scholarly journals First Report of Tan Spot of Wheat Caused by Pyrenophora tritici-repentis in the Pacific Northwest

Plant Disease ◽  
2003 ◽  
Vol 87 (2) ◽  
pp. 203-203
Author(s):  
T. L. Peever ◽  
T. D. Murray
Keyword(s):  
New York ◽  
Pacific Northwest ◽  
Sequence Similarity ◽  
Triticum Aestivum L ◽  
Tan Spot ◽  
Morphological Description ◽  
Morphological Identification ◽  
First Report ◽  
Pyrenophora Tritici Repentis ◽  
The Pacific

In late May 2001, lesions resembling tan spot were observed on lower leaves of winter wheat (Triticum aestivum L.) in early boot stage in Nez Perce County, ID. Abundant sporulation was observed from tan lesions with chlorotic haloes after 2 days incubation in a moist chamber at room temperature. Conidia were multicelled, straw colored, approximately 100 × 15 µm, rounded at the apex, and borne singly on dark brown conidiophores. The fungus fit the morphological description of Drechslera tritici-repentis (Died.) Shoemaker, the anamorphic state of Pyrenophora tritici-repentis (Died.) Drechs. (2). Three single-conidial isolates were sampled from infected plants in a 5 × 1 m area of the affected field and induced to sporulate. Two of the isolates were used to spray-inoculate 3-week-old susceptible wheat (cv. Madsen) in the greenhouse (one plant per isolate, 1 × 105 conidia/ml), and tan spot lesions were apparent 3 to 5 days after inoculation with both isolates. DNA was extracted from all three isolates, and the entire nuclear ribosomal internal transcribed spacer (ITS) was amplified with ITS1 and ITS4 primers (4). Similarly, 610 bp of the 5′ end of the glyceraldehyde-3-phosphate-dehydrogenase gene (gpd) was amplified with gpd-1 and gpd-2 primers (1). ITS and gpd amplicons were direct-sequenced on both strands, and alignment revealed that all three isolates were identical for both regions. A BLAST search of the NCBI database with the ITS sequence revealed P. tritici-repentis accessions AY004808 and AF071348 and D. tritici-repentis accession AF163060 as the closest matches with 100, 99.8, and 98.8% sequence similarity, respectively. A similar search with the gpd sequence revealed P. tritici-repentis accessions AY004838 and AF081370 and P. bromi accession AY004839 as the closest matches with 100, 100, and 99.0% sequence similarity, respectively. These results, coupled with the morphological identification and inoculation results, confirm the identity of the fungus as P. tritici-repentis. Although reported on other grass hosts in the region (3), to our knowledge, this is the first report of tan spot of wheat in the Pacific Northwest. This disease has been of little concern to wheat producers in the Pacific Northwest due to low rainfall and relative humidity during the growing season. References: (1) M. L. Berbee et al. Mycologia 91:964, 1999. (2) M. B. Ellis, Dematiaceous Hyphomycetes. CMI, Kew, Surrey, UK. 1971. (3) R. Sprague. Diseases of Cereals and Grasses in North America (Fungi, Except Smuts and Rusts). Ronald Press Co. New York, 1950. (4) T. J. White et al. Pages 315–322 in: PCR Protocols: A Guide to Methods and Applications. Academic Press Inc., New York, 1990.

scholarly journals First Report of Aecidium magnatum Anamorph of Uromyces acuminatus Causing Rust on Viburnum sargentii in Korea

Plant Disease ◽  
2013 ◽  
Vol 97 (9) ◽  
pp. 1251-1251
Author(s):  
Y. H. Yun ◽  
S. Y. Son ◽  
S. H. Kim
Keyword(s):  
New York ◽  
Sequence Similarity ◽  
The United States ◽  
28S Rdna ◽  
Morphological Data ◽  
Morphological Properties ◽  
Morphological Description ◽  
Mountainous Area ◽  
First Report ◽  
Dna Database

