scholarly journals First Report of Powdery Mildew Caused by Erysiphe betae on Sugar Beet in Korea

Plant Disease ◽  
2017 ◽  
Vol 101 (1) ◽  
pp. 254-254
Author(s):  
J. H. Joa ◽  
K. C. Seong ◽  
I. Y. Choi ◽  
S. E. Cho ◽  
H. D. Shin
Keyword(s):  
Powdery Mildew ◽  
Sugar Beet ◽  
First Report ◽  
Erysiphe Betae

scholarly journals First Report of the Perfect Stage of Powdery Mildew of Sugar Beet in North Dakota Caused by Erysiphe polygoni

Plant Disease ◽  
2007 ◽  
Vol 91 (4) ◽  
pp. 470-470 ◽  
Author(s):  
C. A. Bradley ◽  
P. Burlakoti ◽  
R. S. Nelson ◽  
M. F. R. Khan
Keyword(s):  
Powdery Mildew ◽  
Sugar Beet ◽  
North Dakota ◽  
Leaf Spot ◽  
Genetic Recombination ◽  
The State ◽  
Cercospora Leaf Spot ◽  
First Report ◽  
Perfect Stage ◽  
Erysiphe Polygoni

Powdery mildew caused by Erysiphe polygoni was widespread on sugar beet (Beta vulgaris) in North Dakota during 2006. This disease is generally not prevalent in the state because of the application of fungicides, which also have efficacy against powdery mildew, for control of Cercospora leaf spot caused by Cercospora beticola. Because Cercospora leaf spot pressure was low in 2006, fewer fungicide applications were made in the state, thus allowing for more observations of powdery mildew. Leaf samples from four fields near Amenia, Minto, Prosper, and St. Thomas, ND were collected in mid-September to look for the perfect stage of E. polygoni, since this has recently been observed in Idaho, Colorado, Montana, and Nebraska (1–3). Only the leaves collected from the field near Amenia had visible immature (yellow and brown) globose ascomata; ascomata were not observed on the leaves collected in the other fields. Additional leaves were collected from the field near Amenia in early October; these leaves had immature and mature (black) globose ascomata that were 70 to 105 μm in diameter. Mature ascomata contained ovoid to elliptic asci with one to four hyaline-to-golden pigmented ascospores (20 to 25 × 12 to 20 μm). The color, shape, and size of ascomata, asci, and ascospores were similar to previously reported observations (1–4). The prevalence of the perfect stage in North Dakota is unknown, since no statewide surveys were conducted. To our knowledge, this is the first report of the perfect stage of E. polygoni on sugar beet in North Dakota. The occurrence of the perfect stage could lead to a means for overwintering in this area. Because of the means for genetic recombination, the risk of fungicide resistance and the development of races may increase. References: (1) J. J. Gallian and L. E. Hanson. Plant Dis. 87:200, 2003. (2) R. M. Harveson. Plant Dis. 88:1049, 2004. (3) B. Jacobsen et al. Plant Dis. 89:1362, 2005. (4) E. G. Ruppel. Powdery mildew. Pages 13–15 in: Compendium of Beet Diseases and Insects. E. D. Whitney and J. E. Duffus, eds. The American Phytopathological Society. St. Paul, MN, 1986.

scholarly journals First Report of QOI-insensitive Powdery Mildew (Erysiphe polygoni) on Sugar Beet in the United States

Plant Disease ◽  
2014 ◽  
Vol 98 (7) ◽  
pp. 1004-1004 ◽  
Author(s):  
M. D. Bolton ◽  
O. T. Neher
Keyword(s):  
United States ◽  
Disease Management ◽  
Powdery Mildew ◽  
Sugar Beet ◽  
Untreated Control ◽  
The United States ◽  
Nucleotide Position ◽  
Cytb Gene ◽  
First Report ◽  
Erysiphe Polygoni

