ORCID Profile
0000-0002-4785-4308
Current Organisation
University of Southern Queensland
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Microbial Genetics | Mycology | Plant Biology | Plant Pathology |
Control of Plant Pests, Diseases and Exotic Species in Farmland, Arable Cropland and Permanent Cropland Environments | Expanding Knowledge in the Biological Sciences
Publisher: MDPI AG
Date: 24-04-2023
Abstract: In this study, we evaluated the effectiveness of hyperparasitic fungi in controlling powdery mildew (PM). In a greenhouse, we spray-inoculated single colonies of the melon PM-causing fungus Podosphaera xanthii strain KMP-6N at three different fungal developmental stages (i.e., 5, 10, and 15 days old) with spores of the hyperparasitic fungus Ampelomyces sp. strain Xs-q. After spray inoculation, we collected and counted KMP-6N conidia produced as asexual progeny from PM colonies using an electrostatic rotational spore collector. Collector insulator films were replaced at 24 h intervals until KMP-6N ceased to release additional progeny conidia. Conidial releases from each of the single Xs-q-inoculated KMP-6N colonies gradually reduced, then stopped within ca. 4 and 8 days of the first treatment in 5- and 10-day-old KMP-6N colonies, and within ca. 20 days of the second spray treatment in 15-day-old KMP-6N colonies, respectively. The total numbers of asexual progeny conidia collected from single 5-, 10-, and 15-day-old colonies were ca. 156, 1167, and 44,866, respectively. After electrostatic spore collection, conidiophores in Xs-q-uninoculated KMP-6N colonies appeared normal, whereas almost all conidiophores in 5- and 10-day-old Xs-q-inoculated KMP-6N colonies were completely deformed or collapsed due to the infection of the hyperparasitic fungus. This is the first study to apply electrostatic and digital microscopic techniques to clarify the impact of fungal hyperparasitism on mycohost survival, and, in particular, to assess quantitatively and visually the suppression of conidial release from any PM colonies infected with Ampelomyces.
Publisher: Scientific Societies
Date: 06-2013
DOI: 10.1094/PHYTO-08-12-0198-R
Abstract: Leveillula taurica is an obligate fungal pathogen that causes powdery mildew disease on a broad range of plants, including important crops such as pepper, tomato, eggplant, onion, cotton, and so on. The early stage of this disease is difficult to diagnose and the disease can easily spread unobserved for ex le, in pepper and tomato production fields and greenhouses. The objective of this study was to develop a detection and quantification method of L. taurica biomass in pepper leaves with special regard to the early stages of infection. We monitored the development of the disease to time the infection process on the leaf surface as well as inside the pepper leaves. The initial and final steps of the infection taking place on the leaf surface were consecutively observed using a dissecting microscope and a scanning electron microscope. The development of the intercellular mycelium in the mesophyll was followed by light and transmission electron microscopy. A pair of L. taurica-specific primers was designed based on the internal transcribed spacer sequence of L. taurica and used in real-time polymerase chain reaction (PCR) assay to quantify the fungal DNA during infection. The specificity of this assay was confirmed by testing the primer pair with DNA from host plants and also from another powdery mildew species, Oidium neolycopersici, infecting tomato. A standard curve was obtained for absolute quantification of L. taurica biomass. In addition, we tested a relative quantification method by using a plant gene as reference and the obtained results were compared with the visual disease index scoring. The real-time PCR assay for L. taurica provides a valuable tool for detection and quantification of this pathogen in breeding activities as well in plant–microbe interaction studies.
Publisher: Elsevier BV
Date: 07-2015
Publisher: Naturalis Biodiversity Center
Date: 2021
DOI: 10.3767/PERSOONIA.2021.46.11
Abstract: Novel species of fungi described in this study include those from various countries as follows: Algeria , Phaeoacremonium adelophialidum from Vitis vinifera . Antarctica , Comoclathris antarctica from soil. Australia , Coniochaeta salicifolia as endophyte from healthy leaves of Geijera salicifolia , Eremothecium peggii in fruit of Citrus australis , Microdochium ratticaudae from stem of Sporobolus natalensis , Neocelosporium corymbiae on stems of Corymbia variegata , Phytophthora kelmanii from rhizosphere soil of Ptilotus pyramidatus , Pseudosydowia backhousiae on living leaves of Backhousia citriodora , Pseudosydowia indooroopillyensis , Pseudosydowia louisecottisiae and Pseudosydowia queenslandica on living leaves of Eucalyptus sp. Brazil , Absidia montepascoalis from soil. Chile , Ilyonectria zarorii from soil under Maytenus boaria . Costa Rica , Colletotrichum filicis from an unidentified fern. Croatia , Mollisia endogranulata on deteriorated hardwood. Czech Republic , Arcopilus navicularis from tea bag with fruit tea, Neosetophoma buxi as endophyte from Buxus sempervirens , Xerochrysium bohemicum on surface of biscuits with chocolate glaze and filled with jam. France , Entoloma cyaneobasale on basic to calcareous soil, Fusarium aconidiale from Triticum aestivum , Fusarium juglandicola from buds of Juglans regia . Germany , Tetraploa endophytica as endophyte from Microthlaspi perfoliatum roots. India , Castanediella ambae on leaves of Mangifera indica , Lactifluus kanadii on soil under Castanopsis sp., Penicillium uttarakhandense from soil. Italy , Penicillium ferraniaense from compost. Namibia , Bezerromyces gobabebensis on leaves of unidentified succulent, Cladosporium stipagrostidicola on leaves of Stipagrostis sp., Cymostachys euphorbiae on leaves of Euphorbia sp., Deniquelata hypolithi from hypolith under a rock, Hysterobrevium walvisbayicola on leaves of unidentified tree, Knufia hypolithi and Knufia walvisbayicola from hypolith under a rock, Lapidomyces stipagrostidicola on leaves of Stipagrostis sp., Nothophaeotheca mirabibensis (incl. Nothophaeotheca gen. nov.) on persistent inflorescence remains of Blepharis obmitrata , Paramyrothecium salvadorae on twigs of Salvadora persica , Preussia procaviicola on dung of Procavia sp., Sordaria equicola on zebra dung, Volutella salvadorae on stems of Salvadora persica . Netherlands , Entoloma ammophilum on sandy soil, Entoloma pseudocruentatum on nutrient poor (acid) soil, Entoloma pudens on plant debris, amongst grasses. New Zealand , Amorocoelophoma neoregeliae from leaf spots of Neoregelia sp., Aquilomyces metrosideri and Septoriella callistemonis from stem discolouration and leaf spots of Metrosideros sp., Cadophora neoregeliae from leaf spots of Neoregelia sp., Flexuomyces asteliae (incl. Flexuomyces gen. nov.) and Mollisia asteliae from leaf spots of Astelia chathamica , Ophioceras freycinetiae from leaf spots of Freycinetia banksii , Phaeosphaeria caricis-sectae from leaf spots of Carex secta . Norway , Cuphophyllus flavipesoides on soil in semi-natural grassland, Entoloma coracis on soil in calcareous Pinus and Tilia forests, Entoloma cyaneolilacinum on soil semi-natural grasslands, Inocybe norvegica on gravelly soil. Pakistan , Butyriboletus parachinarensis on soil in association with Quercus baloot . Poland , Hyalodendriella bialowiezensis on debris beneath fallen bark of Norway spruce Picea abies . Russia , Bolbitius sibiricus on а moss covered rotting trunk of Populus tremula , Crepidotus wasseri on debris of Populus tremula , Entoloma isborscanum on soil on calcareous grasslands, Entoloma subcoracis on soil in subalpine grasslands, Hydropus lecythiocystis on rotted wood of Betula pendula , Meruliopsis faginea on fallen dead branches of Fagus orientalis , Metschnikowia taurica from fruits of Ziziphus jujube , Suillus praetermissus on soil, Teunia lichenophila as endophyte from Cladonia rangiferina . Slovakia , Hygrocybe fulgens on mowed grassland, Pleuroflammula pannonica from corticated branches of Quercus sp. South Africa , Acrodontium burrowsianum on leaves of unidentified Poaceae , Castanediella senegaliae on dead pods of Senegalia ataxacantha , Cladophialophora behniae on leaves of Behnia sp., Colletotrichum cliviigenum on leaves of Clivia sp., Diatrype dalbergiae on bark of Dalbergia armata , Falcocladium heteropyxidicola on leaves of Heteropyxis canescens , Lapidomyces aloidendricola as epiphyte on brown stem of Aloidendron dichotomum , Lasionectria sansevieriae and Phaeosphaeriopsis sansevieriae on leaves of Sansevieria hyacinthoides , Lylea dalbergiae on Diatrype dalbergiae on bark of Dalbergia armata , Neochaetothyrina syzygii (incl. Neochaetothyrina gen. nov.) on leaves of Syzygium chordatum , Nothophaeomoniella ekebergiae (incl. Nothophaeomoniella gen. nov.) on leaves of Ekebergia pterophylla , Paracymostachys euphorbiae (incl. Paracymostachys gen. nov.) on leaf litter of Euphorbia ingens , Paramycosphaerella pterocarpi on leaves of Pterocarpus angolensis , Paramycosphaerella syzygii on leaf litter of Syzygium chordatum , Parateichospora phoenicicola (incl. Parateichospora gen. nov.) on leaves of Phoenix reclinata , Seiridium syzygii on twigs of Syzygium chordatum , Setophoma syzygii on leaves of Syzygium sp., Starmerella xylocopis from larval feed of an Afrotropical bee Xylocopa caffra , Teratosphaeria combreti on leaf litter of Combretum kraussii , Teratosphaericola leucadendri on leaves of Leucadendron sp., Toxicocladosporium pterocarpi on pods of Pterocarpus angolensis . Spain , Cortinarius bonachei with Quercus ilex in calcareus soils, Cortinarius brunneovolvatus under Quercus ilex subsp. ballota in calcareous soil, Extremopsis radicicola (incl. Extremopsis gen. nov.) from root-associated soil in a wet heathland, Russula quintanensis on acidic soils, Tubaria vulcanica on volcanic lapilii material, Tuber zambonelliae in calcareus soil. Sweden , Elaphomyces borealis on soil under Pinus sylvestris and Betula pubescens . Tanzania , Curvularia tanzanica on inflorescence of Cyperus aromaticus . Thailand , Simplicillium niveum on Ophiocordyceps c onoti-leonardi on underside of unidentified dicotyledonous leaf. USA , Calonectria californiensis on leaves of Umbellularia californica , Exophiala spartinae from surface sterilised roots of Spartina alterniflora , Neophaeococcomyces oklahomaensis from outside wall of alcohol distillery. Vietnam , Fistulinella aurantioflava on soil. Morphological and culture characteristics are supported by DNA barcodes.
