Pathogenic Specialization inUromyces phaseoliin the United States and Rust Resistance in Beans

Plant Disease ◽  
1984 ◽  
Vol 68 (2) ◽  
pp. 95 ◽  
Author(s):  
J. R. Stavely
Keyword(s):  
United States ◽  
Rust Resistance ◽  
The United States

scholarly journals Differentiation of Molecular Genotypes and Virulence Phenotypes of Puccinia triticina from Common Wheat in North America

2009 ◽  
Vol 99 (6) ◽  
pp. 750-758 ◽  
Author(s):  
M. E. Ordoñez ◽  
J. A. Kolmer
Keyword(s):  
United States ◽  
North America ◽  
Leaf Rust ◽  
Resistance Genes ◽  
Rust Resistance ◽  
Puccinia Triticina ◽  
Leaf Rust Resistance ◽  
The United States ◽  
Rust Resistance Genes ◽  
Leaf Rust Resistance Genes

Wheat leaf rust caused by Puccinia triticina is widely distributed in the wheat growing regions of the United States and Canada, and is subject to selection for virulence phenotype by leaf rust resistance genes in wheat cultivars. The objective of this study was to determine the number of genetically differentiated groups of P. triticina that are currently present in North America. In total, 148 isolates of P. triticina from the 1980s to 2005 were collected from wheat-growing regions of the United States and Canada and tested for virulence on 20 lines of wheat with single genes for leaf rust resistance and for molecular genotype with 23 simple sequence repeat (SSR) markers. In total, 91 virulence phenotypes and 65 SSR genotypes were found. After removal of isolates with identical virulence and SSR genotypes, 125 isolates were included for further analysis. Bayesian cluster analysis indicated five different groups of isolates based on SSR genotypes that also differed for virulence to leaf rust resistance genes Lr2a, Lr2c, Lr3bg, Lr17, and Lr28. Isolates avirulent to Lr14a and Lr20 that have increased since 2003 had SSR genotypes identical or similar to older isolates in one of the five groups, indicating that these isolates were derived by mutation from the previously existing population of P. triticina. The representative collection of P. triticina isolates had characteristics consistent with an asexual dikaryotic population of genetically differentiated groups of SSR genotypes with high levels of heterozygosity and disequilibrium within which stepwise mutation at avirulence or virulence loci regularly occurs.

scholarly journals Additional Sources of Broad-Spectrum Resistance to Puccinia coronata f. sp. avenae from Canadian Accessions of Avena barbata

Plant Disease ◽  
2010 ◽  
Vol 94 (12) ◽  
pp. 1405-1410 ◽  
Author(s):  
M. L. Carson
Keyword(s):  
United States ◽  
Broad Spectrum ◽  
Rust Resistance ◽  
The United States ◽  
Crown Rust ◽  
Puccinia Coronata ◽  
Adult Plant ◽  
United States Department ◽  
Ploidy Levels ◽  
Broad Spectrum Resistance

Crown rust (Puccinia coronata f. sp. avenae) is considered the most damaging disease of oat and the use of race-specific seedling (Pc) genes for resistance has been the primary means of control. As these resistance genes from cultivated oat, Avena sativa, and the wild hexaploid animated oat, A. sterilis, were deployed in oat cultivars, corresponding virulence in the U.S. crown rust population increased rapidly, such that the effective lifespan of a resistant cultivar in the United States is now 5 years or less. Introgression of resistance from diploid and tetraploid Avena spp. into hexaploid oat has been difficult due to the difference in ploidy levels and the lack of pairing of homeologous chromosomes between species. The wild tetraploid slender oat, A. barbata, has been a source of powdery mildew and stem rust resistance in cultivated oat but has largely been unexploited for crown rust resistance. A relatively high percentage of A. barbata accessions from the United States Department of Agriculture (USDA) National Small Grains Collection were resistant to a highly diverse crown rust population in recent tests. Tests of 1,099 A. barbata accessions from the Canadian Plant Gene Resources Center not represented in the USDA collection revealed that a similar percentage (11.4%) were at least moderately resistant at the seedling and adult plant stage when tested with a highly diverse bulk inoculum derived from the St. Paul buckthorn nursery. Eighteen accessions were rated as highly resistant or a mix of highly resistant and resistant plants in both seedling and adult plant tests. Three accessions (CN21531 from Italy and CN26271 and CN26305 from Spain) displayed a unique “blotchy” resistant reaction as adult plants. Resistant accessions were found from throughout much of the natural range of A. barbata but the Western Mediterranean and Lebanon had the highest frequency of accessions with broad-spectrum resistance.

