scholarly journals Ampelomyces strains isolated from diverse powdery mildew hosts in Japan: Their phylogeny and mycoparasitic activity, including timing and quantifying mycoparasitism of Pseudoidium neolycopersici on tomato

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0251444
Author(s):  
Márk Z. Németh ◽  
Yuusaku Mizuno ◽  
Hiroki Kobayashi ◽  
Diána Seress ◽  
Naruki Shishido ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Host Plants ◽  
Morphological Characteristics ◽  
Post Inoculation ◽  
Powdery Mildew Fungus ◽  
Rdna Its ◽  
Pseudoidium Neolycopersici ◽  
Tomato Powdery Mildew ◽  
Internal Transcribed Spacer Rdna ◽  
Complete Collapse

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 diverse Ampelomyces strains using digital microscopic technologies. The developed model system is useful for future biocontrol and ecological studies on Ampelomyces mycoparasites.

scholarly journals Occurrence of Powdery Mildew Caused by Erysiphe buhrii on Dianthus chinensis in Inner Mongolia, China

Plant Disease ◽  
2021 ◽  
Author(s):  
Mo Zhu ◽  
Xiao Duan ◽  
Haoran Guo ◽  
Wei Huang ◽  
Ke Quan ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Inner Mongolia ◽  
Morphological Characteristics ◽  
Signs And Symptoms ◽  
Its Region ◽  
Width Ratio ◽  
Post Inoculation ◽  
Powdery Mildew Fungus ◽  
Medicinal Uses ◽  
Powdery Mildew Disease

Dianthus chinensis is widely cultivated for ornamental and medicinal use in China (Guo et al. 2017). The plant has been used in traditional Chinese medicine for the treatment of urinary problems such as strangury and diuresis (Han et al. 2015). In June and July 2020, powdery mildew-like signs and symptoms were seen on leaves of D. chinensis cultivated on the campus of Inner Mongolia Agricultural University, Hohhot city, Inner Mongolia Province, China. White powder-like masses occurred in irregular shaped lesions on both leaf surfaces and covered up to 50% of leaf area. Some infected leaves were deformed on their edges and some leaf senescence occurred. More than 40 % of plants (n = 180) exhibited these signs and symptoms. Conidiophores (n = 50) of the suspect fungus were unbranched and measured 70 to 140 µm long × 6 to 10 µm wide and had foot cells that were 25 to 48 µm long. Conidia (n = 50) were produced singly, elliptical to cylindrical shaped, 30 to 45 µm long × 12 to 19 µm wide, with length/width ratio of 2.0 to 3.2, and lacked fibrosin bodies. No chasmothecia were found. Based on these morphological characteristics, the fungus was tentatively identified as an Erysiphe sp. (Braun and Cook 2012). Fungal structures were isolated from diseased leaves and genomic DNA of the pathogen extracted utilizing the method described by Zhu et al. (2019). The internal transcribed spacer (ITS) region was amplified by PCR employing the primers PMITS1/PMITS2 (Cunnington et al. 2003) and the amplicon sequenced by Invitrogen (Shanghai, China). The sequence for the powdery mildew fungus (deposited into GenBank under Accession No. MW144997) showed 100 % identity (558/558 bp) with E. buhrii (Accession No. LC009898) that was reported on Dianthus sp. in Japan (Takamatsu et al. 2015). Pathogenicity tests were done by collecting fungal conidia from infected D. chinensis leaves and brushing them onto leaves of four healthy plants. Four uninoculated plants served as controls. Inoculated and uninoculated plants were placed in separate growth chambers maintained at 19 ℃, 65 % humidity, with a 16 h/8 h light/dark period. Nine-days post-inoculation, powdery mildew disease signs appeared on inoculated plants, whereas control plants remained asymptomatic. The same results were obtained for two repeated pathogenicity experiments. The powdery mildew fungus was identified and confirmed as E. buhrii based on morphological and molecular analysis. An Oidium sp. causing powdery mildew on D. chinensis previously was reported in Xinjiang Province, China (Zheng and Yu 1987). This, to the best of our knowledge, is the first report of powdery mildew caused by E. buhrii on D. chinensis in China (Farr and Rossman 2020). The sudden occurrence of this destructive powdery mildew disease on D. chinensis may adversely affect the health, ornamental value and medicinal uses of the plant in China. Identifying the cause of the disease will support efforts for its future control and management.

