scholarly journals Incidence and Distribution of Puccinia coronata and P. graminis on Turfgrass in the Midwestern United States

Plant Disease ◽  
2018 ◽  
Vol 102 (5) ◽  
pp. 955-963
Author(s):  
Brijesh B. Karakkat ◽  
Vonte L. Jackson ◽  
Paul L. Koch
Keyword(s):  
United States ◽  
Stem Rust ◽  
Kentucky Bluegrass ◽  
The United States ◽  
Primary Objective ◽  
Crown Rust ◽  
Puccinia Coronata ◽  
Midwestern United States ◽  
Fungal Populations ◽  
Relationship Of

Crown rust (caused by Puccinia coronata) and stem rust (caused by P. graminis) are two common and destructive diseases of turfgrass in the United States. Crown rust has been associated with perennial ryegrass and stem rust with Kentucky bluegrass when identified based solely on fungal morphology. However, recent studies using molecular identification methods have indicated the host–pathogen relationship of rusts on turf to be more complex. Our primary objective was to quickly and accurately identify P. coronata and P. graminis in symptomatic turfgrass leaves over 3 years on turfgrass samples from across the Midwestern United States. Between 2013 and 2015, 413 samples of symptomatic cool-season turfgrass from Wisconsin and surrounding states were screened using real-time polymerase chain reaction. Of these samples, 396 were Kentucky bluegrass and 17% of them contained P. coronata, 69% contained P. graminis, and 13% contained both P. coronata and P. graminis. In addition, both year and location effects were observed on the distribution of Puccinia spp. collected annually from two locations in southern Wisconsin. This research supports previous conclusions that have identified variability among P. graminis and P. coronata host relationships on turfgrass, and further demonstrates that rust fungal populations on Kentucky bluegrass may not be consistent between locations in the same year or over multiple years at the same location. The increasing evidence of variation in the turfgrass rust populations will likely affect future rust management and turfgrass breeding efforts.

scholarly journals Virulence in Oat Crown Rust (Puccinia coronata f. sp. avenae) in the United States from 2006 through 2009

Plant Disease ◽  
2011 ◽  
Vol 95 (12) ◽  
pp. 1528-1534 ◽  
Author(s):  
M. L. Carson
Keyword(s):  
United States ◽  
Resistance Genes ◽  
The United States ◽  
Crown Rust ◽  
Puccinia Coronata ◽  
The North ◽  
Oat Crown Rust ◽  
Primary Means ◽  
Oat Cultivars ◽  
The U.S

The use of race-specific seedling genes for resistance is the primary means of controlling crown rust of oat (Puccinia coronata f. sp. avenae) in the United States. To better utilize those resistance genes, knowledge of the occurrence and frequency of corresponding virulence in the population of P. coronata f. sp. avenae in the United States is essential. In total, 571 single-pustule isolates of oat crown rust were collected from cultivated and wild oat (Avena sativa and A. fatua, respectively) in the major oat production areas of the United States from 2006 through 2009. They were tested for virulence on seedlings of 31 differential oat lines in the greenhouse. In all, 201 races were found among the 357 isolates from the spring oat region of the north-central United States, and 140 races were found among 214 isolates from the southern winter oat region. The crown rust populations from the winter and spring oat regions were clearly differentiated from one another, differing in the frequency of virulence for 24 of the 31 differentials. Some virulence associations previously reported in the U.S. oat crown rust population were also found in both regions in this survey, even when the dataset was clone corrected. Associations between virulence to the Pc genes were predominately positive in both regions but both positive and negative associations occurred more frequently in the winter oat region, where sexual reproduction does not occur. Some of the virulence diversity in the oat crown rust population in the United States can be related to the deployment of resistance genes in commercial oat cultivars and virulence associations existing in the oat crown rust population. When data from a previous report covering 2001 through 2005 is combined with data reported in this article, the mean virulence of the U.S. populations of crown rust continued to increase from 2001 to 2009. Virulence to Pc38, Pc39, Pc45, Pc48, Pc52, Pc55, Pc56, Pc57, Pc59, Pc62, Pc63, Pc64, Pc68, and Pc96 significantly increased in one or both regions during this time period. No significant declines in virulence frequency were found in either region. Genes for crown rust resistance derived from A. sterilis appear to be as rapidly defeated as has happened to Pc genes from A. sativa. There is an urgent need to find additional sources of effective resistance to P. coronata f. sp. avenae and introgress it into adapted oat cultivars.

