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

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

A taxonomic revision of the hitherto monotypic genus Blumeria was conducted incorporating multi-gene sequence analyses, host preference data and morphological criteria. The sequenced loci included rDNA ITS, partial chitin synthase gene (CHS1), as well as fragments of two unnamed orthologous genes (Bgt-1929, Bgt-4572). The combined evidence led to a reassessment and a new neotypification of B. graminis s. str. (emend.), and the description of seven additional species, viz. B. americana sp. nov. (mainly on hosts of the Triticeae), B. avenae sp. nov. (on Avena spp.), B. bromi-cathartici sp. nov. (on Bromus catharticus), B. bulbigera comb. nov. (on Bromus spp.), B. dactylidis sp. nov. (on Dactylis glomerata as the main host, but also on various other hosts), B. graminicola sp. nov. (on Poa spp. as principal hosts, but also on various other hosts), and B. hordei sp. nov. (on Hordeum spp.). Synonyms were assessed, some were lectotypified, and questionable names previously associated with powdery mildew on monocots were discussed although their identities remained unresolved. Keys to the described species were developed. [ABSTRACT FROM AUTHOR]

Recently published phylogenetic analyses of the Golovinomyces orontii complex revealed that three different species of the genus Golovinomyces may occur on cucurbitaceous hosts, viz., G. bolayi , G. orontii s. str., and G. tabaci. Owing to its morphological characteristics, Erysiphe cucurbitacearum (≡ G. cucurbitacearum) was tentatively reduced to synonym with G. tabaci. However, final conclusions on the identity and status of E. cucurbitacearum , described from China on Cucumis sativus , as putative synonym of G. tabaci required a phylogenetic confirmation and epitypification with ex-epitype sequences. Therefore, a sample of G. cucurbitacearum collected on C. sativus in Xinjiang Uygur Autonomous Region, China, in 2014 (HMJAU-PM91862) has been sequenced and is designated as epitype of the latter species, since its holotype material (HMAS 40016, collected in 1954) turned out to be too old for molecular examinations. As a result of morphological examinations and phylogenetic analyses based on ex-epitype ITS and 28S rDNA sequences, the recently assumed synonymy of G. cucurbitacearum , found on C. sativus in China, with G. tabaci could be confirmed. In addition, two new host species of G. tabaci , viz., Trigonotis peduncularis (Boraginaceae) and Rubia cordifolia (Rubiaceae), were concurrently identified. Trigonotis peduncularis is the first verified boraginaceous host for G. tabaci. • Golovinomyces found on Cucumis sativus was reallocate to as a synonymy of G. tabaci. • Additional host family and host species of G. tabaci were first found. • Phylogenetic analyses and morphology confirmed the results in this study. [ABSTRACT FROM AUTHOR]

An asexual morph of a powdery mildew was found on Buddleja asiatica (Scrophulariaceae) in Nepal. The morphological traits of this powdery mildew strongly resemble those of Phyllactinia species (including Ovulariopsis ) belonging to a phylogenetically basal group closely related to Leveillula species, but phylogenetic examinations and analyses clearly showed that this fungus pertains to Leveillula . Within the latter genus, it seems to be allied to L. duriaei , but clearly differs from this species in having conidiophores arising from superficial hyphae and narrower conidia with different length/width ratios. Therefore, the powdery mildew on B. asiatica is described as Leveillula buddlejae sp. nov. [ABSTRACT FROM AUTHOR]

Since the mid-nineties Phyllactinia fraxini has become frequent in Germany. This species has hitherto been characterized by having straight conidiophore foot cells. However, we found that recent collections from Germany have conidiophores with sinuated and twisted foot cells. So far sinuated foot cells were only known from the related P. fraxinicola , another species with Eastern Asian origin. We thus hypothesized that recent collections from Germany belong to P. fraxinicola which might have been introduced to Europe. Using morphological and molecular rDNA data we found that no introduction took place and that there is only P. fraxini in Germany. [ABSTRACT FROM AUTHOR]

Cystotheca lanestris on the new host Quercus canbyi , Microidium bauhiniicola on the new host Bauhinia macranthera and an undescribed species of Phyllactinia on Mimosa aculeaticarpa have recently been collected in Mexico. Analyses of morphological traits and molecular sequence data led to identifications of the causal agents of the powdery mildew diseases involved. Microidium bauhiniicola , hitherto only known from Argentina and Brazil, is new to Mexico. The phylogenetic analysis revealed an isolated position distant from Microidium indicating an undescribed genus, which is introduced as Bulbomicroidium gen. nov. Sequences derived from a Mexican specimen of C. lanestris on Quercus canbyi agree completely with other North American sequences, but differ from sequences retrieved from Asian collections, suggesting that C. lanestris in Asia is not conspecific with C. lanestris s. str. in North America. A new species of Phyllactinia on Mimosa malacophylla is morphologically similar to P. dalbergiae but readily distinguishable by differences in the asexual morph. Based on morphological peculiarities and results of molecular sequence analyses, this species is described as Phyllactinia mimosae sp. nov. [ABSTRACT FROM AUTHOR]