scholarly journals First Occurrence of Cucurbit Powdery Mildew Caused by Race 3-5 of Podosphaera fusca in Spain

Plant Disease ◽  
2009 ◽  
Vol 93 (10) ◽  
pp. 1073-1073 ◽  
Author(s):  
J. A. Torés ◽  
J. M. Sánchez-Pulido ◽  
F. López-Ruiz ◽  
A. de Vicente ◽  
A. Pérez-García
Keyword(s):  
Powdery Mildew ◽  
Citrullus Lanatus ◽  
Morphological Characteristics ◽  
Fungal Growth ◽  
Powdery Mildew Fungus ◽  
First Occurrence ◽  
New Race ◽  
First Time ◽  
Cucurbit Powdery Mildew ◽  
Podosphaera Fusca

A new race of cucurbit powdery mildew was observed for the first time on melon (Cucumis melo) in three research greenhouses in the Axarquia area of southern Spain during the spring of 2008. Fungal growth appeared as white powdery colonies initially restricted to the upper leaf surfaces. Morphological characteristics of colonies, conidiophores, conidia, germ tubes, and appressoria indicated that the powdery mildew fungus was Podosphaera fusca (also known as P. xanthii) (3), a fungal pathogen extensively reported in the area (1). However, the fungus developed on plants of melon cv. PMR 6, which is resistant to races 1 and 2 of P. fusca, suggesting that the fungus could belong to race 3, a race of P. fusca not yet reported in Spain. Race determination was carried out by inoculating the third true leaf of a set of differential melon genotypes that were maintained in a greenhouse. Symptoms and colonization observed on cvs. Rochet, PMR 45, PMR 6, and Edisto 47 indicated that the isolates belonged to race 3-5 of P. fusca. Fungal strains of races 1, 2, and 5 of P. fusca (all present in Spain) were used as controls. Pathotype designation was determined by inoculating different cucurbit genera and species (2). In addition to melon, the isolates were pathogenic on zucchini (Cucurbita pepo) cv. Diamant F1, but failed to infect cucumber (C. sativus) cv. Marketer and watermelon (Citrullus lanatus) cv. Sugar Baby; therefore, the isolates were pathotype BC (2). Races 1, 2, 4, and 5 of P. fusca have been previously reported in the area (1). The occurrence of race 3-5 represents another challenge in the management of cucurbit powdery mildew in Spain. References: (1) D. del Pino et al. Phytoparasitica 30:459, 2002. (2) E. Křístková et al. Sci. Hortic. 99:257, 2004. (3) A. Pérez-García et al. Mol. Plant Pathol. 10:153, 2009.

scholarly journals First Report of Soft Rot on Dendrobium officinale caused by Epicoccum sorghinum in China

Plant Disease ◽  
2021 ◽  
Author(s):  
Caiyun Xiao ◽  
Rongyu Li ◽  
Xingchen Song ◽  
Xujun Tian ◽  
Qijun Zhao
Keyword(s):  
Internal Transcribed Spacer ◽  
Elongation Factor ◽  
Morphological Characteristics ◽  
Reference Value ◽  
Soft Rot ◽  
Dendrobium Officinale ◽  
First Report ◽  
Rdna Its ◽  
And Control ◽  
Internal Transcribed Spacer Rdna

In recent years, soft rot is one of the most serious diseases in the production of Dendrobium officinale. In this study, we took the diseased plants of Dendrobium officinale in Guizhou as samples, through Koch's rule and sequence analysis of rDNA internal transcribed spacer (rDNA-ITS), calmodulin (cmdA), the second largest subunit of RNA polymerase Ⅱ (RPB2), elongation factor EF-1 α and β-tubulin (β-Tub), it was determined that the pathogen of Dendrobium officinale soft rot was sorghum accessory cocci. This is our first report on the soft rot of Dendrobium officinale caused by Epicoccum sorghinum in China. The morphological characteristics of the pathogen shown in the study will have a certain reference value for the prevention and control of the soft rot of Dendrobium officinale in the future.

