Search

Powdery mildew on various Acalypha spp. has previously been assigned to Erysiphe acalyphae (≡ Uncinula acalyphae). In a recently published phylogenetic-taxonomic reassessment, it has been revealed that sequences retrieved from this Acalypha powdery mildew form a separate lineage representing a genus of its own for which the old genus name Salmonomyces was reinstated, with the new combination Salmonomyces acalyphae. Pseudoidium javanicum, described from Indonesia on Acalypha javanica, was reduced to synonymy with Salmonomyces acalyphae. Attempts to obtain sequence data from type material of Uncinula acalyphae, described from Kunming, Yunnan Province, China, on Acalypha supera (= Acalypha brachystachya), and efforts to collect fresh Chinese samples for epitypification purposes failed during the course of the works for the abovementioned studies. Therefore, the name Salmonomyces acalyphae was applied to all collections on Acalypha, first and foremost on the basis of the congruence of the morphological characteristics of the asexual morphs on Acalypha supera and other Acalypha spp. Meanwhile, attempts to trace new collections of this powdery mildew on Acalypha supera in Kunming, Yunnan Province, were successful and allow epitypification of Uncinula acalyphae with ex-epitype sequence data. Phylogenetic analyses surprisingly revealed the hidden diversity that two sister species are involved within Salmonomyces, viz., Salmonomyces acalyphae with both anamorph and teleomorph, confined to Acalypha supera in South China as host, and a second species, so far only known as anamorph, with wider host range and distribution, for which the new combination Salmonomyces javanicus, based on Pseudoidium javanicum, being introduced.

Erysiphe adunca s. lat. is a common powdery mildew species, distributed almost worldwide, on hosts of Populus and Salix species. Based on its wide host range and distribution as well as its strong morphological variations, E. adunca s. lat. was previously divided into several species or, alternatively, into varieties. However, comprehensive phylogenetic examinations on the putative monophyly of this species or the existence of a possible E. adunca species complex have not been conducted based on combined morphological and molecular approaches. In this study, we retrieved rDNA (ITS and LSU) sequences of 22 powdery mildew specimens on Populus and Salix spp. collected in China, Germany, Iran, Japan, Russia, and the United States and conducted morphological examinations of these and additional specimens. The morphological and molecular data obtained clearly indicate that E. adunca is a species complex comprised of at least four species., viz., E. adunca s. str. (on Populus spp. in Asia, Europe, and North America), E. capreae, including E. pseudoregularis as a new synonym (on Salix spp., particularly on species in Salix subgen. Vetrix sect. Vetrix in Asia, Europe, and North America), the reinstated E. salicis (on Salix spp. belonging to various subgenera of Salix in Asia and Europe), and E. mandshurica (which has been confirmed as a species of its own on Populus spp., in Asia). In addition to the clear phylogenetic differentiation, the morphology of the asexual and sexual morphs of E. adunca s. str., E. capreae and E. salicis is easily distinguishable. Sequences retrieved from collections on Salix gracilistyla (Uncinula salicis-gracilistylae), a species that was previously considered a variety of Uncinula adunca and Erysiphe adunca, formed a small subclade within the E. salicis clade and are now referred to as Erysiphe salicis var. salicis-gracilistylae comb. nov. Alphitomorpha adunca; Erysiphe capreae and E. salicis are epitypified, and a neotype is designated for Alphitomorpha obtusata, with ex-epitype sequences and, in the latter case, an ex-neotype sequence.

The abstract is available here: https://uscholar.univie.ac.at/o:1600630

A total of 103 tree and shrub samples infected with powdery mildew were collected during 2002&ndash, 2019 from locations within parks, botanical gardens and urban green areas within the Czech Republic and the powdery mildews were morphologically analyzed and identified. The most frequently represented genera were: Erysiphe (27, including former genera Microsphaera and Uncinula), Podosphaera (11, including former genus Sphaerotheca), Phyllactinia (3), Sawadaea (2) and Arthrocladiella (1). New records for the Czech Republic were: E. (U.) arcuata, E. (M.) deutziae, E. (M.) euonymicola, E. (U.) flexuosa, E. (M.) platani, E. (M.) symphoricarpi, E. (M.) vanbruntiana var. sambuci-racemosae, E. (U.) ulmi, Po. amelanchieris, Po. (Sph.) pruinosa and Po. (Sph.) spiraeae. The results were compared with the spectrum of powdery mildew species in the surrounding countries (Slovakia, Hungary, Poland and Germany (Bavaria)).

