Susceptibility of European cultivars of Italian and perennial ryegrass to crown and stem rust

Abstract

Schubiger, F. X., Baert J., Bayle, B., Bourdon, P., Cagas, B., Cernoch, V., Czembor, E., Eickmeyer, F., Feuerstein, U., Hartmann, S., Jakesova, H., Johnston, D., Krautzer, B., Leenheer, H., Lellbach, H., Persson, C., Pietraszek, W., Posselt, U. K., Russi, L., Schulze, S., Tardin, M. C., VanHee, F., Wilkins, P. W., Willner, E., Wolters, L., Boller, B. (2010). Susceptibility of European cultivars of Italian and perennial ryegrass to crown and stem rust. ? Euphytica, 176(2), 167-181. Sponsorship: BBSRC; DefraLINK (Sustainable Livestock Production Programme) IMPF: 01.59 RONO: 00A set of 15 Italian (Lolium multiflorum), three hybrid (L. boucheanum) and 33 perennial ryegrass (L. perenne) cultivars were evaluated for their rust susceptibility in the field. The cultivars were grown in 2001, 2004 and 2007 at 29, 32 and 27 European sites, respectively. Rust incidence was scored during different growth cycles using a scale from one (no rust) to nine (susceptible). Crown rust (Puccinia coronata f. sp. lolii) was the most frequently observed rust species on Italian, hybrid and perennial ryegrass during all three experimental years. There was a highly significant difference in mean crown rust scores among Italian and perennial ryegrass cultivars, respectively, in each of the 3 years. The ranking of the cultivars was very consistent across the different sites within each year (with some exceptions), despite a significant interaction of cultivar response with sites. Moreover, the rank order correlations of mean cultivar rust scores were highly significant (r > 0.9) between the years. Stem rust (P. graminis f. sp. graminicola) occurred almost exclusively on perennial ryegrass. The cultivars showed significant variation in stem rust susceptibility. Rank order correlations of mean cultivar stem rust scores were mostly significant between sites within each year and highly significant between the years. The ranking of perennial ryegrass cultivars was different depending on whether crown or stem rust was scored. However, the rank order correlation between the mean disease scores of the cultivars for the two pathogens was low but still significant. At a particular site the assessment of crown or stem rust was in most cases very consistent over the period of experimentation. Therefore there was no evidence that rust resistance of an individual cultivar was overcome by the rust pathogen at a particular site over the 7 years of experimentation.Peer reviewe

Effect of Weather on the Occurrence of Puccinia Graminis Subsp. Graminicola and Puccinia Coronata F. Sp. Lolii at Lolium Perenne L. and Deschampsia Caespitosa (L.) P. B.

“…The disease leads to a reduction in yields of herbs and grasses, nutritional quality, and tastiness of forage for herbivores (Leonard et al 2004). Schubiger et al (2010) observed Puccinia coronata f. sp. lolii as the most severe disease in Lolium perenne L. Puccinia coronata f. sp.…”

“…lolii was observed in 61 % of plants from the areas of Perugia (Italy) in the south of Europe, Boelshoj (Denmark) in the north of Europe, Loughgall (Northern Ireland), western France, up to Poland and the Czech Republic. Schubiger et al (2010) observed the occurrence of rust on Lolium perenne L. in Italy and found out the first occurrence in June and the most frequent occurrence in August. In our observations, most samples for detection were collected in August of 2009, when rainfall was lower by 41.4 mm, compared to long-term precipitation average.…”

Assessment of Lolium perenne tetraploid clones produced from a diverse diploid breeding population

“…Rust susceptibility was assessed according to the EUCARPIA Multisite Rust evaluation methodology (Schubiger et al, 2010). A scale from 1 to 9 was used: 1 -no rust disease, 2 -traces of rust, 3 -5% of the leaf surface is covered with rust pustules, 4 -10%, 5 -25%, 6 -40%, 7 -60%, 8 -75%, 9 -more than 75% of the foliage covered with rust, dominated by necrotic leaves.…”

Assessment of perennial ryegrass (Lolium perenne L.) genotypes under Latvia agro-ecological conditions

“…For the visual assessment, a 9-point scale was used: lower marks indicate a less pronounced trait expression, while higher marks indicate a more pronounced trait expression. Rust susceptibility was assessed according to the methodology of EUCARPIA Multisite Rust evaluation (Schubiger et al, 2010). A scale from point 1 to 9 was used, where: 1 -no rust disease, 2 -traces of rust, 3-5% of the leaf surface is covered with rust pustules, 4-10%, 5-25%, 6-40%, 7-60%, 8-75%, 9 -more than 75% of the foliage covered with rust, the grass is dominated by necrotic leaves.…”