Resistance against barley leaf rust (Puccinia hordei) in West-European spring barley germplasm

Abstract

The level and type of resistance against leaf rust (Puccinia hordei) was determined in modern spring barley germplasm. In field trials all over Europe most accessions were in some locations and years significantly less infected than the moderately resistant reference 'Grit'. Differentiating P. hordei isolates indicated that most accessions carried hypersensitivity (Rph) genes. A virulence survey indicated that among the known resistance genes, only Rph7 is still fully effective in Europe. Some accessions carried undetermined hypersensitivity resistance gene(s) that were effective to all isolates tested. The level of non-hypersensitivity or partial resistance was assessed from the latency period of the fungus and the percentage of early aborted infection units not associated with plant cell necrosis. These parameters indicated that several accessions had a level of partial resistance higher than that of the highly partially resistant 'Vada'. We concluded that barley breeders have achieved very high levels of partial resistance against P. hordei in spring barley germplasm. barley / leaf rust / partial resistance / virulence / hypersensitivityRésumé -Résistance à la rouille brune (Puccinia hordei) du germplasme d'orge de printemps d'Europe de l'ouest. Le niveau et le type de résistance contre la rouille brune (Puccinia hordei) ont été déterminé chez le germplasme d'orge de printemps. Dans des champs expérimentaux présents dans l'Europe entière, la plupart des accessions ont été pour certains sites et années, moins infectées comparé à la référence 'Grit' qui est modérément résistante. Des isolats de P. hordei différenciés ont indiqué que la plupart des accessions contenaient les gènes d'hypersensitivité Rph. Un test de virulence a indiqué que des gènes Rph connus, seul Rph7 est encore complètement efficace en Europe. Certaines Agronomie 20 (2000) 769-782 769 © INRA, EDP Sciences 2000 Communicated by Hanne Østergård (Roskilde, Denmark) * Correspondence and reprints rients.niks@pv.dpw.wau.nl ** Affiliations are in Appendix

Linkage Disequilibrium Mapping of Morphological, Resistance, and Other Agronomically Relevant Traits in Modern Spring Barley Cultivars

“…Only cultivars without effective hypersensitivity to 'IVP2000' provided the data on the basis of which the level of partial resistance was assessed. Partial resistance is a resistance that is not based on a hypersensitivity reaction, but causes a reduced rate of development of uredia and a reduction in their number (Parlevliet 1975;Niks et al 2000). This resistance against the leaf rust is controlled by few to many genes with additive effects (e.g.…”

Partial Resistance to Leaf Rust in a Collection of Ancient Spanish Barleys

“…Combining these genes through crosses may lead to transgression and increase of the level o partial resistance (PARLEVLIET and KUIPER 1985). In fact, the new varieties of barley already exhibit higher levels of partial resistance to leaf rust than 20 years ago (PARLEVLIET et al 1980;NIKS et al 2000). The presently discovered Spanish lines may be useful additional sources of partial resistance to leaf rust.…”

Identification of QTLs for powdery mildew and scald resistance in barley

“…However, nearly all the R-genes that are being deployed in commercially grown cultivars had a short effective life with the exception of mlo resistance gene (Hovmøller et al, 2000;Xi et al, 2002). This ephemeral effectiveness of resistance has caused breeders to look for other types of resistance such as partial resistance (PR) which appears to be more durable and race-non-specific (Niks et al, 2000). PR has been defined as a resistance causing a reduced rate of epidemic development despite a high, susceptible, infection type (Parlevliet, 1975).…”