First Report of Powdery Mildew Caused by Golovinomyces cichoracearum Dahlia (Dahlia variabilis) from Himachal Pradesh (India)

In 2005, the authors encountered a previously unreported powdery mildew disease of Coreopsis verticillata L. (whorled tickseed) ‘Zagreb’ and C. auriculata L. (lobed tickseed) ‘Nana’ in central Washington and determined the causal agent to be Golovinomyces cichoracearum (DC.) VP Gelyuta. This report documents the occurrence of G. cichoracearum on Coreopsis species in the Pacific Northwest, and describes diagnostic features of the disease and causal agent. Accepted for publication 2 March 2006. Published 5 April 2006.

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First Report of Powdery Mildew Caused by Erysiphe diffusa, Oidium neolycopersici, and Podosphaera xanthii on Papaya in Taiwan

Plant Disease ◽

10.1094/pdis-05-11-0362 ◽

2011 ◽

Vol 95 (9) ◽

pp. 1188-1188 ◽

Cited By ~ 6

Author(s):

J.-G. Tsay ◽

R.-S. Chen ◽

H.-L. Wang ◽

W.-L. Wang ◽

B.-C. Weng

Keyword(s):

Powdery Mildew ◽

Morphological Characteristics ◽

Its Region ◽

Podosphaera Xanthii ◽

Oidium Neolycopersici ◽

First Report ◽

Plastic Bags ◽

The World ◽

Golovinomyces Cichoracearum ◽

Powdery Mildew Fungi

Powdery mildew can be found in most papaya (Carica papaya L.) fields during the winter and spring seasons in Taiwan. It usually causes severe yellowing of the leaf lamina and petiole and serious defoliation. Three types of powdery mildew fungi were isolated from papaya leaves in Chiayi City (23.28°N, 120.28°E) at the beginning of 2008. Conidia of the first one were single, globose, hyaline, and 24 to 36 × 14 to 18 μm (average 30.2 × 15.6 μm) without fibrosin bodies and with straight or occasionally flexuous conidiophores at the base. The second one had short pseudo-chains of two to four conidia which were ellipsoidal to ovoid, hyaline, and 24 to 40 × 12 to 16 μm (average 29.7 × 13.4 μm) without fibrosin bodies. The third type had chains of ellipsoidal conidia that were hyaline, 24 to 28 × 12 to 16 μm (average 26.3 × 14.4 μm) and contained fibrosin bodies. To confirm the identity of the three fungi, the internal transcribed spacer (ITS) region of rDNA was amplified using the primer pairs G1 (5′-TCC GTA GGT GAA CCT GCG GAA GGA T-3′)/Ed2 (5′-CGC GTA GAG CCC ACG TCG GA-3′), G1 (5′-TCC GTA GGT GAA CCT GCG GAA GGA T-3′)/On2 (5′-TGT GAT CCA TGT GAC TGG AA-3′), and S1 (5′-GGA TCA TTA CTG AGC GCG AGG CCC CG-3′)/S2 (5′-CGC CGC CCT GGC GCG AGA TAC A-3′). The alignment of obtained sequences (GenBank Accession Nos. GU358452, 507 bp; GU358451, 580 bp; and GU358450, 455 bp) showed a sequence identity of 100, 99, and 99% with the ITS sequences of Erysiphe diffusa, Oidium neolycopersici, and Podosphaera xanthii (GenBank Accession Nos. FJ378880, EU909694, and GQ927254), respectively. On the basis of morphological characteristics and ITS sequence similarities, these fungi were identified as E. diffusa (Cooke & Peck) U. Braun & S. Takam., O. neolycopersici L. Kiss, and P. xanthii (Castagne) U. Braun & S. Takam., respectively (1,3). Single colonies on papaya leaves infected with powdery mildew were identified in the laboratory and maintained on papaya leaves as inoculum. Pathogenicity was confirmed through inoculations by gently pressing a single colony of each fungus onto leaves of healthy papaya seedlings (cv. Horng-Fe). Five seedlings were inoculated for each fungus and then covered with plastic bags for 2 days. Five noninoculated seedlings served as control. After inoculation, treated plants were maintained separately from the control in different rooms of a greenhouse at 25°C under natural daylight conditions. Seven days after inoculation, typical symptoms of powdery mildew were observed on inoculated plants, but not on noninoculated plants. The same species from diseased lesions following artificial inoculation with each fungus were identified with light microscopy. Papaya was previously described as a host to O. caricae Noack in many tropical and subtropical areas of the world including Taiwan (2). However E. cruciferarum, Golovinomyces cichoracearum, Oidiopsis sicula, O. caricae, O. caricae-papayae, O. caricicola, O. indicum, O. papayae, Ovulariopsis papayae, P. caricae-papayae, P. macularis, P. xanthii, and Streptopodium caricae were reported to infect papaya (4). To our knowledge, this is the first report of papaya powdery mildew caused by E. diffusa and O. neolycopersici in the world and the first report of the three fungi found on papaya in Taiwan. References: (1) U. Braun and S. Takamatsu. Schlechtendalia 4:1, 2000. (2) H. S. Chien and H. L. Wang. J. Agric. Res. China 33:320, 1984. (3) L. Kiss et al. Mycol. Res. 105:684, 2001. (4) J. R. Liberato et al. Mycol. Res. 108:1185, 2004.