The $2.1 billion United States sugar beet (Beta vulgaris L.) industry is the primary provider of domestic sucrose. Sugar beet powdery mildew is caused by Erysiphe polygoni DC and occurs principally in sugar beet growing regions in the western United States. In these regions, the quinone outside inhibitor (QOI) fungicides pyraclostrobin (Headline, BASF, NC) and trifloxystrobin (Gem, Bayer Crop Science, NC) have been important tools to manage powdery mildew since registration in 2002 and 2005, respectively. However, researchers in Idaho reported poor disease management despite QOI application starting in 2011. In 2013, a research plot near Parma, ID, containing natural powdery mildew infection received treatments of pyraclostrobin, trifloxystrobin, or was untreated (control). Since there was no significant reduction in disease levels between QOI-treated blocks and untreated control blocks, experiments were conducted to clone a partial fragment of the E. polygoni cytochrome b (cytb) gene to gain insight into the molecular basis of QOI resistance in this pathosystem. The primers MDB-920 (5′-CACATCGGAAGAGGTTTATA-3′) and MDB-922 (5′-GGTATAGATCTTAATATAGCATAG-3′) were designed based on consensus sequences of several fungal cytb genes obtained from GenBank (data not presented) and used to amplify a 575-bp fragment of the E. polygoni cytb gene using DNA isolated from 12 infected leaf samples collected in September 2013 from the Parma research plot. Each sample consisted of three leaves harvested from three plants (one leaf per plant) in an experimental block. All DNA extraction, PCR, and sequencing procedures were as described previously (1). PCR products derived from six QOI-treated samples and six untreated samples were sequenced directly. Without exception, all QOI-treated samples harbored a point mutation at nucleotide position 143 that encoded a G143A mutation compared with cytb sequence from untreated samples. The two identified cytb haplotypes have been deposited in GenBank under accession numbers KF925325 and KF925326. This is the first report of QOI resistance and the associated cytb G143A mutation in E. polygoni. The G143A mutation has been reported in most QOI-resistant pathogens to date (2). When the G143A mutation dominates in a pathogen population, there is a consistent association with a loss of disease management despite QOI application (3). Careful monitoring and judicious use of QOI fungicides will be necessary to ensure QOI fungicides remain efficacious for sugar beet powdery mildew management in the United States. References: (1) M. D. Bolton et al. Pest Manag. Sci. 69:35, 2013. (2) N. Fisher and B. Meunier. FEMS Yeast Res. 8:183, 2008. (3) U. Gisi et al. Pest Manag. Sci. 58:859, 2002.

scholarly journals First Report of Powdery Mildew Caused by Erysiphe betae on Swiss Chard in China

Plant Disease ◽  
2014 ◽  
Vol 98 (10) ◽  
pp. 1429-1429 ◽  
Author(s):  
Y. Zhang ◽  
F. L. Zhang ◽  
P. Cao ◽  
Y. Liu ◽  
K. Liu ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Its Region ◽  
Central China ◽  
Growth Chamber ◽  
Universal Primers ◽  
Academic Press ◽  
First Report ◽  
Swiss Chard ◽  
Microscopic Evaluation ◽  
Erysiphe Betae

Swiss chard (Beta vulgaris L. subsp. cicla) is a widely planted vegetable in China. From May to June 2013, an outbreak of powdery mildew on Swiss chard cultivar Fangzheng was observed in the commercial fields in Zhoukou city of Henan Province, located in central China. More than 80% of the plants exhibited symptoms of the disease. At the beginning of infection, circular, white, dust-like colonies of powdery mildew occurred mainly on adaxial surfaces of leaves. As the disease progressed, white mycelia covered the foliar parts of plant. No cleistothecia were found on or in collected samples. Upon microscopic evaluation, conidiophores were unbranched with the length of 63 to 126 and width of 7 to 10 μm (n = 50), produced conidia singly, and composed of a cylindrical foot cell followed by one to three short cells. Conidia were colorless, hyaline, ovoid, measured 29 to 40 × 12 to 18 μm (n = 100), lacked fibrosin bodies, and produced germ tubes on the ends of the conidia. The fungus was identified as Erysiphe betae according to the morphological features (1). To verify the identity, the internal transcribed spacer (ITS) region was amplified with the universal primers ITS1 and ITS4 (2) and sequenced. The ITS sequence obtained was assigned as Accession No. KF268348 in GenBank, which showed 100% homogeneity with two ITS sequences of E. betae isolates from UK (DQ164432 and DQ164436). Koch's postulates were conducted by inoculating 15 healthy 5-week-old plants (cv. Fangzheng) with detached infected leaves, which grew in a growth chamber under 22/16°C (day/night), 50% relative humidity, 120 μmol/m2/s light and a 16-h photoperiod. Fifteen non-inoculated plants grew in another growth chamber with the same conditions as control. Symptoms consistent with the infected field plants were observed on the inoculated plants, while no symptoms were found on the control plants. Microscopic observation revealed that the pathogen growing on the inoculated plants was consistent with the morphology of the original fungus. To our knowledge, this is the first report of E. betae infection on Swiss chard in China (3). References: (1) S. Francis. Mol. Plant Pathol. 3:119, 2002. (2) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. M. A. Innis et al., eds. Academic Press, San Diego, CA, 1990. (3) R. Y. Zheng et al. Page 63 in: Flora Fungorum Sinicorum, Vol. 1, Erysiphales. Science Press, Beijing, 1987.