scholarly journals Races of Puccinia graminis Identified in the United States During 2003

Plant Disease ◽  
2005 ◽  
Vol 89 (10) ◽  
pp. 1125-1127 ◽  
Author(s):  
Y. Jin
Keyword(s):  
United States ◽  
Resistance Genes ◽  
Stem Rust ◽  
Rust Resistance ◽  
The United States ◽  
Stem Rust Resistance ◽  
Puccinia Graminis ◽  
Wheat Stem Rust ◽  
Stem Rust Resistance Genes ◽  
Rust Resistance Genes

Stem rust of small grain cereals, caused by Puccinia graminis, is a major disease of wheat, barley, and oat. In order to effectively utilize stem rust resistance in the improvement of small grain cereals, it is necessary to monitor the virulence composition and dynamics in the stem rust population. Races of P. graminis from barberry, wheat, barley, and oat were surveyed across the United States during 2003. Aecial infections on barberry were primarily due to P. graminis f. sp. secalis, as inoculations using aeciospores failed to produce infection on wheat and oat. Race QFCS of P. graminis f. sp. tritici was the most common race identified from wheat and barley. Race QFCS has virulence on stem rust resistance genes Sr5, 8a, 9a, 9d, 9g, 10, 17, and 21 that are used for race identification. Race TTTT was identified in 2003. This race possesses virulence to all 16 stem rust resistance genes present in the wheat stem rust differentials and should be targeted in breeding for stem rust resistance. Race QFCN appeared to be a new race in the U.S. stem rust population. Races QCCJ and MCCF were identified, but at low frequencies. Seven races of P. graminis f. sp. avenae were identified from oat, and races NA-27, NA-29, and NA-67 were the predominant races. Race NA-76 was identified for the first time in the United States.

scholarly journals Resistance to rust (Puccinia arachidis Speg.) identified in nascent allotetraploids cross-compatible with cultivated peanut (Arachis hypogaea L.)

2021 ◽  
Author(s):  
Chandler Maddox Levinson ◽  
Eric Antepenko ◽  
Soraya C. M. Leal-Bertioli ◽  
Ye Chu ◽  
Albert K. Culbreath ◽  
...  
Keyword(s):  
United States ◽  
Leaf Area ◽  
Interspecific Hybrids ◽  
Rust Resistance ◽  
The United States ◽  
Plant Management ◽  
Arachis Species ◽  
Puccinia Arachidis ◽  
Cultivated Peanut ◽  
Peanut Cultivars

Peanut rust, caused by Puccinia arachidis Speg., is a foliar disease that plagues peanut production along with early and late leaf spots, Passalora arachidicola (Hori) U. Braun and Nothopassalora personata (Berk. & M.A. Curtis) U. Braun, C. Nakash, Videira & Crous, respectively. Rust can cause up to 80% yield losses without control and is widespread in tropical countries but is also a sporadic problem in the United States. An integrative plant management strategy with rust resistant peanut cultivars is needed to decrease dependence on costly fungicides and increase yields for farmers who cannot afford or do not have access to fungicides. Only moderate levels of rust resistance have been found in cultivated peanut germplasm, but fortunately, high resistance to rust has been identified in wild Arachis species that can be introgressed into peanut cultivars. In this study, 16 diploid, wild Arachis species, five diploid, interspecific hybrids, 11 unique, allotetraploid interspecific hybrids, and two cultivated peanut controls were tested for resistance to rust. Resistance was evaluated in vitro by incubation time, susceptibility index (calculated based on the number of lesions of different diameters)/ leaf area, total number of lesions/ leaf area, and total number of sporulating lesions/ leaf area. All wild Arachis species tested were very highly resistant to rust, except for A. ipaënsis , the B-genome progenitor of cultivated peanut. Additionally, all interspecific hybrids and synthetic allotetraploids not produced with A. ipaënsis as a parent did not show symptoms for rust. Any of these nine synthetic allotetraploids, BatCor , BatDur 1, BatDur 2, BatSten 1, GregSten , MagCard , MagDio , MagDur , and ValSten 1 are recommended for progression to QTL mapping of rust resistance. These resistance QTLs can be pyramided into peanut cultivars to protect yields in the United States and to increase yields in tropical, developing countries for farmers that cannot afford, or do not have access to, costly fungicides.