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First report of Golovinomyces cichoracearum associated with powdery mildew on Helianthus tuberosus in Korea

Australasian Plant Disease Notes ◽

10.1007/s13314-012-0041-2 ◽

2012 ◽

Vol 7 (1) ◽

pp. 35-37 ◽

Cited By ~ 1

Author(s):

Sung-Eun Cho ◽

Mi-Jeong Park ◽

Ji-Hyun Park ◽

Kyung-Sook Han ◽

Hyeon-Dong Shin

Keyword(s):

Powdery Mildew ◽

Helianthus Tuberosus ◽

First Report ◽

Golovinomyces Cichoracearum

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First Report of Powdery Mildew Caused by Golovinomyces cichoracearum on English Daisy (Bellis perennis) in Italy

Plant Disease ◽

10.1094/pdis-92-3-0484a ◽

2008 ◽

Vol 92 (3) ◽

pp. 484-484 ◽

Cited By ~ 1

Author(s):

A. Garibaldi ◽

A. Minuto ◽

M. L. Gullino

Keyword(s):

Powdery Mildew ◽

Its Region ◽

Northern Italy ◽

Flowering Plant ◽

Pathogenicity Test ◽

First Report ◽

Golovinomyces Cichoracearum ◽

Blastn Analysis ◽

Commercial Farms ◽

Voucher Specimens

Bellis perennis (English daisy) is a flowering plant belonging to the Asteraceae and is increasingly grown as a potted plant in Liguria (northern Italy). In February 2007, severe outbreaks of a previously unknown powdery mildew were observed on plants in commercial farms at Albenga (northern Italy). Both surfaces of leaves of affected plants were covered with white mycelia and conidia. As the disease progressed, infected leaves turned yellow. Mycelia and conidia also were observed on stems and flower calyxes. Conidia were hyaline, ellipsoid, borne in chains (as many as three conidia per chain), and measured 27.7 × 16.9 (15.0 to 45.0 × 10.0 to 30.0) μm. Conidiophores measured 114.0 × 12.0 (109.0 to 117.0 × 11.0 to 13.0) μm and showed a foot cell measuring 78.0 × 11.0 (72.0 to 80.0 × 11.0 to 12.0) μm followed by two shorter cells. Fibrosin bodies were absent. Chasmothecia were not observed in the collected samples. The internal transcribed spacer (ITS) region of rDNA was amplified using primers ITS4/ITS6 and sequenced. BLASTn analysis (1) of the 415 bp obtained showed an E-value of 7e–155 with Golovinomyces cichoracearum (3). The nucleotide sequence has been assigned the GenBank Accession No. AB077627.1 Pathogenicity was confirmed through inoculations by gently pressing diseased leaves onto leaves of healthy B. perennis plants. Twenty plants were inoculated. Fifteen noninoculated plants served as a control. Plants were maintained in a greenhouse at temperatures ranging from 10 to 30°C. Seven days after inoculation, typical symptoms of powdery mildew developed on inoculated plants. The fungus observed on inoculated plants was morphologically identical to that originally observed. Noninoculated plants did not show symptoms. The pathogenicity test was carried out twice. To our knowledge, this is the first report of powdery mildew on B. perennis in Italy. The disease was already reported in other European countries (2). Voucher specimens are available at the AGROINNOVA Collection, University of Torino. References: (1) S. F. Altschul et al. Nucleic Acids Res. 25:3389, 1997. (2) U. Braun The Powdery Mildews (Erysiphales) of Europe. Gustav Fischer Verlag, Jena, Germany, 1995. (3) U. Braun and S. Takamatsu. Schlechtendalia 4:1, 2000.