Previous reports revealed the importance of Thailand for diversity, systematics and evolution of powdery mildews. This report provides records of four additional species and variety belonging to the genus Erysiphe sect. Uncinula (Erysiphales) found in Thailand. Morphological descriptions of powdery mildew specimens found on hosts of four families and molecular phylogenetic analyses based on 28S rRNA gene and rDNA ITS sequences are provided. Three new records of Erysiphe sect. Uncinula spp. for Thailand are listed, and E. liquidambaris var. acalycinae is described.

Brazilian verbena (Verbena brasiliensis, family Lamiaceae) is a highly invasive plant found throughout the southern portion of the United States. As suggested by its name, it originates in South America but has prospered in the US due to its highly ruderal growing pattern and its ability to tolerate drought and disturbance. During the summer of 2019, sixty-four V. brasiliensis plants were growing in the University of Houston's temperature-controlled greenhouse (Houston, TX). Eight plants exhibited symptoms of powdery mildew infection on the stems and adaxial surface of the leaves. White circular powdery colonies with high numbers of aerially dispersing spores were observed on leaves, seemingly uncorrelated with leaf age. Upon examination, chlorosis of leaf tissue was detected in areas of infection. Conidiophores (n=25) were on average 210 μm in length and produced 6 to 9 conidia in true chains. Base-cells of conidiophores branched from hyphae forming right angles and averaged 35 μm long at the base. Conidia were hyaline, ovate, and measured 28-31 × 19-21μm. These structures are typical of the powdery mildew oidium anamorph of the genus Podosphaera. No chasmothecia were observed within colonies.The morphological characteristics and measurements were consistent with those of Podosphaera xanthii (Braun and Takamatsu 2000). Pathogenicity was confirmed by gently rubbing symptomatic V. brasiliensis leaves onto healthy leaves of V. brasiliensis plants (Lee 2013). Fifteen plants were inoculated, and five remained uninoculated to serve as negative controls. Inoculated plants developed powdery mildew symptoms between 6 to 12 days (averaging 10 days), whereas all controls remained disease-free. DNA was extracted from fungal tissue from the original plant, inocula sample, and the newly infected leaves. The internal transcribed region was amplified using the ITS1f and ITS4 primers (White 1990). Three samples, one from the original plant, the inocula, and the reisolated fungi were sequenced, identified using NCBI BLAST, and the resulting sequences were deposited in GenBank (MN818562, (inocula), MN818563 (re-isolate), MN818564 (original)). All three sequences had 98.7% similarity to the P. xanthii on Brazilian verbena reported in South Korea assession number KJ472787 (Cho et al 2014). All three samples were amplified using the mating type primer sets and PCR protocal described in Brewer et al 2011. All three samples were determined to be MAT1-1-1 based on positive and negative control used for MAT1-1-1 and MAT-1-2-1 Positive controls included DNA from confirmed isolates from MAT1-1-1 and MAT-1-2-1 and negative controls were sterile water. Podosphaera xanthii, a common powdery mildew species, has been reported on a large range of important agricultural hosts, especially cucurbits (McCreight 2006). This is the first formal report of P. xanthii in Texas as well as the first report on Brazilian verbena in the United States. While we did not explicitly measure the pathogen's effect on host fitness, infection may result in a reduction in the plant's invasiveness. As Texas is a large producer of cucurbits, this pathogen could impact agriculture in the state. Given the invasive nature of V. brasiliensis in areas of high disturbance, such as agricultural fields and restored prairies, this discovery has broad importance for both agriculture and the ecological conservation of native species. Acknowledgments This work was supported by the National Science Foundation (Award #DEB-1754287), Texas Ecolab, and the University of Houston. References Braun, U., Takamatsu, S. 2000. Phylogeny of Erysiphe, Microsphaera, Uncinula (Erysipheae) and Cystotheca, Podosphaera, Sphaerotheca (Cystotheceae) inferred from rDNA ITS sequences-some taxonomic consequences. Schlechtendalia 4:1-33. Brewer, M. T., Cadle-Davidson, L., Cortesi, P., Spanu, P. D., and Milgroom, M. G. 2011. Identification and structure of the mating-type locus and development of PCR-based markers for mating type in powdery mildew fungi. Fungal Genet. Biol. 48:704-713. Cho, S. E., Park, J. H., Hong, S. H., Kim, B. S., & Shin, H. D. 2014. First report of powdery mildew caused by Podosphaera xanthii on Verbena brasiliensis in Korea. Plant Dis. 98:8, 1159. Lee, H. B. 2013. First report of powdery mildew caused by Podosphaera xanthii (syn. P. fusca)n cocklebur in Korea. Plant Dis. 97(6), 842. McCreight, J. D. 2006. Melon-powdery mildew interactions reveal variation in melon cultigens and Podosphaera xanthii races 1 and 2. Journal of the American Society for Horticultural Science, 131(1), 59-65.