scholarly journals QoI Resistance in Sugar Beet Powdery Mildew (Erysiphe betae) in Scandinavia

2019 ◽  
Vol 20 (3) ◽  
pp. 179-179 ◽  
Author(s):  
Thies Marten Heick ◽  
Anne Lisbet Hansen ◽  
Annemarie Fejer Justesen ◽  
Lise Nistrup Jørgensen
Keyword(s):  
Powdery Mildew ◽  
Sugar Beet ◽  
The United States ◽  
Field Trials ◽  
Active Ingredients ◽  
Management Measures ◽  
Real Risk ◽  
Erysiphe Betae ◽  
European Union Legislation ◽  
Qoi Resistance

Powdery mildew caused by Erysiphe betae is one of the major fungal diseases in sugar beet in Denmark and Sweden. Frequent applications of fungicides mitigate the risk of powdery mildew epidemics and, consequently, reduce yield losses conferred by the disease. So far, mixtures of quinone outside inhibitors (QoIs) and triazoles have provided good efficacy against E. betae in field trials and common farming practice. However, development of fungicide resistance is a real risk, because only a limited number of active ingredients are available for the control of powdery mildew in sugar beet, and several other active ingredients are expected to be banned following reevaluation when the most recent European Union legislation is implemented. The G143A mutation associated with QoI resistance has been previously found in the United States. In this brief, its presence in Europe is reported for the first time. The current finding strongly encourages the adoption of anti-resistance strategies that minimize the spread of QoI resistance in sugar beet powdery mildew. Those strategies should be based on integrated pest management measures, including disease monitoring, the use of resistant cultivars, and the use of biological products. A sole reliance on QoI fungicides for sugar beet powdery mildew control should be avoided.

Erysiphe betae. [Descriptions of Fungi and Bacteria].

1967 ◽  
Author(s):  
J. N. Kapoor
Keyword(s):  
Powdery Mildew ◽  
Sugar Beet ◽  
Succinic Acid ◽  
Geographical Distribution ◽  
Seed Treatment ◽  
Erysiphe Betae ◽  
Lower Infection

Abstract A description is provided for Erysiphe betae. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Beta corolliflora, B. intermedia, B. maritima, B. trigyna, B. vulgaris and B. vulgaris var. cycla (Hirata, 1966). DISEASE: Powdery mildew of sugar beet. GEOGRAPHICAL DISTRIBUTION: Africa (Libya); Asia (Iran, Israel, Japan, Lebanon, Turkey); Europe (widely distributed). (Hirata, 1966). TRANSMISSION: Not known. However, seed treatment with 2, 4-D, heterosuxin, gibberellin and succinic acid has been reported to lower infection (44, 1315).

First Report of Powdery Mildew of Kalanchoe blossfeldiana caused by Sphaerotheca fuliginea (Podosphaera fuliginea) in the Pacific Northwest

2003 ◽  
Vol 4 (1) ◽  
pp. 39
Author(s):  
Dean A. Glawe ◽  
Rita Hummel ◽  
Grace Jack
Keyword(s):  
Powdery Mildew ◽  
Pacific Northwest ◽  
Sphaerotheca Fuliginea ◽  
First Report ◽  
Major Disease ◽  
The Pacific ◽  
Kalanchoe Blossfeldiana ◽  
Extension Center ◽  
Kalanchoë Blossfeldiana

Kalanchoe blossfeldiana Poelln. is a common ornamental houseplant. Although powdery mildew is a major disease of this species, there are no published reports of it in the Pacific Northwest. In August, 2002, powdery mildew was observed on six indoor K. blossfeldiana plants in an office and adjacent laboratory at the Puyallup Research and Extension Center. Accepted for publication 25 March 2003. Published 17 April 2003.

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