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First Report of Powdery Mildew Caused by Golovinomyces cichoracearum on Crotalaria juncea (‘Tropic Sun’ Sunn hemp)

Plant Disease ◽

10.1094/pdis-93-4-0427a ◽

2009 ◽

Vol 93 (4) ◽

pp. 427-427 ◽

Cited By ~ 4

Author(s):

A. J. Gevens ◽

G. Maia ◽

S. A. Jordan

Keyword(s):

United States ◽

Powdery Mildew ◽

Cover Crop ◽

Morphological Characteristics ◽

The United States ◽

Universal Primers ◽

Crotalaria Juncea ◽

First Report ◽

Golovinomyces Cichoracearum ◽

Sunn Hemp

Crotalaria juncea L. (Fabaceae), commonly known as sunn hemp, is a subtropical annual legume grown in the United States as a cover crop that improves soil quality, provides nitrogen, suppresses weeds and nematodes, and adds organic matter to soils. In Florida, sunn hemp is a warm- and short-season cover crop that is typically planted in June and cut and incorporated into soil in September. In 2008, powdery mildew was observed on sunn hemp in a research field in Hastings, FL. This disease is important because it has the potential to impact the health and quality of sunn hemp, and this particular powdery mildew can infect cucurbits that are grown in north Florida from late summer to fall. Fungal growth appeared as typical white, powdery mildew colonies initially seen on upper leaf surfaces, especially along the midvein of infected leaves, but moving to undersides as disease progressed; petioles and floral parts were disease free. As disease progressed, colonies enlarged and coalesced to cover the entire leaf surface; heavily infected leaves senesced and abscised. Infection was primarily seen on the lower, more mature leaves of plants and not on the top 0.6 m (2 feet) of the plant. Mycelia produced white accumulations of conidiophores and conidia. Hyphae were superficial with papillate appressoria and produced conidiophores with cylindrical foot cells that measured 48.5 × 10.0 μm (mean of 100 foot cell measurements) and short chains of conidia. Conidia were hyaline, short-cylindrical to ovoid, lacked fibrosin bodies, borne in chains, had sinuate edge lines with other immature conidia, and measured 22.5 to 40.0 (mean = 29.85 μm) × 12.5 to 20.0 μm (mean = 15.55 μm). The teleomorph was not observed. The nuclear rDNA internal transcribed spacer (ITS) regions were amplified by PCR, using universal primers ITS1 and ITS4, and sequenced (GenBank Accession No. FJ479803). On the basis of morphological characteristics of the asexual, imperfect state that are consistent with published reports of Golovinomyces cichoracearum (2) and ITS sequence data that indicated 100% homology with G. cichoracearum from Helianthus annus (GenBank Accession No. AB077679), this powdery mildew was identified as caused by G. cichoracearum of the classification Golovinomyces Clade III (3). Pathogenicity was confirmed by gently pressing disease leaves onto leaves of healthy C. juncea plants. Inoculated plants were placed into plastic bags containing moist paper towels to maintain high humidity. The temperature was maintained at 24°C, and after 2 days, powdery mildew colonies developed in a manner consistent with symptoms observed under field conditions. A powdery mildew on Crotalaria was previously identified as caused by Microsphaera diffusa Cooke & Peck (1). To our knowledge, this is the first report of G. cichoracearum causing powdery mildew on C. juncea. References: (1) D. F. Farr et al. Fungi on Plants and Plant Products in the United States. The American Phytopathological Society, St. Paul, MN, 1989. (2) D. A. Glawe et al. Online publication. doi: 10.1094/PHP-2006-0405-01-BR. Plant Health Progress, 2006. (3) S. Takamatsu et al. Mycol. Res. 110:1093, 2006.

