IMI Descriptions of PODOSPHAERA DIPSACACEARUMFungi and BacteriaNo. 1968

A. Heavily infected stems and flower heads; bar = 5 cm. B. Detail of ascomata on leaf surface; bar = 500 µm.C. Cluster of ascomata slightly squashed; some have cracked open and from each of those an ascus is protruding;bar = 200 µm. D. Young ascus; bar = 20 µm. E. Ascospore; bar = 10 µm.

Podosphaera dipsacacearum (Tul. & C. Tul.) U. Braun & S. Takam., as ‘dipsacearum’, Schlechendalia 4: 28(2000). [IndexFungorum 464824; Erysiphaceae, Erysiphales]

Erysiphe dipsacacearum Tul. & C. Tul., as ‘dipsacearum’, Selecta Fungorum Carpologia 1: 210 (1861).[IndexFungorum 141455]

Sphaerotheca dipsacacearum (Tul. & C. Tul.) L. Junell, as ‘dipsacearum’, Svensk Botanisk Tidskrift 61:227 (1967). [IndexFungorum 339447]

Diagnostic features. Causing a white powdery mildew on living leaves, stems and flower heads of membersof the Dipsacaceae.

On natural substratum. Habit powdery mildew colonies on living leaves, stems and flower heads,sometimes looking dark on dying and dead leaves if production of ascomata is abundant. Mycelium external

to the plant, colourless to very pale brown, branched, septate, thin-walled, smooth, 5–6 µm wide.Anamorph. Conidiophores colourless, thin-walled, smooth, septate, unbranched, up to c. 8 µm wide, eachwith a single conidiogenous cell at the apex. Conidiogenous cells colourless, thin-walled, smooth, 16–22 ×7–10 µm. Conidial development initiation holoblastic; maturation synchronous; delimitation by a 2-plyseptum; secession schizolytic; in the material studied, only one conidium was seen associated with eachconidiogenous cell, and no conidia were seen with more than one secessional scar. Conidia very few,colourless, aseptate, smooth, 24–32 × 14–18 µm. Teleomorph. Ascomata cleistothecial, superficial, globose,at first yellowish, later becoming brown then dark brown, 70–150 µm diam., each containing one ascus;ascomatal wall composed of brown to dark brown thin-walled cells, 7–12 µm diam., forming a texturaangularis; appendages present, but poorly-defined and looking like mycelium, straight to flexuous, brown,thin-walled, septate, mostly unbranched, 4–6 µm wide. Asci subglobose to short-ellipsoid, rather thick-walled, 60–80 × 50–65 µm, each containing 4–6 ascospores. Ascospores elongated ellipsoid, sometimesslightly curved, colourless, thin-walled, smooth, 28–38 × 13–18 µm, often with one large guttule. Interascaltissue not noted.

ASSOCIATED ORGANISMS & SUBSTRATA: Fungi. Ampelomyces quisqualis Ces.; Cladosporiumcladosporioides (Fresen.) G.A. de Vries; Septoria cephalariae-alpinae Roum. Plantae. Cephalariaalpina (L.) Schrad. ex Roemer & J.A. Schultes, C. armeniaca Bordz., C. caucasica Litv., C. gigantea(Ledeb.) Bobr., C. kotschyi Boiss. & Hohen., C. leucantha Ledeb., C. procera Pančić ex Nyman, C.sublanata Szabó, C. syriaca (L.) Schrad. ex Roemer & J.A. Schultes, C. syriaca subsp. turanica Bobrov.,C. tatarica Roemer & J.A. Schultes, C. transsylvanica (L.) Roem. & Schult., C. uralensis Roem. &Schult. (leaf, stem), Cephalaria sp.; Dipsacus dipsacoides (Kar. & Kir.) V.I. Bochantsev, D. fullonum L.[also as D. sylvestris Huds.] (leaf), D. laciniatus L., D. pilosus L. (leaf, stem), D. sativus (L.) Honckeny(leaf, stem), D. strigosus Willd. ex Roem. & Schult. (leaf, stem), Dipsacus sp. (leaf, stem); Knautiaarvensis (L.) Coult. (leaf, stem), K. drymeia Heuff., K. integrifolia K. Koch, K. longifolia W.D.J. Koch;Morina kokanica Regel, M. persica L., M. wallichiana Royle; Pterocephalus papposus Coult., P.plumosus Coult., Pterocephalus sp.; Scabiosa alpestris Kar. & Kir., S. bipinnata K. Koch, S. caucasicaM. Bieb., S. lucida Vill., S. micrantha Desf., S. ochroleuca L. (leaf, stem), S. persica Boiss., S. proliferaL., S. songarica Schrenk, S. stellata L., S. ucranica L., Scabiosa sp.; Tremastelma palaestinum (L.)Janchen. Associated organism of type specimen. Dipsacus sylvestris.