Publisher: Elsevier BV
Date: 09-1997
Publisher: Springer Science and Business Media LLC
Date: 21-04-2011
Publisher: Elsevier
Date: 2008
Publisher: Springer Science and Business Media LLC
Date: 17-07-2018
DOI: 10.1038/S41598-018-29102-5
Abstract: A little known, unculturable ascomycete, referred to as Phyllachora ambrosiae , can destroy the inflorescences of Ambrosia artemisiifolia , an invasive agricultural weed and producer of highly allergenic pollen. The fungus often remains undetectable in ragweed populations. This work was conducted to understand its origin and pathogenesis, a prerequisite to consider its potential as a biocontrol agent. The methods used included light and transmission electron microscopy, nrDNA sequencing, phylogenetic analyses, artificial inoculations, and the examination of old herbarium and recent field specimens from Hungary, Korea, Ukraine and USA. The Eurasian and the North American specimens of this fungus were to represent two distinct, although closely related lineages that were only distantly related to other lineages within the Ascomycota . Consequently, we describe a new genus that includes Cryptophyllachora eurasiatica gen. et sp. nov. and C. ambrosiae comb. nov., respectively. The pathogenesis of C. eurasiatica was shown in A. artemisiifolia . No evidence was found for either seed-borne transmission or systemic infection. Two hypotheses were developed to explain the interaction between C. eurasiatica and A. artemisiifolia : (i) as yet undetected seed-borne transmissions and latent, systemic infections or (ii) alternative hosts.
Publisher: Elsevier BV
Date: 12-2018
Publisher: MDPI AG
Date: 07-09-2020
Abstract: Erysiphe necator populations, causing powdery mildew of grapes, have a complex genetic structure. Two genotypes, A and B, were identified in most vineyards across the world on the basis of fixed single nucleotide polymorphisms (SNPs) in several DNA regions. It was hypothesized that A populations overwinter as mycelia in grapevine buds, giving rise to so-called flag shoots in spring, and are more sensitive to fungicides than B populations, which overwinter as ascospores and become widespread later in the season. Other studies concluded that the biological significance of these genotypes is unclear. In the spring of 2015, there was a unique opportunity to collect E. necator s les from flag shoots in Hungary. The same grapevines were s led in summer and autumn as well. A total of 182 s les were genotyped on the basis of β-tubulin (TUB2), nuclear ribosomal DNA (nrDNA) intergenic spacer (IGS), and internal transcribed spacer (ITS) sequences. Genotypes of 56 s les collected in 2009–2011 were used for comparison. Genotype A was not detected at all in spring, and was present in only 19 s les in total, mixed with genotype B, and sometimes with another frequently found genotype, designated as B2. These results did not support the hypothesis about temporal isolation of the two genotypes and indicated that these are randomly distributed in vineyards.
Publisher: Elsevier BV
Date: 11-2006
DOI: 10.1016/J.MYCRES.2006.07.016
Abstract: Morphological characteristics of a powdery mildew fungus found on Celtis australis in the Indian Himalayas coincided with those of Pleochaeta indica, described from this tree species in India, as well with those of P. shiraiana, known to infect C. australis and other plant species in Asia. This suggested that the original description of P. indica based on morphological patterns was not well founded and this taxon could be reduced to synonymy with P. shiraiana. However, phylogenetic analyses of the rDNA 28S and ITS sequences determined in some Indian Pleochaeta specimens from C. australis showed that this fungus is closely related, but not identical to P. shiraiana infecting C. sinensis in Japan which served as the basis of the original description of P. shiraiana. Molecular clock analysis of the ITS region and that of the 28S rDNA indicated that the split between the Japanese P. shiraiana infecting C. sinensis and Pleochaeta sp. infecting C. australis in India may have occurred 2.0-8.5 million years ago in the Pliocene and may have coincided with the formation of the Himalayan mountains and the global cooling of the Earth during the late Tertiary. Thus, P. indica is recognized in this study as a distinct phylogenetic species, although our morphological study showed that its description as a morphological species was not well founded. This is a striking ex le of a cryptic species which is genetically different from close relatives but cannot be distinguished from them based on morphology.
Publisher: Wiley
Date: 12-2003
Publisher: Scientific Societies
Date: 05-2008
Abstract: Previous works indicated a considerable variation in the pathogenicity, virulence, and host range of Oidium neolycopersici isolates causing tomato powdery mildew epidemics in many parts of the world. In this study, rDNA internal transcribed spacer (ITS) sequences, and lified fragment length polymorphism (AFLP) patterns were analyzed in 17 O. neolycopersici s les collected in Europe, North America, and Japan, including those which overcame some of the tomato major resistance genes. The ITS sequences were identical in all 10 s les tested and were also identical to ITS sequences of eight previously studied O. neolycopersici specimens. The AFLP analysis revealed a high genetic ersity in O. neolycopersici and indicated that all 17 s les represented different genotypes. This might suggest the existence of either a yet unrevealed sexual reproduction or other genetic mechanisms that maintain a high genetic variability in O. neolycopersici. No clear correlation was found between the virulence and the AFLP patterns of the O. neolycopersici isolates studied. The relationship between O. neolycopersici and powdery mildew anamorphs infecting Aquilegia vulgaris, Chelidonium majus, Passiflora caerulea, and Sedum alboroseum was also investigated. These anamorphs are morphologically indistinguishable from and phylogenetically closely related to O. neolycopersici. The cross-inoculation tests and the analyses of ITS sequences and AFLP patterns jointly indicated that the powdery mildew anamorphs collected from the above mentioned plant species all represent distinct, but closely related species according to the phylogenetic species recognition. All these species were pathogenic only to their original host plant species, except O. neolycopersici which infected S. alboroseum, tobacco, petunia, and Arabidopsis thaliana, in addition to tomato, in cross-inoculation tests. This is the first genome-wide study that investigates the relationships among powdery mildews that are closely related based on ITS sequences and morphology. The results indicate that morphologically indistinguishable powdery mildews that differed in only one to five single nucleotide positions in their ITS region are to be considered as different taxa with distinct host ranges.