scholarly journals First Report of Powdery Mildew Caused by Podosphaera xanthii (syn. P. fusca) on Cocklebur in Korea

Plant Disease ◽  
2013 ◽  
Vol 97 (6) ◽  
pp. 842-842 ◽  
Author(s):  
H. B. Lee
Keyword(s):  
Powdery Mildew ◽  
Natural Infection ◽  
Morphological Characteristics ◽  
Its Region ◽  
Xanthium Strumarium ◽  
Podosphaera Xanthii ◽  
First Report ◽  
Rdna Its ◽  
Causal Fungus ◽  
Powdery Mildew Pathogen

Cocklebur (Xanthium strumarium L., Asteraceae) is an annual broadleaf weed native to the Americas and eastern Asia. The plant is known as one of the worst competitive weeds in soybean fields and also is known to have some phytopharmacological or toxicological properties. In October 2011, a powdery mildew disease was observed on cocklebur growing in a natural landscape at Geomun Oreum located in Jeju Island, South Korea. Initial signs appeared as thin white colonies, which subsequently developed abundant growth on adaxial leaf surfaces. As the disease progressed, brown discoloration extended down infected leaves which withered. Conidia were formed singly and terminally on conidiophores. Primary conidia (20.3 to 28.6 [average 25.1] μm long × 11.1 to 15.2 [14.3] μm wide, n = 30) were ellipsoid with a round apex and truncate base. Conidiophores were straight or slightly curved and 60.1 to 101.7 (97.3) μm long × 8.2 to 13.2 (11.3) μm wide. Chasmothecia were not observed. No fibrosin bodies were observed in the conidia. Morphological characteristics were consistent with descriptions of Podosphaera xanthii (syn. P. fusca) (2,4). To confirm the identity of the causal fungus, the internal transcribed spacer (ITS) region inclusive of 5.8S and 28S rDNA was amplified from white patches consisting of mycelia and conidia on one leaf using ITS1 (5′-TCCGTAGGTGAACCTGCGG-3′) and LR5F (5′-GCTATCCTGAGGGAAAC-3′), and LROR (5′-ACCCGCTGAACTTAAGC-3′) and LR5F primer sets, respectively. The resulting sequences were deposited in GenBank (Accession Nos. JX502022 and JX964999). A NCBI BLASTn search revealed that the rDNA ITS (JX502022) and 28S (JX964999) homologies of isolate EML-XSPW1 represented 99.6% (512/514) and 100% (803/803) identity values with those of P. xanthii (AB040330 and AB462792, respectively). The rDNA ITS and 28S sequence analysis revealed that the causal fungus clustered with P. xanthii (syn. P. fusca), falling into the Xanthii/Fusca phylogenetic group (2,4). Pathogenicity was confirmed through inoculations made by gently pressing infected leaves onto mature leaves of healthy cocklebur plants in the field in August. The six inoculated leaves were sealed in sterilized vinyl bags to maintain humid conditions for 2 days. Seven days after inoculation, symptoms similar to those observed under natural infection were observed on the inoculated plant leaves. No symptoms developed on the uninoculated control plants. A fungal pathogen that was morphologically identical to the fungus originally observed on diseased plants was also observed on inoculated plants. Erysiphe cichoracearum, E. communis, Oidium asteris-punicei, O. xanthimi, P. xanthii, and P. fuliginea have all been reported to cause powdery mildew on cocklebur (1). P. xanthii was first reported on X. strumarium in Russia (3). To our knowledge, this is the first report of powdery mildew on cocklebur caused by P. xanthii in Korea. The powdery mildew pathogen may represent an option for biocontrol of the noxious weed in the near future. References: (1) D. F. Farr and A. Y. Rossman. Fungal Databases, Systematic Mycology and Microbiology Laboratory, ARS, USDA. Retrieved from http://nt.ars-grin.gov/fungaldatabases , December 11, 2012. (2) H. B. Lee. J. Microbiol. 51:1075, 2012. (3) V. A. Rusanov and T. S. Bulgakov. Mikol. Fitopatol. 42:314, 2008. (4) S. Takamatsu et al. Persoonia 24:38, 2010.

scholarly journals First Report of Powdery Mildew Caused by Erysiphe aquilegiae on Columbine in the United States