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First Report of Powdery Mildew Caused by Golovinomyces cichoracearum on Gerbera (Gerbera jamesonii) in Italy

Plant Disease ◽

10.1094/pdis-94-1-0130c ◽

2010 ◽

Vol 94 (1) ◽

pp. 130-130 ◽

Cited By ~ 4

Author(s):

M. Troisi ◽

D. Bertetti ◽

A. Garibaldi ◽

M. L. Gullino

Keyword(s):

Powdery Mildew ◽

Signs And Symptoms ◽

Its Region ◽

The United States ◽

Plant Diseases ◽

Gerbera Jamesonii ◽

First Report ◽

Potted Plants ◽

Golovinomyces Cichoracearum ◽

Blastn Analysis

Gerbera (Gerbera jamesonii) is one of the top 10 economically important flower crops in Europe as well as the United States. The acreage devoted to this crop continues to increase especially for use in landscape typologies. Abundant flowering from spring until autumn allows the use of this plant to decorate gardens, terraces, and borders. During the summer of 2009, an outbreak of a previously unknown powdery mildew was observed on potted gerbera ‘Mini Yellow’ growing in a private garden in Turin (northern Italy). Adaxial leaf surfaces were covered with white mycelium and conidia, and as the disease progressed, infected leaves turned yellow and died. Conidia were hyaline, ellipsoid, borne in chains (three conidia per chain), and measured 16 to 45 × 10 to 30 μm. Conidiophores measured 109 to 117 × 11 to 13 μm and had a foot cell measuring 72 to 80 × 11 to 12 μm followed by two shorter cells measuring 19 to 29 × 11 to 14 and 20 to 32 × 12 to 14 μm. Fibrosin bodies were absent and chasmothecia were not observed in the collected samples. On the basis of its morphology, the pathogen was identified as Golovinomyces cichoracearum. The internal transcribed spacer (ITS) region of rDNA was amplified with primers ITS1/ITS4 and sequenced. BLASTn analysis of the 548-bp fragment showed an E-value of 0.0 and a percentage homology of 99% with G. cichoracearum isolated from Coreopsis leavenworthii (Accession No. DQ871605) confirming diagnosis inferred by morphological analysis. The nucleotide sequence has been assigned GenBank Accession No. GQ870342. Pathogenicity was confirmed through inoculation by gently pressing diseased leaves onto leaves of three healthy potted plants of Gerbera ‘Mini Yellow’. Three noninoculated plants served as the control. Plants were maintained in a greenhouse at temperatures ranging between 20 and 30°C. Inoculated plants developed signs and symptoms after 8 days, whereas control plants remained healthy. The fungus present on inoculated plants was morphologically identical to that originally observed on diseased plants. To our knowledge, this is the first report of the presence of powdery mildew caused by G. cichoracearum on gerbera in Italy. Specimens are available at the Agroinnova Collection at the University of Torino. Gerbera is also susceptible to different powdery mildews. Powdery mildew of Gerbera jamesonii caused by Sphaerotheca fusca was reported in Italy (4). G. cichoracearum on Gerbera jamesonii was reported in North America (2), Argentina (3), and Switzerland (1). References: (1) A. Bolay. Cryptogam. Helv. 20:1, 2005. (2) M. Daughtrey et al. Page 39 in: Compendium of Flowering Potted Plant Diseases. The American Phytopathological Society, St Paul, MN, 1995. (3) R. Delhey et al. Schlechtendalia 10:79, 2003. (4) F. Zaccaria et al. Ann. Fac. Agrar. Univ. Stud. di Napoli Federico II 34:44, 2000.