scholarly journals Molecular Analysis of Turfgrass Rusts Reveals the Widespread Distribution of Puccinia coronata as a Pathogen of Kentucky Bluegrass in the United States

Plant Disease ◽  
2011 ◽  
Vol 95 (12) ◽  
pp. 1547-1557 ◽  
Author(s):  
Lisa A. Beirn ◽  
Melinda Moy ◽  
William A. Meyer ◽  
Bruce B. Clarke ◽  
Jo Anne Crouch
Keyword(s):  
United States ◽  
Kentucky Bluegrass ◽  
The United States ◽  
Rust Fungi ◽  
Puccinia Coronata ◽  
5.8S Rdna ◽  
Rust Diseases ◽  
New Races ◽  
Species Specific ◽  
Identification Techniques

Over the past 10 years, rust diseases have become increasingly prevalent on certain cultivars of Kentucky bluegrass. This pattern suggests that new races or new species of rust fungi may have emerged. To test this hypothesis, 66 samples of turfgrass rust fungi collected from across the United States were evaluated based on sequences of the internal transcribed spacer (ITS)-5.8S rDNA region. Phylogenetic analysis revealed three species: Puccinia coronata, P. graminis, and P. striiformis, comprising 67, 28, and 5% of the samples, respectively. P. coronata was frequently found in association with Kentucky bluegrass, a host–pathogen relationship that has not been previously reported. Comparison of molecular analyses with the use of standard field identification techniques—host association and pustule pigmentation—showed that 58% of the Kentucky bluegrass samples would have been incorrectly diagnosed using nonmolecular criteria. To avoid such misidentifications, a real-time polymerase chain reaction diagnostic protocol was developed for turfgrass-associated P. graminis, P. coronata, and P. striiformis using ITS sequences. Accurate, reproducible, species-specific identifications were made using as few as 50 to 150 urediniospores, even in mixed infections. This study represents the first DNA-based evaluation of turfgrass rust fungi and provides a quick and reliable sequence-based protocol as an alternative to less reliable field-based identification techniques.

Resistance of Prairie Junegrass and Tufted Hairgrass Germplasm to Diseases Common in Temperate Low-Input Turfgrass Systems

2018 ◽  
Vol 19 (4) ◽  
pp. 310-318
Author(s):  
Paul L. Koch ◽  
Kari Hugie ◽  
Eric Watkins
Keyword(s):  
United States ◽  
Genetic Variation ◽  
Kentucky Bluegrass ◽  
The United States ◽  
Primary Objective ◽  
Controlled Environment ◽  
Dollar Spot ◽  
Low Input ◽  
Important Direction ◽  
Turfgrass Breeding

Prairie junegrass and tufted hairgrass are two turfgrass species that are native to the United States and require less water, fertilizer, and pesticide compared with more commonly used turfgrass species such as Kentucky bluegrass. However, little is known about the resistance of these low-input turfgrasses to common turfgrass diseases. The primary objective of this research was to identify disease-resistant germplasm of both prairie junegrass and tufted hairgrass that can be used in future low-input turfgrass breeding efforts. A total of 41 populations of tufted hairgrass and 23 populations of prairie junegrass were evaluated for resistance to Microdochium patch, dollar spot, and rust development in a controlled environment. Genetic variation in disease resistance was clearly present in the unimproved germplasm of both prairie junegrass and tufted hairgrass, providing important direction for future breeding efforts that will allow wider implementation of low-input turfgrass species.

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.

Evidence of occurrence of Crown Rust of Barley Caused by Puccinia coronata var. hordei and sexual reproduction of the pathogen under field conditions in China

Plant Disease ◽  
2021 ◽  
Author(s):  
Xiaxia Tian ◽  
Qiang Yao ◽  
Zedong Zhang ◽  
Xiangrui Cheng ◽  
Jianfeng Qin ◽  
...  
Keyword(s):  
United States ◽  
Sexual Reproduction ◽  
Internal Transcribed Spacer ◽  
The United States ◽  
Crown Rust ◽  
Puccinia Coronata ◽  
Host Specialization ◽  
Wild Oat ◽  
Disease Symptoms ◽  
Internal Transcribed Spacer Sequences

