaceloma and must be placed in Elsinoë. In other cases species names were determined to be unrelated to the type species of the genus in which they are currently placed and are placed in a more appropriate genus. For each new name the history, rationale and importance of the name is discussed. The following new combinations are made: Acanthohelicospora aurea, A. scopula, Bifusella ahmadii, Botryobasidium capitatum, B. rubiginosum, Colletotrichum magnum, Crandallia acuminata, C. antarctica, Elsinoë arachadis, E. freyliniae, E. necator, E. perseae, E. poinsettiae, E. punicae, Entyloma gibbum, Harknessia farinosa, Passalora alocasiae, Protoventuria veronicae, Pseudocercosporella ranunculi, Psiloglonium stygium, Ramularia pseudomaculiformis, Seimatosporium tostum, Thielaviopsis radicicola combs. nov., and Venturia effusa.

Recommendations of generic names in Diaporthales competing for protection or use.

In advancing to one name for fungi, this paper treats generic names competing for use in the order Diaporthales (Ascomycota, Sordariomycetes) and makes a recommendation for the use or protection of one generic name among synonymous names that may be either sexually or asexually typified. A table is presented that summarizes these recommendations. Among the genera most commonly encountered in this order, Cytospora is recommended over Valsa and Diaporthe over Phomopsis. New combinations are introduced for the oldest epithet of important species in the recommended genus. These include Amphiporthe tiliae, Coryneum lanciforme, Cytospora brevispora, C. ceratosperma, C. cinereostroma, C. eugeniae, C. fallax, C. myrtagena, Diaporthe amaranthophila, D. annonacearum, D. bougainvilleicola, D. caricae-papayae, D. cocoina, D. cucurbitae, D. juniperivora, D. leptostromiformis, D. pterophila, D. theae, D. vitimegaspora, Mastigosporella georgiana, Pilidiella angustispora, P. calamicola, P. pseudogranati, P. stromatica, and P. terminaliae.

Phomopsis Stem Canker: A Reemerging Threat to Sunflower (Helianthus annuus) in the United States.

Phomopsis stem canker causes yield reductions on sunflower (Helianthus annuus L.) on several continents, including Australia, Europe, and North America. In the United States, Phomopsis stem canker incidence has increased 16-fold in the Northern Great Plains between 2001 and 2012. Although Diaporthe helianthi was assumed to be the sole causal agent in the United States, a newly described species, D. gulyae, was found to be the primary cause of Phomopsis stem canker in Australia. To determine the identity of Diaporthe spp. causing Phomopsis stem canker in the Northern Great Plains, 275 infected stems were collected between 2010 and 2012. Phylogenetic analyses of sequences of the ribosomal DNA internal transcribed spacer region, elongation factor subunit 1-α, and actin gene regions of representative isolates, in comparison with those of type specimens, confirmed two species (D. helianthi and D. gulyae) in the United States. Differences in aggressiveness between the two species were determined using the stem-wound method in the greenhouse; overall, D. helianthi and D. gulyae did not vary significantly (P≤0.05) in their aggressiveness at 10 and 14 days after inoculation. These findings indicate that both Diaporthe spp. have emerged as sunflower pathogens in the United States, and have implications on the management of this disease.

The Diaporthe sojae species complex: Phylogenetic re-assessment of pathogens associated with soybean, cucurbits and other field crops.

Phytopathogenic species of Diaporthe are associated with a number of soybean diseases including seed decay, pod and stem blight and stem canker and lead to considerable crop production losses worldwide. Accurate morphological identification of the species that cause these diseases has been difficult. In this study, we determined the phylogenetic relationships and species boundaries of Diaporthe longicolla, Diaporthe phaseolorum, Diaporthe sojae and closely related taxa. Species boundaries for this complex were determined based on combined phylogenetic analysis of five gene regions: partial sequences of calmodulin (CAL), beta-tubulin (TUB), histone-3 (HIS), translation elongation factor 1-α (EF1-α), and the nuclear ribosomal internal transcribed spacers (ITS). Phylogenetic analyses revealed that this large complex of taxa is comprised of soybean pathogens as well as species associated with herbaceous field crops and weeds. Diaporthe arctii, Diaporthe batatas, D. phaseolorum and D. sojae are epitypified. The seed decay pathogen D. longicolla was determined to be distinct from D. sojae. D. phaseolorum, originally associated with stem and leaf blight of Lima bean, was not found to be associated with soybean. A new species, Diaporthe ueckerae on Cucumis melo, is introduced with description and illustrations.