Publisher: Wiley
Date: 22-08-2011
Publisher: Cold Spring Harbor Laboratory
Date: 23-11-2018
DOI: 10.1101/476267
Abstract: Due to their comparatively small genome size and short generation time, fungi are exquisite model systems to study eukaryotic genome evolution. Powdery mildew (PM) fungi present an exceptional case where their strict host dependency (a lifestyle termed obligate biotrophy) is associated with some of the largest fungal genomes sequenced so far ( Mbp). This size expansion is largely due to the pervasiveness of transposable elements (TEs), which can cover more than 70% of these genomes, and is associated with the loss of multiple conserved ascomycete genes (CAGs) required for a free-living lifestyle. To date, little is known about the mechanisms that drove this expansion, and information on ancestral PM genomes is lacking. We report the genome analysis of the early- erged PM species Parauncinula polyspora that in contrast to most other PMs reproduces exclusively sexually. The P. polyspora genome is surprisingly small ( Mb) and sparsely equipped with TEs ( %), despite the conserved absence of a common defense mechanism (RIP) involved in constraining repetitive elements. The genome still harbors the majority of the CAGs that are absent in the genomes of the recently evolved PMs. We speculate that TE spread might have been limited by its unique reproduction strategy and host features and further hypothesize that the loss of CAGs may promote the evolutionary isolation and host niche specialization of PM fungi. Limitations associated with this evolutionary trajectory might have been in part counteracted by the evolution of plastic, TE-rich genomes and/or the expansion of gene families encoding secreted virulence proteins.
Publisher: Scientific Societies
Date: 07-2018
Publisher: Elsevier BV
Date: 10-2009
DOI: 10.1016/J.MYCRES.2009.07.010
Abstract: Common ragweed (Ambrosia artemisiifolia) is an invasive and highly allergenic plant species, on which two species, Plasmopara halstedii and Plasmopara angustiterminalis, have been recognized to cause downy mildew disease. In this study, morphological and molecular patterns of seven Plasmopara specimens collected from A. artemisiifolia in Canada, Hungary, and USA were compared with those of P. halstedii and P. angustiterminalis from Helianthus and Xanthium, respectively. Analyses of partial sequences of three genes, namely those for the large subunit (28S) of rDNA, cytochrome c oxidase subunit II (COX2), and NADH dehydrogenase subunit I (ND1) of mtDNA, were carried out to examine the phylogenetic relationships among these specimens using both Bayesian and maximum parsimony methods. All the phylogenetic analyses revealed that the downy mildew pathogens infecting A. artemisiifolia in Hungary and North America clearly represent a lineage distinct from other Plasmopara taxa investigated. The shape of sporangia and the width of trunks and branches also allowed the separation of the specimens parasitic to A. artemisiifolia from P. halstedii on Helianthus annuus and P. angustiterminalis on Xanthium strumarium. Surprisingly, the Hungarian and the Canadian specimens were more closely related to each other than to those from the USA based on COX2 and ND1 mtDNA data, although the D1/D2/D3 sequences of 28S rDNA were identical in all these Plasmopara specimens. The regional distribution of the mtDNA haplotypes seen in this study suggests a transatlantic migration has occurred and would be interesting to follow up with a more detailed s ling. To investigate the ersity within P. halstedii sensu lato, infecting different host plant species, specimens from six asteraceous genera, Ambrosia, Flaveria, Helianthus, Siegesbeckia, Solidago, and Xanthium, were also included in molecular analyses. These represented six distinct lineages according to the host plant genera. These findings might serve as a basis for a taxonomical reassessment of the P. halstedii complex and also for the delimitation of several well-defined species within this complex.
Publisher: Scientific Societies
Date: 03-2011
Abstract: In autumn 2009, during a survey of powdery mildews of solanaceous plants in the United Kingdom, petunia (Petunia × hybrida) plants showing typical symptoms of powdery mildew infections were repeatedly collected in East Malling, Rochester, and Sandringham, UK. Leaves, stems, and petals of the collected plants, grown as outdoor ornamentals, were covered by dense, sporulating, white mycelium. Conidia were ellipsoid-cylindrical, measured 20 to 30 × 10 to 15 μm, and were produced in chains. Germ tubes arose from the ends of conidia and terminated in simple, unlobed apices. Some of the conidiophores were extremely long, up to 250 μm, because the second or third cell, or sometimes the foot cell, was up to 105 to 170 μm long. Other conidiophores were shorter, with no exceptionally long cells, but all of them exhibited a few characteristics in common: their width increased from base to top, sometimes enlarging considerably at a particular point of the foot cell, and basal septa were usually located 7 to 30 μm from the point of branching. Hyphal appressoria were nipple shaped. The teleomorph stage was not found. On the basis of these characteristics, the fungus was identified as Oidium longipes, a recently described (4) and little known pathogen of petunia and other solanaceous plants (1,3). To support the identification of this fungus, DNA was extracted from conidia collected with sterile brushes from single leaves collected in Sandringham, East Malling, and Rochester with a Qiagen DNeasy Plant Kit (Qiagen, Hilden, Germany), and the internal transcribed spacer (ITS) region of the nuclear ribosomal DNA was lified and determined as described in Jankovics et al. (2). The three identical ITS sequences, deposited in GenBank under Accession Nos. HM156495, HM156496, and HM156497, were identical to several ITS sequences of O. longipes, such as AF250777, EU327324, and EU327325. This has also supported that the disease was caused by this species. Herbarium specimens were deposited under the Accession Nos. HAL 2373F, HAL 2374F, and HAL 2375F at the Herbarium of Martin Luther University, Halle, Germany. To our knowledge, this is the first report of O. longipes in the UK. References: (1) A. Bolay. Cryptogam. Helv. 20:1, 2005. (2) T. Jankovics et al. Phytopathology 98:529, 2008. (3) L. Kiss et al. Plant Disease 92:818, 2008. (4) M. E. Noordeloos and W. M. Loerakker. Persoonia 14:51, 1989.
Publisher: Informa UK Limited
Date: 06-2007
Publisher: Akademiai Kiado Zrt.
Date: 03-2006
Publisher: Scientific Societies
Date: 03-2009
Abstract: Scabiosa columbaria (Dipsacaceae) is a popular perennial ornamental in the United States. It is native to Europe and was introduced to North America by nursery trade only recently. In the spring of 2006, symptoms of powdery mildew infection were observed on overwintered plants of S. columbaria cv. Butterfly Blue in a nursery in Cutchogue, NY. White powdery mildew mycelia with abundant sporulation were observed on upper and lower leaf surfaces. The portions of leaves with powdery mildew colonies often showed purplish discoloration. Conidia were cylindric to doliiform, measured 20 to 33 × 10 to 15 μm, and were produced singly on 60 to 130 μm long conidiophores consisting of a foot-cell measuring 20 to 50 × 6 to 10 μm, followed by one to three, 12 to 40 μm long cells. Hyphal appressoria were lobed or multilobed. The teleomorph stage was not found. On the basis of these characteristics, the pathogen was identified as an Oidium sp. belonging to the subgenus Pseudoidium. Recently, an anamorphic powdery mildew fungus with similar morphological characteristics, identified as Erysiphe knautiae, was reported on S. columbaria cv. Butterfly Blue in Washington (2). E. knautiae is a common powdery mildew species of dipsacaceous plants such as Scabiosa spp. and Knautia spp. in Europe and Asia (1). To determine whether the fungus reported here was E. knautiae, DNA was extracted from its mycelium, and the internal transcribed spacer (ITS) region of the ribosomal DNA was lified and sequenced as described earlier (4). No ITS sequences are available in public DNA databases for E. knautiae, thus, we determined this sequence in a specimen of E. knautiae collected from Knautia arvensis in The Netherlands. Herbarium specimens of the Oidium sp. infecting S. columbaria in New York and E. knautiae from the Netherlands were deposited at the U.S. National Fungus Collections under accession numbers BPI 878259 and BPI 878258, respectively. The ITS sequence from Oidium sp. infecting S. columbaria in New York (GenBank Accession No. EU377474) differed in two nucleotides from that of E. knautiae infecting K. arvensis in the Netherlands (GenBank Accession No. EU377475). These two ITS sequences were also more than 99% similar to those of some newly emerged anamorphic powdery mildew fungi: Oidium neolycopersici and other Oidium spp. infecting Chelidonium majus, Passiflora caerulea, and some crassulaceous plants (3,4). Thus, it is unclear whether the fungus reported here was E. knautiae known from Eurasia or an Oidium sp. that has acquired pathogenicity to S. columbaria. To our knowledge, this is the first report of powdery mildew on S. columbaria in New York. References: (1) U. Braun. Beih. Nova Hedwigia 89:1, 1987. (2) D. A. Glawe and G. G. Grove. Online publication. doi:10.1094/PHP-2005-1024-01-BR. Plant Health Progress, 2005. (3) B. Henricot. Plant Pathol. 57:779, 2008. (4) T. Jankovics et al. Phytopathology 98:529, 2008.