Erysiphe bulbouncinula (≡ Bulbouncinula bulbosa) on Koelreuteria paniculata is a powdery mildew native and endemic in China. Fresh samples of this species were collected on K. paniculata in Sichuan Province, China, in 2018. This is the fourth confirmed identification of this species. The original description in 1932 was based on one specimen from Hangzhou and then was described in Nanjing in 1990 and in Taiwan in 1993. The morphology of the new collections of this species is described and illustrated in detail, and agrees well with the original description of the type specimen except for the number of asci (8–16 asci per chasmothecia versus 7–9 asci in the type specimen). To explore the phylogenetic position of this poorly known species, three separate phylogenetic analyses, using partial 28S rDNA and the combination of internal transcribed spacer (ITS) and 28S rDNA sequences, were conducted. The results clearly showed that E. bulbouncinula form a monophyletic clade with strong bootstrap (BS) support (MP = 100%) constituting a sister clade to E. gracilis s. lat., form a subclade with Erysiphe sect. Californiomyces and then form a big group with sect. Typhulochaeta and sect. Uncinula. Phylogenetic results confirm that E. bulbouncinula is more closely allied to Erysiphe than to Phyllactinia. Thus, this species can be maintained in Erysiphe in its current circumscription, confirming Bulbouncinula as a synonym of Erysiphe.

In Switzerland, the manna ash (Fraxinus ornus) is native to the canton Ticino (https://www.infoflora.ch). In September and October 2020, a powdery mildew species of the genus Erysiphe sect. Uncinula was discovered in four…

Celtis sinensis Pers., commonly known as the Chinese hackberry, belongs to the family Cannabaceae. In Korea, the leaves and bark of this tree are used for the treatment of gastrointestinal disorders and lung abscess. In October 2015 to 2018, symptoms of powdery mildew were observed on the leaves of C. sinensis in a garden at Chonnam National University, Gwangju (35°10′0″N, 126°55′0″E), Korea. The symptoms included white powdery colonies on the surfaces of young leaves and brown spots on older leaves. The three specimens were deposited in the Environmental Microbiology Laboratory Herbarium, Chonnam National University, under accession numbers CNUFC PWS1, CNUFC PWS2, and CNUFC PWS3, respectively. The chasmothecia were most abundant on the lower surfaces of the leaves. The hyphal appressoria were lobed, single, or opposite in pairs. The conidiophores were cylindrical, 65 to 87 × 9 to 12 μm, followed by two or three straight cells. The conidia were ellipsoidal or cylindrical, 11.5 to 14.5 × 29 to 33.5 μm. The chasmothecia were 64 to 94.5 × 76.5 to 98.5 μm, globose, and black to dark brown. Each chasmothecium had eight to 16 appendages and was 98.5 to 167.5 μm long and 5.5 to 7.5 μm wide, containing four asci; each ascus contained four to five ascospores. The ascospores were ellipsoidal, 10.5 to 14 × 15.5 to 24.5 μm. On the basis of these characteristics, the fungus is morphologically similar to Erysiphe michikoae, as described by Meeboon et al. (2013). To confirm the morphological identification, genomic DNA was extracted directly from the mycelia and chasmothecia, using a DNA prep kit (Solgent, Daejeon, Korea). The internal transcribed spacer (ITS) regions of the rDNA of three specimens were amplified using the primers ITS5 and PM6, as described by Lee and Nguyen (2016). The ITS sequences from CNUFC PWS1, CNUFC PWS2, and CNUFC PWS3 were deposited at GenBank under accession numbers MK757876, MK757877, and MK757878, respectively. BLASTn with the ITS sequences showed 99% similarity with the sequences of E. michikoae (AB693963) and E. kusanoi (AB475120). Phylogenetic analyses based on the ITS rDNA indicated that the three specimens were identical to E. michikoae. Therefore, the causal pathogen was identified as E. michikoae based on the morphological and molecular analyses. Pathogenicity tests were performed by gently pressing the infected leaves onto 10 healthy leaves of C. sinensis. Powdery mildew symptoms were observed on the inoculated leaves after 10 to 15 days, whereas no symptoms were found on the control. The fungus on the inoculated leaves was morphologically identical to that on the naturally infected plants. Powdery mildew on C. sinensis has been previously reported as E. kusanoi (synonyms: E. kusanoi var. kusanoi, Uncinula kusanoi, and U. kusanoi var. kusanoi) and Pleochaeta shiraiana (synonyms: Uncinula shiraiana and Uncinulopsis shiraiana) in Japan, China, Taiwan, Korea, and South Africa (Farr and Rossman 2019). E. michikoae has been found in only C. jessoensis from Japan (Meeboon et al. 2013). To our knowledge, this is the first report of powdery mildew caused by E. michikoae on C. sinensis in Korea as well as worldwide. This information indicates that E. michikoae is able to infect other Celtis species and may pose as a serious threat to the health of C. sinensis in Korea. Further studies on the host range of E. michikoae are required.

