Bipolaris victoriae (Victoria blight of oats).

Author(s):  
Philip Taylor

Abstract A disease almost unknown prior to 1944 (Romanko, 1957), Bipolaris victoriae is a potentially destructive disease of oats (it reduced the Iowa oat crop by 32% in 1947) (Anon, 1965) that currently has a limited host range and geographical spread. It has been reported from several continents and associated with several crops, however its status as a pathogen on crops could be questioned in all cases with the exception of oats, timothy grass and switch grass. It is seedborne and thus any trade in seed both for cultivation or for livestock feed is a potential means of spread. The virulence of the fungus is due to the production of a peptide often called a host-specific toxin 'victorin'. The disease has generally been controlled through the use of genetically resistant lines but the resistance gene which confers resistance to victorin actually causes plants to become susceptible to crown rust, caused by Puccinia coronata (Lorang et al., 2007).

2021 ◽  
Author(s):  
Philip Taylor

Abstract A disease almost unknown prior to 1944 (Romanko, 1957), Bipolaris victoriae is a potentially destructive disease of oats (it reduced the Iowa oat crop by 32% in 1947) (Anon, 1965) that currently has a limited host range and geographical spread. It has been reported from several continents and associated with several crops, however its status as a pathogen on crops could be questioned in all cases with the exception of oats, timothy grass and switch grass. It is seedborne and thus any trade in seed both for cultivation or for livestock feed is a potential means of spread. The virulence of the fungus is due to the production of a peptide often called a host-specific toxin 'victorin'. The disease has generally been controlled through the use of genetically resistant lines but the resistance gene which confers resistance to victorin actually causes plants to become susceptible to crown rust, caused by Puccinia coronata (Lorang et al., 2007).


Plant Disease ◽  
2001 ◽  
Vol 85 (10) ◽  
pp. 1085-1090 ◽  
Author(s):  
B. D. van Niekerk ◽  
Z. A. Pretorius ◽  
W. H. P. Boshoff

Although crown rust (caused by Puccinia coronata f. sp. avenae) and stem rust (caused by Puccinia graminis f. sp. avenae) are generally considered to be the most widespread and damaging diseases of oat (Avena spp.) in South Africa, pathogenic variability has never been studied. During 1997 and 1998, one dominant crown rust pathotype (SBLL) was identified with virulence to resistance genes Pc40, Pc45, Pc46, Pc51, and Pc54. Four other pathotypes (SGLL, PBBB+Pc35, SDQL, and JBBM+Pc35), occurring at low frequencies and further rendering resistance genes Pc35, Pc39, Pc48, Pc50, Pc52, and Pc64 ineffective, were also detected. Resistance gene Pc40 was postulated in Wisconsin X1588-2; Pc51 in Euro, Maluti, Overberg, OX88I 075-106, Perdeberg, and Swartberg; and Pc39 was confirmed in the cultivar Fidler. During the same period, four stem rust pathotypes were identified with virulence to resistance genes Pg1, Pg2, Pg4, Pg8, Pg9, Pg12,Pg15, and Pga. Resistance gene Pga was postulated in Alpha, OX87 080-1, OX88I 075-106, Sederberg, and W94/4; Pg2 and/or Pg4 in Euro, Perdeberg, Potberg, and Swartberg; and Pg9 in Pallinup and Victorian. Collections of wild oat species Avena fatua, A. byzantina, A. sterilis, and A. barbata were susceptible to all crown rust patho-types, while the four stem rust pathotypes were virulent on all species except A. barbata.


Plant Disease ◽  
2005 ◽  
Vol 89 (8) ◽  
pp. 802-808 ◽  
Author(s):  
K. J. Leonard ◽  
J. A. Martinelli

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.


Plant Disease ◽  
2018 ◽  
Vol 102 (5) ◽  
pp. 955-963
Author(s):  
Brijesh B. Karakkat ◽  
Vonte L. Jackson ◽  
Paul L. Koch

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.


Author(s):  
H.S. Easton ◽  
B.M. Cooper ◽  
T.J. Frasers ◽  
K.H. Widdup

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


Author(s):  
Peter Dracatos ◽  
Jeremy Dumsday ◽  
Alan Stewart ◽  
Mark Dobrowolski ◽  
Noel Cogan ◽  
...  

Author(s):  
Peter Dracatos ◽  
Jeremy Dumsday ◽  
Alan Stewart ◽  
Mark Dobrowolski ◽  
Noel Cogan ◽  
...  

1968 ◽  
Vol 46 (5) ◽  
pp. 613-617 ◽  
Author(s):  
George Fleischmann

Two methods of determining the virulence pattern of oat crown rust, Puccinia coronata f. sp. avenae, populations collected in 1965, 1966, and 1967, in Eastern and Western Canada were compared. The results with a single-pustule isolate from each of 50 field collections were as accurate as those obtained with two single-pustule isolates from 100 or more field collections. The continued use of Bond and Ukraine as differential host varieties is of little value except for purposes of race identification, because they are attacked by most of the isolates.


1963 ◽  
Vol 41 (12) ◽  
pp. 1613-1615 ◽  
Author(s):  
George Fleischmann

A new physiologic race of crown rust, Puccinia coronata Corda f. sp. avenae Erikss., was isolated from oats collected in four Canadian provinces in 1962. This race, 332, is one of the first reported that is capable of attacking both the differential oat varieties Victoria and Saia. A close relationship exists between race 332 and race 216, which suggests that the former may have arisen from the latter by mutation. The evolution of this new race has occurred in the absence of any known Saia type resistance in current commercial varieties, and its survival points up the operation of selective forces other than host resistance on the racial composition of the pathogenic population.


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