Publisher: Springer Science and Business Media LLC
Date: 20-03-2021
Publisher: Scientific Societies
Date: 06-2015
DOI: 10.1094/PHYTO-10-14-0268-R
Abstract: Although Blumeria graminis is an intensively studied pathogen, an important part of its life cycle (namely, the way ascospores initiate primary infections on cereal leaves) has not yet been explored in detail. This study reports, for the first time, the direct observation of this process in B. graminis f. sp. tritici using light and confocal laser-scanning microscopy. All the germinated ascospores produced a single germ tube type both in vitro and on host plant surfaces therefore, the ascosporic and conidial germination patterns are markedly different in this fungus, in contrast to other powdery mildews. Germinated ascospores penetrated the epidermal cells of wheat leaves and produced haustoria as known in the case of conidial infections. This work confirmed earlier studies reporting that B. graminis chasmothecia collected from the field do not contain mature ascospores, only asci filled with protoplasm ascospore development is induced by moist conditions and is a fast process compared with other powdery mildews. Although ascosporic infections are frequent in B. graminis f. sp. tritici in the field, as shown by this study and other works as well, a recent analysis of the genomes of four isolates revealed the signs of clonal or near-clonal reproduction. Therefore, chasmothecia and ascospores are probably more important as oversummering structures than genetic recombination factors in the life cycle of this pathogen.
Publisher: Elsevier BV
Date: 09-2002
Publisher: The Mycological Society of Japan
Date: 05-2015
Publisher: Scientific Societies
Date: 06-2020
DOI: 10.1094/MPMI-02-20-0029-A
Abstract: Powdery mildew of sweet pepper (Capsicum annuum) is an economically important disease. It is caused by Leveillula taurica, an obligate biotrophic ascomycete with a partly endophytic mycelium and haustoria, i.e., feeding structures formed in the mesophyll cells of infected host plant tissues. The molecular basis of its pathogenesis is largely unknown because genomic resources only exist for epiphytically growing powdery mildew fungi with haustoria formed exclusively in epidermal cells of their plant hosts. Here, we present the first reference genome assembly for an isolate of L. taurica isolated from sweet pepper in Hungary. The short read–based assembly consists of 23,599 contigs with a total length of 187.2 Mbp the scaffold N 50 is 13,899 kbp and N 90 is 3,522 kbp and the average GC content is 39.2%. We detected at least 92,881 transposable elements covering 55.5 Mbp (30.4%). BRAKER predicted 19,751 protein-coding gene models in this assembly. Our reference genome assembly of L. taurica is the first resource to study the molecular pathogenesis and evolution of a powdery mildew fungus with a partly endophytic lifestyle.
Publisher: Wiley
Date: 13-11-2006
Publisher: Wiley
Date: 06-2001
Publisher: Springer Science and Business Media LLC
Date: 15-11-2009
Publisher: The Mycological Society of Japan
Date: 05-2011
Publisher: Elsevier BV
Date: 08-2005
DOI: 10.1017/S0953756205003527
Abstract: To understand the phylogenetic relationships and evolution of the powdery mildew genus Sawadaea (Ascomycota: Erysiphaceae), obligate parasitic fungi of maples, we performed molecular phylogenetic analyses based on 47 ITS and ten 28S rDNA sequences. Seven major clades of Sawadaea, each represented by powdery mildew specimens collected from a single or a small number of closely related sections of Acer (maples), were identified in this study, suggesting that a close evolutionary relationship exists between Acer (host) and Sawadaea (parasite). A 6-11-base insertion/deletion was found in the ITS1 region of Sawadaea, and the presence or absence of the indel was consistent within the respective clades. Because the outgroup genera Podosphaera and Cystotheca have no deletions in these sites, deletion of the sequences may have occurred during the ergence of the respective clades of Sawadaea. The seven clades of Sawadaea were ided into two geographical groups, viz. an East Asian and a global group, based on the countries of collection. Calculation of the evolutionary timing of Sawadaea using molecular clocks showed that the ergence of different species of Acer occurred many millions of years before the radiation of Sawadaea. Thus, the close evolutionary relationship between Sawadaea and Acer found in this study might not be due to a true coevolutionary process. Powdery mildew fungi belonging to Sawadaea may have jumped onto Acer spp. long after the radiation of the major sections of these trees, and then expanded their host ranges according to the phylogeny and geographical distribution of Acer.
Publisher: Scientific Societies
Date: 07-2009
Abstract: Common ragweed, native to North America, has recently become invasive in some parts of Europe. In Hungary, it has become the most widespread agricultural weed species and the most important producer of allergenic pollen since the 1990s. During surveys for its fungal plant pathogens to be evaluated as potential biological control agents (1), ragweed plants exhibiting necrotic spots on the leaves and stems were repeatedly found in Heves and Vas counties in Hungary in September 2004 and 2006. Numerous globose and ostiolate pycnidia, 68 to 115 μm in diameter, containing hyaline, unicellular conidia, 3 to 8 μm long, were found in necrotic tissues. On the basis of these characteristics, the fungus was identified as a Phoma sp., and 21 isolates were obtained on Czapek-Dox medium supplemented with 2% malt and 0.5% tetracycline in 2004 and 2006. Two well-sporulating isolates, designated Ph-5 and Ph-17, were selected for further studies. DNA was extracted from mycelium with a Qiagen DNeasy Plant Kit (Hilden, Germany) and the rDNA internal transcribed spacer (ITS) sequences were lified and determined as described by Szentiványi et al. (2). The ITS sequences were identical in these two isolates and were 97 to 98% similar to those of Didymella bryoniae (anamorph Phoma cucurbitacearum), a pathogen of cucurbits, and also to those of other Phoma spp. No ITS sequences identical to those determined in Phoma isolates Ph-5 and Ph-17 were found in GenBank. Sequence data were deposited in GenBank (No. FJ794609). To test the pathogenicity of Ph-17 grown on Czapek-Dox medium with 2% malt, a 2 to 6 × 10 5 conidia/ml aqueous suspension was used to inoculate 2-month-old potted ragweed plants and 1-month-old cucumber cv. Rajnai fürtös, bottle gourd (Lagenaria leucantha) cv. Minibottle, and watermelon (Citrullus lanatus) cv. Sugar Baby, which were all grown from seeds in a greenhouse. Plants were kept in transparent plastic chambers for 6 weeks. Five pots with one to three plants each were used for each plant species tested and the experiment was carried out twice. Noninoculated plants, two pots with one to three in iduals for each species kept in the same way, served as controls. Necrotic spots with pycnidia developed on 38 to 47% of the leaves of all inoculated ragweed plants 18 to 25 days after inoculation, whereas all the cucurbitaceous plants tested, as well as the control ragweed plants, did not develop disease symptoms. Although the Phoma isolate Ph-17 was, based on ITS sequence data, closely related to D. bryoniae, it was not pathogenic to cucurbits. The pathogen was reisolated from two diseased ragweed plants. Several Phoma spp. strains were isolated from Ambrosia artemisiifolia in the United States and Canada (3,4), but to our knowledge, none were isolated outside North America. One of the strains has already been used as a potential biological control agent of ragweed in Canada, but then lost its virulence in culture (3). The biocontrol potential of the Hungarian Phoma sp. isolate Ph-17 against A. artemisiifolia is currently being investigated. To our knowledge, this is the first report of a Phoma sp. on A. artemisiifolia in Europe. References: (1) L. Kiss. Biocontrol Sci. Technol. 17:535, 2007. (2) O. Szentiványi et al. Mycol. Res. 109:429, 2005. (3) M. P. Teshler et al. Ambrosia artemisiifolia L., Common Ragweed (Asteraceae) in: Biological Control Programmes in Canada, 1981-2000. CABI, Wallingford, UK, 2002. (4) L. Zhou et al. Mycologia 97:612, 2005.
