scholarly journals Virulence Associations in Oat Crown Rust

2005 ◽  
Vol 95 (1) ◽  
pp. 53-61 ◽  
Author(s):  
K. J. Leonard ◽  
Y. Anikster ◽  
J. Manisterski

Isolates of Puccinia coronata obtained from natural populations of Avena sterilis in Israel, winter oat (A. sativa) cultivars in Texas, and spring oat cultivars in the Northern Plains states of Minnesota, North Dakota, and South Dakota were analyzed for significance of pairwise virulence associations. Isolates from all three regions were tested on 25 oat lines with single P. coronata (Pc) genes for crown rust resistance from A. sterilis and one line with a Pc gene from A. sativa. Isolates from Israel were tested also on 11 Iowa backcross lines with undesignated crown rust resistance genes from A. sterilis. Four associated virulence groups were identified from significant positive virulence associations that were consistent across all three regions. Group 38 included virulence to Pc-38, Pc-39, Pc-55, Pc-63, and Pc-71; group 45 included virulence to Pc-45, Pc-46, Pc-48, Pc-52, Pc-54, and Pc-57; group 58 included virulence to Pc-35, Pc-40, Pc-58, and Pc-59; and group 61 included virulence to Pc- 36, Pc-51, Pc-56, Pc-60, and Pc-61. Virulence to Pc-70 showed the strongest association to virulences in group 38 but also showed significant association with virulence to Pc-45, Pc-35, and Pc-58. Virulences in group 61 were consistently negatively associated with virulences in group 38 in each region. In Israel, virulences to five of the Iowa lines showed positive associations to virulences in group 61 and negative associations to virulences in groups 38 and 45. Close similarity of reactions of nearly all isolates to Pc-39, Pc-55, and Pc-71 suggest that these genes may be identical or nearly identical alleles.

1980 ◽  
Vol 22 (1) ◽  
pp. 27-33 ◽  
Author(s):  
D. E. Harder ◽  
R. I. H. McKenzie ◽  
J. W. Martens

The inheritance of resistance to oat crown rust was studied in three accessions of Avena sterilis L. Accession CAV 4274 originated from Morocco, CAV 4540 from Algeria, and CAV 3695 from Tunisia. Seedling rust tests on F2 backcross families indicated the presence of two dominant genes for crown rust resistance in CAV 4274. One of these, a gene conditioning resistance to most races tested, was linked or allelic to gene Pc-38, and was designated gene Pc-62. The second gene conferred resistance only to one of the six races studied, and was not tested further. In CAV 4540, a single dominant gene, Pc-63 was possibly allelic with Pc-62 and linked or allelic to Pc-38. Genes Pc-62 and 63 are generally similar to Pc-38 in their resistance spectrum, but these three genes are differentiated by races CR 102, CR 103, and CR 107. A single dominant gene in CAV 3695 appeared to be Pc-50.


2021 ◽  
Vol 22 (20) ◽  
pp. 11183
Author(s):  
Joanna Toporowska ◽  
Sylwia Sowa ◽  
Andrzej Kilian ◽  
Aneta Koroluk ◽  
Edyta Paczos-Grzęda

Crown rust, caused by Puccinia coronata f. sp. avenae, is one of the most destructive fungal diseases of oat worldwide. Growing disease-resistant oat cultivars is the preferred method of preventing the spread of rust and potential epidemics. The object of the study was Pc50-5, a race-specific seedling crown rust resistant gene, highly effective at all growth stages, selected from the differential line Pc50 (Avena sterilis L. CW 486-1 × Pendek). A comparison of crown rust reaction as well as an allelism test showed the distinctiveness of Pc50-5, whereas the proportions of phenotypes in segregating populations derived from a cross with two crown rust-susceptible Polish oat cultivars, Kasztan × Pc50-5 and Bingo × Pc50-5, confirmed monogenic inheritance of the gene, indicating its usefulness in oat breeding programs. Effective gene introgression depends on reliable gene identification in the early stages of plant development; thus, the aim of the study was to develop molecular markers that are tightly linked to Pc50-5. Segregating populations of Kasztan × Pc50-5 were genotyped using DArTseq technology based on next-generation Illumina short-read sequencing. Markers associated with Pc50-5 were located on chromosome 6A of the current version of the oat reference genome (Avena sativa OT3098 v2, PepsiCo) in the region between 434,234,214 and 440,149,046 bp and subsequently converted to PCR-based SCAR (sequence-characterized amplified region) markers. Furthermore, 5426978_SCAR and 24031809_SCAR co-segregated with the Pc50-5 resistance allele and were mapped to the partial linkage group at 0.6 and 4.0 cM, respectively. The co-dominant 58163643_SCAR marker was the best diagnostic and it was located closest to Pc50-5 at 0.1 cM. The newly discovered, very strong monogenic crown rust resistance may be useful for oat improvement. DArTseq sequences converted into specific PCR markers will be a valuable tool for marker-assisted selection in breeding programs.


2020 ◽  
Vol 75 (2) ◽  
pp. 37-45
Author(s):  
SYLWIA SOWA

The best source of crown rust resistance genes (Pc) in genus Avena is a wild hexaploid A. sterilis L. In this study, accessions of A. sterilis gathered from European and North American gene banks, originated from 21 countries were evaluated at the seedling stage for crown rust reaction using the host–pathogen test and two Puccinia coronata f. sp. avenae isolates. Of the 45 oat accessions analyzed, 12 were resistant to one crown rust race (3.2). Resistance to both pathotypes used in the study was observed in two of the accessions, first of which was collected in Libya (AVE 2532) and second in Portugal (CN 26036). Further research is required to evaluate the genetic background of the discovered resistance, however, obtained results provide a valuable first step in the identification of new promising crown rust resistance sources.


1983 ◽  
Vol 25 (4) ◽  
pp. 329-335 ◽  
Author(s):  
L. S. L. Wong ◽  
R. I. H. McKenzie ◽  
D. E. Harder ◽  
J. W. Martens

The inheritance of resistance to Puccinia coronata, awn development, lemma pubescence, and lemma color were studied in the Avena sterilis accessions CAV 4248, CAV 4656, and CAV 4904. Three independent, partially dominant genes (Pc-64, Pc-65, Pc-66) in CAV 4248, one partially dominant gene (Pc-67) in CAV 4656, and a dominant gene (Pc-68) in CAV 4904 were identified which conferred resistance to P. coronata. Genes Pc-64, Pc-65, Pc-66, Pc-67, and Pc-68 conferred resistance to 13, 8, 6, 12, and 14 races, respectively, of the 14 races of P. coronata tested. Gene Pc-68 conferred resistance to all field isolates of P. coronata collected in Canada in 1981 and was found to be closely linked or allelic to gene Pc-46. Awns and lemma pubescence were inherited monogenically in crosses with all three CAV accessions. Grey lemma color was controlled by one gene in CAV 4248 and by two genes in CAV 4656. Brown lemma color was controlled by one gene, which was closely linked or pleiotropic with the gene for lemma pubescence in CAV 4904. There was no association between crown rust resistance and the three floret characters studied.


Crop Science ◽  
1971 ◽  
Vol 11 (3) ◽  
pp. 451-453 ◽  
Author(s):  
George Fleischmann ◽  
R. I. H. McKenzie ◽  
W. A. Shipton

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