2018 ◽  
Vol 19 (1) ◽  
pp. 69-70 ◽  
Author(s):  
Michael Bradshaw
Keyword(s):  
United States ◽  
Powdery Mildew ◽  
Morphological Characteristics ◽  
Late Summer ◽  
Its Region ◽  
Botanical Garden ◽  
The United States ◽  
Molecular Characteristics ◽  
Similar Species ◽  
Powdery Mildew Fungus

Columbine (Aquilegia sp., Ranunculaceae) is a late summer to fall flowering ornamental. Powdery mildew was collected from columbine plants growing outdoors in the botanical garden at the Center for Urban Horticulture, University of Washington (47.65°N; 122.29°W) in October 2016. Morphological characteristics of the fungus were consistent with those of Erysiphe aquilegiae. To confirm species identification, the internal transcribed (ITS) region of rDNA was amplified with the primers ITS4/ITS6. E. aquilegiae (LC009944) was the most similar species with eight nucleotide differences (98.6% similarity). Based on morphological and molecular characteristics, it was concluded that the powdery mildew fungus was E. aquilegiae. To the author’s knowledge, this is the first unequivocal report of E. aquilegiae occurring within the United States. These results are important for the U.S. floral industry, for which Aquilegia is a major crop.

The tomato powdery mildew fungus Oidium neolycopersici

2001 ◽  
Vol 2 (6) ◽  
pp. 303-309 ◽  
Author(s):  
Hannah Jones ◽  
John M. Whipps ◽  
Sarah Jane Gurr
Keyword(s):  
Powdery Mildew ◽  
Oidium Neolycopersici ◽  
Powdery Mildew Fungus ◽  
Tomato Powdery Mildew

scholarly journals First Report of Powdery Mildew Caused by Erysiphe arcuata on Lanceleaf Coreopsis (Coreopsis lanceolata) in Korea

Plant Disease ◽  
2012 ◽  
Vol 96 (12) ◽  
pp. 1827-1827 ◽  
Author(s):  
H. B. Lee
Keyword(s):  
Powdery Mildew ◽  
Invasive Plant ◽  
Signs And Symptoms ◽  
Morphological Data ◽  
Powdery Mildew Fungus ◽  
First Report ◽  
Rdna Its ◽  
The World ◽  
The Usa ◽  
Cut Foliage

Lanceleaf coreopsis (Coreopsis lanceolata L.) is a plant species of the genus Coreopsis in Asteraceae native to the USA. This plant is a bushy perennial species with finely cut foliage and showy round flowers and is increasing as plants used in landscaping in the world. The invasive plant is also planted very commonly along roadsides in Korea. In late October 2011 and August 2012, signs and symptoms of a powdery mildew disease were observed on lanceleaf coreopsis in several land areas near Gwangju-river, Gwangju, Korea. Symptoms included typical white superficial mycelia. The conidia of the powdery mildew fungus occurred on adaxial and abaxial surfaces. Chasmothecia were not observed. Single conidia formed terminally on conidiophores. Conidial morphology was subcylindrical to oblong. Dimension of conidia was 23.6 to 41.4 (avg. 35.1) μm long × 11.3 to 18.2 (avg. 14.8) μm wide. Conidiophores were composed of five to six (up to seven) cells, ranged from 45.7 to 131.2 (avg. 98.1) μm long × 8.2 to 11.1 (avg. 8.3) μm wide with foot-cells straight to slightly flexuous. Oidium anamorph of this fungus matched that of E. arcuata U. Braun, Heluta and S. Takam. described by Pastircakova et al. (3). From extracted genomic DNA, the rDNA ITS was amplified with ITS1F (5′-CTTGGTCATTTAGAGGAAGT-3′) and LR5F (5′-GCTATCCTGAGGGAAAC-3′) primer set. The rDNA ITS homology of the fungus (EML-CDPW1, GenBank Accession No. JX485650) showed 100% (590/590) identity value with E. arcuata (GenBank Accession No. AB252459). The identification of the fungus as E. arcuata was based on morphological data combined with the results of sequence analysis. Until recently, E. arcuata has been known to widespread on Carpinus species of the family Betulaceae including European hornbeam (C. betulus L.) and Chonowski's hornbeam (C. tschonoskii Maxim.) in Asia and Europe since Braun et al. first reported it as a new species in 2006 (1). In Korea, Podosphaera fusca (= Sphaerotheca fusca) and P. fuliginea (= S. fuliginea) were reported to cause powdery mildews on Coreopsis lanceolata. E. cichoracearum (= Golovinomyces cichoracearum), Leveillula taurica, P. fusca (= S. fusca), and Oidium spp. have been reported on Coreopsis spp. in the world (3). To our knowledge, this is the first report of powdery mildew caused by Oidium anamorph of E. arcuata on lanceleaf coreopsis (C. lanceolata) in Korea or elsewhere in the world. References: (1) U. Braun et al. Mycol. Prog. 5:139, 2006. (2) D. F. Farr and A. Y. Rossman. Fungal Databases, Systematic Mycology and Microbiology Laboratory, ARS, USDA. http://nt.ars-grin.gov/fungaldatabases/ , 2012. (3) K. Pastircakova et al. J. Phytopathol. 156:597, 2008.