A Multiplex Real-Time PCR Assay for the Detection of Puccinia horiana and P. chrysanthemi on Chrysanthemum.

Puccinia horiana, the cause of chrysanthemum white rust, is a regulated fungal plant pathogen in the United States, while P. chrysanthemi, the cause of chrysanthemum brown rust, is a widespread but less destructive pathogen. Accurate identification is essential to enforce quarantine measures, but the two species cannot be differentiated visually in the absence of mature spores or symptoms. A multiplex real-time PCR assay was developed to detect and discriminate between P. chrysanthemi and P. horiana. Species-specific hydrolysis probes labeled with different fluorescent dyes were designed based on the rDNA internal transcribed spacer region. Seven fresh samples and 270 herbarium specimens of chrysanthemum rust were tested with the assay with results confirmed using spore morphology. P. horiana and P. chrysanthemi were accurately detected from all fresh samples, and as little as 1 pg of template DNA was reproducibly detected. Of the herbarium specimens, 99% were positive for at least one species using the multiplex assay with 7% positive for both species. This multiplex assay can discriminate between P. chrysanthemi and P. horiana and provides an additional tool for identification of P. horiana to ensure appropriate application of quarantine measures.

Microcyclic rusts of hollyhock ( Alcea rosea ).

Rust fungi infecting hollyhock and other plants in Malveae are frequently intercepted at ports of entry to the USA, particularly Puccinia malvacearum and P. heterogenea. These two species can be difficult to distinguish and can be further confused with other, less common species of microcyclic rust fungi infecting hollyhock: P. heterospora, P. lobata, P. platyspora, and P. sherardiana. Molecular phylogenetic analysis revealed that P. malvacearum and P. heterogenea are closely related, along with P. sherardiana and P. platyspora. A key to the six microcyclic Puccinia species infecting hollyhock is presented.

Revision of Entyloma (Entylomatales, Exobasidiomycetes) on Eryngium.

The genus Entyloma consists of more than 160 species of smut fungi distributed worldwide on dicots, with Apiaceae being one of the main host families. This study aims to clarify the systematics and phylogeny of Entyloma on Eryngium (Apiaceae) with molecular and morphological data. Eleven species from Eryngium are discussed herein. Four of them are described as new taxa: E. carmeli sp. nov. on Eryngium falcatum, E. eryngii-cretici sp. nov. on Eryngium creticum, E. eryngii-maritimi sp. nov. on Eryngium maritimum and E. ho-chunkii sp. nov. on Eryngium yuccifolium. Analysis of the internal transcribed spacer (ITS) region of rDNA is presented and supports the polyphyly of Entyloma on Eryngium.

Mushrooms and Health Summit proceedings.

The Mushroom Council convened the Mushrooms and Health Summit in Washington, DC, on 9-10 September 2013. The proceedings are synthesized in this article. Although mushrooms have long been regarded as health-promoting foods, research specific to their role in a healthful diet and in health promotion has advanced in the past decade. The earliest mushroom cultivation was documented in China, which remains among the top global mushroom producers, along with the United States, Italy, The Netherlands, and Poland. Although considered a vegetable in dietary advice, mushrooms are fungi, set apart by vitamin B-12 in very low quantity but in the same form found in meat, ergosterol converted with UV light to vitamin D2, and conjugated linoleic acid. Mushrooms are a rare source of ergothioneine as well as selenium, fiber, and several other vitamins and minerals. Some preclinical and clinical studies suggest impacts of mushrooms on cognition, weight management, oral health, and cancer risk. Preliminary evidence suggests that mushrooms may support healthy immune and inflammatory responses through interaction with the gut microbiota, enhancing development of adaptive immunity, and improved immune cell functionality. In addition to imparting direct nutritional and health benefits, analysis of U.S. food intake survey data reveals that mushrooms are associated with higher dietary quality. Also, early sensory research suggests that mushrooms blended with meats and lower sodium dishes are well liked and may help to reduce intakes of red meat and salt without compromising taste. As research progresses on the specific health effects of mushrooms, there is a need for effective communication efforts to leverage mushrooms to improve overall dietary quality.

Phomopsis bougainvilleicola prepatellar bursitis in a renal transplant recipient.

Prepatellar bursitis is typically a monomicrobial bacterial infection. A fungal cause is rarely identified. We describe a 61-year-old man who had received a renal transplant 21 months prior to presentation whose synovial fluid and surgical specimens grew Phomopsis bougainvilleicola, a pycnidial coelomycete.