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 divided 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 diverge 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.

A phylogeny of Erysiphe sect. Uncinula on Carpinus spp. was reconstructed using the 28S rDNA sequences and a combined alignment of the 28S, ITS, and IGS rDNA sequences. The analysis was supplemented with morphological data obtained from examination of voucher specimens. A sequence of Erysiphe sect. Uncinula on C. cordata formed a distinct lineage separated from sequences of other Erysiphe species on Carpinus spp., indicating a cryptic species, which is described as E. paracarpinicola. The new species is genetically as well as morphologically most similar to E. carpinicola s. str., but differs in having fewer asci per chasmothecium (mainly 3–5 vs 4–10) and shorter chasmothecial appendages. A key to species of Erysiphe sect. Uncinula on Carpinus spp. is provided.

Two new species of Erysiphe section Uncinula are described and illustrated based on the molecular and morphological analyses: (1) Erysiphe fernandoae sp. nov. on Fernandoa adenophylla is distinct from other Erysiphe species on the plant family Bignoniaceae by having smaller asci, ca 12 appendages per chasmothecium and being found only in Asia; (2) Erysiphe michikoae sp. nov. on Celtis jessoensis differs from Erysiphe kusanoi on other Celtis species in having smaller chasmothecial, ascal and ascospore dimensions, and fewer number of chasmothecium appendages. The phylogenetic relationships of the two new species with other closely related species are discussed based on 28S and ITS rDNA sequences.

A new species and a new variety of Erysiphe sect. Uncinula are described and illustrated. Erysiphe havrylenkoana is a new species found on Nothofagus alpina and N. obliqua in Argentina, and E. prunastri var. japonica is a new variety collected on Prunus maximowiczii in Japan. Erysiphe havrylenkoana differs from E. nothofagi, E. patagoniaca and E. magellanica in having unique helicoid appendages, brownish from the base to the beginning of helicoid part, spirally twisted at the center and straight or not spiral at the upper part with uncinate to circinate tip. The phylogenetic analyses of rDNA sequences clearly showed that the spiral pattern of helicoid appendages is an important morphological character to delimit species among Nothofagus powdery mildews. Erysiphe prunastri var. japonica is distinct from E. prunastri var. prunastri parasitizing hitherto Prunus species from East-Central Asia to Europe by having mainly eight asci per chasmothecium and smooth, rarely septate appendages.

Asexual sporulation (conidiation) is coordinately regulated in the grape powdery mildew pathogen Erysiphe necator but nothing is known about its genetic regulation. We hypothesized that genes required for conidiation in other fungi would be upregulated at conidiophore initiation or full conidiation (relative to preconidiation vegetative growth and development of mature ascocarps), and that the obligate biotrophic lifestyle of E. necator would necessitate some novel gene regulation. cDNA amplified fragment length polymorphism analysis with 45 selective primer combinations produced ≈1,600 transcript-derived fragments (TDFs), of which 620 (39%) showed differential expression. TDF sequences were annotated using BLAST analysis of GenBank and of a reference transcriptome for E. necator developed by 454-FLX pyrosequencing of a normalized cDNA library. One-fourth of the differentially expressed, annotated sequences had similarity to fungal genes of unknown function. The remaining genes had annotated function in metabolism, signaling, transcription, transport, and protein fate. As expected, a portion of orthologs known in other fungi to be involved in developmental regulation was upregulated immediately prior to or during conidiation; particularly noteworthy were several genes associated with the light-dependent VeA regulatory system, G-protein signaling (Pth11 and a kelch repeat), and nuclear transport (importin-β and Ran). This work represents the first investigation into differential gene expression during morphogenesis in E. necator and identifies candidate genes and hypotheses for characterization in powdery mildews. Our results indicate that, although control of conidiation in powdery mildews may share some basic elements with established systems, there are significant points of divergence as well, perhaps due, in part, to the obligate biotrophic lifestyle of powdery mildews.

Taxonomy and nomenclature of new Indian powdery mildew taxa described by Paul & Thakur (2006) have been revised and reassessed on the base of the current phylogenetic generic concept of the Erysiphaceae. The following species are validated, redescribed and illustrated: Erysiphe farmanii sp. nov., E. ficicola sp. nov., E. machiliana sp. nov., E. malloticola sp. nov., E. quercifolia sp. nov., Phyllactinia bauhiniae sp. nov. and P. cassiae-fistulae sp. nov. Furthermore, the following new combinations are introduced: Erysiphe religiosa comb. nov. (= Uncinula aspera var. solani), E. cyclobalanopsidis comb. nov. and E. kumaonensis comb. nov.