scholarly journals First Report of Powdery Mildew (Pseudoidium neolycopersici) on Croton (Codiaeum variegatum var. pictum) in China

Plant Disease ◽  
2015 ◽  
Vol 99 (2) ◽  
pp. 288-288 ◽  
Author(s):  
X.-M. Liu ◽  
Y.-X. Wei ◽  
H. Zhang ◽  
F.-X. Zhou ◽  
J.-J. Pu
Keyword(s):  
Powdery Mildew ◽  
Southern China ◽  
Disease Incidence ◽  
Morphological Characteristics ◽  
Oidium Neolycopersici ◽  
Tomato Plants ◽  
First Report ◽  
Pseudoidium Neolycopersici ◽  
Codiaeum Variegatum ◽  
Pathogenicity Tests

Croton (Codiaeum variegatum (Linn.) var. pictum (Lodd.)) is an ornamental plant commonly grown in southern China. In March 2014, severe powdery mildew infections were observed on crotons in gardens of Hainan University (20.1°N and 110.3°E), Haikou, Hainan province. Disease incidence was estimated in a random batch of 100 plants in three replicates, with the average value approaching 80%. Symptoms first appeared as white circular patches on the adaxial surface and expanded to the abaxial surface, petioles, and stems. The top leaves were the most affected. Upper surfaces of the infected leaves were covered by white, dense mycelia. As the disease progressed, infected leaves turned purple on the lower surfaces and curly before becoming necrotic and abscising from the plant. Powdery mildew was more severe in shaded environments, especially during rainy or foggy weather in early spring. Two hundred conidiophores and conidia were observed microscopically. The conidiophores were straight or occasionally flexuous, 62.3 to 127.6 × 6.2 to 10.2 μm, consisting of two to three straight cells. Conidia were born in solitary on the top of conidiophores. Conidia were hyaline, ellipsoidal, 26.4 to 42.2 × 11.7 to 23.4 μm (average 32.5 × 16.5 μm), contained no distinct fibrosin bodies, and produced a subterminal germ tube. The wrinkling pattern of the outer walls of older conidia was angular or reticulated. Appressoria were single and multilobed. Cleistothecia were not observed. Based on morphological characteristics, the fungus was identified as Oidium neolycopersici (2), which was recently renamed Pseudoidium neolycopersici (L. Kiss) (3). The identity was confirmed by sequence analysis. Genomic DNA was extracted from the foliar powdery mildew colonies using Chelex-100 (Bio-Rad, Shanghai, China). The rDNA internal transcribed spacer (ITS) region was amplified with primers ITS1 and ITS4 (5). The ITS sequence of the representative isolates C01 (GenBank Accession No. KJ890378.1) and four other powdery mildew samples collected from crotons in Hainan University was 100% identical to that of P. neolycopersici isolates from tomato plants such as JQ972700 and AB163927. Inoculations were made by gently pressing diseased leaves onto leaves of five healthy plants of croton and tomato (‘Money maker’). Five non-inoculated croton and tomato plants served as controls. Inoculated and non-inoculated plants were maintained in an incubator at 25°C with a 12-h photoperiod. After eight days, typical powdery mildew symptoms developed on 93% of the inoculated plants, while no symptom developed on the non-inoculated plants. The pathogenicity tests were repeated three times. The same fungus was always re-isolated from the diseased tissue according to Koch's postulates. The pathogenicity tests further confirmed that the pathogen from crotons is P. neolycopersici (Basionym. Oidium neolycopersici (KJ890378.1)), which is commonly known as the tomato powdery mildew. P. neolycopersici is also a pathogen of Normania triphylla (1) and papaya (4). To our knowledge, this is the first report of P. neolycopersici infecting croton. The avenue of this pathogen entering gardens of Hainan University remains unknown. The gardens are located far away from tomato farms. Also no symptom of powdery mildew on croton was observed during surveys in other locations in Haikou. The origin of the pathogen warrants additional research. References: (1) D. Delmail et al. Mycotaxon 113:269, 2010. (2) L. Kiss et al. Mycol. Res. 105:684, 2001. (3) L. Kiss et al. Mycol. Res. 115:612, 2011. (4) J. G. Tsay et al. Plant Dis. 95:1188, 2011. (5) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, CA, 1990.