Viburnum sargentii Koehne belongs to the family Caprifoliaceae. It is a deciduous shrub that grows in wet mountainous area in Korea, Japan, and China. On July 2011, rust symptoms were observed on V. sargentii Koehne in Balwang mountain, Gangwon Province, Korea, at an altitude of 1,450 meters. The specimen was coded as DUCC506 and used to study in detail. Rust symptoms were present on leaves, floral axes, and petioles. The infected lesions slightly swelled and leaflets and leaves were distorted. These caused sharp bends in the petioles and wart-like galls on twigs. Defoliation and deflowering could result when infection was severe. The first symptom was small and pale yellow spots on the upper surfaces of the leaves. As the spots increased in size, they turned brown and tanned. Bright orange or yellow powdery masses of spores were produced in tiny cup-like structures that appeared on the undersurfaces of leaves and the surface of floral axes and petioles. Aecia were gregarious, cupulate, yellowish, and erumpent with a peridium having a lacerate, somewhat recurved margin. Peridial cells were hyaline to whitish, rhomboidal, 18 to 25 (avg. 21.5) × 15 to 20 (avg. 18) μm, smooth to finely verrucose, and not observed in aecial stage on floral axes and petioles. Aeciospores were globose to ellipsoid, 14 to 16 (avg. 15.4) × 15 to 16.5 (avg. 16) μm, hyaline to yellowish, with many verrucose surface and hyaline walls. These morphological properties correspond to the aecial stage of Uromyces acuminatus (1,4). From extracted genomic DNA, the D1 and D2 region of 28S ribosomal DNA was amplified with LROR (5′- ACCCGCTGAACTTAAGC-3′) and LR4 (5′-ACCAGAGTTTCCTCTGG- 3′) primer set. The 28S rDNA sequence of DUCC506 was deposited in GenBank DNA database under accession number KC570451. A nucleotide sequence similarity search through BLAST in the GenBank database revealed that the DUCC506's 28S rDNA shared 98% (607/622) similarity with that of U. acuminatus LD1005 (GU058004). Aecidium magnatum Arthur is the anamorph of U. acuminatus (2). Aecial and telial hosts of U. acuminatus belong to several families of Angiosperms and Spartina spp., respectively. No telial host was found near the infected aecial host V. sargentii. These morphological and molecular results support the morphological data to identify DUCC506 specimen is A. magnatum. To our knowledge, this is the first report of rust caused by A. magnatum on V. sargentii in Korea or elsewhere in the world. Rust caused by A. viburni was reported on V. sargentii in Korea without any morphological description (3). Peoples in Asia are interested in this host plant as it is used for ornamental and medicinal purpose. Therefore, our report would be useful information for the management of V. sargentii. References: (1) G. B. Cummins. The Rust Fungi of Cereals, Grasses and Bamboos. Springer-Verlag, New York, 1971. (2) D. F. Farr et al. Fungi on Plants and Plant Products in the United States. Page 1009. American Phytopathological Society Press, St. Paul, MN, 1989. (3) C. J. Kim. Kor. J. Micorbiol. 1:51, 1963. (4) H. Y. Yun et al. Plant Dis. 94:279, 2010.

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.

scholarly journals First record of Euxestonotus error (Hymenoptera: Platygastridae) in the Pacific Northwest, United States of America

2016 ◽  
Vol 148 (5) ◽  
pp. 616-618 ◽  
Author(s):  
E.R. Echegaray ◽  
R.N. Stougaard ◽  
B. Bohannon
Keyword(s):  
United States ◽  
New York ◽  
Pacific Northwest ◽  
United States Of America ◽  
First Record ◽  
The United States ◽  
Sitodiplosis Mosellana ◽  
Wheat Midge ◽  
The Pacific ◽  
Northwestern Montana

AbstractEuxestonotus error (Fitch) (Hymenoptera: Platygastridae) is considered part of the natural enemy complex of the wheat midge Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae). Although previously reported in the United States of America, there is no record for this species outside the state of New York since 1865. A survey conducted in the summer of 2015 revealed that E. error is present in northwestern Montana and is likely playing a role in the suppression of wheat midge populations.

First Report of Powdery Mildew of Lycium chinense (Chinese Matrimony Vine) Caused by Arthrocladiella mougeotii in the Pacific Northwest

2004 ◽  
Vol 5 (1) ◽  
pp. 16
Author(s):  
Dean A. Glawe
Keyword(s):  
North America ◽  
Powdery Mildew ◽  
Medicinal Plant ◽  
Pacific Northwest ◽  
Morphological Features ◽  
Lycium Chinense ◽  
First Report ◽  
Landscape Plant ◽  
The Pacific ◽  
Plant Grown

Chinese matrimony-vine (Lycium chinense Mill.) is a traditional medicinal plant grown in China and used as a perennial landscape plant in North America. This report documents the presence of powdery mildew on L. chinense in the Pacific Northwest and describes and illustrates morphological features of the causal agent. It appears to be the first report of a powdery mildew caused by Arthrocladiella in the Pacific Northwest. Accepted for publication 10 November 2004. Published 8 December 2004.

