Environment and ryegrass genetics – multisite trial of advanced breeding populations

Abstract

Developing a genomic selection (GS) strategy for ryegrass requires field data for training GS models and to gain insight into how ryegrass agronomic performance varies, within and among populations and across locations. Families from five perennial ryegrass breeding populations are being evaluated in eight trials in Northland, Waikato, Hawke’s Bay, Manawatu and Canterbury to establish a data set for development of a genomic selection model. Statistically robust variances are evident among families within populations, both for visual scoring of herbage bulk and dry matter measurements. Multi-trial analysis of data showed significant (P<0.001) differences among families, robust across trials, even though interaction with trial was also significant in some seasons. Patterns are also evident comparing trials, with relative performance of families being similar for some pairs of trials, but radically different for others. Evidence for specific response of families to severe summer management was not conclusive.