INTERACTIONS & HABITATS: A terrestrial fungus, obligately parasitic on species of the Dipsacaceae, butnot causing a serious disease resulting in death of the plant. Apart from observations where Ampelomycesquisqualis, Cladosporium cladosporioides and Septoria cephalariae-alpinae were also present, nothingis known about associations and interactions with organisms other than the host plant. This species hasbeen recorded from the following habitats: amenity & protected areas (gardens including botanicgardens, parkland with scattered trees); freshwater (marshes); grassland (basic/calcareous, roughpasture); margins (hedgerows, track sides); ruderal (land reclamation sites, quarries, wasteland,woodland edges); woodland (broadleaved semi-natural, mixed, plantations, scrub on limestone).

GEOGRAPHICAL DISTRIBUTION: NORTH AMERICA: USA (Washington). ASIA: Afghanistan, Armenia,Azerbaijan, Iran, Iraq, Israel, Kazakhstan, Kyrgyzstan, Lebanon, Pakistan, Tajikistan, Turkey,Turkmenistan, Uzbekistan. EUROPE: Bulgaria, former Czechoslovakia, France, Germany, Greece,Hungary, Italy, Netherlands, Poland, Romania, Russia (Rostovskaya oblast), Spain, Turkey, Ukraine, UK,former Yugoslavia.

Native to Asia and Europe, status elsewhere unclear. Records up to 150 m above sea level, but probablyalso occurring at higher altitudes.

ECONOMIC IMPACTS: No evaluation has been made of any possible positive economic impact of thisfungus (e.g. as a recycler, as a source of useful products, as a provider of checks and balances within itsecosystem, etc.). Since Dipsacus species are sometimes regarded as invasives, there may be potential touse P. dipsacacearum as part of an integrated biological control programme. No reports of negativeeconomic impacts have been found.

INFRASPECIFIC VARIATION: None reported.

DISPERSAL & TRANSMISSION: By airborne conidia; possibly also by airborne ascospores released inhumid conditions.

CONSERVATION STATUS: Information base. Over 500 records (specimens, databases and bibliographicsources combined, excluding duplicates) from at least 1861 to September 2013, with observations in July,August, September, October and November. Estimated extent of occurrence [calculated using http://geocat.kew.org]. Over 7·7 million km2 (North America: insufficient data; Asia: 4·1 million km2; Europe:3·6 million km2). Estimated area of occupancy [calculated using http://geocat.kew.org]. Well over 1000km2. The method for estimating area of occupancy has produced an artificially low figure. The species islikely to be under-recorded, particularly in recent years, because of the small and declining numbers ofpeople with the skills to search for and identify it. Many of the plants with which it is associated arecommon and widespread species. The species has been described as rare in Israel (VOYTYUK et al.,2007), but appears to be common elsewhere. Threats. Some records are from nature reserves or otherprotected areas and, as a result, some populations are more or less safe. With a host plant common inmany different ecosystems, including ruderal places, habitat loss is not an issue. The potential impacts ofclimate change and pollution on this species are not known. Although members of the Dipsacaceae areoften used as garden plants, there is no evidence of persecution. Population trend. Not known. In theUK, almost all records are more recent than 1960, and c. 40% are more recent than 2000. Evaluation.Using IUCN criteria (IUCN SPECIES SURVIVAL COMMISSION. 2006 IUCN Red List of ThreatenedSpecies [www.iucnredlist.org]. Downloaded on 15 May 2006), the species is assessed globally as LeastConcern. In situ conservation actions. None noted. Ex situ conservation actions. No nucleotidesequences were found in a search of the NCBI GenBank database [www.ncbi.nlm.nih.gov, accessed 1September 2013]. No living strains of this species are listed in the CABI Genetic Resource Catalogue[http://cabi.bio-aware.com/Biolomics.aspx?Table=GRC+catalogue, accessed 1 September 2013]and CBS Online Strain Database [www.cbs.knaw.nl/Collections/Biolomics.aspx?Table=CBS%20strain%20database, 1 September 2013].