scholarly journals Characterizing Virulence of the Pyrenophora tritici-repentis Isolates Lacking Both ToxA and ToxB Genes

Pathogens ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 74 ◽  
Author(s):  
Jingwei Guo ◽  
Gongjun Shi ◽  
Zhaohui Liu
Keyword(s):  
Triticum Aestivum L ◽  
Tan Spot ◽  
Pyrenophora Tritici Repentis ◽  
Tan Spot Disease ◽  
Hard Red Winter Wheat ◽  
Winter Wheat Cultivars ◽  
Race 2 ◽  
Genomic Regions ◽  
Race 4 ◽  
Necrotrophic Effectors

The fungus Pyrenophora tritici-repentis (Ptr) causes tan spot of wheat crops, which is an important disease worldwide. Based on the production of the three known necrotrophic effectors (NEs), the fungal isolates are classified into eight races with race 4 producing no known NEs. From a laboratory cross between 86–124 (race 2 carrying the ToxA gene for the production of Ptr ToxA) and DW5 (race 5 carrying the ToxB gene for the production of Ptr ToxB), we have obtained some Ptr isolates lacking both the ToxA and ToxB genes, which, by definition, should be classified as race 4. In this work, we characterized virulence of two of these isolates called B16 and B17 by inoculating them onto various common wheat (Triticum aestivum L.) and durum (T. turgidum L.) genotypes. It was found that the two isolates still caused disease on some genotypes of both common and durum wheat. Disease evaluations were also conducted in recombinant inbred line populations derived from two hard red winter wheat cultivars: Harry and Wesley. QTL mapping in this population revealed that three genomic regions were significantly associated with disease, which are different from the three known NE sensitivity loci. This result further indicates the existence of other NE-host sensitivity gene interactions in the wheat tan spot disease system.

First Report of Powdery Mildew of Coreopsis Species Caused by Golovinomyces cichoracearum in the Pacific Northwest

2006 ◽  
Vol 7 (1) ◽  
pp. 57
Author(s):  
Dean A. Glawe ◽  
Gary G. Grove ◽  
Mark Nelson
Keyword(s):  
Powdery Mildew ◽  
Pacific Northwest ◽  
Causal Agent ◽  
Diagnostic Features ◽  
First Report ◽  
The Pacific ◽  
Powdery Mildew Disease ◽  
Golovinomyces Cichoracearum

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.

First Report of Powdery Mildew Caused by Leveillula taurica of Field-Grown Sweet Pepper in the Pacific Northwest

2010 ◽  
Vol 11 (1) ◽  
pp. 45 ◽  
Author(s):  
Dean A. Glawe ◽  
Tess Barlow ◽  
Jordan E. Eggers ◽  
Philip B. Hamm
Keyword(s):  
Powdery Mildew ◽  
Economic Impact ◽  
Pacific Northwest ◽  
Sweet Pepper ◽  
Disease Outbreak ◽  
First Report ◽  
Leveillula Taurica ◽  
The Pacific

In August 2009, a grower reported a disease affecting nearly all plants in a drip-irrigated field of sweet pepper cv. Excalibur in Umatilla Co., OR. The fungus was determined to be Leveillula taurica (Lév.) G. Arnaud, previously unreported from this host in Oregon or from field-grown peppers in the Pacific Northwest. This report documents the taxonomic determination of this species and provides information about the disease outbreak, including economic impact. Accepted for publication 18 May 2010. Published 8 July 2010.

First Report of Downy Mildew of Chives Caused by Peronospora destructor in the Pacific Northwest

2003 ◽  
Vol 4 (1) ◽  
pp. 38
Author(s):  
Dean A. Glawe
Keyword(s):  
Downy Mildew ◽  
Pacific Northwest ◽  
Puget Sound ◽  
Washington State ◽  
King County ◽  
Specialty Crops ◽  
First Report ◽  
Peronospora Destructor ◽  
The Pacific ◽  
Allium Schoenoprasum

Chive (Allium schoenoprasum L.) is one of the specialty crops grown by farmers in the Puget Sound region of Washington State. In September, 2002, downy mildew symptoms were observed in a 0.2 hectare field planting of chive near Fall City, King County, WA. Downy mildew had not been reported previously on chive in the Pacific Northwest. Accepted for publication 15 April 2003. Published 12 May 2003.

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