An Asian powdery mildew fungus Erysiphe (Uncinula) kenjiana (Erysiphales, Ascomycota) has been found in Ukraine. This is the first record of this fungus in Europe. In 2007, E. kenjiana was collected on four Ulmus species in Kiev. All locations adjoined railways or an airport. Development of E. kenjiana was epiphytotic. This species was not found on elms surveyed at towns situated north-east, east or south of Kiev. The fungus may have been brought directly to Ukraine by rail or air transport. In 2008, the fungus was also collected in Chernihiv situated north-east of Kiev. It is likely that E. kenjiana will spread over all Ukraine and into countries of central and western Europe in 2009 or later. Molecular phylogenetic analyses using D1/D2 domains of the 28S rDNA and ITS sequences revealed that the Ulmaceae-Cannabaceae-parasitic powdery mildews, including E. kenjiana, form a clade with strong supports, suggesting that these species diverged from a single ancestor and expanded their host ranges within the Ulmaceae and allied Cannabaceae. This hypothesis is supported by these species sharing the unique morphology of enlarged apices on their chasmothecial appendages. These fungi formed part of a larger grouping with species on Fagaceae, Nothofagaceae, Rosaceae, and Sapindaceae with strong statistical supports. These results suggest that Uncinula-like powdery mildew fungi on these plant families exhibit close evolutionary relationships with their hosts.

A comprehensive review of the species, host ranges and geographical distribution of powdery mildew fungi in Iran is presented. The listed fungi belong to eight teleomorphic genera, viz. Blumeria (one species), Erysiphe sect. Erysiphe (14 species), E. sect. Microsphaera (15 species), E. sect. Uncinula (six species), Golovinomyces (nine species), Leveillula (14 species), Neoerysiphe (two species), Phyllactinia (seven species), Podosphaera sect. Podosphaera (three species), P. sect. Sphaerotheca (12 species), and Sawadaea (two species); and one anamorphic genus, Oidium (five species). The 528 host plant species reported in the checklist pertain to 287 genera. The complete checklist of fungi is available on http://staff.guilan.ac.ir/staff/users/khodaparastm/fckeditor_repo/file/Checklist.p df.

The anamorphic state of a powdery mildew on trident maple (Acer buergerianum, Aceraceae), belonging to Sawadaea, has been observed since 1980 in Tokyo and other areas of Japan. Since the autumn of 2003, this fungus has begun to produce chasmothecia in various areas of Japan, which were consistent with Erysiphe nankinensis (= Uncinula nankinensis), but apparently contradictory to the characteristics of the anamorph. Based on a molecular phylogenetic analysis using DNA separately extracted from the anamorph and teleomorph of the fungus on A. buergerianum, it could be demonstrated that sequences of this fungus are sister to Sawadaea. As the anamorph belongs to Oidium subgen. Octagoidium and because of the phylogenetic position within the Sawadaea clade, the new combination Sawadaea nankinensis is proposed for this species. The genus Sawadaea is emended to comprise species with consistently unbranched appendages.

A phylogenetic analysis of the Erysiphe with uncinuloid ascoma appendages (Erysiphe section Uncinula, Erysiphales, Ascomycota) on Carpinus spp. was done using sequences of the rDNA ITS regions and the D1/D2 domains of the 28S rDNA. These results, combined with morphological data, revealed a complex consisting of several distinct taxa. These included the already described Erysiphe carpinicola on C. japonica distinguishable from the Erysiphe sp. on C. betulus and C. tschonoskii as well as the one on C. laxiflora. Thus, it was shown that Oidium carpini, described from Europe on Carpinus betulus, the powdery mildew with uncinula-like ascomata, recently found in Europe on this host, as well as an Erysiphe on C. tschonoskii in Japan, described previously as E. carpinicola, all belong to a single new species, named E. arcuata in this paper. As the powdery mildew on C. laxiflora was also distinct from other known species, it is named E. carpini-laxiflorae in this paper. The already described E. pseudocarpinicola and Erysiphe sp. on Carpinus cordata are two additional taxa, which are morphologically and genetically distinguished from the other species of Erysiphe sect. Uncinula on Carpinus spp.