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First Report of Powdery Mildew on Potato Caused by Golovinomyces cichoracearum in California

Plant Disease ◽

10.1094/pdis.2004.88.3.309c ◽

2004 ◽

Vol 88 (3) ◽

pp. 309-309 ◽

Cited By ~ 2

Author(s):

M. K. Romberg ◽

J. J. Nuñez ◽

J. J. Farrar

Keyword(s):

New York ◽

Powdery Mildew ◽

Standard Error ◽

Disease Spread ◽

Disease Symptoms ◽

First Report ◽

Erysiphe Cichoracearum ◽

Golovinomyces Cichoracearum ◽

Plastic Bag ◽

Field Report

In October 2003, potato plants in three fields (cv. Desiree, Satina, Midas, and Mondial) in Lancaster, California exhibited symptoms and signs of powdery mildew. Disease symptoms were most severe on cvs. Desiree and Santina. Disease expression was greater along sprinkler lines and in localized areas from which the disease spread to surrounding plants. Severely affected plants began collapsing just prior to water cutoff. Early symptoms comprise small dark areas on the adaxial surface of leaves, along the veins, and at the petioles. Dark lesions consisting of mycelia and conidiophores were also visible on the main stems of affected plants. As the disease progressed, leaves were covered by a gray powdery fungal mass, and older leaves became necrotic. Conidial chains arising from the hyaline, epiphytic mycelia consisted of two to eight conidia. The cylindric to doliform conidia measured 16.8 to 22.8 μm wide (mean = 19.2, standard error = 0.36, N = 30) × 28.8 to 45.6 μm long (mean = 32.4, standard error = 0.75, N = 30). No cleistothecia were observed. Identification of the causal agent as Golovinomyces cichoracearum (synonyms G. orontii and Erysiphe cichoracearum) based on morphology was confirmed by internal transcribed spacer (ITS)-polymerase chain reaction (PCR). Conidia were washed off the affected leaves, concentrated by filtration and centrifugation, and sonicated to release genomic DNA. PCR was performed on the sonicated conidia with primers ITS4 and ITS5 (2), and the resulting amplicon was purified and sequenced. BLAST analysis of the ITS sequence revealed a 99% homology to E. cichoracearum from an Ambrosia sp. (GenBank Accession No. AF011292). Pathogenicity was confirmed on potato seedlings cv. Red La Soda. Inoculations were performed twice on six plants (three pots) each time. A sterile brush was used to transfer conidia from the affected leaves to seedlings consisting of two to three fully expanded leaves. A plastic bag was placed around each pot containing two seedlings for 1 to 2 days and then removed. Noninoculated controls were stroked with a sterile brush, placed in a plastic bag for 1 to 2 days, and kept in the greenhouse on a separate bench. Two control plants were included for each inoculation. Plants were maintained in a greenhouse at approximately 25 to 28°C and 40 to 60% relative humidity. After 7 days, dark spots were visible on the leaves of all inoculated plants, and conidiophores with conidia identical to those of the isolate used as the inoculum source were apparent after 10 days. The controls showed no disease symptoms or signs. To our knowledge, this is the first report of powdery mildew caused by G. cichoracearum on potato in California. The first field report of the disease was from Washington in 1950 (1), with subsequent reports from Utah and Ohio. References: (1) J. D. Menzies. Plant Dis. Rep. 34:140, 1950. (2) T. J. White et al. PCR Protocols. Academic Press, New York, 1990.

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First report of the powdery mildew Golovinomyces cichoracearum on Telekia speciosa in Germany.

