Estimated Relation Between Numbers of Urediniospores of<i>Puccinia graminis</i>f. sp.<i>tritici</i>and Rates of Occurrence of Virulence

Schafer, J. F.

doi:10.1094/phyto-75-749

Cited by 56 publications

(28 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Subsequently, the disease progression remained slower and highly retarded among these cultivars. Such partially resistant lines could highly delay evolution of new virulent races of the pathogen because multiple point mutations are extremely rare in normal circumstances (Schafer and Roelfs, 1985;Ali et al, 2008;Tsilo et al, 2010). Likewise, despite the MS infection type exhibited on moderately slow rusting cultivars, leaf rust developed slowly as indicated by their AUDPC values.…”

Section: Area Under Disease Progress Curvementioning

confidence: 99%

Evaluation of wheat cultivars for slow rusting resistance to leaf rust (Puccinia trticina Eriks) in Ethiopia

Hei¹

2017

Afr. J. Plant Sci.

View full text Add to dashboard Cite

show abstract

Section: Area Under Disease Progress Curvementioning

confidence: 99%

Evaluation of wheat cultivars for slow rusting resistance to leaf rust (Puccinia trticina Eriks) in Ethiopia

Hei¹

2017

Afr. J. Plant Sci.

View full text Add to dashboard Cite

show abstract

“…Although the 'probability' theory of Schafer & Roelfs (1985) was questioned (Mundt, 1990), the potential and value of gene combinations has often been demonstrated (Schafer et al, 1963;Samborski & Dyck, 1982;Ezzahiri & Roelfs, 1989;Kolmer et al, 1991). Knott (1989) described gene pyramiding as an important resistance breeding strategy that was applied worldwide for control of the rust diseases of wheat.…”

Section: Introductionmentioning

confidence: 99%

Effects of combinations amongst genes Lr13, Lr34 and Lr37 on components of resistance in wheat to leaf rust

Kloppers

Pretorius

1997

Plant Pathology

View full text Add to dashboard Cite

Gene pyramiding is a breeding strategy whereby host resistance genes are combined together with the objective of prolonging their usefulness in crops such as wheat (Triticum aestivum) for resistance to leaf rust caused by Puccinia recondita f.sp. tritici. When genes are combined they often give reactions different from those given by each component gene alone. Effects of gene combinations in lines Lr13 + Lr34 (T34-13), Lr13 + Lr37 (T13-37) and Lr34 + Lr37 (T34-37) were compared with those of the single gene lines CT263 (Lr13)(T13), RL6058 (Lr34)(T34), RL6081 (Lr37)(T37) and the leaf rust susceptible control, Thatcher. Infection types on plants infected with pathotypes UVPrt2 or UVPrt13 in the glasshouse, and disease severity in the field, demonstrated higher levels of resistance in the combination lines T13-37 and T34-37 than in the lines with the individual genes. The absence of sporulating uredinia in these combination lines prevented quantitative measurements of components such as latent period. In the T34-13 line, no increased resistance to pathotype UVPrt13 was apparent from assessment of the infection types in the glasshouse. Precise measurements of its resistance components showed, however, that it had a longer latent period and smaller uredinia and its resistance was highly effective in the field. There was variation in leaf rust severity amongst sister lines containing both Lr13 and Lr34, suggesting that increased resistance in T13-34 may not be controlled solely by these two genes themselves. Development of fungal structures, and the incidence and area displaying a hypersensitive reaction, were assessed using UV-1A and B-2A fluorescence microscopy filter combinations. Significant restriction of fungal growth during early postinfection stages occurred in the gene combination lines T34-13, T13-37 and T34-37. Colony size in these lines was also significantly reduced compared with that in the single gene lines T13, T34, T37 and the leaf rust-susceptible Thatcher, when either or both pathotypes possessed avirulence for one of the Lr genes. In the compatible T13-34/ UVPrt13 interaction no clear histological evidence of resistance enhancement was observed. The hypersensitive reaction in Lr37 alone or in combination and with either pathotypes, and Lr13 alone or in combination and with UVPrt2 indicated that the major component of the resistance mechanism is posthaustorial. Lr34 had the lowest hypersensitive index and even less hypersensitivity was observed in the Lr34/Lr37 combination line than in Lr37 alone. There was more prehaustorial abortion of infection structures in the line T34-37 than in T34 and T37 with isolate UVPrt2 but not with UVPrt13. It did not appear that abortion of infection structures was a major component of the resistance studied.

show abstract

“…The more unmatched resistance genes a variety contains the more mutational steps are required of the pathogen to overcome the combined resistance. Such multiple resistances seem to express increased durability (Schafer and Roelfs, 1985). Adult plant resistance genes, that were possibly present in our material, were not studied.…”

Section: Discussionmentioning

confidence: 96%

Identification of resistance genes to Puccinia striiformis in seedlings of Ethiopian and CIMMYT bread wheat varieties and lines

Badebo

Stubbs²,

Ginkel

et al. 1990

Netherlands Journal of Plant Pathology

View full text Add to dashboard Cite

In a controlled environment, the reaction was observed of 42 bread wheat varieties and lines inoculated with 19 isolates of yellow rust differing in their virulence to 20 differential varieties. Five varieties and lines showed resistance to all isolates. The remaining ones appeared to have the genes Yr2, Yr3, Yr4, Yr6, Yr7, Yr9 and YrA, either singly or in combination. Yr9 derived from rye was present in 67% of the varieties and lines. Yr4 is the only effective gene in that material as, in Eastern and Central Africa, yellow rust has virulence to the other Yr genes. Recognition of virulence to Yr genes is enhanced by the use of a supplemental set of differential varieties supposedly carrying a single gene.

show abstract

Estimated Relation Between Numbers of Urediniospores ofPuccinia graminisf. sp.triticiand Rates of Occurrence of Virulence

Cited by 56 publications

References 0 publications

Evaluation of wheat cultivars for slow rusting resistance to leaf rust (Puccinia trticina Eriks) in Ethiopia

Evaluation of wheat cultivars for slow rusting resistance to leaf rust (Puccinia trticina Eriks) in Ethiopia

Effects of combinations amongst genes Lr13, Lr34 and Lr37 on components of resistance in wheat to leaf rust

Identification of resistance genes to Puccinia striiformis in seedlings of Ethiopian and CIMMYT bread wheat varieties and lines

Contact Info

Product

Resources

About