Shi, A., and Mmbaga, M. T. 2006. Perpetuation of powdery mildew infection and identification of Erysiphe australiana as the crape myrtle pathogen in mid-Tennessee. Plant Dis. 90:10981101. The fungus Erysiphe lagerstroemiae is commonly known as the powdery mildew pathogen in crape myrtle (Lagerstroemiae indica) in the United States, and Erysiphe australiana is the powdery mildew pathogen reported in Japan, China, and Australia. The teleomorph often used to identify powdery mildew fungi rarely develops in crape myrtle, and in our observations, ascocarps never formed. Our study showed that the crape myrtle pathogen overwintered as mycelia on dormant buds. The internal transcribed spacer (ITS) regions of rDNA and the intervening 5.8S rRNA gene were amplified using standard polymerase chain reaction (PCR) protocols and the universal primer pairs ITS1 and ITS4. PCR products were analyzed by electrophoresis in a 1.5% agarose gel and sequenced, and the ITS PCR product was 666 bp from ITS1/ITS4 and 704 bp from ITS1-F/ITS4. BLAST analysis of the sequence of the PCR products showed identical similarity with E. australiana reported in Japan, China, and Australia. Comparison of ITS sequences with information in the GenBank on other powdery mildew fungi showed a closest alignment (93% similarity) to Erysiphe juglandis that infects walnut. Specific primers for E. australiana were developed and evaluated for use as diagnostic tools. Out of 12 specific primer pairs evaluated, four primer pairs and four double primer pairs were highly specific to E. australiana and did not amplify Erysiphe pulchra of dogwood, Erysiphe syringae of common lilac, Erysiphe circinata of maple, or Phyllactinia guttata of oak. The E. australiana–specific primers amplified 16 samples of crape myrtle powdery mildew collected from diverse locations in midTennessee. These results clearly showed that the crape myrtle powdery mildew in mid-Tennessee was caused by E. australiana. Specific primers reported in this article provide a diagnostic tool and may be used to confirm the identity of crape myrtle powdery mildew pathogen in other areas in the United States and wherever the disease occurs. Additional keywords: Uncinula, Uncinuliella australiana

Erysiphe flexuosa , a powdery mildew parasite of Aesculus species, is believed to have originated in North America where distribution records were confined to regions east of the Rocky Mountains. The fungus recently was found in eastern Washington State and northern Idaho. The fungus can be distinguished readily from other powdery mildews attacking Aesculus species by the presence of two distinctive kinds of chasmothecial appendages. Consistent with previous reports on similar species, observations determined that subulate appendages formed first, on dorsal sides of chasmothecia. The longer, uncinate appendages formed equatorially during later chasmothecial maturation. There are no Aesculus species native to northwest North America that could have hosted an undetected population of the fungus. It appears likely that E. flexuosa became established relatively recently in the inland Pacific Northwest, possibly being introduced on infected host material, similar to the situation in Europe where several reports documented the presence of the fungus beginning in 2000.

A detailed study of a powdery mildew observed on Celtis australis leaves was carried out in the present study. The symptoms appeared as white mycelia on leaves with embedded small black to brown spherical ascomata. Morphological and microscopic analyses of diseased samples revealed that this fungus belongs to Erysiphe section Uncinula. Further investigation identified it as Erysiphe kusanoi which is new to Himachal Pradesh. A description and an illustration of the specimen are given.

The phylogenetic position of Uncinula forestalis within the Erysiphales has been inferred from 5.8S, 18S, and 28S rDNA sequences. Although the appendages of the ascomata are Uncinula-like, i.e. unbranched with curved-coiled apices, U. forestal is is situated at the very base of the large Erysiphales cluster, far from the 'Pseudoidium' clade (Erysiphe, including Microsphaera and Uncinula) and separate from the recently introduced basal genus Parauncinula. U.,forestalis differs morphologically from the species of Erysiphe sect. Uncinula in having terminal, fasciculate (as in Podosphaera tridactyla), septate ascoma appendages and a Euoidium-like anamorph (conidia catenate). In Parauncinula, the appendages are also terminal but not fasciculate, the ascospores are curved, and the anamorph is lacking. Uncinula forestalis is a basal, tree-inhabiting powdery mildew with some additional ancestral characteristics, including Uncinula-like appendages and 6-8-spored asci. The new genus Caespitotheca gen. nov. is described with C.forestalis comb. nov. (syn. Uncinula forestalis) as the type species. We calculated the timing of the divergence of U. forestalis and P. septata using a molecular clock of the Erysiphales (6.5 × 10⁻¹⁰ changes per site per year in domains D1 and D2 of 28S rDNA) and a 28S rDNA data set. The results suggest that the divergence of U. forestalis and P. septata from other Erysiphales occurred between 90 and 80 Myr ago; i.e. the divergence of the two ancestral species may have occurred in the late Cretaceous., 東アジアと南米における絶対寄生菌の隔離分布機構の解明