scholarly journals First Report of Powdery Mildew Caused by Oidium neolycopersici on Tomato in China

Plant Disease ◽  
2008 ◽  
Vol 92 (9) ◽  
pp. 1370-1370 ◽  
Author(s):  
C. W. Li ◽  
D. L. Pei ◽  
W. J. Wang ◽  
Y. S. Ma ◽  
L. Wang ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Average Length ◽  
Pathogenic Fungus ◽  
Fruit Size ◽  
Morphological Characteristics ◽  
Conidial Suspension ◽  
Oidium Neolycopersici ◽  
First Report ◽  
Its Sequence Analysis ◽  
Tomato Powdery Mildew

Tomato powdery mildew can cause remarkable reduction in fruit size and quality (4). In March of 2008, powdery mildew appeared as circular, white colonies on leaves, petioles, and stems of tomato plants grown in greenhouses in Shangqiu, Henan Province, China. The pathogenic fungus had unbranched conidiophores with an average length of 58.4 μm and width of 5.1 μm. Conidia were hyaline, elliptical, and were borne singly. Average length and width of conidia were 30.6 and 15.1 μm, respectively. Germ tubes were straight and formed at the ends or very close to the ends of conidia. Chasmothecium was not found in the collected samples. Different tomato cultivars and species, including Lycopersicon esculentum Mill (cvs. Moneymaker, Micro-Tom, Zaofen, Fenguo, and Zhongza series), L. peruvianum cv. LA2172, and L. hirsutum cv. G1.1560, were inoculated with a conidial suspension with a concentration of 5 × 104 conidia/ml. Plants developed powdery mildew symptoms as early as 4 days after inoculation. Susceptible symptoms developed on all L. esculentum cultivars, while L. peruvianum LA2172 and L. hirsutum G1.1560 displayed complete resistance, which is similar to the results of Bai et al 2004 (1) and Lindhout and Pet 1990 (3). Morphological characteristics of the pathogen on susceptible genotypes were similar to those from naturally infected plants. On the basis of the characteristics of the asexual stage, the pathogen was identified as an isolate of Oidium neolycopersici L. Kiss, which was confirmed by internal transcribed spacer (ITS) sequence analysis. PCR amplification and sequencing of the ITS region were performed with primers ITS1 and ITS4. The nucleotide sequence was assigned GenBank Accession No. EU486992, which had a 100% homology with 10 ITS sequences of O. neolycopersici in GenBank (Accession Nos. EU047559 to 047568) (2). In Asia, the spread of this pathogen has been recently reported in Japan (2). To our knowledge, this is the first report of tomato powdery mildew in China. Voucher specimens are available at the Specimen Center in the Department of Life Science, Shangqiu Normal University. References: (1) Y. Bai et al. Mol. Plant-Microbe. Interact. 18:354, 2005. (2) T. Jankovics et al. Phytopathology 98:529, 2008. (3) P. Lindhout and G. Pet. Tomato Gen. Coop. Rep. 40:19, 1990. (4) J. M. Whipps et al. Plant Pathol. 47:36, 1998.

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