Publisher: Scientific Societies
Date: 07-2021
DOI: 10.1094/PHYTO-12-20-0554-R
Abstract: 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.
Publisher: Public Library of Science (PLoS)
Date: 10-03-2011
Publisher: Proceedings of the National Academy of Sciences
Date: 19-06-2012
Publisher: Informa UK Limited
Date: 05-2015
DOI: 10.3852/15-007
Abstract: The genus Erysiphe (including powdery mildew fungi only known as anamorph, Pseudoidium) is the largest genus in the Erysiphaceae and contains more than 50% of all species in this family. Little is known about the phylogenetic structure of this genus. We conducted a comprehensive phylogenetic analysis of the Microsphaera-lineage, a monophyletic group including species of sects. Microsphaera and Erysiphe, using 401 sequences of nuc ITS1-5.8S-ITS2 and the 28S rDNA regions. This analysis gave many small clades delimited by the host plant genus or family. We identified two deep branches, albeit with moderate bootstrap supports, that ided the 401 sequences into three large groups. In addition, we identified four large clades consisting of homogeneous sequences of powdery mildews from a wide range of host plants beyond family level, namely, the E. aquilegiae clade, the E. alphitoides clade, the E. quercicola clade, and the E. trifoliorum s. lat. clade. Isolates from herbaceous plants were mostly situated in the E. aquilegiae clade and in Group III that was located at the most derived position of the Microsphaera-lineage. On the other hand, the basal part of the Microsphaera-lineage was occupied by isolates from woody plants except for E. glycines that was used as an outgroup taxon. This supports our previous hypothesis that tree-parasitic powdery mildews are phylogenetically primitive in the Erysiphaceae in general, and host-shift from trees to herbs occurred many times independently during the evolution of powdery mildews. Molecular clock analyses suggested that the ergence of the Microsphaera-lineage began ca. 20 million years ago in the Miocene Epoch of the Neogene Period.
Publisher: Wiley
Date: 08-10-2014
DOI: 10.1111/MEC.12908
Publisher: Naturalis Biodiversity Center
Date: 29-06-2020
DOI: 10.3767/PERSOONIA.2020.44.11
Abstract: 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 sw . 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 s le, 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.
Publisher: Wiley
Date: 05-1999
Publisher: Wiley
Date: 04-2004
Publisher: Public Library of Science (PLoS)
Date: 11-05-2021
DOI: 10.1371/JOURNAL.PONE.0251444
Abstract: A total of 26 Ampelomyces strains were isolated from mycelia of six different powdery mildew species that naturally infected their host plants in Japan. These were characterized based on morphological characteristics and sequences of ribosomal DNA internal transcribed spacer (rDNA-ITS) regions and actin gene ( ACT ) fragments. Collected strains represented six different genotypes and were accommodated in three different clades of the genus Ampelomyces . Morphology of the strains agreed with that of other Ampelomyces strains, but none of the examined characters were associated with any groups identified in the genetic analysis. Five powdery mildew species were inoculated with eight selected Ampelomyces strains to study their mycoparasitic activity. In the inoculation experiments, all Ampelomyces strains successfully infected all tested powdery mildew species, and showed no significant differences in their mycoparasitic activity as determined by the number of Ampelomyces pycnidia developed in powdery mildew colonies. The mycoparasitic interaction between the eight selected Ampelomyces strains and the tomato powdery mildew fungus ( Pseudoidium neolycopersici strain KTP-03) was studied experimentally in the laboratory using digital microscopic technologies. It was documented that the spores of the mycoparasites germinated on tomato leaves and their hyphae penetrated the hyphae of Ps . neolycopersici . Ampelomyces hyphae continued their growth internally, which initiated the atrophy of the powdery mildew conidiophores 5 days post inoculation (dpi) caused atrophy 6 dpi and complete collapse of the parasitized conidiphores 7 dpi. Ampelomyces strains produced new intracellular pycnidia in Ps . neolycopersici conidiophores ca . 8–10 dpi, when Ps . neolycopersici hyphae were successfully destroyed by the mycoparasitic strain. Mature pycnidia released spores ca . 10–14 dpi, which became the sources of subsequent infections of the intact powdery mildew hyphae. Mature pycnidia contained each ca . 200 to 1,500 spores depending on the mycohost species and Ampelomyces strain. This is the first detailed analysis of Ampelomyces strains isolated in Japan, and the first timing and quantification of mycoparasitism of Ps . neolycopersici on tomato by phylogenetically erse Ampelomyces strains using digital microscopic technologies. The developed model system is useful for future biocontrol and ecological studies on Ampelomyces mycoparasites.
Publisher: Wiley
Date: 19-03-2008
Publisher: Springer Science and Business Media LLC
Date: 20-10-2015
Publisher: Cold Spring Harbor Laboratory
Date: 10-01-2019
DOI: 10.1101/516781
Abstract: Powdery mildews (PMs), ubiquitous obligate biotrophic plant pathogens, are often attacked in the field by mycoparasitic fungi belonging to the genus Ampelomyces . Some Ampelomyces strains are commercialized biocontrol agents of crop pathogenic PMs. Using Agrobacterium tumefaciens-mediated transformation (ATMT), we produced stable Ampelomyces transformants that constitutively expressed the green fluorescent protein (GFP), to (i) improve the visualization of the PM- Ampelomyces interaction and (ii) decipher the environmental fate of Ampelomyces before and after acting as a mycoparasite. Detection of Ampelomyces structures, and especially hyphae, was greatly enhanced when erse PM, leaf and soil s les containing GFP transformants were examined with fluorescence microscopy compared to brightfield and DIC optics. We showed for the first time that Ampelomyces can persist up to 21 days on PM-free host plant surfaces, where it can attack PM structures as soon as these appear after this period. As a saprobe in decomposing, PM-infected leaves on the ground, and also in autoclaved soil, Ampelomyces developed new hyphae, but did not sporulate. These results indicate that Ampelomyces occupies a niche in the phyllosphere where it acts primarily as a mycoparasite of PMs. Our work has established a framework for a molecular genetic toolbox for Ampelomyces using ATMT.
Publisher: Springer Science and Business Media LLC
Date: 22-12-2016
Publisher: Elsevier BV
Date: 04-2005
DOI: 10.1017/S0953756204001820
Abstract: Pycnidial fungi belonging to the genus Ampelomyces are the most common natural antagonists of powdery mildews worldwide. During a study of the interactions between apple powdery mildew (Podosphaera leucotricha) and Ampelomyces mycoparasites, 52 new Ampelomyces isolates were obtained from P. leucotricha and, in addition, 13 new isolates from other species of the Erysiphaceae in four European countries. Their genetic ersity was screened using single-stranded conformation polymorphism (SSCP) analysis of the internal transcribed spacer (ITS) region of the ribosomal DNA (rDNA). For comparison, 24 isolates obtained from genetic resource collections or other sources were included in this study. Based on the ITS-SSCP patterns, the isolates were placed in eight groups. The isolates belonged to two types based on their growth in culture. The faster-growing and the slower-growing isolates were included in different SSCP groups. A phylogenetic analysis of the ITS sequences of representatives of these groups confirmed the results obtained with the SSCP method, and showed that the faster-growing isolates do not belong to Ampelomyces as suggested by earlier studies. All the isolates from P. leucotricha fell into a distinct SSCP group of genetically homogeneous isolates. This suggests that Ampelomyces mycoparasites which occur in apple powdery mildew are slightly different from the other Ampelomyces groups which contain mycoparasites from various powdery mildew species. This may be because the main growth period of Ampelomyces mycoparasites in apple powdery mildew is isolated in time from that of Ampelomyces isolates that occur in other species of the Erysiphaceae. P. leucotricha starts its life-cycle early in the season, usually in March-April, while most powdery mildews are active in the same environments only late in the year.
Publisher: Akademiai Kiado Zrt.
Date: 05-2002
DOI: 10.1556/AMICR.49.2002.2-3.10
Abstract: Recently, the classical morphological criteria and host range data used in the identification of powdery mildew fungi were supplemented with scanning electron microscope (SEM) and molecular phylogenetic analyses. This paper discusses the joint use of these methods in the identification of powdery mildew anamorphs causing new or emerging plant diseases in different parts of the world.
