Selection for resistance to ryegrass mosaic virus and crown rust (Puccinia coronata Corda) in Italian ryegrass populations

The osmium-maceration technique (osmium–DMSO–osmium method) was used to observe intracellular structures of Italian ryegrass leaves infected with crown rust fungus (Puccinia coronata Corda var. coronata) by scanning electron microscopy. Prolonged maceration with dilute osmium removed the cytoplasmic matrix, and intracellular structures were disclosed in a bold relief. The three-dimensional configuration of nuclei, mitochondria, the endoplasmic reticulum, and other structures of host and parasite cells were visible. Key words: scanning electron microscopy (SEM), osmic maceration, intracellular structure, Puccinia coronata, Italian ryegrass.

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Introgression of crown rust (Puccinia coronata) resistance from meadow fescue (Festuca pratensis) into Italian ryegrass (Lolium multiflorum) and physical mapping of the locus

Heredity ◽

10.1038/sj.hdy.6800344 ◽

2003 ◽

Vol 91 (4) ◽

pp. 396-400 ◽

Cited By ~ 19

Author(s):

H W Roderick ◽

W G Morgan ◽

J A Harper ◽

H M Thomas

Keyword(s):

Physical Mapping ◽

Lolium Multiflorum ◽

Crown Rust ◽

Italian Ryegrass ◽

Puccinia Coronata ◽

Festuca Pratensis ◽

Meadow Fescue

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Virulence of Oat Crown Rust in Brazil and Uruguay

Plant Disease ◽

10.1094/pd-89-0802 ◽

2005 ◽

Vol 89 (8) ◽

pp. 802-808 ◽

Cited By ~ 22

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

Plant Disease ◽

10.1094/pdis-09-17-1353-re ◽

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.

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CROWN RUST ON PERENNIAL RYEGRASS IN FIELD TRIALS

Proceedings of the New Zealand Grassland Association ◽

10.33584/jnzg.1989.50.1867 ◽

1989 ◽

pp. 253-254

Author(s):

H.S. Easton ◽

B.M. Cooper ◽

T.J. Frasers ◽

K.H. Widdup

Keyword(s):

Perennial Ryegrass ◽

Field Trials ◽

Crown Rust ◽

Puccinia Coronata ◽

Rust Infection

Crown rust infection of 11 perennial ryegrass cultivars vaned significantly and consistently over 6 sites. 'Grasslands Ariki,' the new cultivar 'Yatsyn' and Grasslands selections G26 and G33 were less infected than 'Grasslands Nui', 'Ellett' or 'Grasslands Ruanui'. 'Droughtmaster' and 'Marathon' proved more susceptible than most. Keywords: Crown rust, Puccinia coronata. perenmal ryegrass

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