Asexual and sexual morphs of powdery mildews on Fontanesia phillyreoides and Jasminum fruticans , two hitherto unknown host species, have recently been collected in Turkey. Analyses of morphological traits and molecular sequence data led to identifications of the causal agents of the powdery mildew diseases involved. Fontanesia phillyreoides was infected by Phyllactinia fraxini , and the powdery mildew on Jasminum fruticans can be classified as Erysiphe cf. aquilegiae . The latter host showed traces of a co-infection with a second powdery mildew (only asexual morph) belonging to the genus Phyllactinia (= Ovulariopsis ) and morphologically well agreeing with P. fraxini . [ABSTRACT FROM AUTHOR]

To identify powdery mildew fungi infecting Oenothera spp. in Europe, specimens collected worldwide were examined based on morphology and internal transcribed spacer (ITS) sequences of the nuclear rRNA gene complex. The specimens were morphologically barely distinguishable from each other, each exhibiting pseudoidium-type conidiophores but sexual morphs lacking. Surprisingly, based on ITS sequence analyses, these specimens represented two species, i.e. Erysiphe howeana , known to infect Oenothera spp., and Erysiphe cf. alphitoides , which has never been recorded on herbaceous plants. Both species were detected on the invasive O. biennis in different parts of the world including regions where O. biennis was introduced only recently. [ABSTRACT FROM AUTHOR]

The asexual stage of a powdery mildew on Chelidonium majus has been reported from various countries, but the corresponding sexual stage of this fungus has not yet been reported. In Oct 2011, many chasmothecia of this powdery mildew was found on C. majus plants growing in the campus of Jilin Agricultrual University in Changchun, China. The morphological characteristics of the asexual and sexual stages revealed this fungus as Erysiphe macleayae. A sequence of the ribosomal DNA internal transcribed spacer region including the 5.8S rRNA gene, amplified from DNA of several chasmothecia, was 99.8–100% identical to that of E. macleayae records on GenBank. This is the first report of the teleomorph of E. macleayae on C. majus. [ABSTRACT FROM AUTHOR]

Phylogenetic and morphological analyses have been conducted on powdery mildew specimens on different Berberis and Mahonia spp. from Asia, Europe and North America. The present study showed that collections of Erysiphe berberidis exhibit a high degree of morphological plasticity of the sexual morph, in contrast to their morphologically, rather uniform, asexual morph. In phylogenetic tree, all sequences cluster in a large strongly supported clade, without any indication and support for further differentiation into cryptic species. There are three morphological types within E. berberidis s. lat. that contain consistent differences. Until future multi-locus analyses will be available, we prefer to treat these 'morphological types' as varieties. These include Erysiphe berberidis var. berberidis , E. berberidis var. asiatica , and E. berberidis var. dimorpha comb. nov. (≡ Microsphaera berberidis var. dimorpha , M. berberidicola , and M. multappendicis ). To fix the application of species name E. berberidis , an appropriate epitype was designated, with an ITS sequences., (2022, by The Mycological Society of Japan.)

The phylogeny and taxonomy of Podosphaera filipendulae (including P. filipendulensis , syn. nov.) have been examined. Asian, European and North American collections were examined and the nucleotides sequences of their partial rDNA region were determined. In particular, the relationship between P. filipendulae and P. spiraeae was analysed. The results confirmed P. filipendulae and P. spiraeae as two separate, morphologically similar species. The phylogenetic analysis revealed a similar phylogeny to that of the host genera. Although ITS sequences retrieved from Asian, European and North American specimens of P. filipendulae on various Filipendula spp. are identical to sequences from P. macularis on hop, there is consistently one base substitution at the 5'-end of 28S rRNA gene between the species. This result provides evidence that the hop powdery mildew and P. filipendulae are biologically and morphologically clearly distinguished, and should be maintained as two separate species., (2021, by The Mycological Society of Japan.)

A taxonomic revision of the hitherto monotypic genus Blumeria was conducted incorporating multi-gene sequence analyses, host preference data and morphological criteria. The sequenced loci included rDNA ITS, partial chitin synthase gene ( CHS 1), as well as fragments of two unnamed orthologous genes ( Bgt-1929 , Bgt-4572 ). The combined evidence led to a reassessment and a new neotypification of B. graminis s. str. (emend.), and the description of seven additional species, viz. B. americana sp. nov. (mainly on hosts of the Triticeae ), B. avenae sp. nov. (on Avena spp.), B. bromi-cathartici sp. nov. (on Bromus catharticus ), B. bulbigera comb. nov. (on Bromus spp.), B. dactylidis sp. nov. (on Dactylis glomerata as the main host, but also on various other hosts), B. graminicola sp. nov. (on Poa spp. as principal hosts, but also on various other hosts), and B. hordei sp. nov. (on Hordeum spp .). Synonyms were assessed, some were lectotypified, and questionable names previously associated with powdery mildew on monocots were discussed although their identities remained unresolved. Keys to the described species were developed., Competing Interests: none, (2021, by The Mycological Society of Japan, © 2021 Her Majesty the Queen in Right of Canada.)