Based on 18S, 5.8S, and 28S rDNA sequences, the phylogenetic position of Uncinula septata within the Erysiphales has been inferred. Although appendages of the ascomata are uncinula like, i.e., unbranched with curved-coiled apices, U. septata is situated at the very base of the large Erysiphales cluster, far away from the “pseudoidium clade” (Erysiphe emend., including Microsphaera and Uncinula). Morphologically, U. septata differs from the species of Erysiphe sect. Uncinula (≡ Uncinula) in having terminal, pluriseptate ascoma appendages, curved ascospores, and the absense of an anamorph. This species is a basal, tree-inhabiting powdery mildew with some additional ancestral characteristics, viz., uncinula-like appendages and 8-spored asci. The new genus Parauncinula with U. septata as the type species is proposed. Uncinula curvispora (≡U.septata var. curvispora) is tentatively maintained as a separate species, which is also assigned to Parauncinula., 東アジアと南米における絶対寄生菌の隔離分布機構の解明

During the summer and autumn of 1999, symptoms of powdery mildew disease were first observed on Pachypodium lamerei in the Czech Republic. White lesions of irregular shape appeared on leaf margins and spread towards the central vein of the leaf, often followed by necrosis of leaf tissue. In the spring of 2000, the sexual stage (cleistothecia) also appeared on infected leaves. Based on the observations of the morphology of its anamorph and teleomorph stage as well as on results from inoculation experiments, the identity and origin of this powdery mildew species are discussed. Based on the pseudoidium anamorph, this fungus may be clearly assigned to Erysiphe emendation, probably to section Uncinula, since the cleistothecial appendages are non-mycelioid and occassionally circinate at the apex. The fungus is described as a new species Erysiphe pachypodiae sp. nov.

Investigations of fungi of the family Erysiphaceae were carried out between 1981 and 1999. Five species of the genus Uncinula Lev. were collected and studied: U. adunca (Wallr.: Fr.) Lev., U. clandestina (Biv.-Bern.) Schroet., U. necator (Schwein.) Burr., U. prunastri (DC.) Sacc., and U. kusanoi Syd. They were registered as agents of powdery mildew on 14 host plant species. U. adunca, U. clandestina and U. prunastri, as well as 12 host plants, are recorded from this region for the first time. Furthermore, the first record of U. kusanoi on Celtis australis from Europe is included. Taxonomic characteristics of the fungi concerned are presented, localities are recorded, and the frequency of occurrence is noted.

The North American Erysiphe flexuosa (Peck) U. Braun & S. Takamatsu ( Uncinula flexuosa Peck, Uncinuliella flexuosa (Peck) U. Braun) has been found in Germany on Aesculus hippocastanum L. and represents a new powdery mildew disease for Europe. This fungus is described, illustrated, and discussed.

Seasonal use of powdery mildews by the mycophagous ladybird, Illeis koebelei, was observed in Setagaya. In the field, I. koebelei shows seasonal changes in host use and breeds regularly on Microsphaera pulchra var. pulchra that infests Benthamidia florida, Oidium sp., that infests Pyracantha coccinea in spring, Phyllactinia moricola that infests Morus australis, and Sphaerotheca cucurbitae that infests Trichosanthes kllirowii var. japonica in autumn. On these fungus species under laboratory conditions, larval development of the ladybird was completed (within 20 days at 24°C) with a high survival rate. Thus, the seasonal occurrence of I. koebelei may be synchronized with the abundance of essential fungi. This study showed that I. koebelei feeds on 11 species of powdery mildews, including Sphaerotheca, Podosphaera, Microsphaera, Phyllactinia and Oidium. However, no species of the Uncinula, Uncinuliella and Erysiphe genera were suitable food for the ladybird.

Conidial types collected daily in the air above a vineyard in northwest Spain were identified and counted. A total of 26 fungal spore types were recognised; ten of which (Cladosporium, Botrytis, Fusarium-Leptosphaeria type,Torula, Puccinia, Alternaria, Uncinula, Helminthosporium type,Agrocybe andStemphylium) gave a seasonal total concentration exceeding 1000 spores. Seasonal patterns are shown for 12 of the identified taxa.

The following foliicolous fungi on Tabebuia species are described and illustrated: Anhelia tabebuiae sp. nov. and Dictyonella tabebuiae sp. nov. (ascomycetes), Fumagospora tabebuiae sp. nov., Polychaeton tabebuiae sp. nov. and Septoria tabebuiae-impetiginosae sp. nov. (coelomycetes), Cercospora tabebuiae-impetiginosae sp. nov. and Pseudocercospora tabebuiae-roseo-albae sp. nov. (hyphomycetes). Uncinula peruviana was found and described on T. impetiginosa as a first record for Distrito Federal, Brazil.