Czech Mycology ◽

10.33585/cmy.59206 ◽

2007 ◽

Vol 59 (2) ◽

pp. 201-204

Author(s):

Herbert Boyle ◽

Wolfgang Dietrich ◽

Siegfried Bräutigam

Keyword(s):

Powdery Mildew ◽

First Report ◽

Golovinomyces Cichoracearum

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First Report of Powdery Mildew of Pumpkin Caused by Golovinomyces cichoracearum in Neelum Valley, Azad Kashmir

Plant Disease ◽

10.1094/pdis-08-11-0642-pdn ◽

2012 ◽

Vol 96 (6) ◽

pp. 906-906

Author(s):

I. Mukhtar ◽

R. Khurram ◽

A. Hannan ◽

Z. Hayat

Keyword(s):

Powdery Mildew ◽

Infected Plant ◽

Causal Agent ◽

Morphological Observation ◽

Fungal Culture ◽

Voucher Specimen ◽

First Report ◽

Golovinomyces Cichoracearum ◽

Azad Kashmir ◽

Basal Septum

During July 2011, a severe powdery mildew outbreak was recorded in pumpkin (Cucurbita moschata Duch.) fields in economically poor areas in the Neelum Valley (Leswa, Mir Pura, Jura, Kundal Shahi, and Bela). Disease symptoms included grayish white circular to irregular patches consisting of epiphytic mycelia and conidia on both surfaces of the leaves of infected vines. Fungal mycelia and conidiophores were also visible in white powdery patches on the main stems, leaves, and petioles of affected plants. Leaves became necrotic with age. Powdery mildew symptoms were more severe on pumpkin vines located in the shade, and severely affected vines collapsed. A voucher specimen (IR00027) has been deposited in First Fungal Culture Bank of the Pakistan (FCBP), Institute of Agriculture Sciences, University of the Punjab, Lahore, Pakistan. For morphological observation, a clear tape strip was used to remove fungal tissue from infected leaves. The tape was mounted on microscope slides with water and examined with a light microscope (2). Conidiophores were unbranched, cylindrical, erect and arose singly on hyphal cells, 110 to 200 × 6 to 12 μm, composed of a foot cell and three to eight barrel-shaped conidia formed in chains with a sinuate edge, followed with a basal septum at the branching point or slightly displaced from the mycelium. Foot cells were 50 to 80 × 6 to 12 μm, and slightly swollen with constriction at the base. Conidia were cylindrical to doliiform, 30 to 50 × 14 to 20 μm and produced in chains. The length/breadth ratio of the conidia was 1.8 to 2.6. Fibrosin bodies were absent in both conidiophores and conidia. No cleistothecia were observed. Identification of the causal agent as Golovinomyces cichoracearum (DC.) V.P. Heluta (synonym Erysiphe cichoracearum) was based on morphology (1). Pathogenicity was determined using field-infected plant leaves transported to a greenhouse. Fresh conidia of field isolates of G. cichoracearum were transferred by a sterile brush from the affected leaves to fully expanded four to five healthy leaves of three 40-day-old vines. For the control, three vines were stroked with a clean sterile brush and control plants were placed 100 m away from the inoculated plants. For disease development 20°C and 80% relative humidity was maintained in the greenhouse. A plastic sheet was placed around each vine for a week and removed later. Inoculated vines developed visible white spots of powdery mildew on the leaves after 10 days in the greenhouse, whereas control plants remained asymptomatic. Fungal colony and conidial morphology on the leaves of inoculated plants were as described above. Previously, G. cichoracearum has been reported on other cucurbits (3) in the plains of Pakistan. To our knowledge, this is the first report of occurrence of G. cichoracearum as a causal agent of powdery mildew on pumpkin in Neelum Valley, Azad Kashmir. References: (1) U. Braun. Beih. Nova Hedwigia 89:1, 1987. (2) J. C. Correll et al. Plant Dis. 71:248, 1987. (3) A. Wahid et al. Pak. J. Agric. Res. 9:209, 1988.

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