Crown rust of barley, caused by Puccinia coronata var. hordei (Pch), was first reported by Jin and Steffenson in 1992, and the fungus has been reported only in the United States and Hungary. In China, stripe, stem, and leaf rusts have been reported on barley, but not for crown rust. Recently, a sample (HZJ0004) of rust collected from barley in Qilian county, Qinghai, China, appeared different from the three rusts based on color, size, arrangements of uredinia and/or telia. Teliospores had crown-shaped appendages on the top. Based on the disease symptoms and morphology of urediniospores and teliospores, the fungus was identified as Pch. Using the internal transcribed spacer sequences, the isolates HZJ0004 from barley and POR3 from buckthorn (Rhamnus sp.) were clustered in one clade with Pch isolates from barley and Elymus repens but in a different clade from the isolate POC8 from wild oat and the varieties of P. coronata from oats and grasses. At the seedling stage, most of the tested cultivars of barley and rye were susceptible to Pch isolates HZJ0004 and POR3, but the cultivars of oats, triticale, wheat, and the most grasses of Aegilops, Brachypodium, Bromus, Calamagrostis, Deschampsia, Elymus, Festuca, and Phleum were resistant, indicating their host specialization on barley. This is the first report of crown rust on barley in China.

Gender and Marital Satisfaction: Data from the National Survey of Families and Households

1998 ◽  
Vol 83 (1) ◽  
pp. 319-327 ◽  
Author(s):  
Walter R. Schumm ◽  
Farrell J. Webb ◽  
Stephan R. Bollman
Keyword(s):  
United States ◽  
Marital Satisfaction ◽  
Representative Sample ◽  
The United States ◽  
Nationally Representative ◽  
Relationship Of ◽  
The Relationship ◽  
Satisfaction Relationship ◽  
Representative Samples ◽  
Small Support

In 1972, Bernard argued that marriage was good for men and bad for women. Subsequent research noted that wives, on average, reported lower marital satisfaction than husbands. Furthermore, when differences within couples existed on marital satisfaction, the wife was usually the less satisfied spouse; however, most previous studies of the gender/marital satisfaction relationship had not been based on nationally representative samples. A nationally representative sample from the 1988 Survey of Families and Households was used to assess the relationship of gender with marital satisfaction. Within-couple analyses indicated that wives were less satisfied with their marriages than husbands and that, when substantial within-couple differences occurred with respect to marital satisfaction, the wife was usually the less satisfied spouse. Results provide at least small support for feminist assertions about the relatively adverse nature of marriage for women in the United States.

scholarly journals Virulence of Oat Crown Rust in Brazil and Uruguay

Plant Disease ◽  
2005 ◽  
Vol 89 (8) ◽  
pp. 802-808 ◽  
Author(s):  
K. J. Leonard ◽  
J. A. Martinelli
Keyword(s):  
Avena Sativa ◽  
Western Siberia ◽  
Specific Resistance ◽  
The United States ◽  
Crown Rust ◽  
Puccinia Coronata ◽  
South American ◽  
Oat Crown Rust ◽  
High Virulence ◽  
Important Disease

Race-specific resistance to crown rust, the most important disease of oat (Avena sativa) in Bra-zil, often fails within a few years of use in Brazilian cultivars. Virulence of 144 isolates of Puccinia coronata from cultivated oat in Brazil in 1997 to 1999 and 36 isolates from Uruguay in 1994-95 and 1998 was tested on a set of 27 oat crown rust differentials lines, each with a different Pc gene for race-specific resistance. Frequencies of virulence and mean virulence complexity were compared among these five collections from Brazil and Uruguay as well as with mean virulence complexity for a collection of 17 isolates from cultivated oat in western Siberia in Russia. Virulence-avirulence for each of the 27 Pc genes was polymorphic in both Brazil and Uruguay. Virulence frequencies were similar for collections from Brazil in 1998 and 1999 and for the collection from Uruguay from 1998, but there were large differences between the 1997 collection and the 1998 and 1999 collections from Brazil. Mean virulence complexity in both Brazil and Uruguay was greater than reported in the United States and much greater than in the Russian collection of P. coronata. A large number of races of P. coronata were found, with no more than five isolates of any race found in a single year in Brazil or Uruguay. The high virulence complexity and great diversity of virulence polymorphisms in Brazil and Uruguay make it unlikely that race-specific resistance can be effective there even though the South American populations of P. coronata are apparently entirely asexual.

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