Previously undescribed features on the surfaces of powdery mildew conidia were revealed by the scanning electron microscope (SEM), reinforcing differences observable by light microscopy (LM). Four distinct patterns were observed on the septa and 10 on the outer wall, thus categorizing 15 anamorph taxa. Anamorphs of Leveillula, Phyllactinia and Pleochaeta, all had smooth to moderately verrucose septa, but each bore a different distribution of warts on their verrucose outer wall. Annular septa and an echinulate outer wall were unique for the Oidium anamorph of Blumeria. The remaining powdery mildews, all with Oidium states, had either whorled or fibrillar septa. Those with whorled septa are separated into three newly proposed subgenera: Fibroidium for the anamorphs of Podosphaera and Sphaerotheca having conidia with fibrosin bodies and a smooth outer wall; Octagoidium for the dendritic patterned, eight-sided conidia of Sawadaea; and Setoidium for the anamorph of Cystotheca reflecting the setae on the mycelium. Three new subgenera are proposed for those with fibrillar septa: Reticuloidium for conidia with a roughcast outer wall of Erysiphe sect. Golovinomyces; Graciloidium for the unswollen conidia of Arthrocladiella; Striatoidium for conidia of E. sect. Galeopsidis with a striate outer wall. The name Pseudoidium is retained as a subgenus for the anamorphs of E. sect. Erysiphe, Microsphaera and Uncinula which had conidia with a scaly, fibrous outer wall. The patterns on the outer wall of conidia were frequently modified by secondary creasing. These wrinkling patterns, also observable under the LM, proved useful in identification of anamorphs, especially on herbarium specimens. SEM, LM and host range data were used to construct keys for the prediction of the anamorphs of all the powdery mildew genera found in the U.K. The findings, together with teleomorph criteria, also prompted a revision of the Erysiphaceae.

Three important phytopathogenic spores which cause serious fungal diseases on vines (Botrytis, Uncinula andPlasmopara) were monitored from June 2, 1994 to September 21, 1994, in vineyards belonging to ‘Estacion de Enoloxia e Viticultura’ of Ponte San Clodio-Leiro (Ourense), one of the most important vine growing areas of northwest of Spain. The concentrations for each of the genera were correlated with rainfall, humidity, maximum, minimum and average temperatures. These meteorological parameters are currently used to determine chemical sprays to be applied to the vines. The aim was to establish the behaviour of airborne concentrations of spores of these taxa during the period from the flowering to harvest because these are the periods of greatest susceptibility to attack by these pathogens.

An improved protocol, including DNA extraction with Chelex, two amplifications with a nested primer set, and DNA purification by electrophoresis, made it possible to analyze nuclear rDNA sequences of powdery mildew fungi using at most several hundred conidia or 20 cleistothecia. Nucleotide sequence diversity of the nuclear rDNA region containing the two internal transcribed spacers (ITS1 and ITS2) and 5.8S rRNA gene derived from conidia and cleistothecia was investigated for four kinds of powdery mildew fungi including two isolates of the same species. The results showed that the nucleotide sequences of the nuclear rDNA region were highly conserved between the teleomorph and the anamorph. Thus, the nucleotide sequence data obtained from either developmental stage can be used for phylogenetic studies of powdery mildew fungi. The nucleotide sequences of the 5.8S rRNA genes of the four species were highly conserved, but those of their ITS regions were variable. This suggests that the nuclear rDNA region is not suitable for phylogenetic studies of distantly related powdery mildew fungi, because too much sequence diversity exists, within the ITS, and too little phylogenetic information is contained within the 5.8S rRNA gene. However, the ITS region will be useful for phylogenetic comparison of closely related species or intraspecies.

The vegetation of the Nahuel Huapi National Park is characterised by typical Andean patagonic forests with a majority of autochthonous trees like Austrocedrus chilensis, Nothofagus antarctica, N. dombeyi, and N. pumilio. The natural flora is mixed with numerous introduced species. There is a great diversity of parasitic fungi. In this work the powdery mildews which infect both the autochthonous and introduced hosts were studied. Collections were made in summer and autumn in order to obtain the teleomorphic and the anamorphic stages. As a preliminary result fourteen species can be reported: Erysiphe aquilegiae, E. pisi, E. ulmariae var. acaenae, Microsphaera alphitoides, M. baeumleri, M. myoschili, M. oehrensii, M. ovidiae, M. ribicola, Sphaerotheca pannosa, Phyllactinia antarctica, Uncinula magellanica, U. nothofagi, and Oidium mutisiae. Note: Abstract was published in the 6th International Congress of Plant Pathology. July 28–August 6, 1993, Montreal (Quebec), Canada.

The powdery mildew Uncinula heringeriana from leaves of Qualea grandiflora is described and validated. Uncinula viegasii sp. nov. from leaves of Q. parviflora , and U. alvimii sp. nov. from leaves of Bowdichia virgilioides are described from the cerrado of central Brazil. A key for identification of South American species of Uncinula is provided.