Sources of resistance to barley yellow dwarf luteovirus in perennial ryegrass (Lolium perenne) L

Abstract

Genotypes of perennial ryegrass cv. Ellett were classed as susceptible or resistant to infection with the PAV-related isolate of barley yellow dwarf luteovirus (BYDV) on the basis of dry weight yield and the presence or absence of detectable virus as measured with ELISA. In the inoculated treatments, there was a significant (P < 0.05) decrease in plant dry weight of susceptible compared to resistant genotypes, whereas in uninoculated treatments, there was no significant (P > 0.05) difference in yield between the two genotype classes. Superior plants from four cultivars of perennial ryegrass were selected from two field sites on the basis of superior winter growth and seasonal production. In glasshouse experiments, resistance to the virus was detected in these selections. The percentage of infected selections from individual cultivars varied between 18-46%, indicating that at least 50% were resistant to the virus.