scholarly journals Puccinia sorghi in Sinaloa, Mexico Virulent on Corn with the Rp1-D Gene

Plant Disease ◽  
2000 ◽  
Vol 84 (7) ◽  
pp. 810-810 ◽  
Author(s):  
J. K. Pataky ◽  
T. A. Natti ◽  
E. B. Snyder ◽  
C. J. Kurowski
Keyword(s):  
United States ◽  
New York ◽  
North America ◽  
Rust Resistance ◽  
Sweet Corn ◽  
The United States ◽  
Inbred Lines ◽  
Corn Hybrids ◽  
Midwestern United States ◽  
Puccinia Sorghi

Several different Rp genes in corn condition chlorotic fleck resistant reactions to Puccinia sorghi. Rp-resistance has been used successfully for the past 15 years to control common rust on sweet corn in North America. Most, but not all, Rp-resistant sweet corn hybrids carry the Rp1-D gene. In August and September 1999, isolates of P. sorghi were collected from Rp-resistant sweet corn grown in Illinois, Wisconsin, Minnesota, Michigan, and New York. This was the first widespread occurrence in North America of P. sorghi virulent on corn with Rp1-D (2). The origin of this population of P. sorghi with a virulence phenotype new to North America is not known. Since many believe Mexico is the source of common rust inocula for the midwestern United States, it is important to discover if this virulence occurs in Mexico. Forty-one Rp-resistant and nine susceptible sweet corn hybrids were planted 8 December 1999 in a nursery near Los Mochis, Mexico, in the state of Sinalao. Rp-resistant hybrids had been effective against common rust in Los Mochis nurseries prior to 1999. Each hybrid was in a single row of about 30 plants. The Los Mochis nursery also included two replicate rows of sweet corn or field corn inbred lines with one of 17 different single Rp-genes or one of 11 different compound genes for rust resistance (1). Plants were exposed to local populations of P. sorghi. Reactions were rated in March 2000. Sporulating uredinia (susceptible reactions) were abundant on all sweet corn hybrids and on inbreds with Rp1-D. Susceptible reactions also were observed on other inbred lines with Rp-genes except for lines with the single genes: Rp1-E, Rp-G, Rp1-I, Rp1-K, and Rp1-L or lines with the compound rust genes: Rp1-GI, Rp1-G5, Rp1-GDJ, Rp1-GFJ, Rp1-G5JC, Rp1-G5JD, and Rp1-JFC. This pattern of virulence is similar to that of P. sorghi isolates collected in the midwestern United States in 1999. Rp-resistance currently available in most sweet corn hybrids grown in the Midwest will not be effective when this population of P. sorghi spreads from Mexico to the United States. Therefore, other sources of rust resistance need to be incorporated into sweet corn hybrids. References: (1) S. H. Hulbert, Annu. Rev. Phytopathol. 35:292, 1997. (2) J. K. Pataky and W. F. Tracy. Plant Dis. 83:1177, 1999.

Correlative microscopy in distrubuted (client/server) computing environments: tools for catalyzing the rapid dissemination of information about the cell biology of the human prostate

1995 ◽  
Vol 53 ◽  
pp. 682-683
Author(s):  
A. Hakam ◽  
J.T. Gau ◽  
M.L. Grove ◽  
B.A. Evans ◽  
M. Shuman ◽  
...  
Keyword(s):  
United States ◽  
Cell Biology ◽  
Tissue Bank ◽  
The United States ◽  
Prostate Adenocarcinoma ◽  
Correlative Microscopy ◽  
Client Server ◽  
Critical Elements ◽  
Transplant Organ

Prostate adenocarcinoma is the most common malignant tumor of men in the United States and is the third leading cause of death in men. Despite attempts at early detection, there will be 244,000 new cases and 44,000 deaths from the disease in the United States in 1995. Therapeutic progress against this disease is hindered by an incomplete understanding of prostate epithelial cell biology, the availability of human tissues for in vitro experimentation, slow dissemination of information between prostate cancer research teams and the increasing pressure to “ stretch” research dollars at the same time staff reductions are occurring.To meet these challenges, we have used the correlative microscopy (CM) and client/server (C/S) computing to increase productivity while decreasing costs. Critical elements of our program are as follows:1) Establishing the Western Pennsylvania Genitourinary (GU) Tissue Bank which includes >100 prostates from patients with prostate adenocarcinoma as well as >20 normal prostates from transplant organ donors.

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