Breeding perennial ryegrass with better crown rust resistance

Abstract

AbstractImproving rust resistance is one of the main goals in our breeding programme with perennial ryegrasses. We have studied the behaviour of our breeding material over several years in several locations under natural and artificial infection conditions. The narrow sense heritability of crown rust resistance is fairly high (0.46), providing scope for improving resistance, but this optimism is reduced by the negative correlation with yield. The most resistant material yielded 4% less than the most susceptible material. No decline in digestibility is expected when improving the disease resistance. The incidence of crown rust is very variable between years, locations and between spontaneous and artificial infections, creating constraints in selection.Observations for several years and at several locations appear to be the best way to improve rust resistance in perennial ryegrass.