Publisher: Springer Science and Business Media LLC
Date: 11-11-2016
Publisher: Scientific Societies
Date: 05-2005
DOI: 10.1094/PD-89-0491
Abstract: A previous morphological study of Oidium anamorphs responsible for the recent tomato (Lycopersicon esculentum) powdery mildew outbreaks worldwide suggested that, despite controversial data in the literature, the North American epidemics were caused solely by a newly erected species, O. neolycopersici. We report here the first molecular evidence that the North American anamorphs do belong to O. neolycopersici. The internal transcribed spacer sequences of the North American anamorphs of this study were identical with those of three Japanese and four European specimens of O. neolycopersici. A morphological study confirmed that all the North American Oidium anamorphs included in this study produced conidia singly, similar to O. neolycopersici. These fungi were readily distinguished from O. lycopersici, which produces conidia in chains and is known to infect tomato only in Australia. The phylogenetic analysis showed that O. neolycopersici is a distinct powdery mildew species, and it is neither identical nor closely related to any known polyphagous species of the Erysiphaceae. Apparently, it was introduced into the United States and Canada only in the 1990s, but its origin is still unknown.
Publisher: Springer Science and Business Media LLC
Date: 23-05-2006
Publisher: Springer Science and Business Media LLC
Date: 18-10-2006
Publisher: Springer Science and Business Media LLC
Date: 29-08-2017
Publisher: Elsevier BV
Date: 11-2021
Publisher: Springer Science and Business Media LLC
Date: 22-12-2015
Publisher: Frontiers Media SA
Date: 16-07-2020
Publisher: Elsevier BV
Date: 06-2001
Publisher: Scientific Societies
Date: 08-2019
DOI: 10.1094/PHYTO-01-19-0013-R
Abstract: Powdery mildews, ubiquitous obligate biotrophic plant pathogens, are often attacked in the field by mycoparasitic fungi belonging to the genus Ampelomyces. Some Ampelomyces strains are commercialized biocontrol agents of crop pathogenic powdery mildews. Using Agrobacterium tumefaciens-mediated transformation (ATMT), we produced stable Ampelomyces transformants that constitutively expressed green fluorescent protein (GFP) to (i) improve the visualization of the mildew–Ampelomyces interaction and (ii) decipher the environmental fate of Ampelomyces fungi before and after acting as a mycoparasite. Detection of Ampelomyces structures, and especially hyphae, was greatly enhanced when erse powdery mildew, leaf, and soil s les containing GFP transformants were examined with fluorescence microscopy compared with brightfield and differential interference contrast optics. We showed for the first time, to our knowledge, that Ampelomyces strains can persist up to 21 days on mildew-free host plant surfaces, where they can attack powdery mildew structures as soon as these appear after this period. As saprobes in decomposing, powdery mildew-infected leaves on the ground and also in autoclaved soil, Ampelomyces strains developed new hyphae but did not sporulate. These results indicate that Ampelomyces strains occupy a niche in the phyllosphere where they act primarily as mycoparasites of powdery mildews. Our work has established a framework for a molecular genetic toolbox for the genus Ampelomyces using ATMT.
Publisher: Wiley
Date: 12-03-2003
DOI: 10.1002/PS.689
Abstract: There are approximately 40 fungal species that have so far been reported as natural antagonists of powdery mildews or have been tested as their potential biocontrol agents. This review summarizes the published data on their identification, taxonomy, ecology, modes of action and biocontrol efficacy. The results obtained with the two products already registered, AQ10 Biofungicide and Sporodex, are also discussed.
Publisher: Scientific Societies
Date: 02-2018
Publisher: Scientific Societies
Date: 07-2012
Abstract: Pycnidial fungi belonging to the genus Ampelomyces are common intracellular mycoparasites of powdery mildews worldwide. Some strains have already been developed as commercial biocontrol agents (BCAs) of Erysiphe necator and other powdery mildew species infecting important crops. One of the basic, and still debated, questions concerning the tritrophic relationships between host plants, powdery mildew fungi, and Ampelomyces mycoparasites is whether Ampelomyces strains isolated from certain species of the Erysiphales are narrowly specialized to their original mycohosts or are generalist mycoparasites of many powdery mildew fungi. This is also important for the use of Ampelomyces strains as BCAs. To understand this relationship, the nuclear ribosomal DNA internal transcribed spacer (ITS) and partial actin gene (act1) sequences of 55 Ampelomyces strains from E. necator were analyzed together with those of 47 strains isolated from other powdery mildew species. These phylogenetic analyses distinguished five major clades and strains from E. necator that were present in all but one clade. This work was supplemented with the selection of nine inter-simple sequence repeat (ISSR) markers for strain-specific identification of Ampelomyces mycoparasites to monitor the environmental fate of strains applied as BCAs. The genetic distances among strains calculated based on ISSR patterns have also highlighted the genetic ersity of Ampelomyces mycoparasites naturally occurring in grapevine powdery mildew. Overall, this work showed that Ampelomyces strains isolated from E. necator are genetically erse and there is no indication of strict mycohost associations in these strains. However, these results cannot rule out a certain degree of quantitative association between at least some of the Ampelomyces lineages identified in this work and their original mycohosts.
Publisher: Wiley
Date: 12-1998
DOI: 10.1046/J.1469-8137.1998.00316.X
Abstract: This is the first extensive investigation that quantifies natural mycoparasitic relationships in the phyllosphere. The presence of Ampelomyces spp. was quantified in naturally occurring powdery mildew fungi collected in Hungary and Romania between 1992 and 1995. A total of 570 s les was studied representing 27 species (nine genera) of the Erysiphaceae infecting 41 host plant genera. The incidence of Ampelomyces spp., determined as the proportion of s les in which intracellular pycnidia were present, varied between 4.3 and 68.8% in the host fungal genera studied. The intensity of mycoparasitism, defined as a percentage of the powdery mildew mycelia parasitized by Ampelomyces , ranged from 0.15 to 65%. Both the incidence and the intensity of mycoparasitism showed the lowest values in Blumeria graminis (DC.) Speer collected from wild and cultivated monocotyledons, while the highest values were found in Arthrocladiella mougeotii (Lév.) Vassilkov infecting Lycium halimifolium Mill. plants. The paper reports for the first time the natural occurrence of Ampelomyces in Sawadaea bicornis (Wallr.∶Fr.) Homma on maple.
Publisher: Springer Science and Business Media LLC
Date: 21-09-2014
Publisher: Scientific Societies
Date: 07-2023
DOI: 10.1094/MPMI-01-23-0009-LE
Abstract: When comparing the requirements of erse journals to publish microbial ‘Genome Reports,’ we noticed that some mostly focus on benchmarking universal single-copy orthologs scores as a quality measure, while the exclusion of possible contaminating sequences from genomic resources and the possible misidentification of the target microbes receive less attention. To deal with these quality issues, we suggest that DNA barcodes that are widely accepted for the identification of the target microbe species should be extracted from newly reported genome resources and included in phylogenetic analyses to confirm the identity of the sequenced microorganisms before Genome Reports are published. This approach, applied, for ex le, by the journal IMA Fungus, largely prevents the misidentification of the microbes that are targeted for whole-genome sequencing (WGS). In addition, contig similarity values, including GC content, remapping coverage of WGS reads, and BLASTN searches against the National Center for Biotechnology Information nucleotide database, would also reveal contamination issues. The values of these two recommendations to improve the publication criteria for microbial Genome Reports in erse journals are demonstrated here through analyses of a draft genome published in Molecular Plant-Microbe Interactions and then retracted due to contaminations. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .
Publisher: MDPI AG
Date: 24-03-2022
Abstract: Noble rot is a favorable form of the interaction between grape (Vitis spp.) berries and the phytopathogenic fungus Botrytis cinerea. The transcriptome pattern of grapevine cells subject to natural noble rot development in the historic Hungarian Tokaj wine region has not been previously published. Furmint, a traditional white Tokaj variety suited to develop great quality noble rot was used in the experiments. Exploring a subset of the Furmint transcriptome redox and hormonal changes distinguishing between noble rot and bunch rot was revealed. Noble rot is defined by an early spike in abscisic acid (ABA) accumulation and a pronounced remodeling of ABA-related gene expression. Transcription of glutathione S-transferase isoforms is uniquely upregulated, whereas gene expression of some sectors of the antioxidative apparatus (e.g., catalases, carotenoid biosynthesis) is downregulated. These mRNA responses are lacking in berries exposed to bunch rot. Our results help to explain molecular details behind the fine and dynamic balance between noble rot and bunch rot development.