LITERATURE & OTHER SOURCE MATERIAL: AMANO, K. Host Range and Geographical Distributionof the Powdery Mildew Fungi: 741 pp. Japan Scientific Society Press, Tokyo (1986). BAHÇECIOĞLU, Z.& YILDIZ, B. A study on the microfungi of Sivas Province. Turkish Journal of Botany 29: 23–44 (2005).BOLAY, A. Les Oïdiums de Suisse (Erysiphées) [Powdery Mildews of Switzerland (Erysiphaceae)].Cryptogamica Helvetica 20: 176 pp. (2005). BRAUN, U. The Powdery Mildews (Erysiphales) of Europe:337 pp. Gustav Fischer Verlag, Jena (1995). BRAUN, U. & COOK, R.T.A. Taxonomic Manual of theErysiphales (Powdery Mildews). CBS Biodiversity Series 11: 703 pp. (2012). DUGAN, F.M. & GLAWE,D.A. First report of powdery mildew on Dipsacus sylvestris caused by Sphaerotheca dipsacearum inNorth America. Plant Health Progress: DOI: 10.1094/PHP-2006-0607-02-BR (2006). FAKIROVA, V.I.Order Erysiphales. Fungi Bulgaricae 1: 154 pp. (1991). GHASSEMZADEH, Z., KHODAPARAST, S.A.,ABBASI, M. & PEDRAMFAR, H. Study on the Podosphaera section Sphaerotheca (Erysiphaceae) in Iran.Iranian Journal of Plant Pathology 44(3): 191–214 (2008). PANTIDOU, M.E. Fungus-Host Index forGreece: 382 pp. Benaki Phytopathological Institute, Kiphissia, Athens (1973). RANKOVIĆ, B. & ČOMIĆ,L. Contribution to the knowledge of fungi of the genus Sphaerotheca in Yugoslavia. Mycotaxon 63: 301–305 (1997). RUSANOV, V.A. & BULGAKOV, T.S. [as РУСАНОВ, В.А. & БУЛГАКОВ, Т.С.]Мучнисторосяные грибы Ростовской области [Powdery mildew fungi of Rostov region]. Микологияи Фитопатология [Mycology and Phytopathology] 42(4): 314–322 (2008). RUSZKIEWICZ-MICHALSKA,M. & MICHALSKI, M. Phytopathogenic micromycetes in Central Poland. I. Peronosporales andErysiphales. Acta Mycologica 40(2): 223–250 (2005). VOYTYUK, S.O., HELUTA, V.P., WASSER, S.P. &NEVO, E. The genus Podosphaera Kunze (Ascomycota, Erysiphales) in Israel: species composition, hostrange and distribution. Nova Hedwigia 85: 277–298 (2007).

Sources additional to those already cited from literature and the internet.

• Checklist of Fungi of the British Isles [www.fieldmycology.net/GBCHKLST/gbchklst.asp].

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• Cybertruffle [www.cybertruffle.org.uk].• GBIF [http://data.gbif.org].• Google [www.google.co.uk].• Landcare Research New Zealand [http://nzfungi.landcareresearch.co.nz/html/mycology.asp].• National Center for Biotechnology Information [www.ncbi.nlm.nih.gov].• USDA Fungal Databases [http://nt.ars-grin.gov/fungaldatabases].

D.W. MinterCABI Europe, Egham, UK