Plant Pathology (2010) 59, 801 Doi: 10.1111/j.1365-3059.2010.02264.x Peronospora belbahrii causing downy mildew disease on Agastache in the UK: a new host and location for the pathogen B. Henricot a *, J. Denton a , J. Scrace a , A. V. Barnes b and C. R. Lane b a Department of Plant Pathology, The Royal Horticultural Society, Wisley, Woking, Surrey, GU23 6QB; and b The Food and Environment Research Agency, Sand Hutton, York, YO41 1LZ, UK Agastache is a genus of 30 species of aromatic perennials in the family Lamiaceae. In June and July 2009, cultivars of Agastache sp. ‘Tangerine Dreams’, A. mexicana ‘Red Fortune’, A. aurantiaca ‘Apricot Sprite’ and A. cana ‘Purple Pygmy’ at Wisley gardens were infected by downy mil- dew. The symptoms were chlorotic leaf spots eventually turning brown. A downy mildew-like growth was observable underneath the leaf surfaces. Microscopic examination revealed conidiophores typical of Peronos- pora. Conidiophores were straight, monopodially branched (typically 4– 6 times), 137–325 lm in length. Ultimate branchlets were sinuous and obtuse, the longer measuring 12–20 lm, the shorter 5–8 lm. Conidia were olive brown, broadly ellipsoidal to subglobose and measured 22– 30 · 15–25 lm. No oospores were found. The ITS of isolates found on cultivars of A. mexicana ‘Red Fortune’ and Agastache sp. ‘Tangerine Dreams’ (GenBank Accession Nos. GQ390794 and GQ390795) showed 99% homology to a new Peronospora species found on coleus and basil recently named as Peronospora belbahrii (Thines et al., 2009). Specimens were deposited at Kew (K(M)163651 and K(M)163652). To support the molecular identification, conidia were rubbed from infected Agastache leaves onto leaves of four different healthy coleus cultivars (‘Winsome’, ‘Mrs Pilkington’, ‘Roy Pedley and ‘Durham Gala’). After inoculation, a plastic bag was placed on plants for 48 hrs. The plants were misted with water twice a day and left outdoors where the temperature ranged from 14°C to 27°C. Controls were not inoculated. After 14 days, the same downy mildew was found on cvs. ‘Winsome’ and ‘Durham Gala’ whilst the other plants remained healthy. This is the first record of P. belbahrii on Agastache and in the UK. The only other downy mildew species recorded on Agastache is P. lophanti but this species has been found to be conspecific with P. lamii (Shin & Choi, 2006). Peronospora belbahrii is distinct from P. lamii (Belbahri et al., 2005). It was first reported from Africa in 1933, then much later in 1993 in the USA and in 1999 in Europe where it is causing epidemics (Thines et al., 2009).The fungus poses serious threats to production of coleus and other Lamiacae grown commercially. Statutory action has now been taken against this pathogen. References Belbahri L, Calmin G, Pawlowski J, Lefort F, 2005. Phylogenetic analysis and Real Time PCR detection of a presumbably undescribed Peronospora species on sweet basil and sage. Mycological Research 109, 1276–87. Shin HD, Choi YJ, 2006. Peronosporaceae of Korea. Suwon, Korea: National Institute of Agricultural Science and Technology. Thines M, Telle S, Ploch S, Runge F, 2009. Identity of the downy mildew pathogens of basil, coleus and sage with implications for quarantine measures. Mycological Research 113, 532–40. *E-mail: beatricehenricot@rhs.org.uk. Accepted 16 December 2009 at http://www.bspp.org.uk/ndr where figures relating to this paper can be viewed. Plant Pathology (2010) 59, 801 Doi: 10.1111/j.1365-3059.2010.02267.x First report in Korea of powdery mildew of Matricaria chamomilla caused by Golovinomyces cichoracearum M. J. Park, Y. J. Choi, J. G. Han and H. D. Shin* Division of Environmental Science and Ecological Engineering, Korea University, Seoul 136-701, Korea German chamomile (Matricaria chamomilla) is an exotic medicinal herb with many cultivars. Since November 2006, severe infections of a pow- dery mildew have been found on this plant in herb gardens in Taean and Pyeongchang, Korea. Initial symptoms were the spotted growth of a white, superficial mycelium. As the disease progressed, white mycelial growth completely covered the whole plant including the inflorescence. Chasmothecia were formed mainly on stems and lower surface of the leaves. The voucher specimens are kept at Korea University (KUS- F14027, 22492, 22504). Conidiophores were 90–165()220) lm long and producing 2–6 imma- ture conidia in chains with sinuate edge-line. Conidia were ellipsoid or doliform, 30–42 · 16–24 lm, and without distinct fibrosin bodies. Chasmothecia were dark brown, spherical, 95–135 lm in diameter and contained 10–18 asci. Appendages were mycelioid, 12–28 per chasmothe- cium, 0Æ5–2Æ5 times as long as the chasmothecial diameter, 1–5-septate. Asci were shortly stalked, 50–75 · 32–45 lm and two-spored. Ascosp- ores were ellipsoid-ovoid and 22–28 · 15–18 lm. Based on these charac- teristics, this fungus was identified as Golovinomyces cichoracearum (Braun, 1987). To confirm the identification, the ITS rDNA was amplified and sequenced, and the sequence of the region was deposited in GenBank (Accession No. GU048822). Comparison with the sequences available in the GenBank database revealed that the ITS sequence shares 100% similarity with the sequence of Golovinomyces cichoracearum on Achillea millefolium (AB077685). Therefore, the sequence analysis verified the pathogen to be G. cichoracearum. Two powdery mildew species have been reported to infect M. chamomilla (Braun, 1987). Podosphaera fusca (syn. Sphaerotheca fusca, S. fuliginea) has been recorded in Canada, Egypt, Germany, Switzerland, USSR (Farr & Rossman, 2009) and recently in Japan (Tanda, 1998). Golovinomyces cichoracearum (syn. Erysiphe cichora- cearum) is a rather common powdery mildew species infecting German chamomile in Europe (Farr & Rossman, 2009) and Japan (Tanda, 1998) but this is the first report of G. cichoracearum infec- tions of German chamomile in Korea. As German chamomile is becoming widely cultivated in commercial farms for industrial purpose in Korea, powdery mildew infections pose a serious threat to safe production of this herb. References Braun U, 1987. A monograph of the Erysiphales (powdery mildews). Beihefte zur Nova Hedwigia 89, 1–700. Farr DF, Rossman AY, 2009. Fungal Databases, Systematic Mycology & Microbiology Laboratory, ARS, USDA. Retrieved September 30, 2009, from http://nt.ars-grin.gov/fungaldatabases/. Tanda S, 1998. Powdery mildews occurring on some herbal or medicinal plants and their causal fungi. Journal of Agricultural Science, Tokyo University of Agriculture 43, 159–67. *E-mail: hdshin@korea.ac.kr. Accepted 5 January 2010 at http://www.bspp.org.uk/ndr where figures relating to this paper can be viewed. ª 2010 The Authors 801 Journal compilation ª 2010 BSPP