Publisher: Springer Science and Business Media LLC
Date: 29-06-2010
Publisher: Naturalis Biodiversity Center
Date: 30-06-2018
Publisher: Wiley
Date: 04-2004
Publisher: Springer Science and Business Media LLC
Date: 02-10-2010
Publisher: Oxford University Press (OUP)
Date: 02-09-2009
Abstract: Arabidopsis (Arabidopsis thaliana) NADPH oxidases have been reported to suppress the spread of pathogen- and salicylic acid-induced cell death. Here, we present dual roles of RBOHD (for respiratory burst oxidase homolog D) in an Arabidopsis-Alternaria pathosystem, suggesting either initiation or prevention of cell death dependent on the distance from pathogen attack. Our data demonstrate that a rbohD knockout mutant exhibits increased spread of cell death at the macroscopic level upon inoculation with the fungus Alternaria brassicicola. However, the cellular patterns of reactive oxygen species accumulation and cell death are fundamentally different in the AtrbohD mutant compared with the wild type. Functional RBOHD causes marked extracellular hydrogen peroxide accumulation as well as cell death in distinct, single cells of A. brassicicola-infected wild-type plants. This single cell response is missing in the AtrbohD mutant, where infection triggers spreading-type necrosis preceded by less distinct chloroplastic hydrogen peroxide accumulation in large clusters of cells. While the salicylic acid analog benzothiadiazole induces the action of RBOHD and the development of cell death in infected tissues, the ethylene inhibitor aminoethoxyvinylglycine inhibits cell death, indicating that both salicylic acid and ethylene positively regulate RBOHD and cell death. Moreover, A. brassicicola-infected AtrbohD plants hyperaccumulate ethylene and free salicylic acid compared with the wild type, suggesting negative feedback regulation of salicylic acid and ethylene by RBOHD. We propose that functional RBOHD triggers death in cells that are damaged by fungal infection but simultaneously inhibits death in neighboring cells through the suppression of free salicylic acid and ethylene levels.
Publisher: Public Library of Science (PLoS)
Date: 24-03-2015
Publisher: Wiley
Date: 04-2004
Publisher: Wiley
Date: 25-01-2011
Publisher: Oxford University Press (OUP)
Date: 08-2021
DOI: 10.1093/GBE/EVAB182
Abstract: Powdery mildews are among the most important plant pathogens worldwide, which are often attacked in the field by mycoparasitic fungi belonging to the genus Ampelomyces. The taxonomy of the genus Ampelomyces is unresolved, but well-supported molecular operational taxonomic units were repeatedly defined suggesting that the genus may include at least four to seven species. Some Ampelomyces strains were commercialized as biocontrol agents of crop pathogenic powdery mildews. However, the genomic mechanisms underlying their mycoparasitism are still poorly understood. To date, the draft genome of a single Ampelomyces strain, designated as HMLAC 05119, has been released. We report a high-quality, annotated hybrid draft genome assembly of A. quisqualis strain BRIP 72107, which, based on phylogenetic analyses, is not conspecific with HMLAC 05119. The constructed genome is 40.38 Mb in size, consisting of 24 scaffolds with an N50 of 2.99 Mb and 96.2% completeness. Our analyses revealed “bipartite” structure of Ampelomyces genomes, where GC-balanced genomic regions are interspersed by longer or shorter stretches of AT-rich regions. This is also a hallmark of many plant pathogenic fungi and provides further evidence for evolutionary affinity of Ampelomyces species to plant pathogenic fungi. The high-quality genome and annotation produced here provide an important resource for future genomic studies of mycoparasitisim to decipher molecular mechanisms underlying biocontrol processes and natural tritrophic interactions.
Publisher: Scientific Societies
Date: 05-2008
Abstract: This is the first North American report of Oidium longipes, an anamorphic powdery mildew species described recently in Europe. It was found on vegetatively propagated petunia grown in a commercial greenhouse in New Jersey, USA, where it caused a rapidly spreading disease. The pathogen might have originated offshore and may have already been distributed in the United States through horticultural trade. During field surveys in Europe, it was found on petunia in Hungary and Austria as well this is the first report of O. longipes from these two countries. A detailed light microscopy study of American and European specimens of O. longipes, including freshly collected s les and authentic herbarium specimens, revealed that its conidiophore morphology is more variable than illustrated in the original species description or in subsequent works. Microcycle conidiation, a process not yet known to occur in powdery mildews, was repeatedly observed in O. longipes. The rDNA internal transcribed spacer (ITS) sequences were identical in colonies containing different conidiophore types as well as in a total of five specimens collected from petunia in the United States, Austria, Hungary, Germany, and Switzerland. A phylogenetic analysis of the ITS sequences revealed that the closest known relative of O. longipes is O. lycopersici, known to infect tomato only in Australia. Cross-inoculation tests showed that O. longipes from petunia heavily infected tobacco cv. Xanthi, while the tomato and eggplant cultivars tested were moderately susceptible to this pathogen. These results indicate that its spread represents a potential danger to a number of solanaceous crops. Our ad hoc field surveys conducted in 2006 and 2007 did not detect it outside New Jersey in the United States all the other powdery mildew–infected petunias, collected in New York and Indiana, were infected by Podosphaera xanthii. In Europe, most of the powdery mildew–infected petunias examined in this study were infected by P. xanthii or Golovinomyces orontii. Our multiple inoculation tests revealed that the same petunia plants and even the same leaves can be infected concomitantly by O. longipes, O. neolycopersici, G. orontii, and P. xanthii. Thus, it is at present unclear to what extent O. longipes contributes to the powdery mildew epidemics that develop year after year on solanaceous plants in many parts of the world.
Publisher: Naturalis Biodiversity Center
Date: 31-12-2019
DOI: 10.3767/PERSOONIA.2019.43.06
Abstract: Novel species of fungi described in this study include those from various countries as follows: Antarctica , Apenidiella antarctica from permafrost, Cladosporium fildesense fromanunidentifiedmarinesponge. Argentina , Geastrum wrightii onhumusinmixedforest. Australia , Golovinomyces glandulariae on Glandularia aristigera, Neoanungitea eucalyptorum on leaves of Eucalyptus grandis, Teratosphaeria corymbiicola on leaves of Corymbia ficifolia, Xylaria eucalypti on leaves of Eucalyptus radiata. Brazil, Bovista psammophila on soil, Fusarium awaxy on rotten stalks of Zea mays, Geastrum lanuginosum on leaf litter covered soil, Hermetothecium mikaniae-micranthae (incl. Hermetothecium gen. nov.)on Mikania micrantha, Penicillium reconvexovelosoi in soil, Stagonosporopsis vannaccii from pod of Glycine max. British Virgin Isles , Lactifluus guanensis onsoil. Canada , Sorocybe oblongispora on resin of Picea rubens. Chile, Colletotrichum roseum on leaves of Lapageria rosea. China, Setophoma caverna fromcarbonatiteinKarstcave. Colombia , Lareunionomyces eucalypticola on leaves of Eucalyptus grandis. Costa Rica, Psathyrella pivae onwood. Cyprus , Clavulina iris oncalcareoussubstrate. France , Chromosera ambigua and Clavulina iris var. occidentalis onsoil. French West Indies , Helminthosphaeria hispidissima ondeadwood. Guatemala , Talaromyces guatemalensis insoil. Malaysia , Neotracylla pini (incl. Tracyllales ord. nov. and Neotra- cylla gen. nov.)and Vermiculariopsiella pini on needles of Pinus tecunumanii. New Zealand, Neoconiothyrium viticola on stems of Vitis vinifera, Parafenestella pittospori on Pittosporum tenuifolium, Pilidium novae-zelandiae on Phoenix sp. Pakistan , Russula quercus-floribundae onforestfloor. Portugal , Trichoderma aestuarinum from salinewater. Russia , Pluteus liliputianus on fallen branch of deciduous tree, Pluteus spurius on decaying deciduouswoodorsoil. South Africa , Alloconiothyrium encephalarti, Phyllosticta encephalarticola and Neothyrostroma encephalarti (incl. Neothyrostroma gen. nov.)onleavesof Encephalartos sp., Chalara eucalypticola on leaf spots of Eucalyptus grandis × urophylla, Clypeosphaeria oleae on leaves of Olea capensis, Cylindrocladiella postalofficium on leaf litter of Sideroxylon inerme , Cylindromonium eugeniicola (incl. Cylindromonium gen. nov.)onleaflitterof Eugenia capensis , Cyphellophora goniomatis on leaves of Gonioma kamassi , Nothodactylaria nephrolepidis (incl. Nothodactylaria gen. nov. and Nothodactylariaceae fam. nov.)onleavesof Nephrolepis exaltata , Falcocladium eucalypti and Gyrothrix eucalypti on leaves of Eucalyptus sp., Gyrothrix oleae on leaves of Olea capensis subsp. macrocarpa , Harzia metro sideri on leaf litter of Metrosideros sp., Hippopotamyces phragmitis (incl. Hippopota- myces gen. nov.)onleavesof Phragmites australis , Lectera philenopterae on Philenoptera violacea , Leptosillia mayteni on leaves of Maytenus heterophylla , Lithohypha aloicola and Neoplatysporoides aloes on leaves of Aloe sp., Millesimomyces rhoicissi (incl. Millesimomyces gen. nov.) on leaves of Rhoicissus digitata , Neodevriesia strelitziicola on leaf litter of Strelitzia nicolai , Neokirramyces syzygii (incl. Neokirramyces gen. nov.)onleafspotsof
Publisher: Springer Science and Business Media LLC
Date: 23-03-2021
Publisher: Springer Science and Business Media LLC
Date: 08-06-1998
Abstract: Phylogenetic relationships among Ampelomyces isolates, pycnidial hyperparasites and biological control agents of powdery mildews, were inferred from internal transcribed spacer (ITS) sequences of the ribosomal DNA (rDNA). Currently, these hyperparasites are considered to be a single species, A. quisqualis, despite observed morphological and cultural differences. Ten Ampelomyces isolates, representing seven previously defined ITS RFLP groups, were sequenced and analyzed. Sequence- ergence values among isolates belonging to different RFLP groups ranged from 4.3 to 22.4%, suggesting that these isolates may represent different taxa. When Ampelomyces ITS sequences were analyzed by cladistic methods with the sequences of other ascomycetous fungi, they formed two lineages in the Dothideales. Slow-growing Ampelomyces isolates formed a clade with Leptosphaeria microscopica and L. nodorum, whereas fast-growing Ampelomyces isolates formed a clade with Epicoccum nigrum. Sequence- ergence values between these two clades ranged from 17.3 to 22.4%, suggesting that the taxa in the two clades are not closely related and possibly not congeneric. The data presented here indicate that the identification of 'A. quisqualis' isolates used in biological control experiments should be re-evaluated.
Publisher: Scientific Societies
Date: 04-2022
DOI: 10.1094/PHYTO-08-21-0337-A
Abstract: Powdery mildew fungi (Erysiphaceae) are widespread obligate biotrophic plant pathogens. Thus, applying genetic and omics approaches to study these fungi remains a major challenge, particularly for species with hemiendophytic mycelium. These belong to a distinct phylogenetic lineage within the family Erysiphaceae. To date, only a single draft genome assembly is available for this clade, obtained for Leveillula taurica. Here, we generated the first draft genome assemblies of Pleochaeta shiraiana and Phyllactinia moricola, two tree-parasitic powdery mildew species with hemiendophytic mycelium, representing two genera that have not yet been investigated with genomics tools. The Pleochaeta shiraiana assembly was 96,769,103 bp in length and consisted of 14,447 scaffolds, and the Phyllactinia moricola assembly was 180,382,532 bp in length on 45,569 scaffolds. Together with the draft genome of L. taurica, these resources will be pivotal for understanding the molecular basis of the lifestyle of these fungi, which is unique within the family Erysiphaceae.
Publisher: Wiley
Date: 12-2004
Publisher: American Society for Microbiology
Date: 29-10-2019
Abstract: Powdery mildew fungi are widespread and agronomically relevant phytopathogens causing major yield losses. Their genomes have disproportionately large numbers of mobile genetic elements, and they have experienced a significant loss of highly conserved fungal genes. In order to learn more about the evolutionary history of this fungal group, we explored the genome of an Asian oak tree pathogen, Parauncinula polyspora , a species that erged early during evolution from the remaining powdery mildew fungi. We found that the P. polyspora draft genome is comparatively compact, has a low number of protein-coding genes, and, despite the absence of a dedicated genome defense system, lacks the massive proliferation of repetitive sequences. Based on these findings, we infer an evolutionary trajectory that shaped the genomes of powdery mildew fungi.
Publisher: Scientific Societies
Date: 06-2011
Abstract: Peach rusty spot, an economically important disease of peach (Prunus persica var. persica), appears as necrotic spots on fruit. The etiology of the disease is still not well understood, although it has long been suspected that the causal agent is the apple powdery mildew pathogen, Podosphaera leucotricha. This work confirmed this hypothesis based on cross-inoculation experiments and analysis of rDNA internal transcribed spacer sequences polymerase chain reaction lified from rusty spot and peach powdery mildew lesions. Cross-inoculations of apple and peach leaves with P. leucotricha and P. pannosa, the causal agent of peach powdery mildew, showed that (i) young peach fruit, up to 5 cm in diameter, developed symptoms typical of rusty spot following inoculation with P. leucotricha (ii) leaves of ‘Jonagold’ apple seedlings developed powdery mildew infections when inoculated by touching young rusty spot lesions to their surfaces (iii) P. leucotricha sporulated on young peach fruit up to 5 cm in diameter and (iv) peach leaves and young shoots were not susceptible to P. leucotricha, whereas P. pannosa infected all the green parts of peach. A field experiment revealed that there was only a 2- to 3-week period of time during early peach fruit development when the epidermis was susceptible to P. leucotricha. An outcome of this study is that now a clear distinction can be made between the symptoms caused by P. pannosa and P. leucotricha on peach.
Publisher: Informa UK Limited
Date: 09-2015
DOI: 10.3852/15-062
Abstract: Phylogenetic relationships of the Uncinula lineage, which is the basal group in the genus Erysiphe, were investigated with 167 sequences of nuc ITS1-5. 8S-ITS2 and the 28S rDNA regions. Backbone tree analyses with six datasets and two tree-constructing methods revealed that the Uncinula lineage is ided into seven distinct clades. Clades 1-5 each contained a representative powdery mildew species, namely E. australiana in Clade 1, E. liquidambaris in Clade 2, E. adunca in Clade 3, E. fraxinicola in Clade 4 and E. actinidiae in Clade 5. Clade 6 comprises 71 sequences including the Microsphaera lineage and 17 species of the Uncinula lineage, such as E. carpinicola, E. carpinilaxiflorae, E. miyabei, E. glycines and E. necator. Topology tests supported the Microsphaera lineage forming a monophyletic clade in Clade 6, suggesting that Microsphaera-type appendages appeared only once in this clade to erge into the Microsphaera lineage. Clade 7 consists of 72 sequences containing 30 species, including species of sects. Californiomyces and Typhulochaeta, four species from Nothofagus, species of sect. Erysiphe parasitising herbaceous plants belonging to the Asteraceae, Rosaceae and Saxifragaceae. Molecular clock analysis suggests that the major seven clades appeared 50-30 million years ago (Ma) in the Paleogene Period. The Microsphaera lineage may have split from the Uncinula lineage at the boundary of the Paleogene and Neogene, when appendages with dichotomously branched tips appeared. The clade of the species on Nothofagus split from the northern hemisphere species about 20-10 million years ago (Ma) in the Miocene Epoch, and host-shift from trees to herbs also might have occurred in this period.
Publisher: Springer Science and Business Media LLC
Date: 03-2019
Publisher: Informa UK Limited
Date: 11-2004
Location: Hungary
Start Date: 2022
End Date: 2023
Funder: Department of Agriculture, Fisheries and Forestry, Australian Government
View Funded ActivityStart Date: 2020
End Date: 2022
Funder: Grains Research and Development Corporation
View Funded ActivityStart Date: 2019
End Date: 2024
Funder: Grains Research and Development Corporation
View Funded ActivityStart Date: 2021
End Date: 2024
Funder: Australian Research Council
View Funded ActivityStart Date: 2017
End Date: 2018
Funder: Department of Agriculture and Water Resources, Australian Government
View Funded ActivityStart Date: 2008
End Date: 2012
Funder: European Union Seventh Framework Programme
View Funded ActivityStart Date: 2017
End Date: 2020
Funder: European Regional Development Fund
View Funded ActivityStart Date: 08-2021
End Date: 08-2024
Amount: $525,000.00
Funder: Australian Research Council
View Funded Activity